Department of Chemistry, University of California, Irvine, California 92697, USA.
Dalton Trans. 2018 Dec 11;47(48):17285-17290. doi: 10.1039/c8dt03890b.
Although attempts to make the Y(ii) complex, (CpMe3Y)1- (CpMe = C5H4Me), by reduction of CpMe3Y with potassium were unsuccessful and the products of potassium reduction of CpMe3Ln for Ln = La and Pr led to ring-opening reduction of THF, we report that crystallographically-characterizable Ln(ii) complexes of Tb and Ho can be isolated by reducing CpMe3Ln(THF) with KC8 in THF in the presence of 18-crown-6 (18-c-6). X-ray crystallography revealed that these complexes are isolated with a methylcyclopentadienide inverse sandwich countercation: [(18-c-6)K(μ-CpMe)K(18-c-6)][CpMe3Ln] (Ln = Tb, Ho). Although reduction of CpMe3Ln with potassium in the presence of the 2.2.2-cryptand (crypt) chelate has not generally provided fully-characterizable, crystalline products, in the case of Dy, crystals of [K(crypt)][CpMe3Dy] could be isolated.
虽然用钾还原 CpMe3Y 来制备 Y(ii)配合物（CpMe3Y）1-（CpMe = C5H4Me）的尝试并未成功，而且 CpMe3Ln（Ln = La 和 Pr）的钾还原产物导致了 THF 的开环还原，但我们报告说，通过在 THF 中用 KC8 还原 CpMe3Ln（THF），并在 18-冠-6（18-c-6）存在下，可以分离出 Tb 和 Ho 的可结晶表征的 Ln(ii)配合物。X 射线晶体学表明，这些配合物是用甲基环戊二烯基反夹心阳离子分离的：[(18-c-6)K(μ-CpMe)K(18-c-6)][CpMe3Ln]（Ln = Tb，Ho）。虽然用钾在 2.2.2-穴醚（crypt）螯合物存在下还原 CpMe3Ln 通常不能提供完全可表征的结晶产物，但在 Dy 的情况下，可以分离出[K(crypt)][CpMe3Dy]的晶体。
