Studies of the conformation and packing of polysilanes

A series of symmetric and asymmetric poly(di-n-alkylsilanes) have been investigated to assess their minimum-energy conformations, crystal packing, and, in the case of poly(di-n-tetradecylsilane) (PdnTDS), the conformation of the n-alkyl side chains. All of the polymers exhibit a thermochromic transition. X-ray diffraction measurements were made above and below the transition temperature to determine unit cell parameters for both the ordered and disordered phases. A TGTG' silicon backbone conformation has been identified and found to occur routinely in symmetric poly(di-n-alkylsilanes) having side chain lengths between 9 and 14 carbon atoms