Synthesis, structures, and fluorescence of two lead(II) coordination polymers

Two novel Pb(II) coordination polymers: Pb(L)·H2O]n (I) and [Pb(L)·(4,4’-bipy)0.5]n (II) (H2L = N-3-pyridine sulfonyl amino succinic acid), were synthesized and characterized by FT-IR, elemental analysis, and single-crystal X-ray diffraction analysis. The results show that I crystallizes in orthorhombic system, Pbca space group, with a = 7.3492(7) Å, b = 15.4994(15) Å, c = 22.652(2) Å, α=β = γ = 90°, V = 2580.3(4) Å3; The II crystallizes in monoclinic system, P21/n space group, with a = 5.1885(7) Å, b = 19.7136(15) Å, c = 15.4593(11) Å, α = γ = 90°, β = 92.8330(10)°, V = 1579.3(3) Å3. Thermogravimetric analysis (TGA) indicated that I and II can maintain their structure at temperatures between 35∼234 °C and 35∼145 °C, respectively. The solid-state fluorescence of I and II showed that they had stronger fluorescence response than L. It can be seen that the introduction of ligands having aromatic rings can increase the fluorescence intensity of the polymer.