Mantel Claire, Chen Hongyu, Crabtree Robert H, Brudvig Gary W, Pécaut Jacques, Collomb Marie-Noëlle, Duboc Carole
High Magnetic Field Laboratory of Grenoble, HMFL, CNRS-MPI UPR 5021 BP 166, F 38042 Grenoble 9, France.
Chemphyschem. 2005 Mar;6(3):541-6. doi: 10.1002/cphc.200400484.
The isolation, structural characterization, and electronic properties of two six-coordinated chloromanganese (III) complexes, [Mn(terpy)(Cl)3] (1) and [Mn(Phterpy)(Cl)3] (2), are reported (terpy = 2,2':6'2"-terpyridine, Phterpy = 4'-phenyl-2,2':6',2"-terpyridine). These complexes complement a series of mononuclear azide and fluoride Mn(lll) complexes synthesized with neutral N-tridentate ligands, [Mn(L)(X)3] (X = F- or N3 and L = terpy or bpea [N,N-bis(2-pyridylmethyl)-ethylamine)], previously described. Similar to these previous complexes, 1 and 2 exhibit a Jahn-Teller distortion of the octahedron, characteristic of a high-spin Mn(III) complex (S = 2). The analysis of the crystallographic data shows that, in both cases, the manganese ion lies in the center of a distorted octahedron characterized by an elongation along the tetragonal axis. Their electronic properties were investigated by multifrequency EPR (190-475 GHz) performed in the solid state at different temperatures (5-15 K). This study confirms our previous results and further shows that: i) the sign of D is correlated with the nature of the tetragonal distortion; ii) the magnitude of D is not sensitive to the nature of the anions in our series of rhombic complexes, contrary to the porphyrinic systems; iii) the [E/D] values (0.124 for 1 and 0.085 for 2) are smaller compared to those found for the [Mn(L)(X)3] complexes (in the range of 0.146 to 0.234); and iv) the E term increases when the ligand-field strength of the equatorial ligands decreases.
报道了两种六配位氯锰（III）配合物[Mn(terpy)(Cl)₃]（1）和[Mn(Phterpy)(Cl)₃]（2）的分离、结构表征及电子性质（terpy = 2,2':6'2"-三联吡啶，Phterpy = 4'-苯基-2,2':6',2"-三联吡啶）。这些配合物补充了一系列先前描述的用中性N-三齿配体合成的单核叠氮化物和氟化物Mn(III)配合物[Mn(L)(X)₃]（X = F⁻或N₃且L = terpy或bpea [N,N-双(2-吡啶基甲基)-乙胺]）。与这些先前的配合物类似，1和2表现出八面体的 Jahn-Teller 畸变，这是高自旋Mn(III)配合物（S = 2）的特征。晶体学数据分析表明，在这两种情况下，锰离子位于以沿四方轴伸长为特征的畸变八面体的中心。通过在不同温度（5 - 15 K）下对固态进行的多频EPR（190 - 475 GHz）研究了它们的电子性质。这项研究证实了我们先前的结果，并进一步表明：i）D的符号与四方畸变的性质相关；ii）与卟啉体系相反，D的大小对我们这一系列菱形配合物中阴离子的性质不敏感；iii）[E/D]值（对于1为0.124，对于2为0.085）比[Mn(L)(X)₃]配合物的值（在0.146至0.234范围内）小；iv）当赤道配体的配体场强度降低时，E项增加。
