Synthesis of a palladium(II) complex of a N-heterocylic carbene via transmetalation: crystal structure and antibacterial studies

An Ag(I)-N-heterocylic carbene (NHC) complex, [Ag(L)₂]PF₆ (L = 1-(2′-methylbenzyl)-3-(2″-propyl)benzimidazolium), was used as a transfer agent for the synthesis of a Pd(II)–NHC complex, formulated as [PdCl(L)₂(MeCN)]PF₆ (Pd1). The complex Pd1 was characterized by ¹H and ¹³C NMR, FTIR spectroscopy and elemental analysis. Single crystal X-ray diffraction analysis reveals that the Pd(II) atom has a square planar geometry. This complex was screened for its antibacterial potential against the Gram-negative bacteria Escherichia coli (ATCC 25922) and the Gram-positive bacteria Staphylococcus aureus (ATCC 12600). These results are compared with those obtained for a standard antibiotic, ampicillin, and also the corresponding Ag(I)–NHC complex.