Architecture of a Novel Binucleating SNONS Compartmental Ligand: Physico-Chemical Investigation of Its Metal Complexes

• Published in: Bulletin of the Chemical Society of Japan 2002-10, Vol.75 (10), p.2161-2167
• Main Authors: Naik, Anil, Annigeri, Satish, Gangadharmath, Umesh, Revankar, Vidyanand, Mahale, Vinayak, Reddy, Vijaykumar
• Format: Article
• Language: English
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.75.2161

The preparation of a novel pentadentate binucleating compartmental ligand, 2-hydroxy-5-methylisophthalaldehyde bis(p-methoxy thiobenzoylhydrazone), is described together with the corresponding chloro-bridged cobalt(II), nickel(II), copper(II) and zinc(II) complexes, which were characterized based on spectral, magnetic, thermal and electrochemical studies. Cryomagnetic investigations (77–296 K) reveal a strong antiferromagnetic spin-exchange between the copper(II) ions (J based on H = −2JS1. S2 is 305 cm−1). An electrochemical study of the copper(II) complex shows two distinct quasi-reversible redox peaks (E11/2 = −0.4 and E21/2 = −0.69 V vs saturated calomel electrode), indicating a stepwise reduction of the copper centers (CuIICuII → CuIICuI and CuIICuI → CuICuI). The EPR spectrum is typical of a “rhombic compressed local molecular environment”. The ligand and its copper and zinc complexes exhibit fluorescence at room temperature in DMF. All of the compounds under study were screened for antimicrobial action.