Electron spin resonance studies in acrylamide polymerization using rhenium complexes as photosensitizers

Abstract

Acrylamide can be polymerized using new catalytic systems. These are based on rhenium complexes as photosensitizers with triethylamine (TEA). Electron Spin Resonance (ESR) was used for the detection of radicals species which were formed in the polymerization process. Also, we used Spin Trapping to confirm the presence of the acrylamide radical. AM1 and INDO calculations were performed to obtain the optimized geometries and theoretical hyperfine constants of the acrylamide radical. Our results agree with a cyclic process where triethylamine is an electron donor agent reacting with an excited rhenium complex. In this system, we postulate the [Re(II)(CO)(3)L (CF3SO3)]* as the activated species in the catalytic polymerization of acrylamide.