Electron spin resonance and structure of the CO^-₂radical ion

Abstract

Abstract Analysis of the electron spin resonance spectrum shows that CO− 2 radical ions are trapped in sodium formate at room temperature after irradiation of the crystal with high energy γ-rays. This radical is bent with an angle of about 134° and has a 2 A 1 ground state. From the experimental values of the 13C coupling coefficients and the g values, coefficients are derived for the mixing of atomic orbitals in the half-filled 4a 1 molecular orbital which appears to be 14 per cent carbon 2s, 66 per cent carbon 2p z and 11 per cent of each oxygen 2p z . There is also coupling to the sodium nucleus in an adjacent cation.