Main Group Strategies towards Functional Hybrid Materials E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 989

Veröffentlichungsjahr: 2017

Beschreibung

Showcases the highly beneficial features arising from the presence of main group elements in organic materials, for the development of more sophisticated, yet simple advanced functional materials Functional organic materials are already a huge area of academic and industrial interest for a host of electronic applications such as Organic Light-Emitting Diodes (OLEDs), Organic Photovoltaics (OPVs), Organic Field-Effect Transistors (OFETs), and more recently Organic Batteries. They are also relevant to a plethora of functional sensory applications. This book provides an in-depth overview of the expanding field of functional hybrid materials, highlighting the incredibly positive aspects of main group centers and strategies that are furthering the creation of better functional materials. Main Group Strategies towards Functional Hybrid Materials features contributions from top specialists in the field, discussing the molecular, supramolecular and polymeric materials and applications of boron, silicon, phosphorus, sulfur, and their higher homologues. Hypervalent materials based on the heavier main group elements are also covered. The structure of the book allows the reader to compare differences and similarities between related strategies for several groups of elements, and to draw crosslinks between different sections. * The incorporation of main group elements into functional organic materials has emerged as an efficient strategy for tuning materials properties for a wide range of practical applications * Covers molecular, supramolecular and polymeric materials featuring boron, silicon, phosphorus, sulfur, and their higher homologues * Edited by internationally leading researchers in the field, with contributions from top specialists Main Group Strategies towards Functional Hybrid Materials is an essential reference for organo-main group chemists pursuing new advanced functional materials, and for researchers and graduate students working in the fields of organic materials, hybrid materials, main group chemistry, and polymer chemistry.

Leseprobe

Table of Contents

Cover

Title Page

List of Contributors

Preface

1 Incorporation of Boron into π‐Conjugated Scaffolds to Produce Electron‐Accepting π‐Electron Systems

1.1 Introduction

1.2 Boron‐Containing Five‐Membered Rings: Boroles and Dibenzoboroles

1.3 Annulated Boroles

1.4 Boron‐Containing Seven‐Membered Rings: Borepins

1.5 Boron‐Containing Six‐Membered Rings: Diborins

1.6 Planarized Triphenylboranes and Boron‐Doped Nanographenes

1.7 Conclusion and Outlook

References

2 Organoborane Donor–Acceptor Materials

2.1 Organoboranes: Form and Functions

2.2 Linear D‐A Systems

2.3 Non‐conjugated D‐A Organoboranes

2.4 Conjugated Nonlinear D‐A Systems

2.5 Polymeric Systems

2.6 Cyclic D‐A Systems: Macrocycles and Fused‐Rings

2.7 Conclusions and Outlook

References

3 Photoresponsive Organoboron Systems

3.1 Introduction

3.2 Photoreactivity of (ppy)BMes2 and Related Compounds

3.3 Photoreactivity of BN‐Heterocycles

3.4 New Photochromism of BN‐Heterocycles

3.5 Exciton Driven Elimination (EDE): In situ Fabrication of OLEDs

3.6 Summary and Future Prospects

References

4 Incorporation of Group 13 Elements into Polymers

4.1 Introduction

4.2 Tricoordinate Boron in Conjugated Polymers

4.3 Tetracoordinate Boron Chelate Complexes in Polymeric Materials

4.4 Polymeric Materials with B‐P and B‐N in the Backbone

4.5 Polymeric Materials Containing Borane and Carborane Clusters

4.6 Polymeric Materials Containing Higher Group 13 Elements

4.7 Conclusions

Acknowledgements

References

5 Tetracoordinate Boron Materials for Biological Imaging

5.1 Introduction

5.2 Small Molecule Fluorescence Imaging Agents

5.3 Polymer Conjugated Materials

5.4 Conclusion and Future Outlook

References

6 Advances and Properties of Silanol‐Based Materials

6.1 Introduction

6.2 Preparation

6.3 Reactivity

6.4 Properties and Application

References

7 Silole‐Based Materials in Optoelectronics and Sensing

7.1 Introduction

7.2 Basic Aspects of Silole‐Based Materials

7.3 Silole‐Based Electron‐Transporting Materials

7.4 Silole‐Based Host and Hole‐Blocking Materials for OLEDs

7.5 Silole‐Based Light‐Emitting Materials

7.6 Silole‐Based Semiconducting Materials

7.7 Silole‐Based Light‐Harvesting Materials for Solar Cells

7.8 Silole‐Based Sensing Materials

7.9 Conclusion

References

8 Materials Containing Homocatenated Polysilanes

8.1 Introduction

8.2 Synthesis

8.3 Functional Modification of Polysilanes

8.4 Control of the Stereochemistry of Polysilanes

8.5 Control of the Secondary Structure of Polysilanes

8.6 Polysilanes with 3D Architectures

8.7 Applications

8.8 Summary

References

9 Catenated Germanium and Tin Oligomers and Polymers

9.1 Introduction

9.2 Oligogermanes and Oligostannanes

9.3 Preparation of Polygermanes

9.4 Preparation of Polystannanes

9.5 Conclusions and Outlook

Acknowledgements

References

10 Germanium and Tin in Conjugated Organic Materials

10.1 Introduction

10.2 Germanium and Tin‐Linked Conjugated Polymers

10.3 Germanium‐ and Tin‐Containing Conjugated Cyclic Systems

10.4 Summary and Outlook

References

11 Phosphorus‐Based Porphyrins

11.1 Introduction

11.2 Porphyrins Bearing Phosphorus‐Based Functional Groups at their Periphery

11.3 Porphyrins and Related Macrocycles Containing Phosphorus Atoms at their Core

11.4 Conclusions

Acknowledgements

References

12 Applications of Phosphorus‐Based Materials in Optoelectronics

12.1 Introduction

12.2 Phosphines

12.3 Four‐Membered P‐Heterocyclic Rings

12.4 Five‐Membered P‐Heterocyclic Rings: Phospholes

12.5 Six‐Membered P‐Heterocyclic Rings

12.6 Conclusion

Abbreviations

References

13 Main‐Chain, Phosphorus‐Based Polymers

13.1 Introduction

13.2 Polyphosphazenes

13.3 Poly(phosphole)s

13.4 Poly(methylenephosphine)s

13.5 Poly(arylene‐/vinylene‐/ethynylene‐phosphine)s

13.6 Phospha‐PPVs

13.7 Poly(phosphinoborane)s

13.8 Metal‐Containing Phosphorus Polymers

13.9 Additional P‐Containing Polymers

13.10 Summary

Acknowledgements

References

14 Synthons for the Development of New Organophosphorus Functional Materials

14.1 General Introduction

14.2 Phosphorus Transfer Reagents as Emerging Synthetic Approaches to Materials

14.3 Carbene‐Stabilized Molecules as Phosphorus Reagents

14.4 Conclusions and Outlook

References

15 Arsenic‐Containing Oligomers and Polymers

15.1 Introduction

15.2 Chemistry of Organoarsenic Compounds

15.3 Arsenic Homocycles

15.4 Development of C–As Bond Formation for Organoarsenic Compounds

15.5 Properties of Poly(vinylene‐arsine)s

15.6 Properties of 1,4‐Dihydro‐1,4‐diarsinines

15.7 Properties of Arsole Derivatives

15.8 Arsole‐Containing Polymers

15.9 Conclusions

References

16 Antimony‐ and Bismuth‐Based Materials and Applications

16.1 Introduction

16.2 Anion Binding and Sensing Applications

16.3 Small‐Molecule Binding

16.4 Antimony and Bismuth Chromophores

16.5 Conclusion

References

17 High Sulfur Content Organic/Inorganic Hybrid Polymeric Materials

17.1 Introduction

17.2 The Chemistry of Liquid Sulfur

17.3 Waterborne Reactions of Polysulfides

17.4 Controlled Polymerization with High Sulfur‐Content Monomers

17.5 Modern Applications of High Sulfur‐Content Copolymers

17.6 Conclusion and Outlook

Acknowledgements

References

18 Selenium and Tellurium Containing Conjugated Polymers

18.1 Introduction

18.2 Selenium‐Containing Conjugated Polymers

18.3 Tellurium‐Containing Conjugated Polymers

18.4 Conclusions and Outlook

References

19 Hypervalent Iodine Compounds in Polymer Science and Technology

19.1 Introduction

19.2 Applications of Hypervalent Iodine Compounds in Polymer Science and Technology

19.3 Conclusions

Acknowledgements

References

Index

End User License Agreement

List of Tables

Chapter 09

Table 9.1 Comparison of oligostannanes prepared by Dräger [25].

Table 9.2 Molecular weight data for polygermanes, Ge–Si copolymers, and polygermynes prepared by Wurtz coupling (W) and electrochemical (EC), SmI

2

, or ligand substitution (LS).

Table 9.3 Molecular weight data for polygermanes prepared by demethanative coupling of methylated germanes RMe

2

GeH (R = Me, aryl).

Table 9.4 Thermal transitions observed for dialkylpolygermanes and copolymers with silanes [16].

Table 9.5 Molecular weight data, thermal transitions, and polymerization methods for a selection of polystannanes.

Table 9.6 Molecular weight data for polystannanes and copolymers of Sn/Si or Sn/Ge prepared by electrochemical polymerization [62].

Table 9.7 UV‐visible spectral data and

119

Sn NMR chemical shifts for polystannanes.

Table 9.8 From Reference [80]. Comparison of calculated band gap energies for Group 14 metallanes in both TP (

trans‐planar

) and GH (

gauche‐helical

) geometries.

Chapter 18

Table 18.1 Summary of physical and electronic properties as well as OPV device performance data of copolymers listed in Figure 18.6.

Table 18.2 Summary of physical and electronic properties as well as OPV device performance data of copolymers listed in Figure 18.7.

Table 18.3 Summary of physical and electronic properties as well as OPV device performance data of copolymers listed in Figure 18.8.

Table 18.4 Summary of applications of Te‐containing conjugated polymers.

List of Illustrations

Chapter 01

Figure 1.1 p–π* Conjugation between trivalent boron and sp

2

carbon atoms.

Figure 1.2 Examples of Mes

2

B‐substituted functional materials.

Figure 1.3 Calculated HOMO (white rectangles) and LUMO (black rectangles) levels for polyheteroles (B3P86‐30%/CEP‐31G*).

Figure 1.4 (a) Electronic structure of borole and (b) the structure of thienylborole oligomers.

Scheme 1.1

Figure 1.5 Structural parameters for calculated (B3LYP/6‐31G(d)) and X‐ray crystallographically determined structures of pentaarylboroles. Numerical values refer to bond lengths (Å).

Scheme 1.2

Scheme 1.3

Figure 1.6 Examples of borole derivatives prepared from 1‐chloroborole.

