Divergent Crystallographic Architecture for Silver-Flavin Complexes Induced via pH Variation

摘要

Herein we report solid state analysis of the silver-flavin complexes grown under different chemical environments-neutral (complex 1), acidic (complex 2) and basic (complex 3) mediums. While preferred and frequently reported primary coordination is observed in all three cases; involvement of rare secondary coordination in 2 and deprotonated carboxyl functionality of the modified flavin in 3 for silver ion coordination results in discrete, zig-zag and ribbon-like architecture. Crystallographically unique silver ions, anion-pi/lone pair-pi interactions and the argentophilic interactions are some of the unique features observed for silver-flavin complexes. Notably, such extended geometry involving flavin moiety is scarcely reported and these results expand the unexplored coordination horizon of the flavin entities.