Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
Inorg Chem. 2009 Jul 6;48(13):5829-47. doi: 10.1021/ic900154v.
From the reaction mixture of 3,6-dichlorobenzene-1,2-dithiol, H(2)(Cl(2)-bdt), [CrCl(3)(thf)(3)], and NEt(3) in tetrahydrofuran (thf) in the presence of air, dark green crystals of N(n-Bu)(4)[Cr(Cl(2)-bdt)(3)] (S = 1) (1) were isolated upon addition of [N(n-Bu)(4)]Br. Oxidation of the AsPh(4)(+) salt of 1 with [Fc]PF(6) yielded microcrystals of [AsPh(4)][Cr(Cl(2)-bdt)(3)] (S = (1)/(2)) (2) whereas the reduction of 1 with sodium amalgam produced light green crystals of N-(n-Bu)(4)[Cr(Cl(2)-bdt)(3)].thf (S = (3)/(2)) (3). The corresponding maleonitriledithiolato complexes PPh(4)[Cr(mnt)(3)] (S = 1) (4) and PPh(4)[Cr(mnt)(3)] (S = (3)/(2)) (5) have been synthesized. Isoelectronic manganese complexes of 3 and 5, namely, NEt(4)[Mn(Cl(2)-bdt)(3)] (S = (3)/(2)) (6) and PPh(4)[Mn(mnt)(3)] (S = (3)/(2)) (7), have also been prepared. Complexes 1, 6, and 7 have been characterized by single crystal X-ray crystallography. Complexes 1-7 have been electrochemically studied and their UV-vis and electron paramagnetic resonance spectra (EPR) have been recorded; magnetic properties have been elucidated by temperature-dependent susceptibility measurements. It is shown by chromium K-edge and sulfur K-edge X-ray absorption spectroscopy (XAS) that the oxidation state of the central Cr ion in each compound is the same (+III, d(3)) and that all one-electron redox processes are ligand-based, involving one, two, or three ligand pi radical monoanions. Complexes 6 and 7 possess a Mn(IV) ion with three dianionic ligands. The results have been corroborated by broken symmetry (BS) density functional theoretical (DFT) calculations by using the B3LYP functional. Time-dependent DFT calculations have been performed to calculate the metal and sulfur K-pre-edges. It is suggested that the neutral complexes Cr(dithiolene)(3) S = 0 possess octahedral rather than trigonal prismatic CrS(6) polyhedra. Three ligand pi radicals (S(rad) = (1)/(2)) couple antiferromagnetically to the central Cr(III) ion (d(3)) yielding the observed diamagnetic ground state. It is established that the four members of the Cr(dithiolene)(3) (z = 0, 1-, 2-, 3-) electron transfer series are related by ligand-based one-electron transfer processes; for each of the four members it is shown that they contain a central Cr(III) (d(3)) ion, and the CrS(6) polyhedron is a (distorted) octahedron.
从 3,6-二氯苯-1,2-二硫醇、H(2)(Cl(2)-bdt)、[CrCl(3)(thf)(3)]和 NEt(3)在四氢呋喃（thf）中的反应混合物中，在空气存在下，加入[N(n-Bu)(4)]Br 后，可分离出深绿色晶体[N(n-Bu)(4)] (2)[Cr(Cl(2)-bdt)(3)]（S = 1）(1)。用[Fc]PF(6)氧化 1 的 AsPh(4)(+)盐得到[AsPh(4)][Cr(Cl(2)-bdt)(3)]（S = (1)/(2)）(2)的微晶体，而用钠汞齐还原 1 得到浅绿色晶体[N-(n-Bu)(4)] (3)[Cr(Cl(2)-bdt)(3)]。thf（S = (3)/(2)）(3)。已经合成了相应的马来二硫代二腈配合物[PPh(4)] (2)[Cr(mnt)(3)]（S = 1）(4)和[PPh(4)] (3)[Cr(mnt)(3)]（S = (3)/(2)）(5)。还制备了 3 和 5 的等电子锰配合物，即[NEt(4)] (2)[Mn(Cl(2)-bdt)(3)]（S = (3)/(2））(6)和[PPh(4)] (2)[Mn(mnt)(3)]（S = (3)/(2））(7)。复合物 1、6 和 7 已通过单晶 X 射线晶体学进行了表征。对复合物 1-7 进行了电化学研究，并记录了它们的 UV-vis 和电子顺磁共振谱（EPR）；通过温度相关的磁化率测量阐明了磁性性质。通过铬 K 边和硫 K 边 X 射线吸收光谱（XAS）表明，每个化合物中中心 Cr 离子的氧化态相同（+III，d(3)），并且所有单电子氧化还原过程都是配体基的，涉及一个、两个或三个配体π自由基单阴离子。复合物 6 和 7 具有三个二阴离子配体的 Mn(IV)离子。结果通过使用 B3LYP 函数的破对称（BS）密度泛函理论（DFT）计算得到了证实。进行了时变 DFT 计算以计算金属和硫 K 预边缘。建议中性配合物[Cr(dithiolene)(3)] (0) S = 0 具有八面体而不是三角棱柱形 CrS(6)多面体。三个配体π自由基（S(rad) = (1)/(2)）与中心 Cr(III)离子（d(3)）反铁磁耦合，产生观察到的抗磁性基态。已确定[Cr(dithiolene)(3)] (z)（z = 0、1-、2-、3-）电子转移系列的四个成员通过配体基的单电子转移过程相关；对于四个成员中的每一个，都表明它们含有一个中心 Cr(III)（d(3)）离子，并且 CrS(6)多面体是（扭曲）八面体。