Scheme 1.4

Figure 1.7 Effects of aryl‐substitution at the borole ring on the electronic structure.

Scheme 1.5

Figure 1.8 (a) Dibenzoborole and (b) perfluorodibenzoborole.

Figure 1.9 Examples of intramolecular boron–boron one‐electron σ‐bonds.

Figure 1.10 (a) Tip‐substituted dibenzoborole and (b) Mes*‐substituted dibenzoborole.

Figure 1.11 Thiophene‐fused ladder boroles and reference compounds.

Scheme 1.6

Scheme 1.7

Figure 1.12 Borepin and its 1,3‐sigmatropic ring expansion.

Figure 1.13 Benzo‐fused borepins.

Figure 1.14 Dibenzoborepins and benzene‐linked borepins with Mes* groups at the boron centers.

Scheme 1.8 Direct functionalization of thiophene‐fused borepins with a Mes group at the boron center.

Scheme 1.9

Scheme 1.10

Figure 1.15 (a) Dihydro‐diborins, (b) annulated 1,4‐diborins, and (c) aryl‐substituted borepin derivatives.

Figure 1.16 (a) Binuclear metal complexes

43

and

44

, which contain a 1,4‐diborin skeleton, and (b) mesomeric resonance structures for the dibora‐

s

‐indacene dianion.

Figure 1.17 (a) 1,2‐Diborin dianion

45

2–

, as well as (b) dithieno‐fused 1,2‐diborin

46

and its dianion

46

2–

.

Figure 1.18 Different π‐conjugation modes in the dithieno‐fused 1,2‐diborin dianions (a)

46

2–

(2,2′‐bithiophene) and (b)

47

2–

(3,3′‐bithiophene).

Scheme 1.11 Dihydrogen activation by reduced dibenzo‐1,4‐diborins.

Scheme 1.12

Scheme 1.13 Plane‐to‐bowl conversion of

50

and

51

based on the coordination number change on boron.

Figure 1.19 (a) Radical anion and (b) anion of planarized triphenylborane, and (c) example of electron‐transporting materials for OLED application.

Figure 1.20 Boron‐embedded polyaromatic hydrocarbons

55

and

56

.

Figure 1.21 Boron‐embedded π‐conjugated compounds.

Figure 1.22 Boron‐containing polycyclic aromatic hydrocarbons (PAHs).

Scheme 1.14 STM image is reprinted with permission from Ref. 72a.

Chapter 02

Figure 2.1 (a) Selected applications of D‐A organoboranes are highlighted. (b) The electron‐deficient boron center in organoboranes is stabilized by using bulky twisted aromatic systems. The steric congestion around the boron center provides kinetic stability, and the conjugated backbone provides thermodynamic stability in the system. (c) The boron center can reversibly accept an electron or a small Lewis base like fluoride, acting as electron‐transport material or fluoride receptor. (d) D‐A interaction promoted conjugation and charge separation in the system.

Figure 2.2 Borylanilines

1

and

2

shows (a) strong N–H · · · π interactions in their solid‐state facilitated by the strong charge separation in the molecule. The emission spectra (b) and (c) of the compounds in different solvents show strong solvatochromic effects.

Figure 2.3 (a) Energy level diagram of a single layer OLED fabricated with compound

3

. (b)

J–L–V

characteristics of a ITO/BNPB (90 nm)/Al device.

Figure 2.4 Molecular formulae of compounds

4‐9

and their photophysical features. (a) Comparison between two similar systems (

5

and

6

) with two different acceptor strengths. Compared to (Mes)

2

B‐ the (FMes)

2

B‐ unit results in a more prominent redshift of the emission spectra in hexane (black), toluene (red), THF (blue) and acetonitrile (green). (b) The D‐A interaction in compounds

7–9

can be switched off using excess (>5 equivalents) of fluoride, which blocks the boron center, resulting in emission from only the donor moieties. Inset: photographs of solutions of compounds

7

(green),

8

(yellow) and

9

(red) which change to almost identical blue color upon fluoride binding.

Figure 2.5 Compounds

10

and

11

are two examples of “U” shaped D‐A systems. Compound

11

shows three‐color emission switching, depending on fluoride binding to the boron center or protonation of the amine moiety. Fluorescent titration spectra for 1.0 × 10

–5

M solutions of

11

in dichloromethane (

λ

ex

 = 365 nm): (a)

11

titrated with 20 equiv. of TBAF (tetrabutylammonium fluoride); (b) 21 equiv. of TBAF added to

11

and then titrated with 14 equiv. of HBF

4

; (c)

11

titrated with 1.8 equiv. of HBF

4

; (d) 1.8 equiv. of HBF

4

added to

11

and then titrated with 3.0 equiv. of TBAF.

Figure 2.6 Molecular formula and fluorescence spectra of 3‐borylbithiophene derivatives

12–17

: (a) Emission spectra measured in THF and (b) photographs of solids under irradiation at 365 nm.

Figure 2.7 Molecular formulae of compounds

18–20

. (a) Photograph of solutions of

18

in benzene, THF and DMF under UV illumination. (b) Fluorescence images of the flower‐shaped

19

‐PEG 4000 polymer at different temperatures (

λ

ex

 = 335 nm). (c) Corrected emission spectra of

19

recorded in the PEG 4000 solid‐state polymer between 253 and 313 K (

λ

ex

 = 335 nm). (d) Temperature dependence of the transient emission decay of

20

(TB‐3PXZ) doped in CzSi (9‐(4‐

tert

‐butylphenyl)‐3,6‐bis(triphenylsilyl)‐9

H

‐carbazole) films (10 wt%) from 77 to 300 K.

Figure 2.8 Molecular formulae of compounds

21–23

. (a) Emission spectra of

21

in THF/H

2

O mixtures with different water fractions (

f

w

). (b) Plot of (

I

/

I

0

 − 1) values vs water fractions (

f

w

) in THF/H

2

O mixtures of

21

.

I

0

is the photoluminescence intensity in pure THF solution. Inset: photos of

21

in THF/H

2

O mixtures (

f

w

 = 0 and 90%), taken under the illumination of a UV lamp (365 nm). (c) Photograph of aggregation‐induced emission color changes for

22

(

f

w

 = 0, 40, 60, 70, 80, 90 and 95%). (d) STM images of typical information dot patterns under electric fields of opposite polarities for compound

23

cast in a film. Left‐hand side: recording dots, voltage pulses: +2.71 V, 5.29 ms. Middle: recording dots, dot 2 was erased by a voltage pulse (2.01 V). Right‐hand side: new dot was rewritten on the erased region (dot 2 position) of the thin film by applying another forward voltage pulse (+2.71 V, 5.29 ms).

Figure 2.9 Structural formulae of compounds

24–26

.

Figure 2.10 Structural formulae of porous conjugated polymers

27

and

28

.

Figure 2.11 (a) Design of monomer and preparation of porous organic polymer films through electropolymerization. (b) CV curves of BC (

29

) recorded for ten scan cycles (potential from –0.2 to +1.0 V). (c) Thicknesses of the PBC films under different numbers of CV cycles (scan rate of 0.4 V s

–1

). (d) The secondary electron cut‐off obtained by UPS (ultraviolet photoelectron spectroscopy) for the materials either in neat thin films or on ITO.

Figure 2.12 Molecular formulae of macrocycles

30

and

31

are shown. (a) Supramolecular structure of

30

projected along the crystallographic

c

‐axis (only dichloroethane solvent outside the channels shown; Cl yellow). The crystals show blue photoluminescence under UV‐light. (b) Photographs of solutions of

30

in (left to right) toluene, CH

2

Cl

2

and propylene carbonate, irradiated at 365 nm. (c) Cyclic (top) and square‐wave (bottom) voltammograms for compound

30

; oxidation (left) in dichloromethane and reduction (right) in tetrahydrofuran (0.1M [Bu

4

N][PF

6

]) vs Fc

0/+

(Fc = ferrocene) as an internal reference (indicated with an asterisk). (d) Titration of compound

30

with [

n

Bu

4

N]CN in toluene monitored by (left) UV/Vis and (right) fluorescence spectroscopy and illustration of electron‐donor segments for

30

and the corresponding anion complexes.

Figure 2.13 Molecular formulae of compounds

32–37

.

Figure 2.14 Molecular formulae of compounds

38

and

39

are shown. (a) Molecular design principles of boron‐based TADF molecules. (b) Absorption and fluorescence spectra of

38

in toluene (

λ

ex

 = 290 nm). The green and blue lines represent fluorescence spectra at 300 and 77 K and the black line represents UV‐vis spectra. (c) Transient photoluminescence of 6 wt%

38

:polystyrene films (YaG laser, l = 355 nm). Inset: prompt (black) and delayed (red) photoluminescence spectra of

38

:polystyrene films. The red dotted line represents phosphorescence spectra of

38

at 77 K. (d) DFT (density functional theory) computed FMOs of

39

showing that the HOMO and LUMO are located at the donor and the acceptor moieties, respectively.

Chapter 03

Figure 3.1 Alq

3

and examples of N,O‐, N,N‐, and N,C‐chelate boron compounds [15, 16, 20, 22–24].

Figure 3.2 Example of diarylethene (a) [31, 32] and boron‐based photochromic systems (b) [42, 43] and (c) [44].

Figure 3.3 (a) Photochromism of the N,C‐chelate boron compound

10

. (b) UV‐Vis spectra showing the conversion of

10

into

10a

in toluene with 365 nm irradiation. Inset: photographs showing the solution colors of

10

and

10a

. (c) A polystyrene disk doped with

10

. The pattern is generated by placing a mask on the disk and irradiating the disk with a hand‐held UV lamp at 365 nm.

Figure 3.4 Calculated mechanistic pathway for the photochromic transformation of

10

into

10a

at the CAM‐B3LYP/SVP level of theory.

Figure 3.5 Structures of ppy‐based boron compounds

11–14

with different substituents on the backbone [53].

Figure 3.6 (a) Four‐state switching of

11

. (b) UV/Vis absorption spectra and photographs showing the colors of the four states of

11

in benzene.

Figure 3.7 Structures of metal‐containing (ppy)BMes

2

and analogues

15–18

[58–61].

Figure 3.8 Structures of

10

,

19

, and

20

showing the distances of aryl groups from the ppy carbon atom [53].

Figure 3.9 Donor‐substituted N,C‐chelates

21–26

and the colors of the dark isomers

21a

and

22a

[62].

Figure 3.10 Structures of π‐extended N,C‐chelates

27–37

and the crystal structure of

34a

(X = N‐Ph) [18, 19, 53, 54, 65–67].

Figure 3.11 Colors of representative dark isomers based on N,C‐chelate BMes

2

compounds.

Figure 3.12 Phototransformations of

38

and

39

[50].

