Intramolecular hydrogen exchange among the coordinated methane fragments of Cp2W(H)CH3. Evidence for the formation of a .sigma. complex of methane prior to elimination
Hydrogen/deuterium exchange in alkyl-hydride derivatives of ansa-tungstenocene compounds
作者:Malcolm L.H. Green、Stephen L.J. Conway、Linda H. Doerrer
DOI:10.1016/j.poly.2005.05.004
日期:2005.8
The higher n-alkyl hydrides [W(eta-C5H4)CMe2(eta-C5H4)}(R)H](R = (CH2)(n)CH3}, n = 1-4) and the isotopically labelled analogues [W(eta-C5D4)C(CD3)(2)(eta-C5D4)}(R)D], (R = (CH2)(n)CH3} (n = 1-4) and [W(eta-C5H4)CMe2(eta-C5H4)} CD2CD3}H] have been prepared and the hydrogen/deuterium exchange processes under thermal conditions in these compounds have been investigated by NMR spectroscopy. In every case of all the possible alkyl hydrogens of the alkyl groups R only H/D exchange with the alpha-CH2 methylene hydrogens was observed. (c) 2005 Elsevier Ltd. All rights reserved.