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RESEARCH PRODUCT

Synthesis, spectral and magnetic properties of two different 2-nitrobenzoatocopper(II) complexes containing N,N-diethylnicotinamide

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Abstract Two structurally different complexes, [Cu2(2-NO2Bz)4(denia)1]n (1) and [Cu(2-NO2Bz)2(denia)2(H2O)2] (2), were prepared from the same reaction (where 2-NO2Bz = 2-nitrobenzoate, denia = N,N-diethylnicotinamide) and they are reported together with [Cu2(2-NO2Bz)4(DMF)2] (3) (DMF = N,N-dimethylformamide). The compounds under study were characterized by elemental analysis, electronic, IR and EPR spectra, magnetic measurements over the temperature range of 1.8–300 K and X-ray analysis. The molecular structure of (1) is polymeric, (2) is monomeric and (3) is dimeric. In the polymeric chain of (1), the denia molecules serve as bridges between dimeric Cu2(2-NO2bz)4 units. Each Cu(II) atom has a square-pyramidal arrangement with different chromophores, Cu1O4O′ and Cu2O4N. The Cu–Cu distances are 2.699(1) A in the dimeric unit and 7.980(3) A between the dimeric units. In (2) the Cu(II) atom has a tetragonal-bipyramidal environment CuO2N2O′2. In (3) two Cu(II) atoms are bridged by four carboxylate groups of four 2-NO2bz anions in a syn–syn arrangement which create a square base about each Cu(II) atom and an apical position is occupied by the O atom of a DMF molecule (CuO4O′). The Cu–Cu distance of 2.633(1) A is somewhat shorter than in (1). Spectral and magnetic data of the complexes are discussed with their structures.