One dimensional carboxylatocopper(II) coordination polymers with 4-pyridylmethanol

Abstract

Six new benzoatocopper(II) complexes with 4-pyridylmethanol (abbreviated as 4-PM) as an N,O-bridging ligand have been prepared and characterized by single-crystal X-ray analysis: [Cu(4-MeOBz)2(µ-4-PM)(4-PM)]n(1), [Cu(3,5-(NO2)2Bz)2(μ-4-PM)(4-PM)]n(2), [Cu(4-MeSal)2(µ-4-PM)2]n(3), [Cu(5-MeSal)2(µ-4-PM)2]n(4), [Cu(3-NO2Bz)2(μ-4-PM)2)]n (5) and [Cu(4-NO2Bz)2(μ-4-PM)2)]n(6) (where 4-PM = 4-pyridylmethanol, MeOBz = methoxybenzoate, MeSal = methylsalicylate, NO2Bz = nitrobenzoate). All these complexes have been characterized by Elemental analysis, IR spectroscopy, EPR spectroscopy. Spectral properties are in good agreement with structural motif and the g-factors evaluated from the EPR spectra are consistent with coordination sphere of distorted tetragonal symmetry for central copper(II) ions. 4-PM in complexes (1) and (2) has acted like N,O-bridging ligand forming 1D polymers as well as terminal ligand. The coordination sphere of Cu(II) ion in both complexes has been tetragonal–pyramidal. Complexes (3), (4), (5) and (6) have been found of the same type with chromophore trans – CuÓ2N2O2. Cu(II)atoms have lied in the centre of symmetry and have formed hexacoordination in the shape of a distorted octahedral. Individual copper(II) centres have been linked by bridging 4-pyridylmethanol and have formed infinite 1-D “double bridged” chains. The molecules of all complexes have been connected by OH⋯O hydrogen bonds forming supramolecular structures.