Crystal structure of a lapacholate complex with Co(II), a potential antibacterial pharmaceutical

Abstract

The solid state molecular structure of dilapacholate diaquo cobalt (II) di-dimethylformamide, for short [Co(Lap) 2 (H 2 O) 2 ]·2DMF, was determined by X-ray diffraction methods. It crystallizes in the monoclinic space group P2 1 /n with Z = 2 molecules per unit cell. The complex is at a crystallographic inversion centre with the Co (II) ion in a distorted octahedral environment of approximate D 2h local symmetry, coordinated to two lapacholate anions acting as bidentate ligands through their carbonyl and phenolic oxygen atoms, and to two water molecules nearly along the bisector of their oxygen electron lone-pair lobes. The IR absorption spectrum, electronic absorption, TGA data and also a comparison of IR characteristic bands with the corresponding ones of other Co-lapacholates are also discussed. At a concentration of 25 ppm, the new metal complex shows biological activity against several clinical Staphylococcus aureus strains.