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Reorientational Dynamics of the Dodecahydro-Closo-Codecaborate Anion in Cs2B12H12
Published
Author(s)
Kristina Verdal, Terrence J. Udovic, John J. Rush, Ronald L. Cappelletti, Wei Zhou
Abstract
Rapid reorientational motions of the B12H122- icosahedral anion, a key intermediate in borohydride dehydrogenation, are revealed by quasielastic neutron scattering (QENS) measurements of Cs2B12H12 between 430 K and 530 K. At 430 K, over the range of momentum transfers collected, the elastic incoherent structure factor is consistent with a model for reorientation about a single molecular axis. At temperatures of 480 K and higher, however, the reorientation seems to proceed by dynamically similar, independent jumps about two axes: the three-fold and five-fold rotational axes, preserving crystallographic order. Although neutron vibrational spectra demonstrate that the anion torsional modes soften dramatically with increasing temperature, the QENS-derived activation energy for reorientation clearly shows that the anions are not undergoing random rotational diffusion.
, K.
, Udovic, T.
, Kasianowicz, J.
, Cappelletti, R.
and Zhou, W.
(2011),
Reorientational Dynamics of the Dodecahydro-Closo-Codecaborate Anion in Cs<sub>2</sub>B<sub>12</sub>H<sub>12</sub>, Journal of Physical Chemistry Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=907876
(Accessed October 20, 2025)