Electron spin resonance, electron spin echo modulation, and electron nuclear double resonance studies on the photolysis of positively and negatively charged alkylphenothiazines in anionic aerosol dioctyl and cationic cetyltrimethylammonium bromide/hexanol reverse micelles

Abstract

Photoionization of solubilized molecules in organized molecular assemblies has been used as model systems for light energy storage. In this article, positively charged (phenothiazinylalkyl)trimethylammonium bromides (PC[sub n]/TAB, n = 4, 6, 9, 12) and negatively charged sodium alkylphenothiazinesulfonates (PC[sub n]/S, n = 3, 6, 9, 12) incorporated into anionic aerosol dioctyl (AOT) and cationic cetylrimethylammonium bromide (CTAB)/hexanol reverse micelles have been photoionized at 77 K. The photoproduced radicals that are identified as the alkylphenothiazine radical cations are quantitated by electron spin resonance spectroscopy. The photoyield decreases monotonically with increasing interior water pool size ([omega][sub 0]) in anionic AOT reverse micelles and correlates with an increasingly negative interface charge of AOT due to increasing hydration of Na[sup +] conterions. The decrease correlates with a greater distance for electron transfer electron with increasing [omega][sub 0] as shown by the deuteron ESEM results. 48 refs., 13 figs.