2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior

Abstract

Four silver-based coordination polymers, {[Ag(L1)₂]NO₃}_∞ (1), {[Ag(L1)₂]ClO₄}_∞ (2), {[Ag(L2)₂]NO₃·H₂O}_∞ (3) and {[Ag(L2)₂]ClO₄}_∞ (4), were synthesized using the thiomorpholine-4-carbonitrile (L1) and piperazine-1,4-dicarbonitrile (L2) ligands. Compounds 1 and 2 are two-dimensional, while 3 and 4 are three-dimensional. L1 and L2 are 1,4-bis-monodentate ligands in all compounds, while Ag(I) ions are four-coordinated in a slightly distorted tetrahedral geometry. Topological analysis in standard representations suggests that underlying nets in 1 and 2 have an sql topology, while 3 and 4 exhibit a dia topology. Thermal analysis shows that 3 loses crystalline water at room temperature, while other compounds show good thermal stability. All compounds show good photocatalytic activity for photocatalytic degradation of the mordant blue 9 dye, with reaction rates in the range 0.029 to 0.061 min⁻¹. The best result was obtained for compound 4, which can be correlated to its largest lattice volume.