Reaction of dimethylselenourea and selenourea with dibromine to produce selenourea–dibromine, the ‘T’-shaped 1:1 molecular adduct N,N-dimethyl-2-selenourea–dibromine, its solvent of crystallisation-containing analogue and the unusual ionic compound 5[(H2N)(Me2N)CBr]+[SeBr6]2–[Se2Br9]2[Br3]. A low temperature crystallographic reinvestigation of N-methylbenzothiazole-2-selone–dibromine

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Philip D. Boyle, Wendy I. Cross, Stephen M. Godfrey, Charles A. McAuliffe, Robin G. Pritchard and Simon J. Teat


Abstract

The reactions of the selenoamides N,N-dimethyl-2-selenourea, dmsu, selenourea, su and N-methylbenzothiazole-2-selone, mbts, with dibromine has been studied. In all reactions the bulk product formed is the 1∶1 T-shaped addition compound, selenoamide·Br2. The crystal structure of dmsu·Br2 1 has been determined and compared to its solvated analogue, dmsu·Br2·CH2Cl2. Despite the different crystal packing in these two adducts, an asymmetry in d(Se–Br) is exhibited by both, ruling out the possibility that differences in Se–Br bond lengths are attributed solely to crystal packing forces. Both structures are essentially zwitterionic, a negative charge resides on the SeBr2 moiety and the positive charge is supported by the two nitrogen atoms. The recently reported mbts·Br2, previously described as a carbene interacting with SeBr2, was reinvestigated. Considering findings from a low temperature X-ray study and the 13C NMR spectrum, this compound is in fact also best described as zwitterionic, analogous to 1 and previously described structures. An interesting minor product from the reaction of two equivalents of dibromine with dmsu has also been characterised crystallographically. This complicated ionic structure of formula 5[(H2N)(Me2N)CBr]+[SeBr6]2–[Se2Br9]2[Br3] illustrates the susceptibility of certain selenoamides to carbon–selenium bond cleavage when a dihalogen that is more strongly oxidising than I2 or IBr is treated with them in a stoichiometric ratio greater than 1∶1. This curious (and disordered) structure represents the first report of the anion [Se2Br9].


