DISPOSITION OF COPPER(II) IN BETA-CYCLODEXTRIN

Distances of glucose protons in beta-cyclodextrin (BCD) from copper(II ) in copper(II)-beta-cyclodextrin have been determined from H-1 NMR sp in-lattice relaxation time (T1) measurements for the first time. Very low T1p/T2p values indicated the dipolar mechanism to be the most domi nant one in determining the paramagnetic contribution to relaxation. T he distances of copper(II) from BCD glucose protons indicated copper(I I) to be present almost in the centre, inside the cavity in the same p lane as H-1 and H-4. An average distance of about 5.0-5.9 angstrom was obtained for copper(II) from the H-2, H-3, H-1, H-4 and H-6 a and b p rotons in BCD.