Dinuclear silver(I)-N-heterocyclic carbene complexes: Synthesis, characterization and larvicidal activity of bis-imidazolium dinuclear silver(I)-N-heterocyclic carbene complexes

Abstract

New synthesized bis-imidazolium salts that are linked by xylyl derivatives moiety, 1–4 was reacted with Ag2O to facilitate the formation of dinuclear Ag(I)-N-heterocyclic carbene (NHC) complexes, 5–8, respectively. All the synthesized ligand salts and complexes were characterized by 1H and 13C NMR, FTIR spectroscopy and elemental analysis. Molecular structures of compounds 3, 5, and 7 were elucidated by single crystal X-ray diffraction analyses. Larvicidal studies against the Aedes aegypti and Culex quinquefasciatus were carried out on all synthesized compounds following the World Health Organization standard larval susceptibility test. All the imidazolium salts were found inactive while the activity of the dinuclear Ag(I)-NHC complexes on mosquito larvae are varies with the nature of the ligands. Complex 7 has high activity on Ae. aegypti and Cx. quinquefasciatus, emphasising its potential as a larvicidal compound.