title: Sorptive reconstruction of the CuAlCl(4) framework upon reversible ethylene binding.
abstract: Three ethylene adducts to CuAlCl(4) have been characterized by single crystal and/or powder X-ray diffraction, (13)C, (27)Al and (63)Cu MAS NMR and diffuse reflectance UV-vis spectroscopy. (C(2)H(4))(2)CuAlCl(4), a = 7.1274(5) b = 12.509(1) c = 11.997(3) beta = 91.19 degrees, Pc, Z = 4; alpha-(C(2)H(4))CuAlCl(4), a =7.041(3) b = 10.754(8) c =11.742(9) beta = 102.48(6), P2(1), Z = 4 and beta-(C(2)H(4))CuAlCl(4), a = 7.306(2), b = 16.133(3), c = 7.094(1), Pna2(1), Z = 4. Up to 2 equiv of ethylene ( approximately 200 cm(3)/g relative to stp) are sorbed at room temperatures and pressures as low as 300 Torr. The ethylene ligands are bound to copper (I) primarily through a sigma-interaction, because the AlCl(4)(-) groups also bound to copper prevent any significant pi-back-bonding. The olefin binding is reversible and has been characterized by gravimetric and volumetric adsorption analysis and by time and pressure resolved synchrotron powder X-ray diffraction. Comparison of the parent crystal structure to those of the adduct phases provide an atomistic picture of the sorptive reconstruction reactions. These are proposed to proceed by a classic substitution mechanism that is directed by the van der Waals channels of the parent crystalline lattice.
authors.affiliation: Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
authors.forename: Roger M
authors.initials: RM
authors.lastname: Sullivan
authors.forename: Haiming
authors.initials: H
authors.lastname: Liu
authors.forename: D Steve
authors.initials: DS
authors.lastname: Smith
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Hanson
authors.forename: Derek
authors.initials: D
authors.lastname: Osterhout
authors.forename: Michael
authors.initials: M
authors.lastname: Ciraolo
authors.forename: Clare P
authors.initials: CP
authors.lastname: Grey
authors.forename: James D
authors.initials: JD
authors.lastname: Martin