Dinuclear complexes, a one dimensional chain and a two dimensional layer of bismuth(iii) chalcogenones for C–S cross coupling reactions

Abstract

The catalytic application of bismuth(III) coordination polymers has been reported. Dinuclear bismuth(III) chalcogenone complexes, namely, [(L¹)₂BiCl₂(μ²-Cl)]₂ (1), [(L²)₂BiBr₂(μ²-Br)]₂ (4), a 2D layered bismuth(III) thione complex [{(L²)BiCl₂(μ²-Cl)}₂]_∞ (2), and 1D chain [(L¹)Bi(Br)(μ²-Br)₂·CH₃CN]_∞ (3), were isolated by treating the corresponding chalcogenone ligands [1-(2-hydroxyethyl)-3-isopropyl-1H-benzo[d]imidazole-2(3H)-selone (L¹) and 1-(2-hydroxyethyl)-3-isopropyl-1H-benzo[d]imidazole-2(3H)-thione (L²)] with BiX₃ (X = Cl, Br). Complexes 1–4 were characterized by FTIR and NMR spectroscopy, CHNS analysis, and single-crystal X-ray diffraction techniques. Besides, complexes 1–4 were utilized as catalysts in C–S cross-coupling reactions. Catalysts 1–4 were highly active. Interestingly, the 1D coordination polymer 3 displayed superior catalytic efficiency to discrete complexes 1 and 4 and the thione-based 2D coordination layer 2. The scope of the catalytic reaction was demonstrated using catalyst 3 for annulated heterocyclic aryl halides such as 9-chloro acridine and gave excellent yields.