Inducing atypical higher order architecture for silver-flavin complex via nitrile pendent: Structural and antibacterial study

Abstract

Herein, we report rare examples of higher order structural architecture for metal-flavin complexes and investigation pertaining to their antibacterial properties. Notably, while mononuclear discrete units are preferred and frequently reported for flavin-metal complexes; incorporation of a nitrile pendent at N10 position of the modified flavin analogue (nitrile flavin-NF) has resulted in rare higher order architecture for silver-flavin complexes. To the best of our knowledge, a tridentate coordination mode for flavin as observed in complex 2 has never been reported. Significant structural variation and hence the functional behaviour was observed with strongly/weakly coordination nature of the counter-anion. The antimicrobial behaviour was investigated against gram-positive and gram-negative bacteria displaying broad-spectrum antibacterial activity; with complex 1 displaying prominent antibacterial activity among the two silver-flavin complexes studied.