Gallate semiquinone radical tri-anion. Experimental and theoretical studies of the 13C hyperfine coupling constants

• Electron paramagnetic resonance (EPR) of the gallate semiquinone radical tri-anion. Determination hyperfine splittings (HFS) from all 13 C nuclei. Application Karplus-Fraenkel theory. Density functional theory (DFT) calculation constants. Representation solvent effects by polarizable continuum models (PCM). Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is one most abundant phenolic acids found in plant kingdom. In this work, electron spectrum tri-anion (GAS) derived GA air oxidation was measured and analyzed advanced simulation procedures. The observed main surrounded five satellite spectra which a thorough analysis led to determination chemically different nuclei natural abundance. were further characterized detailed linewidth analyses. assignment HFS constants supported results theoretical calculations, using classical, semi-empirical approach, as well quantum chemical procedures based on density (DFT), representing influence combined suggest consistent positions signs for GAS, providing unique insight into spin structure radical.