13C-NMR relaxation studies of alkali metal cryptate complexes

The 13 C spin-lattice relaxation times (T 1 's) of cryptands [2.1.1], [2.2.1] and [2.2.2] as well as those of the corresponding cryptate complexes with Li + , Na + , and K + in CDCl 3 and CH 3 OH:D 2 O (90:10) were measured and the results are interpreted in terms of molecular compression and desolvation effects.