Synthesis of a Fragment of Crystalline Silicon: Poly(Cyclosilane). Issue 2 (29th November 2016)

• Record Type: Journal Article
• Authors: Press, Eric M.; Marro, Eric A.; Surampudi, Sravan K.; Siegler, Maxime A.; Tang, Joel A.; Klausen, Rebekka S.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 2(2017)
• Page Start: 568
• Page End: 572
• Publication Date: 2016-11-29
• Subjects: hybrid materials -- main-group polymers -- polycycles -- silanes -- synthesis design; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201610208
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We report a strategic synthesis of poly(cyclosilane), a well‐defined polymer inspired by crystalline silicon. The synthetic strategy relies on the design of a functionalized cyclohexasilane monomer for transition‐metal‐promoted dehydrocoupling polymerization. Our approach takes advantage of the dual function of the phenylsilyl group, which serves a crucial role both in the synthesis of a novel α, ω‐oligosilanyl dianion and as a latent electrophile. We show that the cyclohexasilane monomer prefers a chair conformation. The monomer design ensures enhanced reactivity in transition‐metal‐promoted dehydrocoupling polymerization relative to secondary silanes, such as methylphenylsilane. Comprehensive NMR spectroscopy yields a detailed picture of the polymer end‐group structure and microstructure. Poly(cyclosilane) has red‐shifted optical absorbance relative to the monomer. We synthesize a σ–π hybrid donor–acceptor polymer by catalytic hydrosilylation. Abstract : A silicon "chip" : A bottom‐up synthesis gives poly(cyclosilane), a well‐defined polymer inspired by crystalline silicon. NMR spectroscopy yields detailed information about poly(cyclosilane) end groups and microstructure, while optical spectroscopy suggests poly(cyclosilane) and related structures represent a new architecture in conjugated polymers.