Gas Sorption by Coordination Complex Hosts

Work by Leonard Barbour at Stellenbosch University, South Africa, has resulted in a coordination compound-based macrocyclic host (7.67) with a continuous channel conceptually analogous to 7.66 

Clathrates are useful for the control of the stereo- and regiospecificity of intra-cavity chemical reactions and can be used to engineer materials properties such as a polarity leading to non-linear optical materials, and ferroelastic or ferroelectric behaviour. 

Hydroquinone and phenol based clathrates including Dianin s compound are based upon cages made up of 6-membered hydrogen bonded rings of hydroquinone and are subject to considerable synthetic variation. 

The a- and P-phases of CTV both contain guests but the guests do not reside in the saucer-shaped cavity. More recent reports of a y-phase and exotic inclusion compounds with Cso and carboranes as well as network structure show that they CTV cavity does include guests, however. 

A particular topical area in inclusion chemistry gas gas soption and separation. Gases of interest include H2 (for application in fuel cells), methane and CO2. Recent developments in crystallography allow crystal structures to be obtained routinely under significant gas pressure. 

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