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

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 pi-pi 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. (C) 2015 Elsevier B.V. All rights reserved.