二苯甲酮晶体的红外反射光谱研究

THE INFRARED REFLECTION SPECTRA STUDY OF BENZOPHENONE CRYSTAL

室温下记录了有机非线性光学晶体二苯甲酮三种不同偏振的红外反射光谱（２００～４００ｄｃｍ－１）。利用Ｋ－Ｋ变换确定了晶格振动模的横、纵频率。根据由Ｋ－Ｋ变换得到的介电常数和折射率的色散曲线外推得到晶体的静态介电常数、高频介电常数和近红外波段的折射率。还对反射带进行了认定。研究表明该晶体二苯甲酮分子间不存在氩键，只以弱的范德华健相结合。结合晶体结构对强反射带出现的原因作了解释。

The infrared reflection spectra (200-4000cm-l) of the benzophenone single crystal have been recorded at room temperature for three different polarizations. The transverseand longitudinal frequencies of the vibrational modes in the range of 231-1660cm-1 weregiven by using K-K transformation. The static dielectric constants, high frenquency dielectricconstants and refractive indices in near-infrared region were determined by extrapolating thedispersion curves of the dielectric constants and refractive indices given by the K-K transformation. The infrared reflection bands have been assigned. It was shown, that the benzophenone molecules in the crystal are bonded each other by weak van der Waals forces. The appearance of strong reflection bands in the polarized spectra was explained by the aid of crystal structure.