〔NH_4（15－C－5）_2〕〔Cd_2（SCN）_5〕配合物的晶体和分子结构

用凝胶法合成了标题化合物［ＮＨ４（１５－Ｃ－５）２］［Ｃｄ２（ＳＣＮ）５］（１５－Ｃ－５＝Ｃ１０Ｈ２０Ｏ５）的晶体，并对其进行了红外光谱、元素分析等各项物理性质的测试，并经Ｘ射线单晶结构分析得到了配合物的全部晶体学数据：Ｍｒ＝９７３．７８，正交晶系，空间群Ｐｎｍａ，晶胞参数ａ＝１０．５０７（１）Ａ，ｂ＝１６．５８４（２）Ａ，ｃ＝２３．４９４（２）Ａ，Ｖ＝４０９３．８（３）Ａ３，Ｚ＝４，Ｄｃ＝２．５８０ｇ／ｃｍ３，μ＝１３．３１ｃｍ（－１），Ｆ（０００）＝１９６８，Ｒ＝０．０７０，Ｒω＝０．０８５。结构分析结果表明，配阳离子是由一个ＮＨ４＋和两个１５－Ｃ－５组成的，ＮＨ４＋没有进入１５－Ｃ－５空腔内，而是位于两个１５－Ｃ－５之间，呈夹心结构；配阴离子是以［Ｃｄ２（ＳＣＮ）５］为单元的阴离子长键，其中一组ＳＣＮ－被四个Ｃｄ离子共享，其余两组ＳＣＮ－被两个Ｃｄ离子共享，呈变形八面体构型。配阳离子［ＮＨ４（１５－Ｃ５）２］＋和配阴离子［Ｃｄ２（ＳＣＮ）５］－间靠静电力结合成配合物晶体。

The Crystal and Molecular Structure of [NH_4(15-C-5)_2] [Cd_2(SCN)_5]

The crystal of title compound [NH4(15-C-5)2][Cd2(SCN)5](15-C-5)=C10H20O5)has been grown in a gel characterized by elemental analysis and infrared spectra. The molecular and crystal structure of the complex has been determined by X-ray diffraction.The crystal structure was sloved by Patterson method and Fourier synthesis, and was refined by full matrix least squares method to final descrepancy factors R= 0. 070 and Rω= 0. 085.The crystal belongs to orthorhombic space group Pnma with cell parameters :a= 10. 507 (1) , b=16. 584(2) ,c=13. 494(2) A ,V=4093. 8(3) A3, Z=4, Dc= 1. 580 g/cm3, μ= 13. 31 cm-1.The result of structure analysis of the complex indicates that the ammonium ion is bonded by two 15-crowns crown ethers to form a complex cation and does not enter into the cavity of the crown ethers. The cadmium(Ⅱ) is bonded by six SCN ion to form an anion chain with a distorted octahedral coordination. The combination between two kinds of the coordination ions is due to electrostatic effect.