Polycatenation and photoluminescence of two zinc coordination polymers based on arched and linear mixed ligands

Abstract

Abstract Two polycatenated coordination polymers, {[Zn3(adc)3(bpp)4]2 · 3H2O}n (1) and [Zn(adc)(bphy)]n (2) (adc = azobenzene-4,4′- dicarboxylate, bpp = 1,3-bis(4-pyridyl)propane, bphy = 1,2-bis(4-pyridyl)hydrazine), have been obtained from Zn(NO3)2∙ 6H2O, linear H2adc ligand and arched bpp/azpy (azpy = 4,4′-azobispyridine) ligands by hydro(solvo)thermal reactions. Compound 1 presents a 2-D structure catenated from 1-D double ladders (1-D → 2-D polycatenation), while compound 2 displays a 3-D structure catenated from 2-D (4,4) stair-stepping layers (2-D → 3-D polycatenation). Luminescence properties of 1 and 2 have been explored, together with study of photoluminescent mechanism by density of states (DOS) calculation.