Main Group Strategies towards Functional Hybrid Materials

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.

Autorentext

Dr. rer. nat. Thomas Baumgartner, is a Professor and Canada Research Chair in the Department of Chemistry, York University, Canada. He is the recipient of several awards, including a Liebig fellowship from the German chemical industry association, an Alberta Ingenuity New Faculty Award, a JSPS invitation fellowship, and a Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt Foundation. Dr. rer. nat. Frieder Jäkle, is a Distinguished Professor in the Department of Chemistry, Rutgers University-Newark, USA. He is the recipient of the NSF CAREER award, an Alfred P. Sloan fellowship, a Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt foundation, the ACS Akron Section Award, and the Boron Americas Award.

Inhalt
List of Contributors xv

Preface xix

**1 Incorporation of Boron into ?-Conjugated Scaffolds to Produce Electron-Accepting -Electron Systems 1
**Atsushi Wakamiya

1.1 Introduction 1

1.2 Boron-Containing Five-Membered Rings: Boroles and Dibenzoboroles 2

1.3 Annulated Boroles 8

1.4 Boron-Containing Seven-Membered Rings: Borepins 11

1.5 Boron-Containing Six-Membered Rings: Diborins 14

1.6 Planarized Triphenylboranes and Boron-Doped Nanographenes 17

1.7 Conclusion and Outlook 21

References 22

**2 Organoborane DonorAcceptor Materials 27
**Sanjoy Mukherjee and Pakkirisamy Thilagar

2.1 Organoboranes: Form and Functions 27

2.2 Linear D-A Systems 29

2.3 Non-conjugated D-A Organoboranes 32

2.4 Conjugated Nonlinear D-A Systems 33

2.5 Polymeric Systems 36

2.6 Cyclic D-A Systems: Macrocycles and Fused-Rings 39

2.7 Conclusions and Outlook 43

References 43

**3 Photoresponsive Organoboron Systems 47
**Soren K. Mellerup and Suning Wang

3.1 Introduction 47

3.1.1 Four-Coordinate Organoboron Compounds for OLEDs 47

3.1.2 Photochromism 49

3.2 Photoreactivity of (ppy)BMes2 and Related Compounds 50

3.2.1 Photochromism of (ppy)BMes2 50

3.2.2 Mechanism 51

3.2.3 Derivatizing (ppy)BMes2: Impact of Steric and Electronic Factors on Photochromism 52

3.2.3.1 Substituents on the ppy Backbone 52

3.2.3.2 Aryl Groups on Boron: Steric versus Electronic Effect 54

3.2.3.3 -Conjugation and Heterocyclic Backbones 56

3.2.3.4 Impact of Different Donors 58

3.2.3.5 Polyboryl Species 60

3.3 Photoreactivity of BN-Heterocycles 62

3.3.1 BN-Isosterism and BN-Doped Polycyclic Aromatic Hydrocarbons (PAHs) 62

3.3.2 Photoelimination of (2-Benzylpyridyl)BMes2 62

3.3.3 Mechanism 64

3.3.4 Scope of Photoelimination: The Chelate Backbone 65

3.3.5 Strategies of Enhancing PE: Metalation and Substituents on Boron 66

3.4 New Photochromism of BN-Heterocycles 68

3.4.1 Photochromism of (2-Benzylpyridyl)BMesF 2 and Related Compounds 68

3.4.2 Mechanism 70

3.5 Exciton Driven Elimination (EDE): In situ Fabrication of OLEDs 70

3.6 Summary and Future Prospects 73

References 74

**4 Incorporation of Group 13 Elements into Polymers 79
**Yi Ren and Frieder Jäkle

4.1 Introduction 79

4.2 Tricoordinate Boron in Conjugated Polymers 80

4.3 Tetracoordinate Boron Chelate Complexes in Polymeric Materials 87

4.3.1 N-N Boron Chelates 88

4.3.2 N-O Boron Chelates 91

4.3.3 N-C Boron Chelates 92

4.4 Polymeric Materials with B-P and B-N in the Backbone 92

4.5 Polymeric Materials Containing Borane and Carborane Clusters 97

4.6 Polymeric Materials Containing Higher Group 13 Elements 101

4.7 Conclusions 105

Acknowledgements 106

References 106

**5 Tetracoordinate Boron Materials for Biological Imaging 111
**Christopher A. DeRosa and Cassandra L. Fraser

5.1 Introduction 111

5.1.1 Introduction to Luminescence 111

5.1.2 Tetracoordinate Boron Dye Scaffolds 113

5.2 Small Molecule Fluorescence Imaging Agents 114

5.2.1 Bright Fluorophores 116

5.2.2 Solvatochromophores 117

5.2.3 Molecular Motions of Boron Dyes 118

5.2.3.1 Molecular Rotors 121

5.2.3.2 Turn-On Probes 121

5.3 Polymer Conjugated Materials 124

5.3.1 DyePolymer Systems 124

5.3.2 Oxygen-Sensing Polymers 126

5.3.3 Energy Transfer in Polymers 129

5.3.4 Conjugated Polymers 130

5.3.5 Aggregation-Induced Emission Polymers 130

5.4 Conclusion and Future Outlook 133

References 133 **6 Advances and ...