Charge transfer polysilanes

The chlorination of [MePhSi]n leads to a reactive group that is remote with respect to the main silicon chain. It is possible to modify the resulting functional polysilane in many ways. For example, recently Sakata and his research group have utilized this approach to anchor tetraphenylporphyrin units as pendant groups on the polysilane backbone (Fig. 7.21). It was observed that in this polymer an intramolecular charge transfer occurs from the silicon main-chain to the porphyrin side-chain [66]. 

Me Si. has C, symmetry, and the vibration spectra of trisilanes have been analysed. Aryl polysilanes give a strong 2p charge transfer in the excited state, which affects both photochemical reaction and photophysical processes, while phenyl substituted... 

Poly silanes 12 which can be obtained by cocondensation of (7,8-diphenylfluoranthene-8-)methyl-dichlorosilane with dichlorodimethylsilane, dichloro-methyl-phenylsilane, or dichlorodiphenylsilane in toluene show an increase in conductivity to the level of semiconductors, after doping with strong electrophiles. The charge-transfer complexes are formed by mixing the polysilanes and electron acceptors, such as antimony pentafluoride, tetracyanoethylene or chlora-nil. The UV absorptions of these complexes shift to... 

Charge Transfer Reaction From The Matrix To Polysilanes... 

An even simpler duplication process based on the same principle is shown in Figure 5.29(B). If a hole-injecting electrode is used instead of a photosensitive layer, simple electrostatic charging allows the pattern to be read and transferred.148 Other new technologies based on the photopatteming of polysilanes are being developed, and may become commercialized in the future. 

The method of preparation of radical ions used in this work is widely known in the field of radiation chemistry (3, 11,12). The radical ions of the solute are produced by a charge- (hole- or electron-) transfer process from y-irradiated low temperature matrices. This method is applicable for the formation of radical ions of polymers including polysilanes (7, 3), and a number of reports about polymer ion radicals have been published so far (72). However, some problems exist in formation of polymer radical ions because of their low solubility and the tendency to be aggregated in low-temperature matrices. Under such conditions. 

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