Self-assembly of imidazoliums salts based on acridine with silver oxide as coordination polymers: Synthesis, fluorescence and antibacterial activity

• Ag-NHCs based on acridine derivative were synthesized and characterized by elemental analysis, NMR and X-ray diffraction.
• Complexes 3c and 3d afforded to one-dimensional zigzag type chain coordination polymers.
• The optical properties and antibacterial activities of silver NHC complexes have been studied.

The reaction of iodomethane, n-butane bromide, bromoethane, benzyl bromide and 9-(1-imidazolyl) acridine obtains the corresponding imidazolium salts, which can further react with NH4PF6, affording 2a–2d. Then, they were treated with silver oxide in CH3CN or DMSO to afford complexes 3a–3d ({Ag [1-acridinyl-3-methylimidazoly-diene]2 (PF6)} (3a), {Ag [1-acridinyl-3-butylimidazoly-diene]2 (PF6) CH3CN} (3b), {Ag [1-acridinyl-3-ethylimidazolydiene] (PF6)}n (3c), {Ag [1-acridinyl-3-benzylimidazoly-diene] (PF6)}n (3d)). 3a and 3b formed mononuclear silver complexes which presented π−π stacking interactions between acriding rings. Amazingly, 3c and 3d formed one-dimensional coordination polymers through self-assembly of N1–Ag1–C16 and N1–Ag1–C14 bonds, respectively. Moreover, 3b, 3c and 3d have been found to have efficient anti-bacterial activity against the Acinetobacter baumannii and P. aeruginosa. In addition, the imidazolium salts and their corresponding silver complexes show a phenomenon of fluorescence quenching.

Imidazolium salts were treated with silver oxide in CH3CN or DMSO to afford complexes 3a–3d. 3a and 3b formed mononuclear silver complexes which shown interesting π−π stacking interactions between acriding rings. Amazingly, 3c and 3d formed one-dimensional coordination polymers through self-assembly of imidazoliums salts and silver oxide, respectively.Figure optionsDownload as PowerPoint slide