希土冠醚类配合物的研究 ⅩⅢ.[Sc(NO_3)_3(H_2O)_3]·(18—C—6)配合物的合成、性质和结构

STUDIES ON COMPLEXES OF RARE EARTH ANDCROWN ETHERS X III.SYNTHES IS, CHARACTERIZATION AND STRUCTURE OF COMPLEX [Sc(NO_3)_3(H_2O)_3]·(18-Crown-6)

在乙腈介质中培养出由硝酸钪与18-冠-6组成的配合物[Sc(NO_3)_3(H_2O)_3]·(18-C-6)的单晶、对配合物进行了熔点测定、元素分析、红外光谱、摩尔电导测定和X射线结构分析。

The single crystal of the complex [Sc(NO3)3(H2O)3]·(18-C-6) has been prepared in acet onitrile medium. The new complex has been characterized by elemental analyses, IR spectra, solubility and molar conductance measurements. The structure of the complex is determined by X-ray single crystal diffraction analyses. The crystal of the complex is orthorhombic, space group Pnma. with cell parameters 15.311(0)A,A = 14.053(9)A,c = 10.862(7)A,V=2337.4A3; Z=4; de = 1.56g / cm3, d0=1.56g / cm3. The structure was solved by direct method and Fourier techniques and refined by least-squares to R = 0.069 and Rw= 0.062 using 1513≥3o(I) observed data. Here the scandium (III) ion is not bonded to the crown ether but is surrounded by three bidcntate nitrate groups and three water molecules. The coordination number of scandium (III) ion is nine. The crown ether 18C6 is held in the lattice by linking to the [Sc(NO3)3(H2O)] unit via hydrogen bond through the coordinated water molecules. The average bond lengths are 2.295A for the Sc-O(NO3-) bonds and 2.190A for the Sc-O(H2O) bonds respectively.