Figure 3.13 Photo‐ and thermal transformations of

40–43

[68].

Figure 3.14 Photoreactivity of

44

/

45

and the walk rearrangement of the BN‐bisnorcaradiene

44a

/

45a

[69].

Figure 3.15 Absorption spectra and colors of the two dark isomers

44a

and

44b

.

Figure 3.16 Polyboryl compounds

46–48

[73, 74].

Figure 3.17 (a) Photoelimination of

49

/

50

; (b) UV/Vis and fluorescence spectra showing the conversion of

50

into

50a

doped 5 wt% in PMMA with 300 nm irradiation. Inset: photograph showing the patterned film fluorescent color of

50a

.

Figure 3.18 DFT Calculated mechanistic pathway for the photoelimination of

49

to

49a

at the CAM‐B3LYP/6‐31 g(d) level of theory [83, 84].

Figure 3.19 Structures of various BN‐heterocycles that undergo photoelimination [80, 84–87].

Figure 3.20 Fluorescent colors of representative BN‐arenes in toluene.

Figure 3.21 Crystal structures of

57

(a) and

57a

(b) [85].

Figure 3.22 Structures of BN‐heterocycles decorated by Pt(

II

) and examples of BN‐heterocycles with non‐mesityl substituent groups on the boron atom [80, 83, 84, 88].

Figure 3.23 (a) Photoreactivity of

67

and

69

. (b) UV‐Vis spectra showing the conversion of

69

into

69a

. Inset: solution colors and HOMO/LUMO orbitals of the S

1

state. (c) Structures of

69a

(left) and

67b

(right) in the solid state. (d) Fatigue resistance cycling experiment between

69

and

69a

with sequential irradiation and heating using relative integrated

1

H NMR peak intensities.

Figure 3.24 Calculated mechanistic pathway for the photoisomerization of

67

at the CAM‐B3LYP/6‐31 g(d) level of theory.

Figure 3.25 Scheme showing the concept of exciton driven elimination as a strategy for

in situ

generation of BN‐arenes in OLEDs.

Figure 3.26 (a) OLED device structure used for investigating the EDE process of compounds

49

and

59

. (b) EL spectral change with time at 5 V for the devices fabricated using

49

(left) and

59

(right). The photographs show the EL colors of the two devices.

Chapter 04

Scheme 4.1 Synthesis of conjugated organoborane polymers by hydroboration polymerization (R = Me,

i

Pr).

Figure 4.1 Examples of the synthesis of conjugated organoborane polymers by Sn–B exchange and illustration of the emission quenching of

2P

with pyridine.

Scheme 4.2 Examples of the synthesis of polyferrocenylboranes by (a) spontaneous borane elimination and (b) ring‐opening polymerization (ROP) of bora[1]ferrocenophanes.

Figure 4.2 Conjugated organoborane polymers (

7P

) obtained by Stille coupling (

n

 = 2–5) or Sn–B exchange polymerization (

n

 = 1) of functional dithienylborane monomers

7M

, their HOMO/LUMO energy levels, and solution and solid‐state emission.

Figure 4.3 Representative conjugated polymers with organoborane groups in the side chains.

Figure 4.4 Synthesis of polythiophenes with conjugated organoborane side chains.

Scheme 4.3 Representative conjugated polymers based on diboraanthracene.

Figure 4.5 (a) Synthesis of polymers based on 9‐borafluorene as a building block; (b) illustration of the luminescence changes upon exposure of a polymer film of

19P

to NH

3

vapors.

Figure 4.6 Synthesis of azaborinine polymer

21P

; illustration of absorption and emission spectra for the polymer (BN‐P) in comparison to oligomers (

n

 = 1 BN1;

n

 = 2 BN2;

n

 = 3 BN3); structures of oligophenylene (PPn) and oligocyclohexadiene (CHDn) analogs.

Figure 4.7 Synthesis of polymers based on a B‐N substituted tetrathienonaphthalene as a building block and AFM images showing differences in the phase separation of thin films.

Figure 4.8 Examples of conjugated polymers based on BODIPY units.

Figure 4.9 Synthesis of conjugated boron‐diiminate polymers; photographs showing their thin‐film emission and illustration of the effect of protonation on the emission of polymer

27P

(R

1

 = NMe

2

, R

2

 = Ph, EHx = 2‐ethylhexyl).

Figure 4.10 Boron formazanate polymer

28P

and photographs of a solution, thin film and powder sample of the polymer.

Figure 4.11 Polymers based on doubly B‐N bridged bipyridines.

Figure 4.12 Selected conjugated polymers containing boron 8‐hydroxyquinolato chromophores.

Figure 4.13 Synthesis of conjugated polymers using a N‐C boron chelate as building block; illustration of the electronic effect of formal B‐N for C‐C replacement.

Figure 4.14 Metal‐catalyzed dehydropolymerization of primary phosphine‐borane adducts: (a)

1

H‐decoupled and (b)

1

H‐coupled

31

P NMR spectra of polymer

33P

(R = Ph).

Figure 4.15 (a) Photograph of isolated polymer

33P

(R = Ph) and (b) SEM image of a micropattern fabricated from

33P

(R = Ph) on a Si wafer by soft‐lithography.

Scheme 4.4 Metal‐free synthesis of polyphosphinoboranes

34P

.

Scheme 4.5 Transition metal‐catalyzed synthesis of polyaminoboranes

35P

.

Figure 4.16 Synthesis of polyiminoborane

37P

and frontier orbital depictions for a discrete tetramer.

Scheme 4.6 Synthesis of hybrid polyaminoboranes

38P

and their use in transfer hydrogenation of imines and carbonyl compounds (X = O, NR′).

Scheme 4.7 Synthesis of hybrid polymers

39P

with NBN units in the main chain.

Figure 4.17 Selected carborane and metallaborane‐functionalized monomers utilized in the synthesis of conducting polymers by electropolymerization; illustration of successive cyclic voltammograms of

41M

.

Scheme 4.8 Synthesis of polyfluorene with pendent carborane moieties.

Figure 4.18 Polyfluorenes with

p

‐ and

o

‐carborane moieties in the main chain; optical images under UV light of the pristine polymer

45P

coated onto a laboratory wipe (1) and in the presence of tetrahydrofuran, ethyl acetate, methylene chloride, acetone, methanol, toluene, and hexanes vapors (2–8, respectively).

Figure 4.19 Synthesis of copolymers

46P

via Sonogashira–Hagihara coupling; photographs of copolymers

46P

in solution and in the film state illustrating the aggregation‐induced emission (AIE) effect.

Figure 4.20 Selected conjugated copolymers with

m

‐carborane and benzocarborane moieties.

Figure 4.21 Bis(terpyridyl)‐functionalized

o

‐carborane

49M

and its complexation with Zn

2+

ions.

Figure 4.22 Synthesis of polymers

50P

and

51P

and illustration of different triads in

50P

(

r

 = 

racemo

,

m

 = 

meso

; the NMe

2

group at the Mamx ligand is omitted for clarity).

1

H NMR signal of the

ortho‐t

Bu group of

50P

exhibits pentad resolution (intensity ratio A : B: C ≈ 1: 2 : 1); photographs of polymer solution and solid.

Scheme 4.9 Dialkylated galla and inda[1]ferrocenophanes and their ring‐opening polymerization.

Figure 4.23 Synthesis of gallafluorene‐containing conjugated copolymers

54P

via metal‐catalyzed cross‐coupling reactions and illustration of their electronic structure and emission colors (Ar = conjugated comonomer).

Scheme 4.10 Synthesis of conjugated polymers containing gallium in the main chain.

Figure 4.24 Illustration of the growth of polymer‐embedded Ga

2

S

3

nanoparticles using a bithiophene‐substituted Ga chelate complex as precursor.

Chapter 05

Figure 5.1 Jablonski diagram of luminescence transitions [1]. S

0

 = singlet ground state, S

n

 = singlet excited state, S

1

 = lowest energy singlet excited state, Ex = excitation, IC = internal conversion, F = fluorescence, ISC = intersystem crossing, RISC = reverse intersystem crossing, T

n

 = triplet excited state, T

1

 = lowest energy triplet excited state, P = phosphorescence.

Figure 5.2 Chemical structures of xanthene dyes with oxygen and bromine heavy atom modifications influencing optical properties.

Figure 5.3 (a) Representative difluoroboron‐containing fluorophores. OBO = difluoroboron dibenzoylmethane, BF

2

dbm (

4

) [28]; OBN = 2‐benzoylmethylenequinoline difluoroborate (

5

) [29]; NBN = 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐

s

‐indacene, i.e. BODIPY (

6

) [30]. Stimuli‐responsive boron materials: (b) oxygen‐sensitive BF

2

dbm(I)PLA (

7

) [31]. (c) Mechanochromic luminescence compound BF

2

AVB (

8

). (d) Images of BF

2

AVB with stimuli‐responsive shear capabilities.

Figure 5.4 Electronic design of boron β‐diketonates: (a) General structure with 4,4′‐dimethoxy‐dibenzoylmethane with difluoroboron (BF

2

;

9

) [17, 42–44], diphenylboron (B(C

6

H

5

)

2

;

10

) [34], dipentafluorophenylboron (B(C

6

F

5

)

2

;

11

) [34], and dicyanoboron (B(CN)

2

;

12

) [36]. (b) Chemical structures of dibenzoylmethane dyes synthesized by Chujo

et al.

[34], with diphenylboron (

13

) and pentafluorophenylboron (

14

) and (c) the resultant changes in the highest occupied molecular orbitals (HOMO) and the fluorescence properties.

Figure 5.5 Structural modifications for color tuning of N,C‐chelated boron luminogens (

15–20

). (a) Chemical structures. (b) Images showing fluorescence in solution (CH

2

Cl

2

) and solid‐state (powders).

Figure 5.6 Blue, green, red boron fluorophores. (a) Chemical structures of BODIPY (

21

) and BODIPY‐cholesterol conjugate (BPYchol). (b) Brightfield image of zebrafish (left) and green fluorescence from BPYchol (right) seven days post yolk fertilization, Adapted with permission from Reference [70]. Copyright 2008. John Wiley & Sons. (c) Chemical structures of triazaborolopyridinium (HPY;

22

) dyes and cysteine‐derived HPY‐conjugate imaging agents for the kinesin spindle protein (KSP). (d) Membrane permeability of HPY (non‐conjugate) in living HeLa cells (left) and potency test of fluorescent cysteine conjugates that retain KSP inhibitory activity (right). Adapted with permission from Hapuarachchige

et al. J. Am. Chem. Soc.

,

2011

, 133, 6780–6790. Copyright 2011. American Chemical Society [71]. (e) Chemical structure of BF

2

formazanate red fluorophores (

23

). (f) Mouse fibroblast cells stained with BF

2

formazanate (left) and 4′,6‐diamidino‐2‐phenylindole (DAPI) (overlay, right).

