Details

Autor(en) / Beteiligte

• Witwicki, Maciej

Titel

Theoretical Characterisation of Phosphinyl Radicals and Their Magnetic Properties: g Matrix

Ist Teil von

• Chemphyschem, 2015-06, Vol.16 (9), p.1912-1925

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2015

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• The g matrices (g tensors) of various phosphinyl radicals (R2P.) were calculated using the DFT and multireference configuration interaction (MRCI) methods. The g matrices were distinctly dependent on the molecular structure of the radical. To thoroughly examine this dependence, the contributions from individual atoms and excited states were calculated. The former revealed the gain from the phosphorus atom to be preeminent unless PO or PS bonds are present in the radical molecule. The contributions owing to excited states arising from electronic transitions between doubly occupied molecular orbitals and the SOMO were clearly positive, as in the case of semiquinone and niroxide radicals. The transitions from the phosphorus lone pair were of paramount importance. Surprisingly, unlike for semiquinones and nitroxides, a significant negative contribution was observed from excitations from the SOMO to unoccupied molecular orbitals. For radicals with PO bonds, this contribution to the g2 component was dominant. What's in a lone pair? As DFT and multireference configuration interaction (MRCI) calculations demonstrate, without the lone pair the magnetic properties of phosphinyl radicals (R2P.) wouldn′t be the same. Although the lone pair determines the value of one g matrix component, owing to the n→SOMO transition (see picture), the effects of other excited states and particular atoms are revealed.