title: High ethene/ethane selectivity in 2,2'-bipyridine-based silver(i) complexes by removal of coordinated solvent.
abstract: Following removal of coordinated CH3 CN, the resulting complexes [Ag(I) (2,2'-bipyridine)][BF4 ] (1) and [Ag(I) (6,6'-dimethyl-2,2'-bipyridine)][OTf] (2) show ethene/ethane sorption selectivities of 390 and 340, respectively, and corresponding ethene sorption capacities of 2.38 and 2.18 mmol g(-1) when tested at an applied gas pressure of 90 kPa and a temperature of (20±1) °C. These ethene/ethane selectivities are 13 times higher than those reported for known solid sorbents for ethene/ethane separation. For 2, ethene sorption reached 90 % of equilibrium capacity within 15 minutes, and this equilibrium capacity was maintained over the three sorption/desorption cycles tested. The rates of ethene sorption were also measured. To our knowledge, these are the first complexes, designed for olefin/paraffin separations, which have open silver(I) sites. The high selectivities arise from these open silver(I) sites and the relatively low molecular surface areas of the complexes.
authors.affiliation: Dept. of Chemical & Biological Engineering, University of Colorado, Boulder, CO, 80309-0424 (USA); Dept. of Chemistry & Biochemistry, University of Colorado, Boulder, CO, 80309-0215 (USA).
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Cowan
authors.forename: William M
authors.initials: WM
authors.lastname: McDanel
authors.forename: Hans H
authors.initials: HH
authors.lastname: Funke
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kohno
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Gin
authors.forename: Richard D
authors.initials: RD
authors.lastname: Noble
keywords: adsorption; alkenes; coordination modes; silver; solvent effects