The nature and structure of electron attachment products in the photoinduced electron transfer reaction DMA + CH2Cl2→hvDMA+ + (electron attachment products) in solid argon has been studied by FTIR spectroscopy (DMA = N,N-dimethylaniline, hν = 4.88 eV Hg lamp radiation) along with extensive ab initio calculations. Two attachment products have been identified: the radical anion of CH2Cl2 and the dichloromethane anion (HCCl2−. The radical anion turns out to have a C1 hydrogen bridged structure (ClHCH…Cl−1). This structure as well as the species of HCCl2− have not been detected before.

Using time resolved Fourier-transform EPR spectroscopy the photoreduction of anthraquinone by triethylamine in 2-propanol solution was investigated. The spin-polarized anthraquinone triplet deactivates by hydrogen transfer from the solvent and electron transfer from triethylamine generating 10-hydroxy-anthroxyl-9 radicals, ketylradicals and semiquinone anion radicals and amine radical cations, respectively. All radicals are spin-polarized by triplet mechanism and partially by radical pair mechanism. Competitive chemical kinetics of triplet deactivation, lifetimes of two different primary radical ion pairs and secondary reduction reactions of ground state anthraquinone have to be included in the kinetic depending on the lifetimes on the Coulomb-coupled radical ion pairs follow unimolecular decay or are amine catalysed depending on the number of amine molecules in the first solvation shell. Furthermore, the absolute amount of spin polarization and spin lattice relaxation rates of the radicals could be determined.