Proton Nuclear Magnetic Relaxation of Spin Labeled β-Cyclodextrin Complexes in an Aqueous Phase

Abstract

The 270MHz H-NMR spectra and the spin-lattice relaxation times, T, , have been measured for aqueous solutions of β-cyclodextrin incubated with various concentrations of both nitroxide spin label 2, 2, 6, 6-tetramethyl-l-piperidinyloxyl (TEMPO) and paramagnetic metal ion gadolinium(III). Remarkable spectral perturbations and paramagnetic nuclear relaxation effects were induced for some s. β-cyclodextrin protons by the addition of TEMPO. In contrast, the effect of the added gadolinium(III) on the spectra of β-cyclodextrin was small, probably because of too weak binding of this metal ion toβ-cyclodextrin to from the inclusion complexes.