Three Pb~(II) coordination polymers based on 2-(pyridin-2-yl)-1 H-imidazole-4,5-dicarboxylic acid: Syntheses, crystal structures, and fluorescent properties

摘要

Three lead coordination polymers, [PbCl(C_(10)H_6N _3O_4)(H_2O) · H_2O]_n (1), [Pb(C_(10)H_6N_3O_4) _2(H_2O)]_n (2) and [Pb_3(C _(10)H_5N_3O_4)_3]_n (3) (C_(10)H_7N_3O_4=2-(pyridin-2-yl)-1H- imidazole-4,5-dicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. In 1, Cl anions connected neighboring wave-like 2D layers, which are constructed with left- and right-handed helical chains, into a 3D network structure with a (6 ~3)(6~5 · 8) topology. In 2, Pb cations are linked into a 3D 6~6 network with left- and right-handed helixes by μ_2-bridging C_(10)H_6N_3O _4 - ligands. In 3, C_(10)H~5N ~3O_4 ~(2-) ligands link Pb_6O_(12) clusters into a 3D (4~(12) · 6~3) network. Their fluorescent properties were also investigated.