Commensurate CO2 Capture, and Shape Selectivity for HCCH over H2CCH2, in Zigzag Channels of a Robust Cu(I)(CN)(L) Metal-Organic Framework.
A novel copper(I) metal-organic framework (MOF), {[Cu(I)2(py-pzpypz)2(μ-CN)2]·MeCN}n (1·MeCN), with an unusual topology is shown to be robust, retaining crystallinity during desolvation to give 1, which has also been structurally characterized [py-pzpypz is 4-(4-pyridyl)-2,5-dipyrazylpyridine)]. Zigzag-shaped channels, which in 1·MeCN were occupied by disordered MeCN molecules, run along the c axis of 1, resulting in a significant solvent-accessible void space (9.6% of the unit cell volume). These tight zigzags, bordered by (Cu(I)CN)n chains, make 1 an ideal candidate for investigations into shape-based selectivity. MOF 1 shows a moderate enthalpy of adsorption for binding CO2 (-32 kJ mol(-1) at moderate loadings), which results in a good selectivity for CO2 over N2 of 4.8:1 under real-world operating conditions of a 15:85 CO2/N2 mixture at 1 bar. Furthermore, 1 was investigated for shape-based selectivity of small hydrocarbons, revealing preferential uptake of linear acetylene gas over ethylene and methane, partially due to kinetic trapping of the guests with larger kinetic diameters.
Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago , P.O. Box 56, Dunedin 9054, New Zealand.
Reece G
RG
Miller
School of Chemistry, The University of Sydney , Camperdown, New South Wales 2006, Australia.
Peter D
PD
Southon
School of Chemistry, The University of Sydney , Camperdown, New South Wales 2006, Australia.
Cameron J
CJ
Kepert
Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago , P.O. Box 56, Dunedin 9054, New Zealand.
Sally
S
Brooker