A Two-Dimensional Terrace-Like N-Heterocyclic-Pb(Ii) Coordination Compound: Structure and Photoluminescence Property

The first example of lead compound from Pb(NO3)(2) and H3L N-heterocyclic ligand (H3L = (HO2C)(2)(C3N2) (C3H7)CH2(C6F4)(C6H3)CO2H), [Pb-4(L')(4)]center dot 5H(2)O 1 (L' = OOC(C3H7)(C3N2)CH2(C6H4)(C6H3)COO), has been obtained under hydrothermal condition by decarboxylation, and characterized by elemental analysis, IR, TG-DTA, and single-crystal X-ray diffraction. Compound 1 possesses a rare two-dimensional upper-lower offset terrace-like layer structure. In 1, crystallographic distinct Pb(II) ion adopts five-coordination geometry, and two lattice water molecules occupy the voids between 2-D layers. Results of solid state fluorescence measurement indicate that the emission band 458 nm may be assigned to pi*-n and pi*-pi electronic transitions within the aromatic systems of the ligand L', however, the emission bands centred at 555 nm, 600 nm and 719 nm may be derived from phosphorescent emission (lambda(excitation) = 390 nm).