GROUND-STATE AND EXCITED-STATE CONFORMATIONAL HETEROGENEITY OF THE 2'-NAPHTHYLBUTADIENE CHROMOPHORE OF A FLUORESCENT CHOLESTEROL ANALOG PROBE

Steady-state, time-resolved, and temperature-dependent fluorescence studies, together with molecular orbital calculations, have been used to investigate the photophysical behavior of the 2′-naphthyldiene side chain of a novel fluorescent cholesterol analogue with the aim of establishing the utility of this molecule as a cell membrane probe. The photophysics is largely governed by the presence of two ground-state conformers, i.e., the s-cis and s-trans rotamers about the single bond adjacent to the naphthyl group. The presence of this ground-state conformational equilibrium could prove useful in monitoring changes in membrane order. An excited-state viscosity-dependent process of the s-cis conformer also shows promise to be exploited to study membrane dynamics. © 1990 American Chemical Society.