Synthetic, Structural and Vibrational Spectroscopic Studies in Bismuth(III) Halide/N,N′-Aromatic Bidentate Base Systems. I Large-Cation (2,2′-Bipyridinium and 1,10-Phenan- throlinium) Salts of Polyhalobismuthate(III) Ions

Abstract

Syntheses and room-temperature single-crystal X-ray studies are recorded for a variety of salts of cations derived from protonated 2,2′-bipyridine and 1,10-phenanthroline (bpyH⁺ and phenH⁺) with polyhalobismuthate(III) anions. ‘[(phenH)(phenH₂)(H₂O)₂] [BiCl₆]’ is triclinic, P^-1, a 9·791(1), b 9·338(3), c 8·311(3) Å, α 73·46(3), β 69·71(2), γ 86·36(2)°, Z = 1; conventional R on |F| was 0·027 for N_o 4852 independent ‘observed’ (I > 3σ(I)) reflections. [BiCl₆]^3- is closely octahedral, accompanied by an interesting protonation/hydrogen-bonding array among the other moieties. The latter comment applies also to ‘[(phenH₂)(H₂O)][BiCl₅]_(∞|∞)’, monoclinic, P2/c, a 8·388(1), b 12·004(1), c 17·146(3) Å, β 98·26(1)°, Z = 4, R 0·047 for N_o 2670, the anion array being a one-dimensional polymer with bridging chlorine atoms occupying cis sites in the pseudo-octahedral coordination sphere of the bismuth. [bpyH₂]₄ [Bi₄Cl₂₀] is monoclinic, P2₁/c, a 14·228(4), b 14·217(2), c 16·254(4) Å, β 110·14(2)°, Z = 2, R 0·045 for N_o 2777; in the novel centrosymmetric tetramer, the four bismuth atoms are bridged into a square array by four linearly coordinated halogen atoms at the centres of the edges, a pair of these lying cis in the pseudo-octahedral coordination sphere of each bismuth. [bpyH]₃ [Bi₂Cl₉] is triclinic, P^-1 a 19·288(7), b 14·251(3), c 7·644(3) Å, α 75·02(2), β 80·15(3), γ 72·76(2)°, Z = 2, R 0·072 for N_o 3600, the two pseudo-octahedrally coordinated bismuth atoms being bridged by three chlorine atoms on a mutual octahedral face, [Cl₃Bi(µ-Cl)₃BiCl₃]^3-. [phenH] [BiCl₄]_(∞|∞),H₂O is triclinic, space group P^-1, a 12·119(7), b 10·169(6), c 7·247(4) Å, α 69·30(4), β 75·05(4), γ 77·92(5)°, Z = 2, R 0·035 for N_o 2348. The anion is a one-dimensional polymer, successive metal atoms being bridged by pairs of chlorine atoms lying cis in the pseudo-octahedral coordination sphere. [bpyH]₄ [Bi₂I₁₀] is monoclinic, P2₁/n, a 13·426(4), b 14·396(6), c 14·539(5) Å, β 101·31(3)°, Z = 2, R 0·11 for N_o 1862; the anion is of the form [I₄Bi(µ-I)₂BiI₄]^4- with quasi-octahedral bismuth. [bpyH] [BiI₄]_(∞|∞) is monoclinic, C2/c, a 12·442(5), b 18·41(2), c 7·714(2) Å, β 92·80(3)°, Z = 4, R 0·080 for N_o 850, with a polymeric one-dimensional anion comparable to that in [phenH] [BiCl₄]_(∞|∞),H₂O. The structure of the 2,6-dimethylpyridinium salt of [BiCl₆]^3- is also recorded, as its acetonitrile solvate; triclinic, P^-1, a 15·025(2), b 10·357(3), c 9·964(1) Å, α 83·14(2), β 89·32(1), γ 86·61(2)°, Z = 2, R 0·046 for N_o 3601; there is also an isomorphous bromide, and also an isostoichiometric bromide modelled as monoclinic, Cm, a 18·128(6), b 10·348(2), c 10·241(2) Å, β 121·31(3)°, Z = 2, R 0·050 for N_o 1379. Bands in the far-infrared and Raman spectra due to the v(BiCl) modes are assigned in [(phenH)(phenH₂)(H₂O)₂] [BiCl₆] and [bpyH₂]₄ [Bi₄Cl₂₀], and are discussed in relation to the structures of the complexes.