Figure 5.7 Solvatochromism of methoxy‐substituted dinaphthoylmethane (dnmOMe;

24

) and the boronated counterpart (BF

2

dnmOMe;

25

). Solvents from left to right = toluene, dichloromethane (CH

2

Cl

2

), acetone, THF, chloroform, acetonitrile (ACN).

Figure 5.8 Ultrasensitive mitochondrial polarity sensing. (a) Chemical structure of near‐IR emitting polarity sensor (

26

). (b–j) Mitochondrial polarity in cancer cell line, HepG2, (b–e) and normal human liver cells, HL‐7702, (g–j) cells stained with MCY‐BF

2

(10 μM). (b, g) Green channels collected at 760–770 nm. (c, h) Red channels collected at 790–800 nm. (d, i) Bright‐field images. (e) Ratiometric image between images (c) and (b), and (j) is the ratiometric image between images (g) and (h). (f) Output of the mean ratio in images (e) and (j).

Figure 5.9 Molecular design of molecular rotor luminophores. Red arrows indicate bonds that can rotate and influence viscosity or aggregation‐dependent emission. (a) Difluoroboron β‐diketonates (OBO;

27–29

) [39, 97, 98]. (b) Difluoroboron β‐ketoiminates (OBN;

30–32

) [102, 104, 105]. (c) Difluoroboron β‐diiminates (NBN;

33–35

) [106–108]. (d) BODIPY molecular rotor (

36

) pioneered by Kuimova

et al

. with varying side chains including alkyls (C

10

, C

12

, and C

16

) [109–112], a charged side chain (2

+

) [113], farnesyl oil (F) [114], and steroid, lithocholic acid (Lith) [115].

Figure 5.10 Viscosity‐dependent emission and wash‐free membrane imaging. (a) Chemical structure of DBX‐Red (

37

) showing rotation and planarization in fluid and viscous environments. (b) Associated spectral changes in the total emission spectra. (c) Carbetocin coupled dye (DXB‐CBT;

38

), wherein the bioactive ligand (CBT) binds oxytocin G protein‐coupled receptor in membranes. (d) Wash‐free fluorescence imaging of membranes in HEK293T cells stably expressing the wild‐type oxytocin receptor (OTR cells).

Figure 5.11 DNA binding boron dyes. (a) Chemical structures of methylpiperazine‐substituted dyes with varying conjugation length (

39–41

). (b) Mechanism of fluorescence turn on from a twisted unbound state to a bound state. (c) DNA staining with

39

(green) and membrane staining with CellMask Deep Red™. (d) Turn‐on response of

39

to adenine and thymine DNA base pairs. (e) One‐probe, multicolor images of

40

(DNA bound = green, cytosol = blue, red = membrane stain CellMask Deep Red™).

Figure 5.12 CRANAD series for sensing amyloid β deposits (

42–45

). (a) Chemical structures for imaging Aβ40 aggregates (CRANAD‐2) [130], water soluble Aβ40 (CRANAD‐58) [131], and brown adipose tissue (CRANAD‐29) [132]. Dual functional imaging agent plus copper‐dependent crosslinking inhibitor for amyloid β (CRANAD‐28) [133]. (b) Fluorescence “turn‐on” of CRANAD‐2 (100 nM) induced by Aβ aggregates (red line); CRANAD‐2 alone in PBS (black line); (inset) CRANAD‐2 only (emission intensity is amplified 30‐fold). Adapted with permission from Reference [130]. (c, d) Two‐photon

in vivo

images of CRANAD‐28 labeling in a nine‐month‐old APP/PS1 mouse. (c) Through a thinned‐skull window 15 min after i.v. infusion of the dye. Both cerebral amyloid angiopathies and amyloid plaques were labeled with CRANAD‐28. (d) Panels show zoomed‐in single focal plane examples of cerebral amyloid angiopathies (white arrowhead in (c), expanded in left‐hand panel of (d)) and amyloid plaques (yellow arrowhead in (c), expanded in right panel of (d)). Blood vessels were labeled with Texas‐red dextran. Red punctate signals are auto‐fluorescence intracellular structures. Scale bar: 25 µm.

Figure 5.13 Design of boron‐functionalized material. (a) Chemical structure and design strategy of borylated bipyridine (BOBIPY;

46

). (b) Peptoid‐functionalized BOBIPY via an azide click reaction (

47

). (c) Fluorescent confocal microscopy of peptoid conjugate in HeLa cells. Left: the emission bandwidth was set to 487–543 nm; middle: brightfield; right: merge.

Figure 5.14 Multi‐emissive BF

2

dbmPLA materials and fabrication. (a) Synthesis of dye–PLA conjugate via lactide ring opening polymerization. (b) Molecular weight dependent emission. (c) TEM of nanoparticles fabricated from dye–PLA conjugate via nanoprecipitation and (d) prompt fluorescence in air (F) and delayed emission under N

2

(RTP) of BF

2

dbmPLA nanoparticles in aqueous suspension.

Figure 5.15 Dual‐emissive BF

2

dbm(I)PLA (

50

) nanoparticles. (a) Chemical structure. (b) Images under UV light of nanoparticles at varying oxygen concentration. (c) Total emission spectra of nanoparticles at various oxygen concentrations. Images and spectra were generated in the Fraser Lab at the University of Virginia from previously reported materials and methods [31]. (d, e)

In vivo

imaging of the breast cancer 4T1 mammary carcinoma tumor region in a mouse window chamber model in carbogen (d; 95% O

2

), room air (e; 21% O

2

) and nitrogen (f; 0% O

2

). Emission intensity was averaged from 430 to 480 nm (fluorescence) and 530 to 600 nm (phosphorescence) then plotted ratios are shown.

Figure 5.16 Hydrogen‐bonding dyes for macromolecular assembly for oxygen sensing. (a) Structure of bis‐ureidopyrimidinone‐modified boron dye (BF

2

dbm‐bis‐UPy;

51

). (b) Schematic illustration of the formation of the hydrogen‐bonded supramolecular polymer based nanoprobe (SPNP) by a mini‐emulsion method. Monomers consist of BF

2

dbm‐bis‐UPy (blue), diphenyl anthracene‐bis‐UPy (purple), and a Pd‐porphyrin‐bis‐UPy (red). (c) Confocal luminescence images and ratiometric luminescence images (

λ

ex

 = 405 nm) of HeLa cells incubated with SPNPs (0.325 × 10

−6

M in water) at 21% and 1% O

2

concentrations. In luminescence imaging, the emission channels of 430–470 and 660–740 nm were collected. In ratiometric imaging, the ratio of emission intensity at 660–740 nm to that at 430–470 nm was chosen as the detected signals.

Figure 5.17 Energy‐transfer scaffold of boron materials. (a) Chemical structures of Rhodamine B–BF

2

dbmOMe dyad (RhB‐BF

2

dbm;

52

), boron dye–PLLA (B‐PLLA;

53

) and Rhodamine B–PLLA (RhB‐PLLA;

54

) materials. (b) Images of a dibenzoylmethane‐derived boron dye (BF

2

dbm) and RhB‐BF

2

dbm dyad in CH

2

Cl

2

under UV illumination. (c) Fabrication of PLLA energy transfer nanoparticles by co‐precipitation of B‐PLLA and RhB‐PLLA. (d) Fluorescence micrographs of neuronal cells incubated with commercial Rhodamine B (

λ

ex

 = 543 nm). (e) Neurons labeled with energy transfer nanoparticles (

λ

ex

 = 790 nm; emission filter range: 550–740 nm); scale bars: 30 µm.

Figure 5.18 Semiconducting conjugated polymer dots (Pdots) with highly emissive BODIPY fluorophores. (a) Chemical structures of BODIPY monomers for green (

55

; 520 Pdot), orange (

56

; 600 Pdot), and red (

57

; 690 Pdot) emission and an example of a conjugated polymer after Yamamoto polymerization with other aromatic monomers (

58

with fluorene and benzothiadiazole). (b) Total emission spectra of Pdots fabricated from conjugated polymers. (c) Confocal fluorescence microscopy images of MCF‐7 cells labeled with BODIPY Pdot‐SA probes (Pdots were fabricated with streptavidin for cell‐surface markers).

Figure 5.19 Conjugated AIE polymers for cell imaging [103, 184, 185]. (a, b) Chemical structures of boron ketoiminate AIE polymers used for cell imaging (

59–63

). (c) Imaging of increasing water fraction of polymer

63

. (d) Confocal laser scanning microscopy (CLSM) images of MCF‐7 cells stained with polymer

63

. Fluorescence images were recorded under 405 nm excitation wavelength. Scale bar: 30 μM.

Chapter 06

Scheme 6.1 Survey of synthetic approaches to silanols.

Scheme 6.2 Adduct formation, gradual abstraction and replacement of the silanol proton.

Scheme 6.3 Selected polyfunctional silanols for which adduct formation has been demonstrated.

Figure 6.1 Packing of 4,4′‐bpy adducts of

2

(a), and DmpSi(OH)

3

and

t

BuSi(OH)

3

(b). The 2,6‐R

2

C

6

H

3

(SiMe

3

)‐ unit in

2

was omitted for clarity.

Figure 6.2 Calculated charges (Mulliken: italic, NBO: in brackets) of the oxygen atoms in the isoelectronic methylsilanetriolate, methylphosphonate and methylsulfonate monoanions (B3LYP//6‐311 + G(d)).

Figure 6.3 Gradual transition from metal oxide to metal–π‐interaction with increasing size of the alkali metal cation. The shortest metal–carbon contacts in these compounds fall below the sum of the van der Waals radii by 19% (Li), 24% (Na), and 28% (K).

Scheme 6.4 Condensation reactions leading to POSS cages.

Scheme 6.5 Selected condensation reactions of bulky substituted silanetriols.

Scheme 6.6 Modification of oxidic surfaces with silanetriols via a two‐step process composed of hydrogen bonding (reversible) and covalent bonding (irreversible).

Figure 6.4 Illustration of the lithographic process (a) and structural features (b) obtained by this method as analyzed with AFM: (c) image and (d) cross section).

Figure 6.5 Patterning of adhesive zones via photocatalytic degradation for in situ surface modification immersed in the cell‐culture medium.

Figure 6.6 Sketch of the fabrication process of amphiphobic cellulose sheets. (a) Cellulose microfibers of commercial filter paper; (b) rougher cellulose fibers of filter paper resulting from alkaline solution etching; (c) cellulose nanofiber of etched filter paper with deposited titania–PFOTMS composite ultrathin films; (d) and (e) structure of titania–PFOTMS ultrathin film‐modified cellulose nanofiber; (f) resulting amphiphobic cellulose sheet.

