Phosphonothioate hydrolysis through selective P-S bond scission by molybdenum metallocenes

L. Y. Kuo, C. P. Smith, A. R. Head, Dennis L Lichtenberger

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

We present an overview of the phosphonothioate hydrolytic chemistry promoted by molybdenum organometallics as well as new results on solvent effects. The metallocene bis(η 5-cyclopentadienyl) molybdenum(IV) dichloride (Cp2MoCl2 Cp=η5-C 5H5) and the methylated analog, (CH3Cp) 2MoCl2 hydrolyzes the compound O,S-diethyl phenylphosphonothioate (DEPP) whose core functional group mimics the neurotoxin VX. This is one of the few examples of phosphonothioate degradation yielding exclusively the desired P-S bond scission under mild aqueous conditions (pH 7, 25°C). The solvent composition affects the monomer-dimer equilibrium of aquated molybdocenes which in turn dictates the rate of DEPP hydrolysis. Kinetic and equilibrium results are presented to show that the monomer is the active species. Moreover, photoelectron spectroscopy data indicate that while the methylated (CH3Cp)2MoCl2 has a higher monomer concentration compared to Cp2MoCl2, the former has a diminished electrophilic molybdenum center that is key in phosphonothioate hydrolysis.

Original languageEnglish (US)
Pages (from-to)283-295
Number of pages13
JournalMain Group Chemistry
Volume9
Issue number3-4
DOIs
Publication statusPublished - 2010

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Keywords

  • DEPP
  • Diphenylphosphonothioate
  • Hydrolysis
  • Metallocene
  • Molybdenum metallocene
  • Monomer-dimer equilibrium
  • Phosphonothioate

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Organic Chemistry
  • Materials Chemistry

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