Structure modulation, argentophilic interactions and photoluminescence properties of silver(i) coordination polymers with isomeric N-donor ligands

Abstract

Synthesis, crystal structure, and photoluminescence studies of a one dimensional silver coordination polymer {[Ag(L1)(CH₃CN)][Ag(L1)(OTf)](OTf)}_n (1) comprising of Ag(I) and a new flexible organic linker bis(pyridine-3-ylmethyl)terephthalate (L1) exhibiting closed-shell d10⋯d10 argentophilic interaction, is reported. The compound 1 consists of two kinds of (double and single stranded) 1D coordination polymeric chains running parallel and displaying short Ag(I)⋯Ag(I) distances. Notably, the coordinated triflate anion, μ2-bridging mode of acetonitrile and stacking interactions play an important role in the realization of 1D quadruple metal–organic chain in compound 1. Treatment of silver triflate with isomeric ligand, bis(pyridine-2-ylmethyl)terephthalate (L2) resulted in a polymorph of previously reported 1D zigzag coordination polymer {[Ag(L2)](OTf)(H₂O)}_n (2). Both organic ligands and Ag coordination polymers are characterized by various analytical techniques. Crystal and molecular structures of the isomeric ligands (L1, L2) and their Ag(I) coordination polymeric architectures (1, 2) are correlated with their photoluminescence properties.