Figure 6.7 TEM image of a cerasome.

Figure 6.8 Survey of silanol‐based catalysts.

Figure 6.9 X‐ray crystal structure of the active site of thermolysin including the silanediol inhibitor.

Scheme 6.7 Comparison of the transition state of amide or ester hydrolysis with their structural silanol mimics.

Figure 6.10 Surface tension of aqueous solutions of silanetriols

4

.

Chapter 07

Figure 7.1 Essence of molecular design of siloles and fused siloles.

Scheme 7.1 Conventional synthetic approaches to 2,3,4,5‐tetraarylsiloles

1

and

4

.

Scheme 7.2 Standard synthesis of dibenzosiloles

5

and dithienosiloles

6

.

Figure 7.2 Frontier molecular orbitals of silole.

Figure 7.3 LUMOs of dimethylated cyclopentadiene, silole, dibenzosilole, and dithienosilole (σ*–π* conjugation can be found at the yellow dotted circles).

Figure 7.4 Aggregation‐induced emission of

7

. The luminescence image is reprinted with permission from Reference [12a].

Figure 7.5 Typical architectures of OLEDs.

Figure 7.6 Electron‐transporting siloles

8

and

9

.

Figure 7.7 Poly(3,6‐dibenzosilole)s

10

and

11

acting as host materials for OLEDs.

Figure 7.8 Benzosiloles

12

and

13

acting as hole‐blocking materials for OLEDs.

Figure 7.9 Light‐emitting siloles

14–16

applicable to OLEDs.

Figure 7.10 Siloles

17

and

18

acting as both emitter and hole/electron‐transporting materials.

Figure 7.11 Emissive poly(2,7‐dibenzosilole)

19

and dibenzosilole‐containing copolymers

20

and

21

.

Figure 7.12 UV‐emissive poly(3,6‐dibenzosilole)

22

and blue‐emissive copolymer

23

.

Figure 7.13 Blue‐emissive fused naphthosilole

24

applicable to OLEDs.

Figure 7.14 Bottom‐gate/top‐contact type OFET device architectures.

Figure 7.15 Semiconducting dithienosilole‐thiophene copolymers

25

and

26

.

Figure 7.16 Semiconducting dithienosilole‐based polymer

27

.

Figure 7.17 Semiconducting dithienosilole‐based oligomer

28

.

Figure 7.18 Semiconducting silaindacenodithiophene‐based polymers

29

and

30

.

Figure 7.19 Schematic diagram of a bulk heterojunction polymer solar cell and current versus voltage plot of a solar cell:

V

m

and

J

m

(voltage and current at maximum power output, respectively),

V

OC

(open‐circuit voltage),

J

SC

(short‐circuit current),

P

in

(input solar power), FF (fill factor), and PCE (power conversion efficiency).

Figure 7.20 Light‐harvesting fluorene‐based polymer

31c

and dibenzosilole‐based polymer

31 s

.

Figure 7.21 Light‐harvesting dithienocyclopentadiene‐based polymer

32c

and dithienosilole‐based polymer

32 s

.

Figure 7.22 Light‐harvesting dithienosilole‐based polymers

33

and

34

.

Figure 7.23 Light‐harvesting silaindacenodithiophene‐based polymers

35

and

36

.

Figure 7.24 Light‐harvesting bis‐silicon‐bridged dithienocarbazole‐based polymer

37

.

Figure 7.25 Light‐harvesting dithienosiloles

38

and

39

.

Figure 7.26 Light‐harvesting dithienosiloles

40

and

41

, applicable to dye‐sensitized solar cells.

Figure 7.27 Tetraarylsilole‐based sensor materials

7

and

42–46

: (a) plot of fluorescence intensity vs concentration of

46

in HeLa cells and (b) photoluminescence spectra of

7

in DPA upon bubbling with different volumes of CO

2

(

V

CO2

).

Figure 7.28 Pentaphenylsilole‐containing polymer

47

applicable to doxorubicin detection.

Figure 7.29 AIE‐active tetraphenylsilole‐containing cyclosiloxanes

48

and

49

.

Figure 7.30 Polysilole

50

and dibenzosilole‐based polymers

51

and

52

for explosive detection.

Chapter 08

Scheme 8.1 Wurtz‐type reductive coupling of dichlorosilanes.

Scheme 8.2 Synthetic methods for polysilanes. (a) Ring‐opening polymerization of cyclotetrasilanes, (b) catalytic dehydrogenative coupling of hydrosilanes, and (c) anionic polymerization of masked disilenes.

Scheme 8.3 Functional modification of polysilanes.

Scheme 8.4 Substitution of an amino group of an amino‐substituted polysilane.

Figure 8.1 Chemical structures of conformationally locked oligosilanes.

Figure 8.2 Categories of dihedral angles of a tetrasilane unit (T

–

and T

+

:

transoid

; G

–

and G

+

:

gauche

; A:

anti

).

Figure 8.3 Chemical structure of helical oligo‐ and polysilanes.

Scheme 8.5 Schematic representation of the preferential induction of a helical conformation of oligosilanes by complexation with helical amylose.

Scheme 8.6 Synthesis of hollow shell cross‐linked micelles and water‐soluble nanometer‐sized metal particles using polysilane block copolymers.

Figure 8.4 AFM (tapping mode) image of hollow spherical particles derived from polysilane shell cross‐linked micelles.

Figure 8.5 UV‐Vis absorption spectrum, photograph of a solution in water, and TEM image of nanometer‐sized Au metal particles derived from the polysilane shell cross‐linked micelles.

Figure 8.6 Fabrication of an optical waveguide: (a) conventional method and (b) polysilane‐based method.

Scheme 8.7 Pd/(PSi‐Al

2

O

3

) (poly(methylphenyl)silane‐supported palladium/alumina hybrid catalyst)‐catalyzed hydrogenation in a flow system.

Chapter 09

Figure 9.1 Group 14 inorganic polymers (a) and their σ‐conjugated linear chain of interacting 3‐, 4‐ or 5sp

3

orbitals (b).

Scheme 9.1

Scheme 9.2

Figure 9.2 Comparison of the bond distances (pm) and bond angles (°) in molecular representations of the a hexagermane [24] (a) and a hexastannane [25] (b).

Scheme 9.3

Figure 9.3 Schematic representations of symmetrical and asymmetrical polygermanes and poly(dithienogermole)s (DT).

Scheme 9.4

Scheme 9.5

Scheme 9.6

Scheme 9.7

Scheme 9.8

Figure 9.4 Schematic representations of optically active polygermanes [40] and a

potentially

crosslinkable polygermane [41].

Scheme 9.9

Figure 9.5 DSC analysis of ‐[(

n

Hex)

2

Ge]

n

‐ (

M

w

 = 9.7 × 10

5

Da): () heating, (‐ ‐ ‐ ‐) cooling.

Figure 9.6 UV spectrum of a film of ‐[(

n

Hex)

2

Ge]

n

‐ as a function of temperature (°C): () 22, (– – –) –3, and (‐ ‐ ‐ ‐) ‐11.

Scheme 9.10

Scheme 9.11

Scheme 9.12 [53]

Scheme 9.13 Electrochemical polymerization of R

2

SnCl

2

[46], (

n

Bu)

2

SnCl

2

with (

n

Bu)

2

SiCl

2

or (

n

Bu)

2

GeCl

2

[62], and RSnCl

3

[63].

Scheme 9.14 Catalytic dehydrocoupling of diorganostannanes.

Scheme 9.15 Hafnocene catalyzed dehydrocoupling of (

n

Bu)

2

SnH

2

[67].

Scheme 9.16 Proposed mechanism for the dehydropolymerization of stannanes [70].

Scheme 9.17

Scheme 9.18 Synthesis of chiral polystannanes.

Scheme 9.19 TMEDA catalyzed dehydrocoupling of stannanes.

Scheme 9.20 Preparation of alternating polystannanes.

Scheme 9.21 Proposed degradation mechanism of polystannanes.

Figure 9.7 Electronic spectra of (a) (

n

Bu)

3

Sn‐(

n

Bu

2

Sn)

n

‐Sn(

n

Bu)

2

‐(CH

2

)

2

OEt (

n

 = 0–4) [79] and (b) Ph

3

Sn‐((

t

Bu)

2

Sn)

n

‐SnPh

3

(

n

 = 1–4) [25].

Figure 9.8 Computed band structures for (a) ‐[Ph

2

Ge]

n

‐, (b) ‐[PhHGe]

n

‐ and (c) ‐[H

2

Ge]

n

‐ revealing σ − σ skeletal bonding from the overlap of primarily the Ge 4p

z

AOs in the HOMO and the absence of bonding in the LUMO orbitals that are mainly contributed from the Ge 4s and 4p

x

AOs. The purple, brown, and pink balls represent Ge, C, and H atoms, respectively.

Figure 9.9 First band gap energies of Group 14 metallanes [MH

2

]

n

,

(M = Si, Ge, Sn) modeled using TD‐DFT at the LSDA/SDD level [80].

Chapter 10

Scheme 10.1 Preparation of poly(silylene‐ and germylene‐diethynylene)s

Scheme 10.2 Preparation of germapericyclynes.

Scheme 10.3 Preparation of germylene‐ethynylene polymer.

Figure 10.1 Structures of pyrene derivatives.

Scheme 10.4 Preparation and structures of fluorene‐ and carbazole‐containing ethynylene polymers.

Scheme 10.5 Synthesis of polymers composed of ferrocene and group 14 element units via ROP of metalla[1]ferrocenophanes.

Scheme 10.6 Synthesis of borylstannylferrocences and interaction with fluoride anion.

Figure 10.2 Structures of germanium and tin‐containing fused ferrocene compounds.

Figure 10.3 HOMO and LUMO energy levels and profiles of silole and cyclopentadiene as derived from DFT calculations at the B3LYP/6‐31G(d,p) level of theory [28].

Figure 10.4 Structures of dithienylcyclopentadiene and group 14 metalloles.

Figure 10.5 Structures of AIE‐active siloles and germoles.

Scheme 10.7 Synthesis of germole‐containing conjugated polymer via Yamamoto coupling.

Scheme 10.8 Synthesis of macrocyclic germole‐phenylene compounds.

Scheme 10.9 Synthesis of germole‐containing polymer via Ti‐Ge transmetalation.

Scheme 10.10 Synthesis of 1,1‐silole/germole polymers.

Scheme 10.11 Synthesis of mono‐ and bi‐stannole compounds.

Scheme 10.12 Synthesis of mono‐, bi‐, ter‐, and poly‐stannoles.

Scheme 10.13 Synthesis of stannole‐containing polymer via Ti‐Sn transmetalation.

Scheme 10.14 Synthesis of stannole‐containing polymer via Stille cross coupling.

