Slow Solvation Dynamics of Dimethylformamide in a Nanocavity. 4-Aminophthalimide in β-Cyclodextrin

Abstract

Solvation dynamics of a nonaqueous solvent, N,N-dimethylformamide (DMF) has been studied for the first time in a β-cyclodextrin (β-CD) cavity using picosecond time dependent fluorescence Stokes' shift and 4-aminophthalimide (4-AP) as a probe. Solvation dynamics of confined DMF molecules within the β-CD cavity is found to be described by a component of 400 ± 50 ps (25%) and a slow component of 8 ± 1 ns (75%). This is substantially slower than the solvation time (∼1 ps) in bulk DMF.