Formation and X-ray structural characterization of the chiral and racemic forms of a bis-macrocyclic phosphoramide

The 1,3,2,4-diazadiphosphetidine ring 1, bearing two macrocyclic units, rea cts with ethanol to form the chiral bis-macrocycle 2, including an asymmetr ic phosphorus center. 2 has been isolated as its chiral and racemic crystal line forms; both were structurally characterized using X-ray crystallograph y. The bis-macrocyclic molecule has a similar shape in the two crystal form s. A water molecule is complexed in one of the macrocylic units, inducing s trong conformational changes respectively to the uncomplexed one.