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Rotational disorder of bis(mesitylene)vanadium in channels of a triazine inclusion compound
Ist Teil von
CrystEngComm, 2013-01, Vol.15 (4), p.811-8115
Erscheinungsjahr
2013
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Electron paramagnetic resonance (EPR) was applied to study rotational disorder of bis(mesitylene)vanadium (VBM,
S
= ½) in channels of 2,4,6-tris(4-Br-phenoxy)-1,3,5-triazine. To ensure a magnetically dilute system, decamethylbis(cyclopentadienyl)ruthenium was used as a main guest to fill the channels. X-ray diffraction confirmed inclusion formation, resulting in an incommensurate host-guest system. EPR spectra were measured using prismatic single crystals oriented to have
B
o
either parallel to the channel axis
c
or at any angle in between
c
and the perpendicular direction. Temperature-dependent spectra were recorded down to 80 K. The analysis revealed two types of paramagnetic guest entities,
i.e.
VBM (I) and VBM (II). Both showed dynamical effects due to a reorientational motion. VBM (I) is confined to show a molecular axis
z
distributed around
c
by a small angle (± 1.25°), whereas for VBM (II) the distribution is completely disordered. The reorientational motions are frozen at low temperature giving for VBM (II) a powder-like EPR spectrum. Analysing EPR intensities allowed us to conclude that the ratio of (I)/(II) species is of the order of 1.5.
Electron paramagnetic resonance (EPR) was applied to study rotational disorder of bis-(mesitylene)-vanadium (VBM,
S
= ½) diluted in the channels of 2,4,6-tris(4-Br-phenoxy)-1,3,5-triazine filled with a Ru complex. Two different sets of VBM's molecules show different orientational distribution and mobility.