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  • Effect of magnetic fields on the methyl rotation in a paramagnetic cobalt( ii ) complex. Quasielastic neutron scattering studies
Title: Effect of magnetic fields on the methyl rotation in a paramagnetic cobalt( ii ) complex. Quasielastic neutron scattering studies
Molecular dynamics is a fundamental property of metal complexes. These dynamic processes, especially for paramagnetic complexes under external magnetic fields, are in general not well understood. Quasielastic neutron scattering (QENS) in 0–4 T magnetic fields has been used to study the dynamics of Co(acac) 2 (D 2 O) 2 ( 1-d4 , acac = acetylacetonate). At 80–100 K, rotation of the methyl groups on the acac ligands is the dominant dynamical process. This rotation is slowed down by the magnetic field increase. Rotation times at 80 K are 5.6(3) × 10 −10 s at 0 T and 2.04(10) × 10 −9 s at 4 T. The QENS studies suggest that methyl groups in these paramagnetic Co( ii ) molecules do not behave as isolated units, which is consistent with results from earlier magnetic susceptibility studies indicating the presence of intermolecular interactions. DFT calculations show that unpaired electron spin density in 1 is dispersed to the atoms of both acac and H 2 O ligands. Methyl torsions in 1-d4 have also been observed at 5–100 K in inelastic neutron spectroscopy (INS). The QENS and INS results here help understand the dynamics of the compound in the solid state.  more » « less
Award ID(s):
1633870
PAR ID:
10099989
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
20
Issue:
32
ISSN:
1463-9076
Page Range / eLocation ID:
21119 to 21126
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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