Mantel Claire, Hassan Alia K, Pécaut Jacques, Deronzier Alain, Collomb Marie-Noëlle, Duboc-Toia Carole
Grenoble High Magnetic Field Laboratory, MPI-CNRS UPR 5021, BP 166, 38042 Grenoble Cedex 9, France.
J Am Chem Soc. 2003 Oct 8;125(40):12337-44. doi: 10.1021/ja034652+.
The isolation, structural characterization and electronic properties of three new six-coordinated Mn(III) complexes, [Mn(bpea)(F)(3)] (1), [Mn(bpea)(N(3))(3)] (2), and [Mn(terpy)(F)(3)] (3) are reported (bpea = N,N-bis(2-pyridylmethyl)-ethylamine; terpy = 2,2':6',2' '-terpyridine). As for [Mn(terpy)(N(3))(3)] (4) (previously described by Limburg J.; Vrettos J. S.; Crabtree R. H.; Brudvig G. W.; de Paula J. C.; Hassan A.; Barra A-L.; Duboc-Toia C.; Collomb M-N. Inorg. Chem. 2001, 40, 1698), all these complexes exhibit a Jahn-Teller distortion of the octahedron characteristic of high-spin Mn(III) (S = 2). The analysis of the crystallographic data shows an elongation along the tetragonal axis of the octahedron for complexes 1 and 3, while complex 2 presents an unexpected compression. The electronic properties were investigated using a high-field and high-frequency EPR study performed between 5 and 15 K (190-575 GHz). The spin Hamiltonian parameters determined in solid state are in agreement with the geometry of the complexes observed in the crystal structures. A negative D value found for 1 and 3 is related to the elongated tetragonal distortion, whereas the positive D value determined for 2 is in accordance with a compressed octahedron. The high E/D values, in the range of 0.103 to 0.230 for all complexes, are correlated with the highly distorted geometry present around the Mn(III) ion. HF-EPR experiments were also performed on complex 1 in solution and show that the D value is the only spin Hamiltonian parameter which is slightly modified compared to the solid state (D = -3.67 cm(-1) in solid state; D = -3.95 cm(-1) in solution).
报道了三种新型六配位锰（III）配合物[Mn(bpea)(F)(3)] (1)、[Mn(bpea)(N(3))(3)] (2) 和 [Mn(terpy)(F)(3)] (3) 的分离、结构表征及电子性质（bpea = N,N-双(2-吡啶甲基)-乙胺；terpy = 2,2':6',2''-三联吡啶）。至于[Mn(terpy)(N(3))(3)] (4)（先前由林堡J.；弗雷托斯J. S.；克拉布特里R. H.；布鲁德维格G. W.；德保拉J. C.；哈桑A.；巴拉A-L.；迪博克-托亚C.；科隆布M-N.在《无机化学》2001年，40卷，1698页中描述），所有这些配合物都表现出高自旋锰（III）（S = 2）所特有的八面体的 Jahn-Teller 畸变。晶体学数据分析表明，配合物1和3的八面体沿四方轴伸长，而配合物2呈现出意外的压缩。使用在5至15 K（190 - 575 GHz）之间进行的高场和高频电子顺磁共振（EPR）研究对电子性质进行了研究。在固态中测定的自旋哈密顿参数与晶体结构中观察到的配合物几何形状一致。配合物1和3的负D值与伸长的四方畸变有关，而配合物2测定的正D值与压缩的八面体一致。所有配合物的高E/D值在0.103至0.230范围内，与锰（III）离子周围高度畸变的几何形状相关。还对配合物1在溶液中进行了高频电子顺磁共振实验，结果表明D值是唯一与固态相比略有改变的自旋哈密顿参数（固态中D = -3.67 cm(-1)；溶液中D = -3.95 cm(-1)）。
