Theoretical studies of magnetic interactions in 3 ' 5 '-dihydroxyphenyl nitronyl nitroxide crystal

In order to investigate the ferromagnetic interaction in the 3', 5'-dihydro xyphenyl nitronyl nitroxide (RSNN), semiempirical and ab initio molecular o rbital calculations were carried out for several pair models of RSNN molecu les extracted from the X-ray crystal structure. It was shown that the effec tive exchange interaction (J(ab)) for the nearest neighbor pair is ferromag netic in accordance with the experimental results. For the pairs related wi th the double hydrogen bonds, the sign of the calculated J(ab) values mainl y corresponds with the experimental result, however partialy conflict. The hydroxyl groups contribute to the magnetic interaction in the RSNN crystal.