Crystal structure of cis-dichlorobis-(2,2′-bipyridyl)gallium(III) tetrachlorogallate(III)

Abstract

The compound of empirical formula GaCl₃(bipy)(bipy = 2,2′-bipyridyl) has been shown by X-ray single-crystal study to be cis-[Cl₂Ga(bipy)₂]⁺[GaCl₄]^–. The crystals are orthorhombic with cell dimensions a= 14·900 ± 0·002, b= 12·469 ± 0·002, and c= 13·561 ± 0·002 Å, space group Pccn, Z= 8. Diffractometer data were refined by least-squares methods to a final R of 0·052 for 1907 observed reflections. The cation and anion are required to have symmetry C₂. The cation has a cis-configuration with Ga–Cl 2·265 ± 0·001 and Ga–N 2·095 ± 0·004 and 2·111 ± 0·004 Å. The N–Ga–N angle of 77·2 ± 0·1° is a consequence of the rigid nature of the bipyridyl ligand. The remaining angles are much closer to the idealized values. The Ga–Cl distances in the tetrahedral GaCl₄⁺ ion are 2·171 and 2·162 Å(both ±0·002 Å) with the Cl–Ga–Cl angles varying from 107·0—110·9 ± 0·1°. The distances in the two ions are compared with each other and also with those of other gallium compounds.