Scheme 10.15 Synthesis of fluorinated dibenzoborole derivatives via transmetalation of dibenzostannole with BBr

3

.

Scheme 10.16 Synthesis of annulated germoles.

Scheme 10.17 Synthesis of an AIE‐active spiro‐germole.

Scheme 10.18 Synthesis of methoxy‐ and fluorine‐substituted dibenzogermoles.

Figure 10.6 Structures of conjugated oligomers with electron‐accepting perfluorodibenzogermole units.

Figure 10.7 Structures of group 14 element‐bridged triphenylenes.

Scheme 10.19 Synthesis of conjugated dibenzogermole polymers.

Scheme 10.20 Synthesis of triphenylene derivatives from dibenzostannoles.

Figure 10.8 Structures of DTG‐containing conjugated polymers.

Figure 10.9 Structures of DTG‐related polymers and oligomer.

Figure 10.10 HOMO and LUMO energy levels of dithienometallole derivatives derived from DFT calculations at the B3LYP/6‐31G(d) level of theory.

Figure 10.11 Current density–voltage profiles of cells with the structure ITO/PEDOT:PSS/polymer:PC

71

BM/LiF/Al, where the polymer is

60

or

61a

.

Figure 10.12 Structures of a spiro‐condensed DTG and DTG‐containing silsesquioxanes.

Scheme 10.21 Synthesis and reactions of dichlorodithienogermoles.

Figure 10.13 Structures of dithienostannoles.

Figure 10.14 HOMO and LUMO profiles of dithienostannole, as derived from density functional theory calculations at the B3LYP/LanL2DZ level of theory.

Figure 10.15 Crystal packing in compound

92a

.

Figure 10.16 Structures of diselenophenogermoles and benzofuran‐fused metalloles.

Scheme 10.22 Synthesis of dipyridinogermoles.

Scheme 10.23 Synthesis and structures of groups 14 metalacycloheptatriene and dimetalamacyclohexadiene.

Chapter 11

Figure 11.1 Representative structures of phosphorus‐based porphyrin materials.

Scheme 11.1 Synthesis and P‐functionalizations of

meso

‐phosphinoporphyrins.

Scheme 11.2 Synthesis of phosphametallacycle‐fused porphyrin dimers.

Scheme 11.3 Heck reactions catalyzed by porphyrin‐appended phosphapalladacycles.

Scheme 11.4 Synthesis of porphyrin‐based PCP pincer complexes and their catalytic activities in allylation reactions.

Scheme 11.5 Synthesis and reaction of

meso

‐triphenylphosphonio‐ZnOEP.

Scheme 11.6 Synthesis of

meso

‐triphenylphosphonioporphyrins.

Scheme 11.7 Synthesis of β‐triphenylphosphonio‐ZnTPP.

Scheme 11.8 Synthesis of rigid β‐phosphonio‐ZnTPP dimers.

Scheme 11.9 Synthesis of flexible β‐phosphonio‐ZnTPP dimers and trimer.

Scheme 11.10 Synthesis of

meso

‐(diphenylphosphoryl)porphyrins.

Scheme 11.11 Self‐assembly of heterodimers and heterotrimers consisting of

meso

‐phosphorylporphyrins.

Scheme 11.12 Supramolecular assembly of

meso

‐(diphenylphosphoryl)porphyrins.

Scheme 11.13 Synthesis of

meso

‐phosphorylporphyrins.

Scheme 11.14 Self‐assembly of

29‐M

.

Scheme 11.15 Synthesis of 1D heterometallic coordination polymers.

Scheme 11.16 Synthesis of β‐dialkoxyphosphoryl‐TPPs.

Scheme 11.17 Self‐assembly of zinc phosphorylporphyrins and redox potentials of the dimers.

Scheme 11.18 Synthesis of phosphoryl‐substituted phthalocyanines.

Scheme 11.19 Fabrication of an OPV containing a tetraphosphono‐ZnPc interface.

Scheme 11.20 Synthesis of phosphoniophthalocyanines.

Scheme 11.21 Synthesis of ZnPcs bearing phosphoryl groups at the periphery.

Scheme 11.22 Synthesis of ZnPcs bearing eight phosphoryl groups at the periphery.

Scheme 11.23 Synthesis of PXN

2

‐porphyrins.

Scheme 11.24 Complexation reactions of PXN

2

‐porphyrins.

Scheme 11.25

P

‐Oxygenation reactions of PXN

2

‐porphyrins.

Scheme 11.26 Synthesis of a

P

‐confused carbaporphyrinoid.

Scheme 11.27 Synthesis of tri‐ and tetra‐phosphaporphyrinoids.

Scheme 11.28 Synthesis of PXN

2

‐calixpyrroles.

Scheme 11.29 Synthesis of Au

I

complexes of a PSN

2

‐calixpyrrole.

Scheme 11.30 Synthesis and crystal structures of Pd

II

and Pt

II

complexes of a PSN

2

‐calixpyrrole.

Scheme 11.31 Synthesis of phosphaferrocene‐containing P

2

N

2

‐ and PSN

2

‐calixpyrroles.

Scheme 11.32 Synthesis of PXN

2

‐calixphyrins.

Scheme 11.33 Complexation reactions of PXN

2

‐calixphyrins and Mizoroki–Heck reaction catalyzed by

67

.

Chapter 12

Figure 12.1 Organophosphorus materials used in optoelectronic devices.

Figure 12.2 Common structures of phosphine oxide materials.

Figure 12.3 Phosphine materials as charge‐transport layers.

Figure 12.4 Selected hosts based on phosphine oxides and carbazole.

Figure 12.5 Selected hosts based on phosphine oxides and other scaffolds.

Figure 12.6 Examples of phosphine oxide materials as hosts for TADF emission.

Figure 12.7 Blue, green, yellowish green, yellow, and orange TADF OLED devices based on SFXSPO (

36

) as the host.

Figure 12.8 Examples of phosphine oxide‐based emitters.

Figure 12.9 Diphosphacyclobutane diradicals

49–51

used in FET devices.

Figure 12.10 Dihydrophosphetes for OLEDs.

Figure 12.11 General structures of phosphole based materials.

Figure 12.12 Phosphole‐based systems used as charge transport layers.

Figure 12.13 Phosphole‐based system used as a phosphorescent host.

Figure 12.14 Phosphole derivatives as emitters in OLEDs and WOLEDs.

Figure 12.15 Normalized electroluminescence spectra and CIE coordinates of devices based on the percentage of compound 72 in a DPVBi matrix.

Figure 12.16 Flexible organic light‐emitting diode (FOLED) based on phosphole

72

doped in DPVBi.

Figure 12.17 Fused phosphole derivatives as emitters in OLEDs and WOLEDs.

Figure 12.18 Phosphole‐based dyes utilized in DSSCs.

Figure 12.19 Phosphole containing polymers used for OSC devices.

Figure 12.20 (a) Phosphole containing materials used for electrochromic devices. (b) Photoluminescence (upon exposure to UV‐light) of the electrochromic device containing compound

92

before (left) and after applying potential (right).

Figure 12.21 Benzophosphole‐oxide substituted alkynylgold(

III

) complex

96

.

Figure 12.22 Nature of the PN bond in phosphazene and representation of PP and CP.

Figure 12.23 Phosphazene derivatives used in solar cells and OLEDs.

Chapter 13

Scheme 13.1 Polymerization routes to polyphosphazenes.

Figure 13.1 Selected polyphosphazenes.

Figure 13.2 Polyphosphazenes with alkyl‐ or proton‐substituents.

Scheme 13.2 Thermal polymerization of cyclophosphazene

6

.

Figure 13.3 Examples of poly(thionylphosphazene)s.

Figure 13.4 Film‐ and membrane‐forming polyphosphazenes bearing cycloalkoxy‐substituents.

Scheme 13.3 Routes to poly(phosphole)s.

Figure 13.5 Examples of phosphole‐containing polymers.

Figure 13.6 Thiophene‐containing poly(phosphole)s.

Figure 13.7 Poly[2,5‐bis(2‐thienyl)phosphole]s.

Figure 13.8 Bis(thienyl)phosphole‐containing polymer

15

.

Scheme 13.4 Poly(phosphole)s prepared by metal‐catalyzed cross‐coupling.

Figure 13.9 Fluorene‐phosphole polymers.

Scheme 13.5 Phosphole‐containing homopolymer

24

.

Scheme 13.6 Polymerization of phosphaalkenes.

Scheme 13.7 Polymerization of the chiral phosphaalkene‐oxazoline

28

.

Figure 13.10 Substitution patterns of poly(methylenephosphine)s.

Scheme 13.8 Isomerization‐polymerization of phosphaalkenes.

Scheme 13.9 Homo‐ and copolymers derived from the chiral oxazoline‐phosphaalkene

32

.

Scheme 13.10 Reactions of poly(methylenephosphine)s.

Figure 13.11 TEM micrographs of nanostructures obtained from the solution self‐assembly of PMP‐PI block copolymers (PI = polyisoprene) with the phosphine complexed to gold(

I

). (a) PI

404

‐

b

‐PMP

32

∙AuCl; (b) PI

222

‐

b

‐PMP

77

∙AuCl; (c) PI

164

‐

b

‐PMP

85

∙AuCl. We are grateful to Drs. K. J. T. Noonan, B. H. Gillon and V. Cappello for obtaining these images that are related to their published work in Reference [81].

Figure 13.12 Examples for poly(arylene‐phosphine)s.

Scheme 13.11 Synthesis of poly(

p

‐phenylenephosphine)

38

.

Scheme 13.12 Synthesis of poly(vinylenephosphine)s.

Scheme 13.13 Synthesis of poly(

p

‐phenylenediethynylene‐phosphine)s.

Figure 13.13 Photograph showing the luminescent behavior of solutions of (a) PPYP and (b) PPYP∙O during irradiation with UV‐light. We are grateful to Benjamin Rawe and Michael Scott for providing this image.

Scheme 13.14 Synthesis of a poly(

p

‐phenylenevinylene)s by thermal polymerization.

Scheme 13.15 Synthesis of a poly(

p

‐phenylenevinylene)s by phospha‐Wittig reaction.

Figure 13.14 Diphosphene polymer

45

.

Figure 13.15 Colors of selected phospha‐PPVs and model compounds compared to their carbon analogues. We are grateful to Prof. John Protasiewicz for providing this photograph.

Scheme 13.16 Rhodium‐catalyzed polymerization of phosphinoboranes.

Figure 13.16 Isolated metal‐free, high‐molecular‐weight poly(phosphinoborane)

52

(a) and SEM images of micropatterns fabricated on silicon wafers by soft‐lithography (b)–(d).

Scheme 13.17 Metal‐free addition polymerization of phosphinoboranes.

