Abstract
Two new cobalt(III) six-coordinated complexes, [Co-III(TpivPP)Cl(py)].THF (1) [TpivPP is alpha,alpha, alpha,alpha-tetrakis (o-pivalamidophenyl)porphyrin known as the picket fence porphyrin and THE is tetrahydrofuran] and [Com(III)(TpivPP)Cl(4,4'-byp)].2H(2)O (2) (4,4'-bpy is 4,4'-bipyridine), have been synthesized and characterized by UV-Vis, IR,H-1 NMR and MS spectroscopy. The UV-Vis data confirmed the creation of hexa-coordinated Co(III)-meso-porphyrin complexes by the red shifted Soret bands of these derivatives. The proton NMR spectra of 1 and 2 clearly indicated that these derivatives are cobalt(III) diamagnetic porphyrin complexes. The molecular structures of these two Co(III) derivatives were determined by X-ray single crystal analysis. The Co(III) cations, chlorido ligands and nitrogen atoms of the pyridine and the pyridyl moieties lie on a two-fold axis of symmetry. The equatorial plane is formed by four nitrogen atoms of the porphyrin core of 1 and 2, whereas the apical positions are occupied by the chlorido ligands and the nitrogen atoms of the pyridine ligand and the pyridyl group of the 4,4'-bipyridine ligand of compounds 1 and 2 respectively. In the crystal packing of 1 and 2, the [Co-III(TpivPP)Cl(L)] (L = pyridine or 4,4'-bipyridine) molecules are arranged in one-dimensional chains parallel to the [010] direction, and voids are located between these chains. Gram-positive and Gram-negative bacteria have been tested against the starting materials and complexes 1 and 2. The results show that the cobalt(III) porphyrin derivatives are highly effective compared to the H(2)TpivPP free base porphyrin and that 1 and 2 derivatives have a higher growth inhibition against Escherichia coil and Bacillus subtilis bacteria. (C) 2016 Elsevier Ltd. All rights reserved.