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 (HQ_T: R = CH₂C(CH₃)₃; HQ_C: R = C₆H₁₁) with Cd(O₂CCH₃)₂·2H₂O in EtOH the derivatives [Cd(Q_T)₂(EtOH)₂] 1 and [Cd(Q_C)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 Q_T ligands trans to each other. When the reaction between HQ_T or HQ_C 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(Q_T)₂(L)] and [Cd(Q_C)₂(L)] were always obtained. In the six-coordinate derivatives [Cd(Q_C)₂(1,10-phenanthroline)] and [Cd(Q_T)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.