Synthesis, spectroscopic, magnetic and biological activity studies of copper(II) complexes of an antipyrine Schiff base

• Published in: Transition metal chemistry (Weinheim) Vol. 25; no. 5; pp. 522 - 528
• Main Author: Ismail, Kamal Z
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.10.2000
• Subjects: Copper
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1023/A:1007072911095

The Schiff base, 4-(2-pyrrolylmethylideneamino)antipyrine (HPAP), (1), and its copper(II) complexes were synthesized and characterized by elemental analysis and by physical and spectral methods such as i.r., u.v.-vis., ^sup 1^H-n.m.r., ^sup 13^C-n.m.r. and e.s.r. as well as by molar conductance and magnetic moment determinations. Both the bis-ligand, [(HPAP)^sub 2^Cu]X^sub 2^ (4, 5), [(PAP)^sub 2^Cu] (6), and the dimer, [(PAP)Cu]^sub 2^X^sub 2^ (2, 3), complexes were isolated. In these complexes, the Schiff base acts as a bidentate or tridentate neutral or monobasic ligand. Interaction of the isolated [(PAP)Cu]^sub 2^Cl^sub 2^ (2), with strong coordinating organic bases was studied and the resultant adducts, [(PAP)CuLs]Cl; Ls = pyridine (7), α-picoline (8), β-picoline (9), γ-picoline (10) or n-propylamine (11), were isolated and characterized. Biological activity screening was studied and an activity correlation coefficients matrix was constructed for HPAP and the copper(II) complexes against gram-positive, gram-negative and fungi species. The copper content, structure of the complex as well as the degree of exposure of the metal center control the biological activity of the isolated complexes.[PUBLICATION ABSTRACT]