A chiral cylinder-like metallomacrocycles bis tri-N-heterocyclic carbene silver(I): Synthesis, characterization and anticancer study

Through self-assembly, the preparation of trinuclear carbene complexes from polycarbene ligands and sil-ver(I) ions has been investigated. Reactions between 1,3,5-tris(bromomethyl)benzene with three equimo-lar N-substituted alkyl benzimidazole yielded the formation of numerous aromatic backbone scaffolds tris-benzimidazolium salts, H3L (1-5). Further reaction of the salts with Ag2O resulted in the formation of bis tri-NHC trinuclear silver(I) complexes with the formula of [Ag3L2] middot3PF6 (6-10) (where NHC = N-heterocyclic carbene). Structure elucidation from single-crystal X-ray diffraction data revealed that com-plex 9 is a cylindrical-like structure featuring three silver(I) atoms sandwiched between two tricarbene ligands with the aromatic backbone of each ligand arranged in eclipsed conformation with the formula of [Ag3L2] middot3PF6middot3MeCN (9). The anticancer study of the salts and complexes was carried out using Etopo-side as the positive control. Subsequently, only complexes 6-10 were found to have potential anticancer agents, with 6 and 8 being more active than the positive control.(c) 2022 Elsevier B.V. All rights reserved.