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 – CuO2N2O2. 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 O−H···O hydrogen bonds forming supramolecular structures.