Hyperfine Interactions in X-Irradiated Magnesium Phosphite Hexahydrate

Abstract

An analysis of the electron spin resonance spectra of X‐irradiated single crystals of MgHPO₃·6H₂O has shown that the principal long‐lived paramagnetic species produced by irradiation is a PO₃ fragment. This fragment retains the same orientation within the unit cell as the undamaged molecule. The parallel and perpendicular components of the diagonal (electron‐spin) — (nuclear‐spin) coupling dyadic for the phosphorus nucleus are found to be of the same sign and of magnitude 2210 and 1730 Mc, respectively. These results are compared with theoretical values of the distributed dipole and contact hyperfine interactions calculated on the assumption that the unpaired electron is located in an sp³ hybrid orbital centered on phosphorus.