Characterization of reaction products of several bis(β-diketonato)copper(II) compounds with 1H-pyrazoles. Adducts, DI- and tetranuclear complexes, and coordination polymers

Abstract When [Cu(L 1 ) 2 ] (HL 1 = aliphatic β-diketone with branched alkyl groups) and [Cu(L 2 ) 2 ] (HL 2 =aliphatic β-diketone with linear alkyl groups) were allowed to react with 1H-pyrazoles (Hpzl), tetranuclear complexes [Cu 4 (μ 4 -O)(L 1 ) 4 (μ-pzl) 2 ] and dinuclear complexes [Cu 2 (L 2 ) 2 (μ-pzl) 2 ] were produced respectively, but the reactions of [Cu(L 3 2 ] (HL 3 = aroyl- or heteroaroylacetone) with 1H-pyrazole (Hpz) gave coordination polymers [{Cu(L 3 )(μ-pz)} n ] and/or adducts [Cu(L 2 ) 2 (Hpz) n ] ( n = 1 and/or 2). The substituent effects of the β-diketonato ligands on the reaction products are discussed. The structure of one of the tetranuclear products Cu 4 (μ 4 -O)(dibm) 4 (μ-4-mpz) 2 ] (Hdibm = 2,6-dimethylheptane3,5-dione; 4-Hmpz = 4-methyl-1 H-pyrazole) has been determined by X-ray analysis. The structures of some of the other products are estimated on the basis of their IR and diffuse reflectance spectra.