STUDY OF CRYSTAL STRUCTURE AND RAMAN SPECTRA OF Cd（NH2 CSNHNH2）（SCN）2 CRYSTAL

摘要

＜正＞ In this paper,we report the crystal structure and Raman spectra of the title com-pound（thiosemicarbazide cadmium thiocyanate,TSCCTC）which is a new nonlinear optical crystal forthe first time.The crystal is orthorhombic and its space group is P212121 with unit cell parametersa=6.996（2）,b=10.776（3）,c=12.978（3）（?）and z=4.The central ion Cd2+is five-coordinated andthe coordination polyhedron is a distorted square pyramid.The thiosemicarbazide acts as bidentateligand to form a five-member ring with Cd2+ion,and one of the thiocynates as bridging ligand to bridgetwo Cd2+ions.Isofrequency Raman spectra show that there is no phase transition in the crystal fromroom temperature to the decomposed temperature.