THE X-RAY DIFFRACTION ANALYSIS AND SPECTRAL STUDIES OF MIXED ANIONIC (1/1)CD-3(II)[(FE-III/CO-III)(CN)(6)](2)CENTER-DOT-14H(2)O

摘要

Refinement of the crystallographic structure of (1:1) Cd-3(II) [(Fe-III/Co-III) (CN)(6)](2) . 14H(2)O (I) has been carried out by means of three-dimensional single-crystal X-ray diffractometry. This novel disordered mixed anionic complex crystallizes in the cubic space group Fm (3) over bar m (Z=11/3) with a(0)=10.638(1) Angstrom. Based on 166 unique reflections, the employed full-matrix least-squares method yielded a final reliability factor of R=0.041 (R(w)=0.047) and a goodness-of-fit value (Sigma(2)) of 1.79. Indexed power diffraction data are reported and evaluated according to the quantitative figures-of-merit F-21=114 (0.007, 25) and M(20)=154.9. A thermal gravimetric analysis revealed 14 eater molecules per formula unit and the experimental density is 1.93(5) Mg m(-3) [calc., 1.87(1) Mg m(-3)]. The divalent Cd atoms are linked to the (1:1) mixed metal atoms by linear cyanide bridging. The disordered structure I is isomorphous with the hydrated cobalticyanides of Mn and Cd. A hydrogen-bonding network is set up within cavities of the crystal lattice created by the molecular disorder. Selective geometric parameters as well as conoscopic and IR spectral results are presented. (C) 1997 Academic Press. [References: 28]