Hybrid iodoplumbates with metal complexes: syntheses, crystal structures, band gaps and photoelectric properties.

With the in situ-generated [Pb(MCP)(4)](2+) (HMCP+ = 1-methyl-4-(carboxyl)pyridinium) or [M(phen)(3)](2+) (M = Co, Fe and Ni; phen = 1,10-phenanthroline) complexes as structural directing agents and charge-balancing ions, we solvothermally synthesized and structurally characterized four new organic-inorganic hybrid iodoplumbates. Compound K-2[Pb(MCP)(4)]Pb3I10 (1) represents the first K+ and [Pb(MCP)(4)](2+) co-templated hybrid haloplumbate, and exhibits a curve-like anionic layer of [Pb3I10](n)(4n-). Compounds [M(phen)(3)]Pb2I6CH3CN (M = Co (2), Fe (3) and Ni (4)) have isostructural phases, and feature a one-dimensional (1D) [Pb2I6](n)(2n-) anionic chain characteristic of pyramid-like [PbI5] units. The optical property studies show that compounds 1-4 exhibit semiconductor behaviors with the band gaps of 1.98-2.68 eV. In addition, the title compounds exhibited interesting photoelectrical responsive properties, with the photocurrent density in the order of 1 > 3 > 2 > 4. The thermal stabilities of the title compounds 1-4, as well as the theoretical band structure and density of states (DOS) of compounds 1 and 2 have also been studied.