Radiation Damage in Organic Crystals. I. CH(COOH)2 in Malonic Acid1

摘要: An analysis of the electron magnetic resonance single crystals malonic acid that were subjected to x-ray damage indicates that: (a) principal long-lived paramagnetic species produced by darnage is gen atoms this radical are oriented in crystalline lattice same way as these arranged parent undamaged molecule. (c) The z,x,y components diagonal (electron-spin) - (nuclear-spin) coupling dyadic for proton attached alpha -carbon atom found be relative sign and magnitudes 29. 61, 91 Mc, respectively. In orthogonal axis system, z CH bond direction x perpendicular plane three carbon atoms. These results excellent agreement with theoretical values distributed dipole contact hyperfine interactions show molecule a pi -electron radical, unpaired concentrated almost entirely on spin density in-plane sigma -proton negative. observed g-factors g/sub x/ = 2.0026, y/ 2.0035, z/ 2.0033 good qualitative withmore » previous estimates quantities. (auth)« less