Journal of Physical Chemistry A, Vol.109, No.42, 9465-9470, 2005
Photoinduced ethane formation from reaction of ethene with matrix-isolated Ti, V, or Nb atoms
The reactions of matrix-isolated Ti, V, or Nb atoms with ethene (C2H4) have been studied by FTIR absorption spectroscopy. Under conditions where the ethene dimer forms, metal atoms react with the ethene dimer to yield matrix-isolated ethane (C2H6) and methane. Under lower ethene concentration conditions (similar to 1:70 ethene/Ar), hydridic intermediates of the types HMC2H3 and H2MC2H2 are also observed, and the relative yield of hydrocarbons is diminished. Reactions of these metals with perdeuterioethene, and equimolar mixtures of C2H4 and C2D4, yield products that are consistent with the production of ethane via a metal atom reaction involving at least two C2H4 molecules. The absence of any other observed products suggests the mechanism also involves production of small, highly symmetric species such as molecular hydrogen and metal carbides. Evidence is presented suggesting that ethane production from the ethene dimer is a general photochemical process for the reaction of excited-state transition-metal atoms with ethene at high concentrations of ethene.