Group 6 Metal Complexes of the η⁵-Pentamethyl[60]fullerene

A molybdenum pentamethyl[60]fullerene bromo tricarbonyl complex, Mo(η5-C60Me5)Br(CO)3 (3), was successfully synthesized by the reaction of C60Me5Br (2) with Mo(CO)3(EtCN)3. Treatment of 3 with I2 afforded an iodo complex, Mo(η5-C60Me5)I(CO)3 (4). The reaction employing C60Me5K (5) prepared from C60Me5H (1) and KH, followed by treatment with Mo(CO)3(EtCN)3 and then Diazald, gave a nitrosyl complex, Mo(η5-C60Me5)(NO)(CO)2 (6). Complex 6 was converted to a molybdenum(IV) complex, Mo(η5-C60Me5)Cl2(NO)(CO) (7), by the reaction with PCl5. A molybdenum(VI) complex, Mo(η5-C60Me5)O2Br (8), was obtained by exposure of 3 in air. Tungsten- and chromium-nitrosyl complexes, W(η5-C60Me5)(NO)(CO)2 (9) and Cr(η5-C60Me5)(NO)(CO)2 (10), were synthesized similarly to 6. Complex 10 gave a dithiocarbonate complex, Cr(η5-C60Me5)(η5-S2COEt)(NO) (11) through the reaction among 10, ethanol, and carbon disulfide. Compounds 1, 3, 4, 6, 8, and 11 were characterized by X-ray crystallography.