Synthetic, Structural and Vibrational Spectroscopic Studies in Bismuth(III) Halide/N,N′-Aromatic Bidentate Base Systems. IV Bismuth(III) Halide/N,N′-Bidentate Ligand (1 : 1) Systems

Abstract

Room-temperature single-crystal X-ray studies are recorded for a number of adducts of BiX₃ and N,N′-bidentate ligand (2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)), devoid of coordinated solvent. BiBr₃/bpy/MeCN (1 : 1 : 1) is triclinic P^-1, a 12·129(2), b 9·955(4), c 7·748(1) Å, α 73·14(2), β 77·34(1), γ 69·79(2)°, Z = 2; conventional R on |F| was 0·036 for N_o 2252 independent ‘observed’ (I > 3σ(I)) reflections. The phen analogue is isomorphous, a 11·586(3), b 10·839(6), c 7·769(10) Å, α 73·70(7), β 76·67(7), γ 70·34(4)°, Z = 2, R 0·042 for N_o 800. BiI₃/bpy (1 : 1) is triclinic, P^-1, a 11·742(4), b 9·261(1), c 8·261(3) Å, α 86·46(2), β 71·48(3), γ 67·25(2)°, Z = 2, R 0·043 for N_o 1164. All complexes are centrosymmetric binuclear [(N,N′-bidentate)X₂Bi(µ-X)₂BiX₂(N,N′-bidentate)] with six-coordinate pseudo-octahedral bismuth(III). Attempts to produce a chloride analogue have resulted, in the case of N,N′-bidentate = bpy, in a novel adduct of BiCl₃/bpy 1 : 1·5 stoichiometry, monoclinic, P2₁/c, a 9·377(8), b 17·699(5), c 21·58(1) Å, β 107·82(6)°, Z = 8, R 0·055 for N_o 1804. The complex is [(bpy)₂Cl₂Bi(µ-Cl)BiCl₃(bpy)], containing seven- and six-coordinate bismuth. Bands in the far-infrared spectra due to the v(BiX) vibrations in [(bpy)₂Cl₂Bi(µ-Cl)BiCl₃(bpy)] and [(bpy)I₂Bi(µ-I₂)BiI₂(bpy)] are assigned and discussed in relation to the structures of the complexes.