聚乙炔的CH面外振动红外光谱研究

A Study on the Infrared Spectrums of Vibrations Outside of the CH Plane for Polyacetylene

采用从头计算方法 ,计算了反式和顺式聚乙炔的氢原子在垂直于聚乙炔分子面方向振动的红外光谱 计算表明 ,Gibson等用红外吸收实验所测得的谱线的确是聚乙炔的CH面外振动产生的谱线 经 10 0℃长时间加热后 ,顺式聚乙炔变为反式聚炔 ,但波数为 74 0cm- 1 的谱线仍保留 5

We have used an ab initio method to calculate the electronic structures of cis\| and trans\|polyacetylene and infrared spectrums for the vibrations of hydrogen atoms perpendicular to the molecular plane. Our calculations show that the spectrum line measured in the infrared absorption experiment by Gibson et al . is indeed the spectrum line led by oscillations outside of the CH plane of polyacetylene. After long time heating at 100℃, cis\|polyacetylene changes to trans\|form, yet the spectrum with a wave number of 740 cm -1 remains 5% residual in intensity.