ESR and other spectral studies on copper(II) complexes with 2,3-disubstituted quinazoline-(3H)-4-ones

Abstract

A number of copper(II) complexes of some tridentate ONO donors and bidentate OO and ON donors in the form of 2,3-disubstituted quinazolin-(3H)-4-ones have been synthesized and characterized based on analytical, conductivity, magnetic, IR, electronic and ESR spectral data. The reaction between copper(II) acetate and tridentate ONO donor ligands such as 2-(R)-3-(X)-substituted quinazoline-(3H)-4-ones, where R = methyl/phenyl and X = 2′-hydroxyphenylamino (MHBQ/PHBQ), yielded neutral complexes of the type Cu(ONO) 2. The bidentate OO or ON donor ligands like 2-(R)-3-(X)-substituted quinazoline-(3H)-4-ones, where R = methyl/phenyl and X = carboxymethyl (MCMQ/PCMQ), furylamino (MFQ/PFQ), acetamino (MAQ/PAQ), uramino (MUQ/PUQ) and thiouramino (MTUQ/PTUQ), yielded neutral complexes of the type Cu(OO) 2 or Cu(ON) 2(CH 3COO) 2. The IR spectral data of the metal complexes indicate that the ligands like MHBQ and PHBQ act as uninegative tridentate, MCMQ and PCMQ act as uninegative bidentate and MFQ, PFQ, MAQ, PAQ, MUQ, PUQ, MTUQ and PTUQ act as neutral bidentate ligands. The reflectance spectral studies of these complexes indicate that they contain square-planar or tetragonal geometry around copper(II).