Microwave assisted synthesis, spectroscopic and antibacterial studies of bis(cyclopentadienyl)hafnium(IV) derivatives with benzil bis(aroyl hydrazones)

Abstract

The reactions of (g 5 -C 5 H 5 ) 2 HfCl 2 with benzil bis(hydrazones) (LH 2 ), derived from benzil and aromatic acid hydrazides (benzoic, 2-chlorobenzoic, 4-chlorobenzoic, 2-methylbenzoic or 4-methoxybenzoic) have been studied in anhydrous tetrahydrofuran in the presence of n-butylamine by both conventional methods and by microwave heating. Binuclear complexes of type [{(g 5 -C 5 H 5 ) 2 HfCl} 2 (L)] were obtained in both cases. Tentative structural conclusions are drawn for the reaction products based upon analyses, electrical conductance, magnetic moment and spectral (UV-vis, IR, 1 H NMR and 13 C NMR) data. A FAB-mass spectrum of one compound was also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the complexes and free ligands against various bacterial strains.

Synthesis, characterization and extraction studies of some metal (II) complexes containing (hydrazoneoxime and bis-acylhydrazone) moieties

“…However, the signal of primary carbon of methyl groups appear at 22.20 ppm Table 2. These data are in agreement with that previously reported for similar compounds [22,32,[34][35][36].…”

Microwave-Assisted Synthesis of Coordination and Organometallic Compounds

“…The ligands and complexes possessed inhibiting potential against various fungal, viral and bacterial strains. Similarly, reactions of (η 5 -C 5 H 5 ) 2 HfCl 2 with benzil bis(hydrazones) (LH 2 ), derived from benzil and aromatic acid hydrazides (benzoic, 2-chlorobenzoic, 4-chlorobenzoic, 2-methylbenzoic or 4-methoxybenzoic) were studied in anhydrous THF in the presence of n-butylamine by both conventional methods and by MWH, isolating binuclear complexes of type [{(η 5 -C 5 H 5 ) 2 HfCl} 2 (L)] (Sinha et al, 2008). The stoichiometric reactions of titanocenedichloride or zirconocenedichloride with monofunctional bidentate ligands 29 and 30, derived from heterocyclic ketones and semicarbazide hydrochloride and 2-hydroxy-N-phenyl benzamide, resulted in the formation of unsymmetrical complexes 31 (reactions 8-11) Poonia et al, 2008).…”