Synthesis of Functional Organometallic Complexes Involving a Pentahaptofullerene Ligand

五苯基化的富勒烯阴离子C_<60>Ph_5-是通过有机铜试剂在C_<60>上加成五倍得到的，它的金属配合物是一类新的环戊二烯衍生物，可以通过母体化合物的去质子化来制备。C_<60>分子中的12个五边形中有1个与C_<60>分子中剩余的50个sp^2碳原子被周围的5个带有苯基的sp3碳原子所隔离。先前的x射线晶体学研究揭示了五个苯基在环戊二烯基（Cp）部分周围形成的高度独特的空腔结构，但未能提供这些独特分子的电子性质信息。在本研究项目中，我们进行了ab-initio分子轨道计算和电化学实验，得到了存在内腔同共轭的证据，即在C_<60> ph_5和C_<60>Ph_5H中，上部Cp和下部C_<50>基团通过C_<60>笼内部发生电子相互作用。我们还发现，C_<70>与一种器官铜试剂反应得到了三加成产物[C_< 70> Ar_3H, Ar = 4-CF_3-C_6H_4]，其亚结构为3个sp^3碳。三加合物与金属醇氧化物脱质子生成相应的金属配合物C_<70>Ar_3M [M=K, Tl]。从头算分子轨道计算和x射线衍射研究结果表明，C_<70>Ar_3-在C_<70>Ar_3-中与金属的配位是eta^5-独立基，而不是eta^3-配位体。

The pentaphenylated fullerene anion C_<60>Ph_5-, which is obtained through the five-fold addition of an organocopper reagent to C_<60>, and its metal complexes represent a new class of cyclopentadiene derivatives, which can be prepared through deprotonation of the parent compond. One out of twelve pentagons in C_<60> is isolated from the remaining 50 sp^2 carbon atoms of the C_<60> molecule by five surrounding sp3 carbon atoms each bearing a phenyl group. The previous X-ray crystallographic studies revealed the highly unique cavity structure formed around the cyclopentadienyl (Cp) moiety by the five phenyl groups, but failed to give us information on the electronic properties of these unique molecules. In this research project, we have carried out ab-initio molecular orbital calculations and electrochemical experiments and obtained evidence that there is endohedral homoconjugation, that is, an electronic interaction between the upper Cp and the lower C_<50> moiety in C_<60>Ph_5-and C_<60>Ph_5H through inside of the C_<60> cage.We also found that the reaction of C_<70> with an organ ocopper reagent gives a trisaddition product [C_<7O>Ar_3H, Ar = 4-CF_3-C_6H_4] with an indene-like substructure flanked by the three sp^3 carbons in a quantitative yield. The trisadduct was deprotonated with metal alkoxides to form the corresponding metal complexes C_<70>Ar_3M [M=K, Tl]. The results of ab initio molecular orbital calculations and X-ray diffraction study suggested that C_<70>Ar_3- coordinates to the metal as an eta^5-indenylide rather than a eta^3-ligand in C_<7O>Ar_3M.