Scheme 13.18 Synthesis of poly(phosphinoborane)s via boryl‐phosphonium iodide.

Scheme 13.19 Synthesis of poly(ferrocenylphosphine)s.

Scheme 13.20 Ring‐opening polymerization of strained [1]phosphaferrocenophanes.

Scheme 13.21 Synthesis of organic–inorganic block copolymers.

Scheme 13.22 “Migration insertion polymerization” of carbonyl(phosphinoalkyl)iron(

II

) (

64

).

Figure 13.17 Selection of polymers with stereogenic phosphorus centers.

Figure 13.18 Branched organophosphorus polymer prepared using a phosphane‐ene reaction.

Chapter 14

Figure 14.1 Examples of organophosphorus building blocks.

Figure 14.2 Structures of white and red phosphorus.

Figure 14.3 Structure of black phosphorus.

Figure 14.4 Comparison of the cyanate and phosphaethynolate ions.

Scheme 14.1 Synthesis of alkaline and alkaline‐earth metal phosphaethynolates.

Scheme 14.2 Synthesis of [Na(OCP)•(DME)

2

]

2

.

Scheme 14.3 Synthesis of Na(OCP)•(dioxane)

2.5

.

Scheme 14.4 Resonance structures of the phosphaethynolate anion.

Scheme 14.5 Synthesis of four‐membered P‐heterocycles via [2 + 2] cycloaddition reactions.

Scheme 14.6 Synthesis and resonance structures of phosphinecarboxamide.

Scheme 14.7 Synthesis of anionic

P

‐heterocycles via [2 + 2] and [3 + 2] cycloaddition reactions.

Scheme 14.8 Synthesis of anionic

P

‐heterocycles via [2 + 2] cycloaddition reaction.

Scheme 14.9 Synthesis and reactivity of sodium phosphinin‐2‐olate.

Scheme 14.10 Synthesis and reactivity of triphospha‐heterocyclic anions.

Scheme 14.11 Synthesis of 2,4,6‐tri(hydroxy)‐1,3,5‐triphosphinine [C

3

P

3

(OH)

3

].

Scheme 14.12 Reactivity of C

3

P

3

heterocycles with main group and transition metal reagents.

Scheme 14.13 Synthesis of tungsten‐complexed anionic phospha‐Wittig reagents.

Scheme 14.14 Synthesis of tungsten‐complexed phospha‐Wittig‐reagent.

Scheme 14.15 Examples of metal‐phosphinidene complexes.

Scheme 14.16 Synthesis of metal‐free Wittig reagent.

Scheme 14.17 Synthesis of phospha‐poly(phenylenevinylene)s using a diphospha‐Wittig reagent.

Scheme 14.18 Synthesis of tetradentate ligand using a phospha‐Wittig reagent.

Scheme 14.19 Synthesis of phosphine‐phosphaalkene ligand using a phospha‐Wittig reagent.

Scheme 14.20 Synthesis of bidentate diphosphine ligands using phospha‐Wittig reagents.

Scheme 14.21 Mechanism of the phospha‐Wittig–Horner reaction.

Scheme 14.22 Synthesis and reactivity of metal‐free phospha‐Wittig–Horner reagent.

Scheme 14.23 Generation and

in situ

reactivity of P

2

.

Scheme 14.24 Synthesis and reactivity of phosphadibenzonorbornadiene derivatives.

Scheme 14.25 Synthesis and reactivity of NHC‐stabilized diphosphorus complex.

Scheme 14.26 Synthesis and reactivity of CAAC‐stabilized phosphorus complexes.

Scheme 14.27 Normal and abnormal reactivity of NHCs with phosphaalkenes.

Chapter 15

Figure 15.1 Proposed structures of Salvarsan.

Scheme 15.1 Synthesis of

cyclo

‐(MeAs)

5

and

cyclo

‐(PhAs)

6

.

Scheme 15.2 Formation of linear poly(methylarsine) with a ladder structure.

Scheme 15.3 Classical methodologies for C–As bond formation.

Figure 15.2 Generation of diiodoarsine from

cyclo

‐(AsPh)

6

.

Figure 15.3

In situ

‐generation of nucleophilic organoarsine, and subsequent nucleophilic substitution.

Scheme 15.4 Radical reactions of tetraphenyldiarsine or tetraphenyldiphosphine and phenylacetylene.

Scheme 15.5 Ring‐collapsed radical alternating copolymerization (RCRAC) of arsenic homocycles with terminal alkynes.

Scheme 15.6 Synthesis of 1,4‐dihydro‐1,4‐diarsinines by reaction of arsenic homocycles and alkynes.

Scheme 15.7 Proposed mechanism for the reaction of cyclooligoarsines and alkynes.

Figure 15.4 Synthesis of

cis

‐DHDA

t

Bu and

trans

‐DHDA

t

Bu and their ORTEP diagrams.

Figure 15.5 Synthesis of

cis

‐DHDADA and its ORTEP diagram.

Scheme 15.8 Low‐temperature dehydrating imidation polymerization of

cis

‐DHDADA with 1,3‐bis(4′‐aminophenoxy)benzene.

Scheme 15.9 Syntheses of 2,5‐diaryl‐arsoles and 2,5‐diaryl‐phospholes.

Scheme 15.10 Synthesis and Suzuki–Miyaura coupling of dithienoarsole.

Figure 15.6 Frontier orbitals of 1,2,5‐triphenylarsole (calculated at the B3LYP/6‐31G+(d,p) level of theory).

Scheme 15.11 Suzuki–Miyaura coupling of 2,5‐diaryl‐arsole and 2,5‐diaryl‐phosphole.

Scheme 15.12 Suzuki–Miyaura polycondensation of the dithienoarsole.

Figure 15.7 (a) PL spectra of the model compound and the dithienoarsole polymer. (b) Photographs of the dithienoarsole polymer under UV‐irradiation.

Scheme 15.13 Synthesis of arsole‐containing polymer via post‐element‐transformation technique.

Chapter 16

Scheme 16.1 Competitive anion binding experiment between phosphonium‐borane and stibonium‐borane Lewis acids.

Figure 16.1 Crystal structure of

1‐F

.

Figure 16.2 Cyanide and azide binding to a bidentate stibonium borane.

Figure 16.3 Crystal structures of

1‐CN

and

1‐N

3

.

Scheme 16.2 Fluoride binding at Sb in T‐shaped Au‐Sb and Hg‐Sb complexes.

Figure 16.4 Representation of low‐lying σ* orbitals giving rise to coordination non‐innocence in heterobimetallic Sb–M complexes.

Scheme 16.3 Synthesis of tris(phosphinyl)stibine platinum complexes

5–8

illustrating coordination non‐innocent behavior.

Figure 16.5 Crystal structure of

8

exhibiting dative Pt

→

Sb bonding.

Scheme 16.4 Geometrical and photophysical change of the tris(phosphinyl)stibine palladium complex [

9

]

+

with fluoride binding at Sb.

Figure 16.6 Crystal structures of (a) [

9

]

+

and (b)

9‐F

showing the formation of the lantern complex.

Scheme 16.5

o

‐Chloranil oxidation and fluoride‐binding behavior, respectively, of bis(phosphinyl)stibine platinum complexes

10

and

11

.

Figure 16.7 Crystal structure of

11‐F

.

Scheme 16.6 “Turn‐off” response to fluoride binding in tri(9‐anthryl)borane [24].

Scheme 16.7 Tri(9‐anthryl)‐substituted main group species studied by Yamaguchi and Tamao [25].

Scheme 16.8 Fluoride binding to anthryl‐stibonium compound

16

[2].

Figure 16.8 Fluorescence turn‐on response of [16]

+

to fluoride in 9 : 1 H

2

O : DMSO, pyridine buffered pH 4.8 with 10 mM CTABr.

Figure 16.9 (a) Ground‐state structure of

16

. (b) Tetrahedral excited‐state structure of

16

. (c) Seesaw excited‐state structure of [16]

+

. Inset: simplified MO diagram showing the change in energy of the frontier molecular orbitals in structures shown in (a)–(c).

Figure 16.10 1‐Pyrenyl‐ and 3‐perylenyl‐substituted stibonium compounds studied as fluorescent fluoride sensors in aqueous media [27].

Figure 16.11 Fluorescence turn‐on response of [

18

]

+

to fluoride in 9 : 1 H

2

O : DMSO, pyridine buffered pH 4.8 with 10 mM CTABr.

Figure 16.12 Spirocyclic tetrachlorocatecholato‐ and catecholato‐biphenylstiborane complexes.

Scheme 16.9 Fluoride binding to a neutral alizarin‐substituted stiborane.

Figure 16.13 Colorimetric and fluorescent turn‐on response of

21

to fluoride in a biphasic CH

2

Cl

2

: H

2

O (pH 4.8) system.

Scheme 16.10 Fluoride binding in the pocket of a bifunctional bis(stiborane) [30].

Figure 16.14 Crystal structure of [

22‐F

]

−

showing the chelating Sb–F–Sb motif.

Figure 16.15 Crystal structure of

23a‐

O

2

spiro

‐endoperoxide from O

2

uptake of

23a

.

Scheme 16.11 Reversible dioxygen binding to an amidophenolato‐stiborane and proposed mechanism [33].

Figure 16.16 Amidophenolato‐ and catecholate‐stiborane complexes explored for O

2

reactivity [34a, d, e].

Scheme 16.12 Steric control of O

2

binding at an asymmetrically substituted amidophenolato‐stiborane complex [34c].

Scheme 16.13 Oxygen transfer chemistry of amidophenolato‐stiborane complexes to a Mn‐based oxygen carrier complex [34c].

Scheme 16.14 Synthesis of oxygen‐sensing polymer

Poly‐Sb‐Qmet

incorporating catecholato‐stiborane units [36].

Figure 16.17 Photographs of

Sb‐QMet

‐containing polymer film before and after 3 days exposure to oxygen in ambient air.

Scheme 16.15 CO

2

reactivity of Me

3

Sb(OH)

2

∙H

2

O [39].

Scheme 16.16 CO

2

insertion of hypervalent Bi(

III

) hydroxide/oxide complexes [41].

Figure 16.18 Crystal structure of one isomer of [

27

]

2

‐CO

3

.

Scheme 16.17 Reversible CO

2

insertion by azabismocine complexes

28‐OH

and

28‐OMe

[42].

Scheme 16.18 2,2′‐thiobis(phenolato)bismuth complexes

29‐OMe

and

29‐I

with catalytic activity in the synthesis of propylene carbonate from propylene oxide and CO

2

[43].

Figure 16.19 Crystal structures of dimeric (a)

29‐OMe

and (b)

29‐I

.

Figure 16.20 CO

2

‐reactive oxide‐ and sulfide‐bridged azabismocine complexes [45].

