Surprisingly great difference in reactivity depending upon the ring size: Solvolysis and molecular structure study of some N-trimethylsilylated cyclic ureas

Roland Szalay, Gábor Pongor, Veronika Harmat, Zsolt Böcskei, Dezso Knausz

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11 Citations (Scopus)


The molecular structure of N-trimethylsilylated five- (1a-c), six- (2a,b) and seven-membered (3) cyclic ureas was studied by single crystal X-ray diffraction method and quantum chemical calculations. Solvolysis rate constants of compounds in n-octanol/tetrahydrofuran mixtures were determined by gas chromatography. An alternative sampling method eliminating the effect of the hot injector was also developed in the rate measurement of 2a. The half-lives of the five-membered rings (1a,b) were found to be at least three orders of magnitude higher than those of the six- (2a,b) and seven- (3) membered ones. Relationship between the reactivity and the extent of the pseudo- pentacoordination around the silicon centre in reactants was found. The results are in correlation to our simple static (structure-based) predictive model established previously.

Original languageEnglish
Pages (from-to)1498-1506
Number of pages9
JournalJournal of Organometallic Chemistry
Issue number6
Publication statusPublished - Mar 15 2005



  • Pseudo-pentacoordination
  • Reactivity
  • Silyl
  • Solvolysis
  • Urea

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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