Hydrogenolysis of cycloalkanes on a tantalum hydride complex supported on silica and insight into the deactivation pathway by the combined use of 1D solid-state NMR and EXAFS spectroscopies

Franck Rataboul, Mathieu Chabanas, Aimery De Mallmann, Christophe Copéret, Jean Thivolle-Cazat, Jean-Marie Maurice Basset*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Hydrogenolysis of cyclic alkanes is catalysed by [≡SiO)2Ta-H] (1) at 160 °C and leads to lower alkanes and cyclic alkanes including cyclopentane. The turnover number is correlated with the number of carbon atoms of the cyclic alkanes, and therefore while cycloheptane is readily transformed, cyclopentane does not give any product (<1%). The mechanism of ring contraction probably involves carbene de-insertion as a key carbon-carbon bond-cleavage step. The reluctance of cyclopentane to undergo hydrogenolysis was further studied: under the reaction conditions cyclopentane reacts with 1 to give the corresponding cyclopentyl derivative [(≡SiO)2Ta-C5H9] (13), which evolves towards cyclopentadienyl derivative [(≡SiO)2Ta(C5H5)] (14) according to both solid-state NMR and EXAFS spectroscopies. This latter complex is inactive in the hydrogenolysis of alkanes, and therefore the formation of cyclopentane in the hydrogenolysis of various cyclic alkanes is probably responsible for the de-activation of the catalyst by formation of cyclopentadienyl complexes.

Original languageEnglish (US)
Pages (from-to)1426-1434
Number of pages9
JournalChemistry - A European Journal
Volume9
Issue number6
DOIs
StatePublished - Mar 17 2003

Keywords

  • Alkanes
  • EXAFS spectroscopy
  • Hydrogenolysis
  • NMR spectroscopy
  • Tantalum

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Fingerprint

Dive into the research topics of 'Hydrogenolysis of cycloalkanes on a tantalum hydride complex supported on silica and insight into the deactivation pathway by the combined use of 1D solid-state NMR and EXAFS spectroscopies'. Together they form a unique fingerprint.

Cite this