Selective carbon monoxide uptake by porous materials with metal carbanions

Abstract

Metal organic framework compositions and methods for CO gas separations from mixed gas sources are provided. A modified CO-selective metal-organic framework M-R-MFU-4l, where M is a divalent metal and R is a carbon substituent is particularly effective for CO separations. The material remains intact upon exposure to CO and retains high capacities over extended cycling. One framework, Co3.8Zn1.2Me3.8Cl0.2(btdd)3, CoMe-MFU-4/, leverages pseudo-open metal sites for a highly effective separation process. Because of the spin transition mechanism and the reorganization induced by a strong field ligand, the framework selectively coordinates multiple CO to each Co single site at 25 degrees Celsius. The sluggish desorption of CO in contrast to other potential components in a gaseous stream which desorb rapidly, such as N2, H2, CH4, ethylene, facilitates the isolation of high purity CO via a kinetic separation.

Dependencies are inferred from the claim text.