Figure 16.21 Crystal structure of

31a

, showing the small Bi–S–Bi angle in these complexes.

Scheme 16.19 CO

2

and CS

2

reactivity of bridged NCN pincer complexes of Sb and Bi [46, 47].

Figure 16.22 Crystal structure of terminal Sb‐carbonate

32‐CO

3

.

Scheme 16.20 CO

2

and COS insertion into the Bi–C bond of an NCN pincer bismuth oxyaryl complex [48].

Figure 16.23 Luminescent dithienophosphole compounds.

Figure 16.24 Phosphorescent dithienobismole compounds [50].

Figure 16.25 Crystal structure of

36

(a) Crystals of

35

at room temperature under air under ambient light (b) and under UV laser irradiation at 375 nm (c).

Figure 16.26 Luminescent dithienostibole compounds [51].

Figure 16.27 Luminescent bismole‐containing conjugated polymer [52].

Chapter 17

Figure 17.1 Examples of exposed deposits of elemental sulfur from hydrodesulfurization.

Figure 17.2 (a) Synthetic scheme for the homo‐ROP of S

8

; (b) digital images of elemental sulfur before and above the ceiling temperature required for ring‐opening homopolymerization (ROP).

Figure 17.3 Synthesis scheme for AuNP synthesis in liquid elemental sulfur and copolymerization of divinylbenzene (DVB, a mixture of 1,3 or 1,4 isomers).

Figure 17.4 Synthetic scheme for the inverse vulcanization of sulfur with 1,3‐diisopropenylbenzene to form poly(S‐

r

‐DIB) copolymers that readily melt processed via casting into PDMS master to form a wide range of molded objects.

Figure 17.5 (a) Inverse vulcanization of elemental sulfur with 1,4‐diphenylbutadiyne (DiPhDY) yielding poly(sulfur‐

co

‐1,4‐diphenylbutadiyne). (b) Photographs of liquid sulfur and poly(S‐

r

‐Sty). (c) Synthetic scheme for sulfur–styrene copolymerization and proposed structure of poly(sulfur‐

random

‐styrene) copolymers.

Figure 17.6 Solution

1

H and

13

C,

13

C DEPT NMR spectra for poly(S‐

r

‐Sty) and proposed microstructure fragment in the copolymer.

Figure 17.7 (a) Inverse vulcanization with sulfur with ProDOT‐Sty and DIB to prepare soluble pre‐polymers that were electropolymerized after spin coating onto ITO electrodes. (b) SEM of electropolymerized films on ITO electrodes. (c) Structural cartoon of electropolymerized polythiophene‐sulfur films. (d) Electrochemical impedance spectroscopy of electropolymerized films with increasing scan number showing dramatically reduced charge transfer resistance.

Figure 17.8 Interfacial polymerizations of aqueous polysulfide sodium salts with 1,2,3‐trichloropropane to form well‐defined polysulfide colloids of tunable particle size.

Figure 17.9 ROMP of

N

‐cyclohexyl‐norbornene‐dicarboximide followed by cyclic sulfide functional norbornene comonomer to form block copolymer micelles via polymerization induced self‐assembly process.

Figure 17.10 Cycling performance of Li‐S battery from poly(S‐

r

‐DIB) copolymer (10 wt% DIB, 1 kg scale) to 640 cycles with charge (filled circles) and discharge (open circles) capacities, as well as coulombic efficiency (open triangles). Cycles 1–499 were run at a rate of C/10 (167.2 mA g

–1

); cycles 500–599 at C/2 (836 mA g

–1

), and cycles 600–640 at C/10 (167.2 mA g

–1

).

Figure 17.11 (a) Schematic for poly(S‐

r

‐DIB) with controllable S‐S content where copolymers are readily solution or melt processed into either lenses or thin films, both of which are critical forms required for imaging or optical characterization. (b) Plot of refractive index vs wavelength (nm) of conventional polymers (PS, PMMA) vs high

n

poly(S‐

r

‐DIB) from 50 to 90 wt% sulfur. (c) Thermal imaging of human subject through 80 wt% S8 poly(S‐

r

‐DIB) film (~1 mm) in the mid‐IR (3–5 µm) regime; (d) Thermal imaging of human subject through PMMA film (~1 mm) in the mid‐IR (3–5 µm) regime (dotted white line the area where the subject is sitting).

Chapter 18

Figure 18.1 Structures of electron‐rich homo‐polymers containing thiophene and selenophene.

Figure 18.2 UV‐vis spectra of

3

in chlorobenzene (b) and as a thin film (d). Spectra for

rr

‐P3HT in chlorobenzene (a) and as a thin film (c) are shown for comparison.

Figure 18.3 Cyclic voltammetry data of

3

(solid line) and

rr

‐P3HT (dotted line) coated on a graphite electrode in acetonitrile containing 0.1 M Bu

4

NPF

6

.

Figure 18.4 UV‐vis absorption spectra of PTV, PSV, PSV‐

co

‐PTV and corresponding physical blends of PSV and PTV in chlorobenzene solution (ca. 10

−5

M repeat units).

Figure 18.5 Structures of widely applied donor and acceptor building blocks.

Figure 18.6 Benzodithiophene‐benzothiadiazole copolymers containing Se atoms.

Figure 18.7 Benzodithiophene‐thienothiophene copolymers containing Se atoms.

Figure 18.8 Benzodithiophene‐diketopyrrolopyrrole and benzodithiophene‐thienopyrrole‐4,6‐dione copolymers containing Se atoms.

Figure 18.9 Structures of Te‐containing polymers.

Scheme 18.1 Cross‐coupling methods for the synthesis of tellurophene‐containing copolymers.

Scheme 18.2 Preparation of pinacolborane‐substituted chalcogenophene monomers by metallacycle transfer from a zirconacycle intermediate.

Figure 18.10 (a) Solution absorption spectra of

30

before and after gradual addition of bromine. (b) Absorption spectra of untreated thin films of

30

(1), Br

2

‐treated films (2), and Br

2

‐treated films after thermal annealing (3). (c) Photographs of solutions and films of

30

before and after bromine addition.

Figure 18.11 (a) Absorption spectra of

31a

solutions treated with various amounts of Br

2

. Insert: photographs of a

31a

solution before and after Br

2

addition. (b) Absorption spectra of

31a

thin films (solid line),

31a

thin films after Br

2

treatment (dashed line), and the Br

2

treated

31a

thin films after thermal annealing at 150 °C (dash‐dotted line). Insert: photographs of

31a

films before and after Br

2

exposure. (c) Schematic demonstration of reversible addition, coordination and removal of Br

2

with Te atoms in

31a

.

Chapter 19

Scheme 19.1 Early examples of preparation of polyvalent iodine(

III

) and iodine(

V

) compounds.

Figure 19.1 Formation of a linear fragment L

i

‐X‐L

ii

via 3c‐4e HV bonds between a central atom X and ligands L

i•

and L

ii•

, and energy diagram of the formed molecular orbitals.

Figure 19.2 Most common classes of HV iodine compounds.

Scheme 19.2 Bond homolysis and ligand‐exchange reactions involving HV iodine(

III

) compounds with applications in the synthesis of polymeric materials.

Figure 19.3 Structures of diaryliodonium salts used as photoinitiators (a) for the polymerization of various monomers (b).

Scheme 19.3 Photochemistry of diaryliodonium salts.

Scheme 19.4 Mechanism of the cationic photopolymerization of 1,2‐cyclohexene oxide initiated by diaryliodonium salts.

Figure 19.4 Structures of symmetric and asymmetric diaryliodonium hexafluorophosphates used as photoinitiators.

Figure 19.5 Diaryliodonium butyltriphenylborate photoinitiators.

Scheme 19.5 Preparation of the (9‐oxo‐9

H

‐fluoren‐2‐yl)‐phenyl‐iodonium hexafluoroantimonate.

Scheme 19.6 Direct versus sensitized photolysis of diaryliodonium salts.

Scheme 19.7 Photodecomposition of (diacetoxy)iodo benzene.

Scheme 19.8 Conventional and “pseudoliving” radical polymerizations mediated by (diacetoxyiodo)benzene under UV‐ and visible‐light‐irradiation, respectively (M = monomer).

Scheme 19.9 Exchange of acetoxy groups in (diacetoxy)iodoarenes with polymerizable carboxylate (methacrylate) groups to produce inimers

in situ

.

Scheme 19.10 Ligand‐exchange of the acetoxy groups in (diacetoxyiodo)benzene with azide anions to form HV iodine‐based precursors of azide (and methyl) radicals. Formation of highly branched multiazidated polymers via one‐pot procedures and their functionalization with alkenes (for instance, the fluorescent pyrenyl 4‐pentyonate) under “click” chemistry conditions.

Scheme 19.11 Direct azidation of polystyrene using ligand‐exchange reaction between (diacetoxy)iodobenzene and trimethylsilyl azide and preparation of graft copolymers using click reaction between the multiazidated product and poly(ethylene oxide) monomethyl ether 4‐pentynoate.

Scheme 19.12 Post‐polymerization modification of aldoxime‐substituted polymers by oxidation with (diacetoxy)iodobenzene (DAIB) followed by a reaction with a functional alkyne.

Figure 19.6 Polymer‐supported HV iodine (PSHVI) reagents.

Scheme 19.13 Prepartion of polymer‐supported reagent bearing hypervalent iodine groups as counter anion.

Scheme 19.14 Preparation of PSHVI reagents bearing various reactive groups.

Scheme 19.15 Synthesis and regeneration, and reuse, of poly[4‐(diacetoxyiodo)styrene] (PSHVI‐1).

Scheme 19.16 Palladium‐catalyzed oxidative acetoxylation of arene and alkane C–H bonds using PSHVI‐1.

Scheme 19.17 Plausible reaction pathway and synthesis of organyltellurophosphates using PSHVI‐1.

Scheme 19.18 Typical reactions of PSHVI‐2.

Scheme 19.19 Synthesis of PS‐IBS.

Scheme 19.20 Oxidation of alcohols and sulfides using PS‐IBS and regeneration of PS‐IBS.

Scheme 19.21 Preparation of polymeric diaryliodonium salts and cross‐coupling reactions with salicylaldehyde.

Scheme 19.22 Preparation of polyesters with HV iodine atoms in the main chain.

Scheme 19.23 Preparation of polymer with iodonium salt in the main chain.

Scheme 19.24 Preparation of polymer with iodonium salt in the main chain using (diacetoxyiodo)benzene.

Scheme 19.25 Preparation of polyimidothioether with a diaryliodium salt in the main chain.

Scheme 19.26 Catalytic activation of iodosylbenzene with KBr and the oxidation of alcohols.

Scheme 19.27 Preparation of HV iodine based cyclic oligomers.

Guide

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