Copolymers of 2‐acrylamido‐2‐methylpropanesulfonic acid and aromatic vinyl compounds as potential media for photosensitized electron transfer reactions

In an expectation as potential media for photosensitized electron transfer reactions, polymers carrying both strong electrolytic and hydrophobic segments were prepared by the copolymerization of 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) and styrene. The AMPS segments were found to have a remarkable power to solubilize the hydrophobic segments into water, i.e., even a copolymer with a styrene mole fraction of 0,72 is still soluble in water. Salt effect on the reduced viscosity, broadening of NMR spectra in D 2 O, and enhanced excimer fluorescence of styryl groups in aqueous solution indicated a pronounced hydrophobic interaction of a number of styryl groups along the chain in the copolymer with high styrene content. 8‐Anilinonaphthalene‐1‐sulfonic acid, 1,6‐diphenyl‐1,3,5‐hexatriene, and a cyanine dye were used as fluorescent probes for the hydrophobic microdomains. The results suggested that the microdomains are highly hydrophobic in nature but less capable to solubilize the fluorescent probes than the surfactant micelles. An electron microscopic image of the copolymer was also discussed as a supporting evidence for the presence of microdomains.