Kapre Ruta R, Bothe Eberhard, Weyhermüller Thomas, DeBeer George Serena, Wieghardt Karl
Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
Inorg Chem. 2007 Jul 9;46(14):5642-50. doi: 10.1021/ic700600r. Epub 2007 Jun 14.
The reaction of 3 equiv of the ligand 2-mercapto-3,5-di-tert-butylaniline, H2[LN,S], or 3,5-di-tert-butyl-1,2-benzenedithiol, H2[LS,S], with 1 equiv of [MoO2(acac)2] or WCl6 (acac=acetonylacetate(1-)) in methanol or CCl4 afforded the diamagnetic neutral complexes [MoV(LN,S)2(LN,S)]0 (1), [MoV(LS,S)2(LS,S)] (2), and [WV(LS,S)2(LS,S)] (3), where (LN,S)- and (LS,S)- represent monoanionic pi-radical ligands (Srad=1/2), which are the one-electron oxidized forms of the corresponding closed-shell dianions (LN,S)2- and (LS,S)2-. Complexes 1-3 are trigonal-prismatic members of the electron-transfer series [ML3]z (z=0, 1-, 2-). Reaction of 2 and 3 with N(n-Bu)4 in CH2Cl2 under anaerobic conditions afforded paramagnetic crystalline [N(n-Bu)4][MoV(LS,S)3] (4) and [N(n-Bu)4][WV(LS,S)3] (5). Complexes 1-5 have been characterized by X-ray crystallography. S K-edge X-ray absorption and infrared spectroscopy prove that a pi-radical ligand (LS,S)- is present in neutral 2 and 3, whereas the monoanions [MV(LS,S)3]- contain only closed-shell dianionic ligands. These neutral species have previously been incorrectly described as [MVI(L)3]0 complexes with a MoVI or WVI (d0) central metal ion; they are, in fact MV (d1) (M=Mo, W) species: [MoV(LS,S)2(LS,S)] and [WV(LS,S)2(LS,S)] with a diamagnetic ground state St=0, which is generated by intramolecular, antiferromagnetic coupling between the MV (d1) central ion (SM=1/2) and a ligand pi radical (L*S,S)- (Srad=1/2).
在甲醇或四氯化碳中，3当量的配体2-巯基-3,5-二叔丁基苯胺（H2[LN,S]）或3,5-二叔丁基-1,2-苯二硫醇（H2[LS,S]）与1当量的[MoO2(acac)2]或WCl6（acac = 乙酰丙酮阴离子(1-)）反应，得到抗磁性中性配合物[MoV(LN,S)2(LN,S)]0（1）、[MoV(LS,S)2(LS,S)]（2）和[WV(LS,S)2(LS,S)]（3），其中(LN,S)-和(LS,S)-代表单阴离子π-自由基配体（Srad = 1/2），它们是相应闭壳双阴离子(LN,S)2-和(LS,S)2-的单电子氧化形式。配合物1 - 3是电子转移系列[ML3]z（z = 0, 1-, 2-）的三角棱柱成员。在厌氧条件下，2和3与N(n-Bu)4在二氯甲烷中反应，得到顺磁性晶体[N(n-Bu)4][MoV(LS,S)3]（4）和[N(n-Bu)4][WV(LS,S)3]（5）。配合物1 - 5已通过X射线晶体学表征。硫K边X射线吸收和红外光谱证明中性的2和3中存在π-自由基配体(LS,S)-，而单阴离子[MV(LS,S)3]-仅包含闭壳双阴离子配体。这些中性物种以前被错误地描述为具有MoVI或WVI（d0）中心金属离子的[MVI(L)3]0配合物；实际上它们是MV（d1）（M = Mo，W）物种：[MoV(LS,S)2(LS,S)]和[WV(LS,S)2(LS,S)]，基态为抗磁性St = 0，这是由MV（d1）中心离子（SM = 1/2）与配体π自由基(L*S,S)-（Srad = 1/2）之间的分子内反铁磁耦合产生的。
