水合五异硫氰铬(Ⅲ)酸钾的18-冠-6配合物的合成、性质及晶体和分子结构

在硅凝胶中培养了标题配合物的单晶,确定了它的组成,并进行了热谱、可见光谱、红外光谱及其他多项物理性质的测试和表征,其结果与单晶X射线衍射分析的结果一致。晶体学数据:分子式K(18-冠-6)(H_2O)]K(18-冠-6)]Cr(H_2O)(NCS)_5]·H_2O,空间群C_(2h)~5—P2_1/n,a=8.592(5),b=22.976(10),c=24.372(4)A,13=96.57(4)~0,Z=4。结构用直接法解出,全矩阵最小二乘方修正,R=0.046。结果表明,铬(Ⅲ)由五个异硫氯酸根离子和一水分子配位形成一畸变八面体形的配合阴离子。一个钾离子由一个冠醚和另一水分子配位;另一钾离子由另一冠醚和一配位于铬(Ⅲ)的硫氯酸根的硫原子配位,即该N(3)-C(3)-S(3)桥连在Cr和K(2)之间;两钾离子均是7配位。第三个水分子通过氢键与阴离子的配位水分子和两个冠醚环上的醚氧原子相连。

THE SYNTHESIS,CHAR CTERS,CRYSTAL AND MOLECULAR STRUCTURE OF COMPLEX OF 18-CROWN-6 AND AQUA POTASSIUM PEN TAISOCYANATO-AQUO-CHROMATE

The title complex crystals have been grown in silica gel and characterized by elemental and thermal analyses, vissible and infrared spectra etc.The crystal and molecular structure has been determined by X-ray diffraction.The results confirm inference based on spectra.Crystallographic details formula C29H54N5O15S2Cr-K2, monoclinic system, space group C2h5-P21/n,a = 8.592(5), b =22.976(10), c=24.372(4) A, B= 96.57(4), Z = 4 .The structure was solved by direct methods and △F syntheses and then refined by full- matrix least-souares method. The fina value of R is 0.046. The results indicate that chromium (Ⅲ) ion is coordi nated by ive isothiocyanates and a water molecule to form a distorted octahedral complex anion. One of two potassium ions, which are 7-coordinated, is coordinated by a crown and another water molecule;the other by another crown and the sulphur atom of a thiocyanate liking with Cr(Ⅲ) to form a bridge K(2)-SCN-Cr. The third water molecule combines the water molecule in the complex anion and two oxygen atoms O(4') and O(3) of crowns through hydrogen bonds.