CONFORMATION AND DYNAMICS IN SOLUTION OF AN N-QUATERNARIZED BENZOPHENONE DERIVATIVE - A MOLECULE ACTIVE AS UV FILTER

The dynamics and conformation of N,N-dimethyl-N-\3-(benzoyl-4-phenoxy)\-N-n-dodecylammonium bromide, 1, have been established in two solvents (CDCl3 and DMSO-d6) by the use of C-13 spin-lattice relaxation rates, non-selective and selective proton spin-lattice relaxation rates, and H-1-{H-1} nuclear Overhauser enhancement (nOe) experiments. The data obtained are consistent with two main mean conformations for compound 1: a ''linear'' conformation in CDCl3 and a folded conformation in DMSO-d6 where the alkyl chain forms a loop toward the aromatic moiety.