Copper(II) and Nickel(II) complexes of the non-steroidal anti-inflammatory drug indomethacin containing aromatic chelating N,N-donor ligand: Synthesis and structural studies

• DOI: 10.1016/j.molstruc.2020.129069
• Publication Date: 2020-08-12T12:44:48Z
• Authors: Ginikachukwu G. N...; Sunita Salunke-Ga...; Archana S. Patil; Ray J. Butcher; Misitura Lawal; Mercy O. Bamigboye; Joshua A. Obaleye
• Keywords: Octahedral molecular geometry; Phenanthroline; Triclinic crystal system

Abstract Two complexes [Cu(indo)2(phen)(H2O)];Cu-1 and [Ni(indo)2(phen)(H2O)2].1.5H2O;Ni-1, were synthesized by the reaction of their respective metal(II)acetates with indomethacin (indo) [1-(4-chlorobenzoyl)-5‑methoxy‑2-methyl-1H-indole-3-acetic acid)] and a nitrogen donor heterocyclic ligand 1,10-phenanthroline (phen) in acetonitrile: water mixture (9:1 v/v), by refluxing at 80 °C for 3 h. The complexes were characterized by physicochemical, spectroscopic, and TG analysis. X-ray structural analysis showed that both complexes crystallizes in the triclinic space group P-1. Cu-1 consists of Cu(II) in square pyramidal geometry and coordinated to two monodentate indomethacin ligands, a bidentate 1,10-phenanthroline, and one aqua ligand. Intermolecular O-H···O, C-H···O, C-H···Cl, Cl···Cl, and C-H···π interactions in Cu-1 were responsible for the stability of the complex. Ni-1 is centrosymmetric and consists of Ni(II) in a distorted octahedral geometry, involving two trans monodentate indomethacin ligands, a bidentate 1,10-phenanthroline ligand, and two cis aqua ligands. There were two lattice water molecules outside the coordination sphere of Ni-1, that participated in extensive O-H···O interactions. The complex was further stabilized by C-H···O, C-H···π, and π···π interactions. The monodentate coordination of the carboxylato oxygen of indomethacin ligand in the complexes was confirmed from the FTIR studies. TG analysis provided information on the stability and decomposition pattern of the complexes.