Conformational Properties of Boron-Bridged Dimethylethylenediamino Bis(boratabenzene) Zirconium(IV) and Iron(II) Complexes
作者:Arthur J. Ashe、Saleem Al-Ahmad、Xiangdong Fang、Jeff W. Kampf
DOI:10.1021/om000861g
日期:2001.2.1
reaction of 14 with ZrCl4 afforded the boron-bridged dimethylethylenediamino bis(boratabenzene) zirconium dichloride complex 8, while reaction of 14 with FeCl2 afforded the corresponding dimethylethylenediamino-bridged iron(II) complex 9. The structures of 8 and 9 were determined by X-ray diffraction. In each case the boratabenzene units are bridged by an approximately C2-symmetric dimethylethylenediamino
1-氯-1- boracyclohexadiene(反应12)与N,N- “二甲基-N,N ” -双(三甲硅烷基)乙-1,2-二胺,随后LDA得到的二锂盐N, “ -双(1-硼烷基苯)-N,N′-二甲基亚乙基-1,2-二胺(14)。14与ZrCl 4的反应提供了硼桥连的二甲基乙二氨基双(硼苯苯)二氯化锆配合物8,而14与FeCl 2的反应提供了相应的二甲基乙二氨基桥连的铁(II)配合物9。8和9的结构通过X射线衍射测定。在每种情况下,硼烷苯单元都被约C 2对称的二甲基乙二胺基桥联,形成8和9个手性。通过2D 1 H NOESY确定对映异构体8的相互转化的势垒为21.2±0.2 kcal / mol,而根据可变温度13 C NMR光谱确定为9的相应势垒为16.9±0.5 kcal / mol。这两个势垒都涉及绕环外ππ键的旋转。与相应的桥联的环戊二烯基络合物10和11进行了比较。