Solvation dynamics of 4-aminophthalimide (4-AP) in dioxane-water mixtures display a slow component of 350-500 ps. This is attributed to transient dioxane-water clusters and rupture of water-dioxane hydrogen bond. A detailed analysis indicates that there is no preferential solvation of 4-AP in dioxane-water mixture. The solvent shift of the emission maximum of 4-AP in a solution is shown to be controlled by hydrogen bond parameters of the solvent. (C) 2003 Elsevier B.V. All rights reserved.