Polymeric lead(II) phosphor featuring cubane [Pb-4] and [Pb-8] units: Organic vs inorganic binding competition, colour regulation and white luminescence

摘要

Lead based compounds are attracting functional material with novel photophysical properties, but restricted by their varied coordination and difficulties in structural control. Two new polymeric compounds of {[Pb-8(mu(4)-O)(2)(mu(3)-OCH3)(6)Cl-2][Pb-4(mu(3)-OH)(4)](NO3)(8)} (1) and {[Pb-4(mu(3)-O)(mu(3)-OCH3)(3)](NO3)(3)} (2) were solvothermally synthesized, charactering cubane [Pb4O4] and [Pb8O8] building units extended by high-coordinated NO3-. The two compounds provide a rare system to evaluate Pb(II) binding competition to various inorganic ligands of CH3O-, Cl-, O-2(-) and NO3-, over a linear pyridine-carboxylate linker. The 1 generated at higher temperature of 130 degrees C exhibits near-sunlight white emission, stemming from extremely sophisticated chemical environments of twelve crystallographic independent Pb(II) ions. A decreased temperature of 100 degrees C leads to 2 with strong blue emission under high-energy excitation and coexisted weak yellow colour under low-energy, benefited to precise colour regulation by changing the intensity of dual excitation.