Crystallisation temperature control of stoichiometry and selectivity in host–guest compounds
The host H, 9,9′-(ethyne-1,2-diyl)bis(fluoren-9-ol), has been employed to study its selectivity towards the close boiling alcohol pair, 2-propanol and tertiary butanol. H is selective for tertiary butanol at low temperatures, but includes both guests without discrimination at high temperatures. Concomitantly higher guest/host ratios were observed at lower temperatures, in agreement with the literature. The kinetics of solid–host: guest–vapour enclathration was successfully measured by powder X-ray diffraction.