On the Interaction of Acylpyrazolonates with Zinc(II) Acceptors: the Role of Ancillary Ligands.

Inorganica Chimica Acta 2000, v. 307, pp.97-105

F. Marchetti, C. Pettinari, R. Pettinari, D. Arriva, S. Troyanov, A. Drozdov

Abstract. From the interaction of 1-phenyl-3-methyl-4-R-C(=O)-pyrazol-5-one (HQT: R = CH2C(CH3)3; HQC: R = C6H11) with Zn(O2CCH3)2.2H2O in MeOH, derivatives [Zn(QT)2(H2O)] (1), [Zn(QT)2(MeOH)2] (2) and [Zn(QC)2(MeOH)2] (3) have been obtained. By heating 1 under vacuum the anhydrous [Zn(QT)2] (4) afforded. 1 and 3 react with N2-donor ligands 1,10-phenanthroline (phen) and 2,2'-bipiridyl (bipy) in chloroform yielding [Zn(QT)2(phen)] (5), [Zn(QC)2(phen)] (6), [Zn(QT)2(bipy)] (7) and [Zn(QC)2(bipy)] (8) respectively. Carrying out the reaction between HQT and Zn(O2CCH3)2.2H2O in the presence of N,N,N'-trimethylethylendiamine (trime) or N,N,N',N'-tetramethylethylendiamine (tmeda), the adducts [Zn(QT)2(trime)] (9) and [Zn(QT)2(tmeda)] (10), respectively, have been synthesised. In 9 the zinc was found six-co-ordinate in a sligthly distorted octahedral environment, due to steric requirements of acylpyrazolonato and diamine donors. Finally 2 interacts in Et2O with imidazole (im), 1-methylimidazole (1-Meim), diethylamine (Et2NH) and 1-methylimidazolin-2-thione (Hmimt) affording [Zn(QT)2(imH)2] (11), [Zn(QT)2(N-Meim)2] (12), [Zn(QT)2(Et2NH)2] (13) and [Zn(QT)2(Hmimt)]2 (14) respectively. All compounds 1-14 have been characterised both in the solid and solution state with analytical and spectral data.

Coordination Chemistry Laboratory