Solvent induced reactivity of 3,5-dimethylpyrazole towards zinc (II) carboxylates

• Published in: Dalton transactions : an international journal of inorganic chemistry no. 36; pp. 7428 - 7436
• Main Authors: Sarma, Rupam, Kalita, Dipjyoti, Baruah, Jubaraj B
• Format: Journal Article
• Language: English
• Published: England 01.01.2009
• Subjects: Carboxylic Acids - chemistry; Crystallography, X-Ray; Molecular Conformation; Pyrazoles - chemistry; Solvents - chemistry; Zinc - chemistry
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/b905534g

The reactions of 3,5-dimethylpyrazole with zinc(II)acetate dihydrate and varieties of aromatic carboxylic acids led to formation of mono-nuclear zinc complexes of composition [Zn(HDMP)2(RCO2)2] (R = C6H5, p-CH3-C6H4, p-NO2-C6H4 etc. HDMP = 3,5-dimethylpyrazole) in methanol, whereas the same reactants in dimethylformamide (DMF) gave binuclear 3,5-dimethylpyrazolato bridged zinc carboxylate complexes containing monodentate 3,5-dimethylpyraozole ligands with composition [Zn2(mu-DMP)2(HDMP)2(RCO2)2]. The mononuclear complexes can be converted to the corresponding binuclear complexes by simply dissolving in DMF. The reaction of zinc(II)acetate dihydrate with p-nitrobenzoic acid and 3,5-dimethylpyrazole in different solvents gave solvated mononuclear complexes of the corresponding solvent. All these solvated complexes having the core [Zn(HDMP)2(p-NO2-C6H4CO2)2] contain two structurally independent molecules in the asymmetric unit (Z' = 2).