The reaction of ytterbium(II) iodide (YbI2) with 4.5 equiv of hexamethylphosphoric triamide (hmpa) in tetrahydrofuran (thf) gave [Yb(hmpa)4(thf)2]I2 (1) as yellow crystals. A similar reaction of SmI2 with hmpa afforded black-purple [SmI2(hmpa)4] (2) after recrystallization from toluene. When 10 equiv of hmpa were used in the reaction with SmI2, [Sm(hmpa)6]I2 (3) was obtained as purple blocks. Complexes 1—3 have been structurally characterized by crystallographic studies. The structural data of these complexes satisfactorily explain the hmpa effects observed in SmI2-promoted reactions, and also provide a guideline for the use of HMPA in these reactions.
在
四氢呋喃(THF)中,
镱碘化物(YbI2)与4.5当量的六甲基
磷酸三胺(HMPa)反应,生成黄色晶体[Yb(HMPa)4(THF)2]I2(1)。
钐碘化物(
SmI2)与HMPa发生类似反应,在
甲苯中重结晶后得到黑紫色[ (HMPa)4](2)。当与 反应时使用10当量的HMPa,得到紫色块状物[Sm(HMPa)6]I2(3)。通过晶体学研究,对1-3号复合物的结构进行了表征。这些复合物的结构数据很好地解释了 促进反应中观察到的HMPa效应,也为在这些反应中使用HMPa提供了指导。