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Endohedral fullerene with μ3-carbido ligand and titanium-carbon double bond stabilized inside a carbon cage.

Research paper by A L AL Svitova, K B KB Ghiassi, C C Schlesier, K K Junghans, Y Y Zhang, M M MM Olmstead, A L AL Balch, L L Dunsch, A A AA Popov

Indexed on: 05 Apr '14Published on: 05 Apr '14Published in: Nature communications



Abstract

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)-C80 with an icosahedral Ih(7) carbon cage. Single-crystal X-ray diffraction and spectroscopic studies of the compound reveal an unprecedented endohedral cluster with a μ3-carbido ligand and Ti-C double bond. The Ti(IV) in TiLu2C@I(h)-C80 can be reversibly reduced to the Ti(III) state. The Ti = C bonding and Ti-localized lowest unoccupied molecular orbital in TiLu2C@Ih-C80 bear a certain resemblance to titanium alkylidenes. TiLu2C@I(h)-C80 is the first metallofullerene with a multiple bond between a metal and the central, non-metal atom of the endohedral cluster.