Reactivity of the Substituted Butadienes, Isoprene and Myrcene, with Decamethylsamarocene
2001; American Chemical Society; Volume: 20; Issue: 26 Linguagem: Inglês
10.1021/om010729w
ISSN1520-6041
AutoresWilliam J. Evans, Dimitrios G. Giarikos, C.B. Robledo, Voon S. Leong, Joseph W. Ziller,
Tópico(s)Coordination Chemistry and Organometallics
ResumoThe interaction of the substituted diene monomers isoprene, C5H8, and myrcene, C10H16, with a lanthanide was probed by examining their chemistry with (C5Me5)2Sm. CH2CHC(Me)CH2 reacts with (C5Me5)2Sm to form the bimetallic [(C5Me5)2Sm]2[μ-η2:η4-CH2CHC(Me)CH2], 1. Both (C5Me5)2Sm components in 1 exhibit trivalent metrical parameters. One Sm is oriented toward all four of the dienyl carbon atoms at distances of 2.604(9)−2.799(8) Å, and the other Sm interacts with only two carbons at distances of 2.544(9) and 2.674(9) Å. CH2CHC(CH2)CH2CH2CHCMe2 reacts with (C5Me5)2Sm to form [(C5Me5)2Sm]2[μ-η2:η4-CH2CHC(CH2)CH2CH2CHCMe2], 2, which is similar in structure to 1. The double bond of the pendant olefinic substituent attached to the diene in myrcene does not coordinate. The structures of 1 and 2 are compared to the (C5Me5)2Sm/PhC⋮CPh bimetallic reaction product [(C5Me5)2Sm]2[μ-η1:η1-PhCCPh], 3, which also contains two (C5Me5)2Sm units attached to an unsaturated hydrocarbon, but has equivalent trivalent (C5Me5)2Sm units. Each Sm in 3 interacts with the reduced (PhC⋮CPh)2- primarily through a 2.52−2.54 Å Sm−C bond, although an ortho phenyl carbon is oriented toward each metal at a distance of >2.96 Å.
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