Novel bis(acylpyrazolonato)cadmium(II) derivatives and their reactivity toward aromatic and aliphatic N2-donor ligands

Abstract

By reaction of 1-phenyl-3-methyl-4-R-C(O)-pyrazol-5-one (HQT: R = CH2C(CH3)3; HQC: R = C6H11) with Cd(O2CCH3)2·2H2O in EtOH the derivatives [Cd(QT)2(EtOH)2] 1 and [Cd(QC)2(EtOH)2] 2 have been synthesised. Complex 1 has a molecular structure with a slightly distorted octahedral coordination of the cadmium atom with EtOH and QT ligands trans to each other. When the reaction between HQT or HQC and Cd(O2CCH3)2·2H2O was carried out in the presence of bidentate N-donor ligands L (L = 1,10-phenanthroline, 2,2′-bipyridyl, N,N′,N′-trimethylethylenediamine or tetramethylethylenediamine), [Cd(QT)2(L)] and [Cd(QC)2(L)] were always obtained. In the six-coordinate derivatives [Cd(QC)2(1,10-phenanthroline)] and [Cd(QT)2(tetramethylethylenediamine)] the cadmium atom is in a strongly distorted octahedral environment due to steric requirements of the bidentate N2-donor ligands. All complexes synthesized have been characterized spectroscopically by IR, 1H and 113Cd NMR. The behavior in solution is also discussed.