Anionic ruthenium(II) alkyls with ancillary diene and dienyl ligands: Synthesis and structures of [(eta(2),eta(2)-C7H8)RuMe4](2-) and [(eta(3),eta(2)-C8H11) RuMe3]

摘要

Treatment of the ruthenium(II) diene complexes [(eta(2),eta(2)-nbd) RuCl2](n) or [(eta(2),eta(2)-cod)RuCl2](n) with 4 equiv. of methyllithium in the presence of N,N,N', N'-tetramethylethylenediamine (tmed) yields the methyl complexes [Li(tmed)](2)[(eta(2),eta(2)-nbd)RuMe4] (1) and [Li(tmed)](2)[(eta(3),eta(2)-C8H11)RuMe3] (2), respectively, where nbd = norbornadiene and cod = 1,5-cyclooctadiene. In the latter compound, the cyclooctadiene ligand has been deprotonated to afford a eta(3),eta(2)-1,2,3: 5,6-cyclooctadienyl group. Both complexes were studied by H-1 and C-13{H-1} NMR spectroscopy, and the crystal structure of 2 was determined. One lithium atom in 2 is four-coordinate and bridges between one ruthenium-bound methyl group and one of the wingtip allylic carbon atoms in the eta(3),eta(2)-C8H11 ligand. The other lithium atom is five-coordinate, and forms contacts with the other two Ru-Me groups and with the other wingtip carbon atom of the allyl unit. (c) 2007 Elsevier B. V. All rights reserved.