Endohedral fullerene with μ3-carbido ligand and titanium-carbon double bond stabilized inside a carbon cage
Endohedral fullerene with μ3-carbido ligand and titanium-carbon double bond stabilized inside a carbon cage
复制标题
DOI：
10.1038/ncomms4568
复制
发表时间：
2014-04-01
影响因子：
16.6
通讯作者：
Popov, A. A.
中科院分区：
文献类型：
--
作者：
Svitova, A. L.;Ghiassi, K. B.;Popov, A. A.
在本工作之前已知的所有金属富勒烯中，金属原子与内嵌簇中的非金属原子形成单个高极性键。考虑到有机钛化合物的多样性，这对于钛是相当令人惊讶的。在这里，我们表明，在氨，三聚氰胺或甲烷的存在下，混合的钛-镥金属富勒烯的电弧放电合成意外地导致形成具有二十面体I-h（7）碳笼的TiLu 2C @I-h-C-80。单晶X射线衍射和光谱研究表明，该化合物具有一个前所未有的具有μ（3）-碳基配体和Ti-C双键的内配体簇。TiLu 2C @I-h-C-80中的Ti（IV）可以可逆地还原为Ti（III）状态。TiLu 2C @I-h-C-80中的Ti = C键和Ti定域的最低未占分子轨道与烷叉钛有一定的相似性。TiLu 2C @I-h-C-80是第一个在金属和内嵌簇的中心非金属原子之间具有多重键的金属富勒烯。
In all metallofullerenes known before this work, metal atoms form single highly polar bonds with non-metal atoms in endohedral cluster. This is rather surprising for titanium taking into account the diversity of organotitanium compounds. Here we show that the arc-discharge synthesis of mixed titanium-lutetium metallofullerenes in the presence of ammonia, melamine or methane unexpectedly results in the formation of TiLu2C@I-h-C-80 with an icosahedral I-h(7) carbon cage. Single-crystal X-ray diffraction and spectroscopic studies of the compound reveal an unprecedented endohedral cluster with a mu(3)-carbido ligand and Ti-C double bond. The Ti(IV) in TiLu2C@I-h-C-80 can be reversibly reduced to the Ti(III) state. The Ti = C bonding and Ti-localized lowest unoccupied molecular orbital in TiLu2C@I-h-C-80 bear a certain resemblance to titanium alkylidenes. TiLu2C@I-h-C-80 is the first metallofullerene with a multiple bond between a metal and the central, non-metal atom of the endohedral cluster.