OH studies have been reported on molecules adsorbed on surfacesI0 and in crystalline" and polymeric12 systems. Only crystals and liquid monolayers, so far, offer a well-defined location and environment. In this context the recent reports by Lahav and coworkers of the photoaddition of guest ketones to deoxycholic acid are particularly intere~ ting.'~ In this communication we report that urea inclusion compounds provide an environment wherein ...
