Hydrogen/deuterium exchange in alkyl-hydride derivatives of ansa-tungstenocene compounds

The higher deuterated n-alkyl hydrides [W{(η-C5H4)CMe2(η-C5H4)}(R)H](R = {(CH2)nCH3}, n = 1-4) and [W{(η-C5H4)CMe2(η-C5H4)}{CD2CD3}H] undergo hydrogen/deuterium exchange processes under thermal conditions and in every case of all the possible alkyl hydrogens of the alkyl groups R only H/D exchange with the α-CH2 methylene hydrogens was observed.