A Theoretical Study of the Electron Spin Resonance Spectra of Cycloheptatrienyl

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The ESR spectra of the cycloheptatrienyl radical (CHT) have been studied theoretically, and the orbital degeneracy of the ground state of CHT has been decisively confirmed. The static Jahn-Teller effect and out-of-plane puckering do not occur. The spin densities have been calculated according to the prescriptions of the simple Huckel, approximate UHFLCAO-MO, Pariser-Parr and valence bond theories. The modifications of the dynamic Jahn-Teller effect and of the unusually strong coupling between the CHT molecule and the lattice through the crystal field have been discussed. The hyperfine structure of the high temperature spectra in naphthalene has been quantitatively explained, and the hyperfine structure of the low temperature spectra in naphthalene has been semi-quantitatively explained. The pi-electron contribution to the spectroscopic splitting factor, g[subscript z, subscript z], has been estimated and shown to account for the low temperature polycrystalline g-factors. The role of the spin-orbit interaction in inducing spin-lattice relaxation has been examined in the light of the strong lattice-CHT coupling