Structures and Spectral Properties of Some Bis(carboxylato)copper(II)-Pyrazole Complexes. I. Preparation of Bis(trifluoroacetato)tetrakis(pyrazole)copper(II)

Abstract

Abstract The preparation of several kinds of [Cu(tfa)2(Hpzl)4] (Htfa = trifluoroacetic acid; Hpzl = 1H-pyrazoles) by stoichiometric reactions of [Cu(hfac)2] (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) with a pyrazole in petroleum ether is reported. As isolable intermediate of this reaction, [Cu(hfac)2(Hpzl)4] was obtained in some cases. The structure of [Cu(tfa)2(4-Hmpz)4] (1e) (4-Hmpz = 4-methyl-1H-pyrazole) has been determined by X-ray analysis. The structures of other [Cu(tfa)2(Hpzl)4] are estimated on the basis of their IR spectra.