A combined experimental and theoretical study on the synthesis, spectroscopic characterization of Magnesium(II) porphyrin complex with DMAP axial ligand and antifungal activity

Abstract

We report in the present paper the synthesis, the spectroscopic, structural, and electrochemical properties of a new magnesium(II) coordination compound namely the bis(4-dimethylaminopyridine)[meso-tetra(p-tolyl)porphyrinato)]magnesium(II) dichloromethane disolvate complex with the formula [Mg(TTP)(DMAP)2]•2CH2Cl2 (I). This species crystallizes in the triclinic crystal system with the centrosymmetric space group P-1. The crystal lattice of (I) is stabilized by C__H…Cg (Cg is the centroid of a phenyl ring) and C__H…Cl intermolecular interactions. Further insights on these weak intermolecular contacts are provided by the Hirshfeld surface analysis. This new Mg(II) porphyrin species was characterized by 1H NMR, IR, fluorescence, UV/Vis spectroscopy and ESI-HRMS mass spectrometry. A cyclic voltammetry investigation of this new metalloporphyrin was also reported. Furthermore, the bioactivity of the H2TTP free base porphyrin, the [Mg(TTP)] starting material and [Mg(TTP)(DMAP)2]•2CH2Cl2 (I) was evaluated in vitro, by examining their inhibitory effect against three strains of Candida viz. C. albicans, C. glabrata and C. tropicalis with MIC values in the range 2.5 to 10 μg.mL−1. The screening of the susceptibility of M. canis and T. rubrum clinical strains on the three porphyrinic derivatives is also reported.