Metal–organic frameworks with six- and four-fold interpenetration and their photoluminescence and adsorption property

Abstract

Three-dimensional interpenetrated metal–organic frameworks (MOFs) {[ZnL₂]·4H₂O}_n (1) and {[Cu(HL)₂(H₂O)₂]Cl₂}_n (2) were synthesized by reactions of the corresponding metal salt and 1-(imidazol-1-yl)-4-(imidazol-4-yl)benzene (HL) with and without addition of sodium hydroxide, respectively. Complex 1 is a 6-fold interpenetrated porous 6⁶dia framework filled with water molecules, in which the metal atom has distorted tetrahedral coordination geometry and the ligand was deprotonated. While complex 2 with octahedral Cu(II) is a 4-fold interpenetrated dia framework with chloride as counteranions and no deprotonation of the ligand occurred. In addition, the stability, photoluminescence and the adsorption properties of the complexes were studied.