THE REACTIVITY OF (C5ME5)2SM(THF)2 WITH BIS(2-PYRIDYL)ETHENE INCLUDING THE SYNTHESIS OF [(C5ME5)2SM]2 (MU-ETA-2-ETA-2-PYCHCHPY) FROM [(C5ME5)2SM]2[MU-ETA-3-ETA-3-1,2,3,4-(PY)4C4H4] BY REDUCTIVE C-C BOND-CLEAVAGE

(C5Me5)2Sm(THF)2, 1, reacts with 1,2-bis(2-pyridyl)ethene to form [(C5Me5)2Sm]2(mu-eta2:eta2-pyCHCHpy), 2, in 80% yield if the reaction stoichiometry is 2.1. Combination of the same reagents in a 1:1 ratio forms [(C5Me5)2Sm]2[mu-eta3:eta3-1,2,3,4-(py)4C4H4], 3, in 78% yield. Both 2 and 3 have been characterized by X-ray crystallography. 2 and 3 can be interconverted by reacting pyCH-CHpy with 2 and by reacting (C5Me5)2Sm(THF)2 with 3. 2 crystallizes from hexane with one hexane per bimetallic unit in the orthorhombic space group Pbcn with a = 14.693(5) angstrom, b = 15.415(3) angstrom, c = 50.173(7) angstrom, V = 11364(5) angstrom3, and Z = 8 for D(calcd) = 1.295 g cm-3. 3 crystallizes from hexane/toluene with one hexane per bimetallic unit in the monoclinic space group C2/c with a = 17.397(4) angstrom, b = 29.338(9) angstrom, c = 15.063(3) angstrom, beta = 123.810(13)-degrees, V = 6388(2) angstrom3, and Z = 4 for D(calcd) = 1.34 g cm-3.