Investigation of magnetic interaction pathways by experimental electron density measurements: application to an organic free radical, p-(methylthio)phenyl nitronyl nitroxide
S. Pillet et al., Investigation of magnetic interaction pathways by experimental electron density measurements: application to an organic free radical, p-(methylthio)phenyl nitronyl nitroxide, NEW J CHEM, 25(1), 2001, pp. 131-143
The [X-(X+N)] electron density distribution in a 3D ferromagnetic purely or
ganic free radical, p-(methylthio)phenyl nitronyl nitroxide, is reported an
d analysed in terms of magnetic interactions. From the atomic charges obtai
ned by multipolar refinement against the X-ray data, a charge transfer by i
ntermolecular hydrogen bonds between the O-N-C-N-O fragment of the nitronyl
ring and the methylthio group is pointed out. Rotation of the oxygen lone
pairs is also observed in the direction corresponding to short intermolecul
ar N-O . . .O-N contacts. The topological analysis of the electron density
allows us to characterise the bonding scheme in this radical and clearly de
monstrates an electron delocalisation from the two oxygen to the sulfur ato
m through the phenyl ring. The atomic vibrations are investigated and their
influence on the intermolecular interactions is discussed.