Synthesis, crystal structure and spectroscopic characterization of the Co(II) bis(pyridine) "picket fence" porphyrin complex. Potential application as antibacterial agent

In this work, we describe the synthesis, spectroscopic and structural properties of the new compound bis(pyridine)(alpha, beta, alpha, beta-tetrakis (o-pivalamidophenyl) porphyrinato) cobalt (II) [CoII(TpivPP)(py)2] (I). The molecular structure determined by X-rays of the compound shows that this species is a six-coordinate cobalt (II) metalloporphyrin. The UV-visible spectrum of (I) shows that the value of the Soret band (415 nm) is shifted towards the green with respect to the free base H2TpivPP while the lambda max values of the Q band are 530 and 563 nm. The proton NMR spectrum of (I) clearly indicated that these derivatives are cobalt(II) paramagnetic porphyrin complexes. Zones of inhibition are studied against the bacterial strains Escherichia coli, Streptococcus pneumoniae and the fungal strains Aspergillus niger, Aspergillus fumigatus. The reported results show that cobalt porphyrin has better antibacterial and antifungal efficacy against gram-positive and gram-negative strains of bacteria as well as fungal strains.