Mercury coordination polymers with flexible ethane-1,2-diyl-bis-(pyridyl-3-carboxylate): Synthesis, structures, thermal and luminescent properties

Abstract

The reaction of the flexible ligand, ethane-1,2-diyl-bis-(pyridyl-3-carboxylate), (L) with HgI2 and HgBr2 salts under the same experimental conditions leads to the formation of two coordination polymers with different motifs: {[Hg(L)(Br2)]}n(1) and {[Hg(L)(I2)]}n(2).In both compounds, the ligand, (L) acts in a μ2-N:N′-bidentate fashion to link HgBr2 and HgI2 units to form a linear and helical chain motif, along [100] for (1) and [001] for (2). The ethylene moiety of (L) has gauche and trans conformation in compounds (1) and (2), respectively. The flexible conformation of L produces differences in the optical and crystal properties of the two compounds.