Hydrothermal synthesis and crystal structure of [(CH3NH3)(1.03)K-2.97]Sb12S20 center dot 1.34H(2)O

摘要

A novel thioantimonate(III) [(CH3NH3)(1.03)K-2.97]Sb12S20. 1.34H(2)O was synthesized hydrothermally. It crystallizes in space group P (1) over bar, with a = 11.9939(7) Angstrom, b = 12.8790(8) Angstrom, c = 14.9695(9) Angstrom, alpha = 100.033(1)degrees, beta = 99.691(1)degrees, gamma = 108.582(1)degrees, V = 2095.3(2) Angstrom(3), and Z = 2. The structure is determined from single crystal X-ray diffraction data collected at room temperature and refined to R(F) = 0.037. In the crystal structure, each Sb(III) atoms has short bonds (2.37-2.58 Angstrom) to three S atoms. The pyramidal [SbS3] groups share common S atoms forming two types of centrosymmetric [Sb12S20] rings with the same topology. These rings are interconnected by weaker Sb-S bonds (2.92-3.29 Angstrom) into 2-dimensional layers. Adjacent layers are parallel with K+ and CH3NH3+ ions and H2O molecules located between them. Variation of bond valence sums calculated for the Sb(III) cations is found to be correlated with the coordination geometry. This is interpreted as due to the stereochemical activity of their lone electron pairs. (C) 1998 Academic Press. [References: 27]