Group 15 systems ladder polymers

The absorption spectra of the synthesized ladder polymers (see Fig. 14.3) display two groups of signals in the visible part of the spectrum. One of these, with an absorption maximum Amax of 396-402 nm (with vibrational fine structure 356 and —375 nm) is very similar to the absorptions of the 7r-system of the angular polyacene structure of Scherf and Chmil described previously, although shifted somewhat (-30 nm) hypsochromically... 

Fig. 30.2 Chemical composition of various paraphenylene systems, (a) Parahexaphenyl (PHP) (b) polyparaphenylene (PPP) (c) paraphenylene-type ladder polymer (LPPP) and (d) a copolymer of PPP and LPPP (CoLPPP). The Y substituent of the material LPPPs is either a hydrogen atom or a methyl group (m-LPPP).

Translating the system to polymeric charge-transfer complexes of the types polymer with donor - - acceptor monomer, polymer with donor- -polymer with acceptor, and polymer with acceptor -t- donor monomer led to a new class of compounds [6] that have electrical conductivities of up to lO Scm". The idea of inserting electron acceptor and donor groups alternately in one molecule was realized in the synthesis of substituted ladder-like polyquinones with -S- and -NH groups [7]. 

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