A layered solution crystal growth technique and the crystal structure of (C6H5C2H4NH3)(2)PbCl4

Single crystals of the organic-inorganic perovskite (C6H5C2H4NH3)(2)PbCl4 h ave been grown at room temperature using a layered solution approach. The b ottom solution layer, contained within a long straight tube, consists of Pb Cl2 dissolved in concentrated aqueous HCl. A less dense layer of methanol i s carefully placed on top of the HCl/PbCl2 solution using a syringe. Finall y, a stoichiometric quantity of C6H5C2H4NH2 (relative to the PbCl2) is adde d to the top of the column. As the layers slowly diffuse together, well-for med crystals of (C6H5C2H4NH3)(2)PbCl4 appear near the interface between the HCl/PbCl2 and C6H5C2H4NH2 solutions. The thick, plate-like crystals are we ll suited for X-ray crystallography studies. Room temperature intensity dat a were refined using a triclinic (P (1) over bar) cell (a = 11.1463(3)Angst rom, b = 11.2181(3)Angstrom, c = 17.6966(5)Angstrom, alpha = 99.173(1)degre es, beta = 104.634(1)degrees, gamma = 89.999(1)degrees, V = 2111.8(1) Angst rom(3), Z = 4, R-f/R-w = 0.031/0.044). The organic-inorganic layered perovs kite structure features well-ordered sheets of corner-sharing distorted PbC l6 octahedra separated by bilayers of phenethylammonium cations. Tilting an d rotation of the PbCl6 octahedra within the perovskite sheets, coupled wit h organic cation ordering, leads to the unusual in-sheet 2a(p) x 2a(p) supe rstructure, where a(p) is the lattice constant for the ideal cubic perovski te. (C) 1999 Academic Press.