Phase Behavior of n-Alkyl-substituted Polysilanes
2003-09-26, Mueller, Christian, Peter, Christine, Frey1, Holger, Schmidt, Claudia
Polysilanes are high-molecular-weight polymers with a pure silicon chain as backbone and organic side chains. The σ-conjugation of the silicon backbone leads to interesting properties, such as strong UV absorption and photoconductivity. Poly(di-n-alkylsilanes) with n-alkyl side chains longer than ethyl form mesophases, in which the polymers are hexagonally packed in two dimensions but have highly flexible backbones. Such condis (conformationally disordered) crystals, characterized by a dynamic exchange between different conformations, are also known for other polymers, for example, polysiloxanes and polyphosphazenes. A clear proof of the backbone mobility in these mesophases is provided by solid-state NMR spectroscopy.