Three new copper(II) halides with simple pyridine alcohols

Three Cu(II) halido complexes of 3-pyridinepropanol (3-pyprop), 2-pyridineethanol (2-pyet), and 2-pyridinemethanol (2-pymet) have been prepared and investigation of their crystal structures undertaken. All the reported products contain simple pyridine alcohols as neutral ligands. Cu(3-pyprop)₂Br₂, 1, exhibits square-planar coordination geometry with the axial sites involved in weak bridging contact with the neighboring units to form infinite chains. Reaction of CuBr₂ with 2-pyet leads to an ionic complex [Cu(2-pyet)₂Br]Br, 2, with distorted square-pyramidal coordination environment: the Cu center in the cation is surrounded by two 2-pyet ligands, coordinated in chelating manner, and a bromide. Reaction of CuCl₂ with 2-pymet resulted in the formation of a dinuclear ionic complex Cu₂(2-pymet)₄Cl₂]Cl₂·2H₂O, 3. The centrosymmetric cation consisted of two Cu ions doubly bridged by chlorides and coordinated by chelating 2-pymet ligands. The positive charge is balanced by free chlorides involved in hydrogen bonds with the lattice water molecules.