457063-93-3Relevant academic research and scientific papers
Sigma- versus Pi-coordination in bis-indenyl- and bis-2-methallyl imido complexes of hexavalent molybdenum and tungsten: DF-calculations and crystal structure analysis
Radius, Udo,Sundermeyer, Jrg,Peters, Karl,Von Schnering, Hans Georg
, p. 1226 - 1235 (2008/10/08)
Bis-indenyl and bis-2-methallyl imido complexes [(C9H7)2M(NR)2] (M = Mo, W; R = tert-butyl, mesityl) 1 - 4 and [(H3C-C3H4)2M(NtBu)2] (M = Mo, W) 6, 7 have been prepared starting from [Mo(NtBu)2Cl2] or [M(NR)2Cl2L2] (M = W, R = tBu, L = py; M = Mo, W, R = Mes, L2 = dme) and indenyl lithium or 2-methallyl magnesium bromide, respectively. According to spectroscopic data and the crystal structure of 4 there are two different coordination modes of the indenyl ligands, [(η3C9H7)M(NR)2(η 1-C9H7)], in solution as well as in the solid state. These compounds show fluxional rearrangements in solution, namely σ, π-exchange of η1- and η3-coordinated ligands. Similar behavior has been observed for the 2-methallyl complexes 6 and 7 in solution. In agreement with experimental observations, DF calculations on models of 6 strongly suggest a (σ+π)-coordination mode of the η3-coordinated ligand.
