尿素和尿素—Fe配位化合物的晶格振动光谱研究

Lattice Vibrational Spectral Study of Urea and Fe-urea Complexes

采用直接固相反应将尿素与氯化铁(摩尔比6∶1)混合,经充分研磨合成了尿素铁盐配位化合物,并对其拉曼光谱和红外吸收光谱进行了研究。由于金属原子的影响,尿素分子的一些特征振动频率发生了变化:CO伸缩振动和NH2的对称弯曲振动的频率下降;而CN伸缩振动和NH2反对称弯曲振动的频率增加。对尿素以及尿素—Fe(III)的晶格振动模进行了识别。研究结果表明:Fe与尿素中的氧原子发生了配合而形成配位物。

Urea-Fe complexes were synthesized by grounding the mixture of urea and ferric chloride hexahydrate in a mole ration of 6∶1. The Raman and infrared absorption spectra of product as well as urea have been measured. Some changes in the spectra of complexes are ob- served: the CO stretching vibrations and the symmetrical NH2-deformation vibrations shift to a lower frequency; the CN stretching and antisymmetrical NH2-deformation frequencies in- crease. The spectra reveal that the products synthesized are the urea-Fe complexes. The as- signments of vibrational modes of urea and urea-Fe complexes were discussed. The analysis results indicate that the urea forms oxygen-to-metal bands with Fe(III).