Giant Ising-type magnetic anisotropy in trigonal bipyramidal Ni(II) complexes: experiment and theory.
This paper reports the experimental and theoretical investigations of two trigonal bipyramidal Ni(II) complexes, [Ni(Me(6)tren)Cl](ClO(4)) (1) and [Ni(Me(6)tren)Br](Br) (2). High-field, high-frequency electron paramagnetic resonance spectroscopy performed on a single crystal of 1 shows a giant uniaxial magnetic anisotropy with an experimental D(expt) value (energy difference between the M(s) = ± 1 and M(s) = 0 components of the ground spin state S = 1) estimated to be between -120 and -180 cm(-1). The theoretical study shows that, for an ideally trigonal Ni(II) complex, the orbital degeneracy leads to a first-order spin-orbit coupling that results in a splitting of the M(s) = ± 1 and M(s) = 0 components of approximately -600 cm(-1). Despite the Jahn-Teller distortion that removes the ground term degeneracy and reduces the effects of the first-order spin-orbit interaction, the D value remains very large. A good agreement between theoretical and experimental results (theoretical D(theor) between -100 and -200 cm(-1)) is obtained.
Laboratoire de Chimie et Physique Quantiques, Université de Toulouse 3, 118 route de Narbonne, 31062 Toulouse cedex 06, France.
Renaud
R
Ruamps
Rémi
R
Maurice
Luke
L
Batchelor
Martial
M
Boggio-Pasqua
Régis
R
Guillot
Anne Laure
AL
Barra
Junjie
J
Liu
El-Eulmi
el-E
Bendeif
Sébastien
S
Pillet
Stephen
S
Hill
Talal
T
Mallah
Nathalie
N
Guihéry