The magnetic coupling in organic biradicals has been analyzed by means of ab initio wave function-based methods. Attention is focused on the coupling between the spin moments localized on the NO-groups in meta and para phenylene-bridged nitroxides, and bis(nitronyl) nitroxide and bis(imino) nitroxide biradicals. The leading mechanisms governing the coupling have been isolated by means of class-partitioned CI calculations. It was found that the mechanisms of the coupling in the para and meta phenylene-bridged nitroxides are similar to that found in transition metal complexes, while for the other biradicals the dominance of other mechanisms (like the spin polarization) imposes restrictions on the computational strategy to be followed to best estimate the coupling.
Analysis of the magnetic coupling in nitroxide organic biradicals
ANGELI, Celestino;
2011
Abstract
The magnetic coupling in organic biradicals has been analyzed by means of ab initio wave function-based methods. Attention is focused on the coupling between the spin moments localized on the NO-groups in meta and para phenylene-bridged nitroxides, and bis(nitronyl) nitroxide and bis(imino) nitroxide biradicals. The leading mechanisms governing the coupling have been isolated by means of class-partitioned CI calculations. It was found that the mechanisms of the coupling in the para and meta phenylene-bridged nitroxides are similar to that found in transition metal complexes, while for the other biradicals the dominance of other mechanisms (like the spin polarization) imposes restrictions on the computational strategy to be followed to best estimate the coupling.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
