Bridged bithiophenes

K. Okita, Y. Harima, K. Yamashita, and M. Ishikawa, Synthesis and optical, electrochemical, and electron-transporting properties of silicon-bridged bithiophenes, Organometallics, 18 1453-1459 (1999). 

A number of papers have appeared describing calculations of polymers based on bridged bithiophenes and their carbon, silicon, or germanium analogs (Chart 12.2). In 1995, Toussaint and Bredas [18] reported band structure calculations on polymer 10 with the VEH technique. The calculated bandgap... 

CHART 12.2 Polymers based on bridged bithiophenes and their analogs. 

A couple of studies of copolymers of bridged bithiophenes and EDOT have also been reported, starting with the random copolymer 87 reported by Huang and Pickup [132] in 1998 (Chart 12.12). Copolymer 87 was prepared by electropolymerization of 4 1 mixtures of 4-dicyanomethylene-4ff-cyclopenta[2,l-b 3,4-b j dithiophene and EDOT to give films with conductivities of 0.052—0.69 S cm ... 

Sannicolo et al. first reported the electropolymerization of a Ceo-derivatized bridged bithiophenic precursor (235) [431]. Ferraris et al. have described the synthesis and the electropolymerization of a bithiophene with a Cgo group attached at P-position by an alkyl spacer (236), whereas processable PT copolymers were postfunctionalized with Cgo to give polymers [432]. Recently, PT with Cgo groups connected to the rr-conjugated polymer chain by a phenyl polyether linker has been prepared by electropolymerization of bithiophene 237 [427,433]. While the donor backbone and the acceptor moiety do not interact in the ground state, a photoinduced electron transfer between the PT chain and the attached Cgo group has been demonstrated by ESR measurements. 

Breath figure, 6-34-6-35 Bridged bithiophenes, 12-4, 12-22 Bridged dithienylethylenes, 12-26 Brittle, cracked films, 9-24... 

Y. le, M. Nitani, M. Ishikawa, K.-i. Nakayama, H. Tada, T. Kaneda and Y. Aso, Electronegative oligothiophenes for n-type semiconductors difluoromethylene-bridged bithiophene and its oligomers, Org. Lett., 9, 2115-2118... 

Two important silole-based building blocks are BS [77,78] and TS [79, 80]. The first is also known as silafluorene (SiE, in which a silicon atom replaces the carbon atom in the 9-position of fluorene the second is the silicone-bridged bithiophene (Fig. 17). In both structures the LUMO energy level is lowered by a g -k conjugation within the silole ring. 

Chen C-H, Hsieh C-H, Dubose M, Cheng Y-J, Hsu C-S (2010) Synthesis and characterization of bridged bithiophene-based conjugated polymers for photovoltaic applications acceptor strength and ternary blends. Macromolecules 43 697... 

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