부산대학교 도서관

The isochronal thermal decomposition of polysilane, -(SiH2)n-, has been investigated at temperatures up to 335°C by in situ infrared spectroscopy. The studies were performed, in vacuo, on compressed discs of polysilane in a KBr matrix. Dehydrogenation was measured by the reduction of the infrared stretching ωs(2100 cm-1), bending ωb(910 cm-1), wagging ωw(865 cm-1) and rocking ωr(650 cm-1) integrated band intensities. The wavenumbers of the infrared-active modes of -(SiH2)n- given in parenthesis correspond to room temperature samples. Loss of hydrogen occurs at relatively low temperatures, ca. 140-200°C, and is essentially complete at 335°C. The integrated intensities of each band show an equal decrease with time. However, the peak position of the essentially degenerate symmetric and asymmetric stretching mode shifted systematically to lower wave-numbers in the region 2100 cm-1-2080 cm-1 on dehydrogenation. No shift was effected in the doublet of peaks in the range 800-950 cm-1 under the same conditions. The width (f.w.h.m.) of the 650 cm-1 band decreased with a reduction in the hydrogen content. This band exhibited a slight red shift of 10 cm-1 on dehydrogenation. Preliminary studies of the oxidized polysilane films demonstrated that rearrangement of [SiH2O] groupings to [SiH2O2] groupings takes place at elevated temperatures.