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

Abstract

A number of copper(I1) complexes of some tridentate Q-N-0 donors and bidentate O-O and Q-N donors in the form of 2,3_disubstituted quinazolin-(3H)-4-ones have been synthes~ed and ~haracte~ed based on analytical, conductivity, ma~~tic, IR, electronic and ESR spectral data. The reaction between copper (I1) acetate and tridentate O-N-O donor ligands such as 2-(R)-3-(X)-substituted quin~oline”(3H)“~ones, R = methyl/phenyl and X = 2’-hydroxyphenylamino where (MHBQ/PHBQ), yielded neutral complexes of the type Cu(O-N-O),. The bidentate O--O or Q-N donor ligands like 2- (R)-3-(X)-substituted quinazoline-(3H)-4-ones, where R = methyl/phenyl and X = carboxy- methyl (M~MQ~PCMQ), furylamino (MFQ~PFQ), acetamino (MAQ~PAQ~, uramin~ (MUQ/PUQ) and thiouramino (MTUQ~~UQ)~ yielded neutral complexes of the type Cu(O--O), or Cu(O--N)2(CH~COO)z. 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 unin~gative bidentate and MFQ, PFQ, MAQ, PAQ, MUQt 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 (I1).