화학공학소재연구정보센터
Inorganic Chemistry, Vol.34, No.14, 3780-3784, 1995
Crystal-Structure of (3-Chloroanilinium)(8)Nicl10 and a Temperature-Dependent X-Ray-Diffraction Study of the Jahn-Teller Distortion in (3-Chloroanilinium)(8)Cucl10
The synthesis and crystal structure of (3-chloroanilinium)(8)NiCl10, C48H56N8Cl18Ni, are reported. Crystals of the compound are triclinic, P (1) over bar, with a = 8.682(1) Angstrom, b = 13.900(2) Angstrom, c = 14.128(2) Angstrom, alpha = 81.77(1)degrees, beta = 72.37(1)degrees, gamma = 77.19(1)degrees, and V = 1579.1(5) Angstrom(3) (Z = 1). The final R value is 6.46%. The structure contains compressed octahedral NiCl64- anions, with Ni-Cl-eq(av) = 2.490(3) Angstrom and Ni-Cl-ax = 2.383(2) Angstrom. This difference in bond length (0.11 Angstrom) is due to an axial strain present in the structure. The structure of the isomorphic compound (3-chloroanilinium)(8)CuCl10 has been redetermined at room temperature and determined at three lower temperatures. Two models were used to refine the structure. Model 1 assumes no disorder of the anion. In this model, the geometry of CuCl64- ion in (3-chloroanilinium)(8)CuCl10 appears to be a compressed octahedron. However, the anisotropic displacement parameters along the four long bond directions are anomalously large. The analyses of these anisotropic displacement parameters suggest the presence of 2-fold disorder for the Cl atoms involved in the four long Cu-CI bonds. The refinement of this 2-fold disordered model (model 2) gave an elongated rhombic octahedral coordination the CuCl64- ion with more reasonable displacement parameters and lower R values at all temperatures. The combination of lattice strain and Jahn-Teller distortion gives Cu-Cl bond lengths of approximately 2.29, 2.38, and 2.81 Angstrom at -117 degrees C.