Lead–organic frameworks containing trimesic acid: facile dissolution–crystallization and near-white light emission

Abstract

Three new, closely similar Pb-based organic frameworks synthesized using a simple and optimized dissolution–crystallization method with benzene-1,3,5-tricarboxylic acid (H3BTC) are reported along with their structural characterizations and photoluminescent properties. Compound 1, Pb(HBTC)(1,4-dioxane)0.5, crystallizes in the C2/c space group (a = 17.239(2) Å, b = 7.0225(8) Å, c = 19.911(2) Å, β = 104.735(10)°); compound 2, Pb2(HBTC)2(H2O)5, crystallizes in the P1̅ space group (a = 7.3989(4) Å, b = 8.2196(4) Å, c = 10.1437(5) Å, α = 94.336(4)°, β = 104.943(4)°, γ = 108.270(3)°); and compound 3, Pb(HBTC)(DMF), crystallizes in the P21/n space group (a = 10.5004(3) Å, b = 7.1398(3) Å, c = 17.1285(5) Å, β = 102.160(2)°). All three compounds are built from a slightly different one-dimensional (1D) structure interconnected into three-dimensional metal–organic frameworks by HBTC– ligands forming different pore sizes, in which the 1D moieties and pore sizes are governed by the solvent used during synthesis. Among the three compounds, compounds 1 and 2 exhibit solid state photoluminescence with 2 showcasing an interesting, near white-light emission, single-component phosphor with CIE coordinates of (0.33, 0.36).