Reduction of Dinitrogen to Planar Bimetallic M₂(μ<i>-</i>η²:<i>η</i>²-N₂) Complexes of Y, Ho, Tm, and Lu Using the K/Ln[N(SiMe₃)₂]₃ Reduction System

The reaction of Ln[N(SiMe3)2]3 with K under N2 in THF forms the dinitrogen complexes {[(Me3Si)2N]2(THF)Ln}2(μ-η2:η2-N2) (Ln = Y, Ho, Tm, and Lu) previously available only for lanthanides with highly reducing divalent states, that is, Tm, Dy, and Nd. The Y and Lu complexes are the first diamagnetic complexes of this type. The Ln2N2 moiety is planar, and the 1.268(3) and 1.285(4) Å NN distances in these complexes are consistent with the presence of (N2)2-.在氮气氛围下，于四氢呋喃(THF)中，Ln[N(SiMe3)2]3与金属钾发生反应，生成了双核氮桥联配合物{[(Me3Si)2N]2(THF)Ln}2(μ-η2:η2-N2)（其中Ln为钇(Y)、钬(Ho)、铥(Tm)以及镥(Lu)）；这类配合物此前仅能通过还原性极强的二价镧系元素（即铥(Tm)、镝(Dy)和钕(Nd)）制备得到。该类配合物中的钇(Y)与镥(Lu)衍生物为此类首例抗磁配合物。此类配合物中的Ln2N2结构单元呈平面构型，其对应的1.268(3)与1.285(4)埃(Å)的N-N键长，与二价氮阴离子(N2)2-的存在形式相符。