Ruthenium(II) Complexes of Pentamethylated [60]Fullerene. Alkyl, Alkynyl, Chloro, Isocyanide, and Phosphine Complexes

A ruthenium chloro dicarbonyl complex bearing a pentamethylated [60]fullerene ligand,
Ru(η5-C60Me5)Cl(CO)2 (1), was prepared by the reaction of [RuCl2(CO)3]2 with C60Me5K in
THF. A variety of ligand exchange reactions involving the carbonyl and chloro ligands took
place on the ruthenium metal attached directly to the exterior of the fullerene framework.
Treatment of 1 with a phosphine ligand afforded phosphine complexes, Ru(η5-C60Me5)Cl(PEt3)(CO) (2) and Ru(η5-C60Me5)Cl(PPh3)(CO) (3). Isocyanide complexes, Ru(η5-C60Me5)Cl(tBuNC)(CO) (4), Ru(η5-C60Me5)Cl(MeNC)(CO) (5), and Ru(η5-C60Me5)Cl(XylNC)(CO) (6; Xyl
= 2,6-dimethylphenyl), were also prepared by reaction with an appropriate isocyanide ligand,
while the use of a large excess of the same isocyanides gave bis(isocyanide)complexes, Ru(η5-C60Me5)Cl(tBuNC)2 (7) and Ru(η5-C60Me5)Cl(XylNC)2 (8). Metathetic replacement of the
halogen atom on the transition-metal fullerene complexes was achieved:  methyl and
(trimethylsilyl)methyl Grignard reagents reacted with 1 to give a methyl complex, Ru(η5-C60Me5)Me(CO)2 (9), and a (trimethylsilyl)methyl complex, Ru(η5-C60Me5)(CH2SiMe3)(CO)2
(10), respectively. Alkynylation reactions gave various alkynyl complexes, Ru(η5-C60Me5)(C⋮CPh)(CO)2 (12), Ru(η5-C60Me5)(C⋮CnBu)(CO)2 (13), Ru(η5-C60Me5)(C⋮CSiMe3)(CO)2 (14),
and Ru(η5-C60Me5)(C⋮CH)(CO)2 (15). X-ray single-crystal structure analyses and electrochemical studies of a series of new ruthenium fullerene complexes were performed.