R. Sarpal, M. Belletěte, G. Durocher
Apr 15, 1994
Citations
0
Influential Citations
7
Citations
Journal
Chemical Physics Letters
Abstract
Abstract The solubilization behavior of five substituted derivatives of the main chromophore 2-phenyl-3,3-dimethyl-3H-indole has been studied in sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) aqueous micelles by flourescence-decay lifetime measurements. These derivatives are as follows: 2-((p-amino)phenyl)-3,3-dimethyl-3H-indole (I), 2-((p-dimethylamino)phenyl)-3,3-dimethyl-3H-indole ((II), 2-((p-amino)phenyl)-3,3-dimethyl-5-carboethoxy-3H-indole (III), 2-((p-methylamino)phenyl)-3,3-dimethyl-5-carboethoxy-3H-indole (IV) and 2-(p-dimethylamino)phenyl)-3,3-dimethyl-5-carbo exthoxy-3H-indole (V). Polarity- and viscosity-dependent fluorescence lifetimes and intensities of these molecular probes have been used to elucidate the micellar solubilization site. All molecular probes in CTAB and molecules I, II and V in SDS were found to occupy only one solubilization site, the intercalative binding in CTAB and the surface binding in SDS. Molecules III and IV were shown to be able to recognize both sites in SDS. The data have been interpreted in terms of the functionality effect of these molecules and on the basis of morphologies of SDS and CTAB. It is found that a small substitution of a methyl group by a hydrogen atom on the 3H-indole chromophore renders the probe capable to recognize two sites in a micelle with surface roughness like SDS.