Pyrazolyl Pd(II) complexes containing triphenylphosphine: Synthesis and antimycobacterial activity

Abstract

Complexes of the type trans-[PdCl2(HL)(PPh3)], where HL = pyrazole (1); 3,5-dimethylpyrazole (2); 4-nitropyrazole (3); 4-iodopyrazole (4) and PPh3 = triphenylphosphine, were synthesized and characterized by elemental analyses, infrared and H-1 NMR spectroscopies. Single-crystal X-ray diffraction determination on 3.0.9 CHCl3 and 4 showed that the coordination geometry around Pd(II) is nearly square-planar, with the chloro ligands in a trans configuration. In vitro antimycobacterial evaluation demonstrated that compound 4 displayed a minimum inhibitory concentration (MIC) of 7.61 +/- 2.18 mu M, being superior to the values observed for some commonly used antituberculosis drugs and other metal-based complexes. (C) 2015 Elsevier Ltd. All rights reserved.