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DOI: 10.1039/A903057C (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1999, 1683-1688

Formation and characterization of methoxy isothiocyanate (CH3ON[double bond, length half m-dash]C[double bond, length half m-dash]S) and methyl cyanate N-sulfide (CH3OC[triple bond, length half m-dash]N+–S–) as radical cations and neutrals in the gas phase

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Robert Flammang, Pascal Gerbaux, Monique Barbieux-Flammang, Carl Th. Pedersen, Allan T. Bech, Eva H. Mørkved, Ming Wah Wong and Curt Wentrup

Abstract

Dissociative ionization of heterocyclic precursors has provided a convenient source of isomeric [CH3O,C,N,S]˙+ radical cations. Metastable ion (MI), collisional activation (CA), neutralization–reionization (NR) spectra, and ion–molecule reactions, performed in a hybrid tandem mass spectrometer of sectors–quadrupole–sectors configuration, have demonstrated the isothiocyanate, CH3ON[double bond, length half m-dash]C[double bond, length half m-dash]S˙+ a, and the nitrile N-sulfide, CH3OC[triple bond, length half m-dash]N–S˙+ b, connectivities. For the sake of comparison, a potential precursor of the isocyanate, CH3SN[double bond, length half m-dash]C[double bond, length half m-dash]O˙+ c, was also investigated. The gas phase stability of the corresponding neutral molecules is indicated by the NR and NR/CA spectra. In addition, consecutive collisional activation processes (MS/MS/MS spectra) were used to characterize the structures of metastable ions which, in several cases, were found to be different from the corresponding ions generated in the ion source. Calculated ionization energies and enthalpies of reaction with NO˙ (at the G2(MP2,SVP) level) support the experimental characterization of ions a and b.

References

  1. (a) W. Kirmse, Chem. Ber., 1960, 93, 2353 CAS; (b) K. A. Jensen and C. Pedersen, Adv. Heterocycl. Chem., 1964, 3, 263 CAS; (c) C. Wentrup and P. Kambouris, Chem. Rev., 1991, 91, 363 CrossRef CAS.
  2. (a) C. Wentrup, S. Fischer, A. Maquestiau and R. Flammang, J. Org. Chem., 1986, 51, 1908 CrossRef CAS; (b) P. Kambouris, T.-K. Ha and C. Wentrup, J. Phys. Chem., 1992, 96, 2065 CrossRef CAS.
  3. K. A. Jensen, S. Burmester and T. A. Bak, Acta Chem. Scand., 1967, 21, 2792 CAS.
  4. C. Th. Pedersen, R. Flammang, M. W. Wong and C. Wentrup, J. Chem. Soc., Perkin Trans. 2, in the press Search PubMed.
  5. (a) A. Maquestiau, R. Flammang, M. Plisnier, C. Wentrup, P. Kambouris, M. R. Paton and J. K. Terlouw, Int. J. Mass Spectrom. Ion Processes, 1990, 100, 477 CrossRef CAS; (b) P. Kambouris, M. Plisnier, R. Flammang, J. K. Terlouw and C. Wentrup, Tetrahedron Lett., 1991, 32, 1487 CrossRef CAS.
  6. R. Flammang, M. Barbieux-Flammang, P. Gerbaux, C. Wentrup and M. W. Wong, Bull. Soc. Chim. Belg., 1997, 106, 545 CAS.
  7. P. Gerbaux, PhD Thesis, University of Mons-Hainaut, 1999.
  8. For a recent review, see: C. A. Schalley, G. Hornung, D. Schröder and H. Schwarz, Chem. Soc. Rev., 1998, 27, 91 Search PubMed.
  9. S. G. Lias, J. E. Bartmess, J. F. Liebman, J. L. Holmes, R. D. Levin and W. G. Mallard, J. Phys. Chem. Ref. Data, 1988, 17, Supplement no. 1.
  10. R. Flammang, P. Gerbaux and M. W. Wong, Chem. Phys. Lett., 1999, 300, 183 CrossRef CAS.
  11. R. Flammang, P. Gerbaux, E. H. Mørkved, M. W. Wong and C. Wentrup, J. Phys. Chem., 1996, 100, 17452 CrossRef CAS.
  12. M. T. NguyenR. Flammang, in preparation.
  13. M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, V. G. Zakrzewski, J. A. Montgomery, Jr., R. E. Stratmann, J. C. Burant, S. Dapprich, J. M. Millam, A. D. Daniels, K. N. Kudin, M. C. Strain, O. Farkas, J. Tomasi, V. Barone, M. Cossi, R. Cammi, B. Mennucci, C. Pomelli, C. Adamo, S. Clifford, J. Ochterski, G. A. Petersson, P. Y. Ayala, Q. Cui, K. Morokuma, D. K. Malick, A. D. Rabuck, K. Raghavachari, J. B. Foresman, J. Cioslowski, J. V. Ortiz, B. B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. Gomperts, R. L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng, A. Nanayakkara, C. Gonzalez, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen, M. W. Wong, J. L. Andres, C. Gonzalez, M. Head-Gordon, E. S. Replogle and J. A. Pople, GAUSSIAN 98, Gaussian Inc., Pittsburgh, PA, 1998.
  14. L. A. Curtiss, P. C. Redfern, B. J. Smith and L. Radom, J. Chem. Phys., 1996, 104, 5148 CrossRef CAS.
  15. P. Gerbaux, Y. Van Haverbeke, R. Flammang, M. W. Wong and C. Wentrup, J. Phys. Chem. A, 1997, 101, 6970 CrossRef CAS.
  16. B. Ruscic and J. Berkowitz, J. Chem. Phys., 1994, 101, 7975 CrossRef CAS.
  17. (a) R. Flammang, D. Landu, S. Laurent, M. Barbieux-Flammang, C. O. Kappe, M. W. Wong and C. Wentrup, J. Am. Chem. Soc., 1994, 116, 2005 CrossRef CAS; (b) M. W. Wong, R. Flammang and C. Wentrup, J. Phys. Chem., 1995, 99, 16849 CrossRef CAS; (c) P. Gerbaux, R. Flammang, E. H. Mørkved, M. W. Wong and C. Wentrup, J. Phys. Chem. A, 1998, 102, 9021 CrossRef CAS.
  18. R. H. Bateman, J. Brown, M. Lefevere, R. Flammang and Y. Van Haverbeke, Int. J. Mass Spectrom. Ion Processes, 1992, 115, 205 CrossRef CAS.
  19. R. Flammang, Y. Van Haverbeke, C. Braybrook and J. Brown, Rapid Commun. Mass Spectrom., 1995, 9, 795 CAS.
  20. P. Gerbaux, R. Flammang and Y. Van Haverbeke, Int. J. Mass Spectrom. Ion Processes, 1999, 184, 39 Search PubMed.
  21. C. Larsen, K. Steliou and D. N. Harpp, J. Org. Chem., 1978, 43, 337 CrossRef CAS.
  22. In fact, this compound was prepared by treating the commercially available (Aldrich) 3,4-dichloro-1,2,5-thiadiazole with sodium methoxide (E. H. Mørkved , to be published). The product appears to be identical with the sample previously described in the literature: A. P. Komin, R. W. Street and M. Carmack, J. Org. Chem., 1975, 40, 2749 Search PubMed.
  23. E. Hoggarth, J. Chem. Soc., 1952, 4811 RSC.
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