References

  1. S. M. Godfrey, C. A. McAuliffe, R. G. Pritchard and S. Sarwar, J. Chem. Soc., Dalton Trans., 1997, 1031 Search PubMed.
  2. B. Regelmann, K. W. Klinkhammer and A. Schmidt, Z. Anorg. Allg. Chem., 1997, 623, 1633 Search PubMed.
  3. S. M. Godfrey, S. L. Jackson, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Dalton Trans., 1997, 4499 Search PubMed.
  4. S. M. Godfrey, S. L. Jackson, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Dalton Trans., 1998, 4201 Search PubMed.
  5. (a) F. Cristiani, F. Demartin, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chem., 1994, 33, 6315 Search PubMed; (b) F. Demartin, P. Deplano, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chem., 1993, 32, 3694 Search PubMed; (c) F. Cristiani, F. Demartin, F. A. Devillanova, F. Isaia, G. Saba and G. Verani, J. Chem. Soc., Dalton Trans., 1992, 3553 Search PubMed; (d) F. Bigoli, A. M. Pellinghelli, P. Deplano, F. A. Devillanova, V. Lippolis, M. L. Mercuri and E. F. Trogu, Gazz. Chim. Ital., 1994, 124, 445 Search PubMed; (e) F. Demartin, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chim. Acta, 1997, 255, 203 Search PubMed.
  6. P. D. Boyle, W. I. Cross, S. M. Godfrey, C. A. McAuliffe, R. G. Pritchard and S. Teat, J. Chem. Soc., Dalton Trans., 1999, 2219 Search PubMed.
  7. D. J. Williams, D. Vanderveer, B. R. Crouse, R. R. Raye, T. Carter, K. S. Hagen and M. Brewer, Main Group Chem., 1997, 2, 61 Search PubMed.
  8. F. A. Devillanova, P. Deplano, F. Isaia, V. Lippolis, M. L. Mercuri, S. Piludu, G. Verani and F. Demartin, Polyhedron, 1998, 17, 305 Search PubMed.
  9. S. Akabori and Y. Takanohashi, J. Chem. Soc., Perkin Trans. 1, 1991, 479 Search PubMed; Chem. Lett., 1990, 251 Search PubMed.
  10. H. C. Bell and C. S. Gibson, J. Chem. Soc., 1925, 127, 1877 Search PubMed.
  11. Y. Takanohashi, N. Tabata, T. Tanase and S. Akabori, J. Chem. Soc., Perkin Trans. 1, 1993, 813 Search PubMed; J. Organomet. Chem., 1993, 450, 103 Search PubMed.
  12. M. Miura, Y. Takanohashi, Y. Habata and S. Akabori, (a)J. Chem. Soc., Perkin Trans. 1, 1995, 1719; (b)Tetrahedron Lett., 1994, 35, 8213 Search PubMed.
  13. S. Larsen and L. Henriksen, Acta Chem. Scand., Ser. A, 1984, 38, 289 Search PubMed.
  14. S. M. Godfrey, N. Ho, C. A. McAuliffe and R. G. Pritchard, Angew. Chem., Int. Ed. Engl., 1996, 35, 2343 Search PubMed; S. M. Godfrey, C. A. McAuliffe, R. G. Pritchard and J. M. Sheffield, J. Chem. Soc., Dalton Trans., 1996, 3309 Search PubMed; N. Bricklebank, S. M. Godfrey, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Dalton Trans., 1996, 157 Search PubMed; S. M. Godfrey, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Chem. Commun., 1994, 45 Search PubMed.
  15. C. K. Johnson, ORTEP II, Report ORNL-5138, Oak Ridge National Laboratory, Oak Ridge, TN, 1976.
  16. H. M. K. K. Pathirana, T. J. Weiss, J. H. Reibenspies, R. A. Zingaro and E. A. Meyers, Z. Kristallogr., 1994, 209, 697 Search PubMed.
  17. S. M. Godfrey, D. G. Kelly, A. G. Mackie, P. P. MacRory, C. A. McAuliffe, R. G. Pritchard and S. M. Watson, J. Chem. Soc., Chem. Commun., 1991, 1447 Search PubMed.
  18. S. M. Godfrey, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Chem. Commun., 1993, 2875 Search PubMed.
  19. S. Husebye, S. V. Lindeman and M. D. Rudd, Acta Crystallogr., Sect. C, 1997, 53, 809 Search PubMed.
  20. Handbook of Chemistry and Physics, ed. D. R. Lide, CRC Press, Boca Raton, FL, 76th edn., 1995–1996, section 9-10 Search PubMed; J. S. Rutherford and C. Calvo, Z. Kristallogr., 1969, 128, 229 Search PubMed; H. Hope, Acta Crystallogr., 1965, 18, 259 Search PubMed; T. Srikishnan, Acta Crystallogr., Sect. C, 1988, 44, 290 Search PubMed; J. Nakayama, A. Mizumura, I. Akiyama, T. Nishio and I. Iida, Chem. Lett., 1994, 77 Search PubMed.
  21. S. Hasche, O. Reich, I. Beckmann and B. Krebs, Z. Anorg. Allg. Chem., 1997, 623, 724 Search PubMed.
  22. B. Krebs, E. Luhrs and L. Stork, Z. Kristallogr., 1987, 178, 127 Search PubMed; B. Krebs, E. Luhrs and F.-P. Ahlers, Angew. Chem., Int. Ed. Engl., 1989, 28, 187 Search PubMed; S. Hauge, K. Maroy and T. Odegard, Acta Chem. Scand., Ser. A, 1988, 42, 56 Search PubMed.
  23. G. M. Sheldrick, Programs for crystal structure analysis (release 97-2), University of Göttingen, 1998.
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