乙烯与基质隔离的钛、钒或铌原子反应产生的光致乙烷生成。

Photoinduced ethane formation from reaction of ethene with matrix-isolated Ti, V, or Nb atoms.

作者信息

Thompson Matthew G K, Parnis J Mark

机构信息

Departments of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, and Trent University, Peterborough, Ontario K9J 7B8, Canada.

出版信息

J Phys Chem A. 2005 Oct 27;109(42):9465-70. doi: 10.1021/jp0447542.

DOI:10.1021/jp0447542

PMID:16866395

Abstract

The reactions of matrix-isolated Ti, V, or Nb atoms with ethene (C(2)H(4)) 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 (C(2)H(6)) and methane. Under lower ethene concentration conditions ( approximately 1:70 ethene/Ar), hydridic intermediates of the types HMC(2)H(3) and H(2)MC(2)H(2) are also observed, and the relative yield of hydrocarbons is diminished. Reactions of these metals with perdeuterioethene, and equimolar mixtures of C(2)H(4) and C(2)D(4), yield products that are consistent with the production of ethane via a metal atom reaction involving at least two C(2)H(4) 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.

摘要

通过傅里叶变换红外吸收光谱研究了基质隔离的钛、钒或铌原子与乙烯（C₂H₄）的反应。在乙烯二聚体形成的条件下，金属原子与乙烯二聚体反应生成基质隔离的乙烷（C₂H₆）和甲烷。在较低乙烯浓度条件下（乙烯/氩约为1:70），还观察到HMC₂H₃和H₂MC₂H₂类型的氢化中间体，并且烃类的相对产率降低。这些金属与全氘代乙烯以及C₂H₄和C₂D₄的等摩尔混合物的反应产生的产物与通过涉及至少两个C₂H₄分子的金属原子反应生成乙烷的情况一致。未观察到任何其他产物表明该机制还涉及生成诸如分子氢和金属碳化物等小的、高度对称的物种。有证据表明，在高浓度乙烯下，乙烯二聚体生成乙烷是激发态过渡金属原子与乙烯反应的一般光化学过程。