Syntheses and properties of imidazole- and imidazolato-copper(II) complexes

Bis(acetato)bis(imidazole)copper(II) ([Cu(CH3C00)2(HIm)2], [1], bis(acetato)tetrakis(imidazole)copper(II) ([Cu (CH3C00)2(HIm)4], [2]), and poly[bis (imidazolato)copper(II)][Cu(Im)2]n, three isomers [3]=[4], [5], and [6]) were synthesized, and the thermal properties and the configuration of these complexes were investigated by thermal analysis and measurements of magnetic moments and electronic spectra. The magnetic moments of [1]and [2], which were highly soluble in water, methanol and ethanol, were 1.83-1.88 BM. The complexes [3]-[6], which were sparingly soluble in ordinary solvents, had the subnormal magnetic moment of 1.47-1.65 BM, and the magnetic interaction was observed to exist between Cu(II)-Cu(II). It was presumed that [1]and[2]in the solid state were the complexes of the square planar type and the distorted octahedral type, respectively. The complexes [3]and[4]blue in color, being the same isomers, were the polynuclear complexes of the square planar type, and [6] green in color was a polynuclear complex of the octahedral type. The configuration of the polynuclear complex[5]purple in color could not be estimated. The complex[6]of the three isomers of [Cu(Im)2]n revealed the high thermal stability.