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Ethylene complexes of gold( i ) have been stabilized by electron-rich, κ 2 -bound tris(pyrazolyl)borate ligands. Large up-field shifts of olefinic carbon NMR resonances and relatively long CC distances of gold bound ethylene are indicative of significant Au( i ) → ethylene π-backbonding relative to the analog supported by a weakly donating ligand, consistent with the computational data. 

Abstract Propylene is a crucial building block to produce many industrial‐scale chemicals including polypropylene. The separation of propylene from propane to reach the high‐purity levels needed for downstream applications is a difficult task due to the close similarities in their physical properties. The olefin/paraffin separation including that involving propylene mainly relies on highly energy‐intensive distillation processes and accounts for nearly 0.3% of the global energy consumption. The utility of a copper complex supported by a fluorinated bis(pyrazolyl)borate is demonstrated to accomplish the separation of propylene from propane repeatedly, under mild conditions with high selectivity. Complete characterization of a rare, copper(I) propylene complex is also reported including the molecular structure. 

Abstract The copper(I), silver(I), and gold(I) metals bind π‐ligands by σ‐bonding and π‐back bonding interactions. These interactions were investigated using bidentate ancillary ligands with electron donating and withdrawing substituents. The π‐ligands span from ethylene to larger terminal and internal alkenes and alkynes. Results of X‐ray crystallography, NMR, and IR spectroscopy and gas phase experiments show that the binding energies increase in the order Ag 

Abstract Purification of C₂H₄from an C₂H₄/C₂H₆mixture is one of the most challenging separation processes, which is achieved mainly through energy‐intensive, cryogenic distillation in industry. Sustainable, non‐distillation methods are highly desired as alternatives. We discovered that the fluorinated bis(pyrazolyl)borate ligand supported copper(I) complex {[(CF₃)₂Bp]Cu}₃has features very desirable in an olefin–paraffin separation material. It binds ethylene exclusively over ethane generating [(CF₃)₂Bp]Cu(C₂H₄). This molecular compound exhibits extremely high and record ideal adsorbed solution theory (IAST) C₂H₄/C₂H₆gas separation selectivity, affording high purity (>99.5 %) ethylene that can be readily desorbed from separation columns. In‐situ PXRD provides a “live” picture of the reversible conversion between [(CF₃)₂Bp]Cu(C₂H₄) and the ethylene‐free sorbent in the solid‐state, driven by the presence or removal of C₂H₄. Molecular structures of trinuclear {[(CF₃)₂Bp]Cu}₃and mononuclear [(CF₃)₂Bp]Cu(C₂H₄) are also presented.