Synthesis of thermotropic liquid crystalline polycarbo-siloxanes and manifestation of nonclassical conjugation in polymer backbone

Polysiloxanearylenes gain mesogenic ability by introduction of methylene jo int group between Si-atom and phenylene core of rigid section as it was sho wn previously. The investigation of model compounds showed the existence of electronic interaction between Si-atom and beta -carbon atom of the backbo ne known in siliconorganic chemistry as beta -effect. The effect is conside red as an example of nonclassical conjugation. An attempt to synthesize the polymer built from such segments led to obtaining of a nonclassicaly polyc onjugated backbone. Preliminary characterization of polydimethylsilylxylili dene obtained as first example of nonclassicaly polyconjugated polymer is p resented and mechanism of polyconjugation is proposed.