Binuclear bismuth halide complexes (N-Me(2,2'-BipyH))2[Bi2X10] (X = Cl, Br): Syntheses, crystal structures, and optical properties

Abstract

Binuclear halide complexes (N-Me(2,2'-BipyH)₂[Bi₂X₁₀] (X = Cl (I), Br (II); 2,2'-Bipy = 2,2'-bipyridine) are synthesized by the reaction of solutions of [BiX₆]^3– and (N-Me(2,2'-BipyH)(NO₃)₂ in 2 M HX. The structure of [Bi₂X₁₀]^4– anions consists of octahedral fragments {BiX₆} linked by two μ₂-bridging halide ligands. The structures of the compounds are determined by X-ray diffraction analysis (CIF files CCDC 1455987 (I) and 1455988 (II)). The forbidden gap width E_g is determined for complex II from the diffuse reflectance spectrum.