Synthesis, spectral and electrochemical studies of 2-(arylazo)heterocycle complexes of zinc(II). Single-crystal X-ray structure of [Zn(papm)Cl-2 center dot CH3OH] (papm=2-(phenylazo)pyrimidine)

2-(Arylazo)pyridines (aap) (R-C6H4-N=N-C5H4N, 1) and 2-(arylazo)pyrimidines (aapm) (R-C6H4-N=N-C4H3N2, 2); R = H (a), o-Me (b), m-Me (c), p-Me (d), p- Cl (e) are used to synthesise title compounds. The complexes are characteri sed by elemental analyses, IR, UV-Vis and H-1 NMR spectral data. Single-cry stal X-ray structure of dichloro-{2-(phenylazo)pyrimidinelzine}-zinc(II)(.) methanol suggests that the complex is a distorted trigonal bipyramidal symm etric around Zn(II), and Cl(1), Cl(2), N(4) (N (azo)) make the trigonal pla ne. Zn(II) moves downwards by 0.12 Angstrom from the centre of gravity of t he plane. Two axial positions are occupied by N(1) (N(pyrimidine)) and meth anol-O. Molecular packing shows one-dimensional infinite chain via hydrogen bonding. The EHMO calculation has been carried out to explain the electron ic behaviour of the complexes and the results are compared with that of cop per(I) complex. (C) 2001 Elsevier Science Ltd. All rights reserved.