新的NLO化合物Ce(MoO_2)(OH)(IO_3)_4的合成和晶体结构

Synthesis and Crystal Structure of a Novel NLO Compound-Ce(MoO_2)(OH)(IO_3)_4

新的NLO化合物Ce(MoO2)(OH)(IO3)4由水热法在170℃下制备得到。X射线单晶结构分析表明,该化合物以极性空间群P21结晶,晶体学参数为:a=0.70144(8)nm,b=1.41554(10)nm,c=0.70969(6)nm,β=115.318(7),°V=0.6369(1)nm3,Z=2。Ce(MoO2)(OH)(IO3)4的晶体结构是由八配位的Ce3+阳离子,高度畸变的MoO66-八面体,和碘酸根阴离子基团组成的复杂三维网所构成。分析其结构表明,含有I(3)和I(4)的碘酸根基团的孤电子对的合成方向指向极化轴b,从而导致晶体结构具有非中心对称性。此外,红外光谱进一步证实了MoO6-6,IO-3基团和Mo-OH作用的存在。

A novel NLO compound, Ce（MoO2）（OH）（IO3）4, has been prepared by hydrothermal method at 170 ℃. The X-ray single crystal structural analysis shows that it crystallizes in the polar space group P21 with a= 0.70144（8） nm,b= 1.41554（10） nm,c= 0.70969（6） nm,β=l15.318（7）°,V = 0.6369 （ 1 ） nm^3 and Z = 2. The crystal structure of Ce （ MoO2 ） （OH） （ IO3 ） 4 consists of a complex three-dimensional network formed by eight-coordinated Ce^3＋ cations, strongly distorted MoO6^6- octahedra, and bridging iodate anions. An examination of the crystal structure reveals that the I （3）- and I （4）- containing iodate groups display a net alignment of their stereochemicaUy active nonbonded electron pairs along the polar b-axis, which makes the structure noncentrosymmetric. The infrared spectra further confirmed the presence of MoO6^6- and IO3^- groups as well as Mo-OH interactions.