Synthesis and Physical Properties of Pentamethylmanganocene, (C<sub>5</sub>Me<sub>5</sub>)Mn(C<sub>5</sub>H<sub>5</sub>), and the Inclusion Compounds [(C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>Yb]<sub>2</sub>[(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>M] (Where M = V, Cr, Fe, Co)
作者:Marc D. Walter、Carol J. Burns、Phillip T. Matsunaga、Michael E. Smith、Richard A. Andersen
DOI:10.1021/acs.organomet.6b00554
日期:2016.10.24
The inclusion complexes of composition (Cp*Yb-2)(2)(Cp2M) (M = V, Cr, Fe, and Co; Cp* = eta(5)-C5Me5; Cp = eta(5)-C5H5) are isolated in the solid state. The crystal structure of one of them, M = Co, shows that the Cp2Co metallocene is sandwiched between two Cp*Yb-2 metallocenes with two long Yb center dot center dot center dot C bond distances of 2.914(6) angstrom, one from each of the Cp rings of Cp2Co. When M = Mn and Ni are used, the ring exchange products, Cp*MCp, are isolated along with Cp*YbCp, a hydrocarbon-insoluble green solid isolated as the thf adduct. This Cp for Cp* exchange reaction is the only currently available synthesis for the low-spin pentamethylmanganocene and the pentamethylytterbocene. The crystal structures and magnetic and related physical properties of Cp*MCp, M = Mn, Co, and Ni (Organometallics 1985, 4, 1680), are reported and analyzed. The origin of the different relative rates of Cp* for Cp ring exchange is traced to the kinetic lability resulting from the (e(1g)*)(2) electronic structure of Cp2M, M = Mn and Ni.