Coordination chemistry of the ligand 7-aza-1-hydroxy-benzotriazole. Crystal structures and antimicrobial activity of the catena-poly-[μ-chlorido(μ-7-aza-1-oxy- κ2N:O-benzotriazolyl-κN)]cobalt(II)methanol coordination polymer and of a new polymorph of the free ligand 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol

Reaction of cobalt chloride and 7-aza-1-hydroxy-benzotriazole (HOazbt) in alcoholic solution results in formation of the polymeric compound [Co(C5H3N4O)(CH3OH)Cl](n). The compound has been characterized by elemental analysis, IR spectroscopy, and its 3D structure was determined by X-ray diffraction. Also its antimicrobial activity was determined. The distorted octahedral high-spin cobalt(II) coordinated by both coordinated mono- and bidentate ionized HOazbt ligands, is featuring a two-dimensional (6,4) honey-comb-like coordination polymer. The 2D hexagonal layers are interconnected with a strong O-H center dot center dot center dot O R-2(2)(8) second-level hydrogen bonding ring motif in the a-direction. A new free-ligand polymorph is found, and its 3D has been structure determined. H-bonding interactions in the three polymorphs are discussed using the DET/MP2 and Hirshfeld surface calculations. (C) 2010 Elsevier Ltd. All rights reserved.