The structures, phase transitions, and morphology of polysilanes.

The results of structural studies of polysilanes in solution and in the solid state are reviewed. In the case of poly(di- n-hexylsilane) a detailed description of the polymer chain conformation and microstructure, crystal structure, polymer morphology, and the solid state phase transition is provided. Less complete analyses have been reported for poly(di-n-butylsilane), poly(di-n-pentysilane), and other polysilanes. A wide range of structural probes has been employed including X-ray and electron diffraction, UV, IR, Raman, NMR, light scattering, and DSC. Many of the interesting properties of the polysilanes can be related to the nature of the solid state structures. Variable temperature studies have been especially useful in this regard.