Laboratoire de Chimie et Physique Quantiques, Université de Toulouse 3, 118 route de Narbonne, 31062 Toulouse cedex 06, France.
J Am Chem Soc. 2013 Feb 27;135(8):3017-26. doi: 10.1021/ja308146e. Epub 2013 Feb 15.
This paper reports the experimental and theoretical investigations of two trigonal bipyramidal Ni(II) complexes, Ni(Me(6)tren)Cl (1) and Ni(Me(6)tren)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.
本文报道了两个三角双锥镍（II）配合物[Ni(Me6tren）Cl]（ClO4）（1）和[Ni(Me6tren）Br]（Br）（2）的实验和理论研究。单晶 1 的高磁场、高频电子顺磁共振谱研究表明，其具有巨大的单轴各向异性磁各向异性，实验测得的 D（expt）值（基自旋态 S = 1的 M（s）= ± 1 和 M（s）= 0 分量之间的能量差）估计在-120 至-180 cm-1之间。理论研究表明，对于理想的三角双锥镍（II）配合物，轨道简并导致一级自旋轨道耦合，导致 M（s）= ± 1 和 M（s）= 0 分量分裂约-600 cm-1。尽管 Jahn-Teller 畸变消除了基态简并并降低了一级自旋轨道相互作用的影响，但 D 值仍然很大。理论和实验结果之间存在很好的一致性（理论 D（ theor ）在-100 至-200 cm-1之间）。
