Synthesis of an octanuclear Eu(III) cage from Eu(4)(2+): chloride anion encapsulation, luminescence, and reversible MeOH adsorption via a porous supramolecular architecture.

The octanuclear complex [Eu8L4(1,4-BDC)2Cl8(MeOH)12].4Cl.2MeOH.18H2O (2) was obtained from the reaction of the tetranuclear Eu(III) species [Eu4L2Cl2(OH)4(H2O)4(MeOH)2].2Cl.7MeOH.2H2O (1) and 1,4-H2BDC (H2L = bis(5-bromo-3-methoxysalicylidene)ethylene-1,2-phenylenediamine, 1,4-H2BDC = 1,4-benzenedicarboxylic acid). Both 1 and 2 were structurally characterized by X-ray crystallography, and their luminescence properties were determined. The cagelike structure of 2 encapsulates two chloride anions via MeOH...Cl hydrogen bonding. In the solid state, 2 has an open three-dimensional network with extended channels and is capable of reversible MeOH adsorption.