NMR Studies of Iron (III) N-Methyl-N-Phenyldithiocarbamate and Its meta- and para-Fluorophenyl Derivatives

Abstract

The proton and fluorine magnetic resonance spectra of these compounds are interpreted using a model where the iron atom is in an intermediate crystal field of octahedral symmetry. The various proton and fluorine isotropic hyperfine-interaction constants in the A61 and the T22 states are calculated, and the approximations to determine these constants are examined. A method is outlined whereby an estimate of the ratio of the molecular vibrational partition functions in the T22 and A61 states can be ascertained from the NMR and the magnetic moment measurements. From the aromatic proton and fluorine hyperfine-interaction constants the electron spin densities in the A61 state are estimated and the results discussed. It is shown that fluorine substitution in the aromatic ring has little effect on the various hyperfine-interaction constants in both states.