Synthesis and magnetic behaviour of poly(1,3-phenylene)-based polyradical carrying N-tert-butylaminoxyl radicals

(Note: The full text of this document is currently only available in the PDF Version )

Hiroyuki Oka, Tomoki Tamura, Yozo Miura and Yoshio Teki


Abstract

The synthesis and magnetic behaviour of poly[6-(N-oxyl-N-tert-butylamino)biphenyl-3,3′-ylene] 2 are described. Polyradical 2 was prepared by the Pd-catalyzed polycondensation of N-tert-butyl-2,4-dibromoaniline and 1,3-phenylenebis(trimethylene boronate), followed by oxidation with 3-chloroperoxybenzoic acid. The degree of polymerisation determined by SEC (size exclusion chromatography) was ∼18. Polyradical 2 was stable in both solution and the solid state. The spin concentrations of 2 determined by EPR and SQUID were 0.75 and 0.82 spin per repeating unit, respectively. Magnetic susceptibility (χ) measurements on 2 were carried out on a SQUID magnetometer and these showed that the magnetic interaction between the unpaired electron spins was antiferromagnetic (θ=–0.98 K). The fact that no ferromagnetic interaction was observed was ascribed to a twisting of the nitroxide moieties from the π-conjugated main chain, and this was confirmed by X-ray crystallographic analysis of the corresponding model monoradical, N-tert-butyl-N-(2,4-diphenylphenyl)aminoxyl.


References

  1. J. S. Miller, A. J. Epstein and W. M. Reiff, Chem. Rev., 1988, 88, 201 CrossRef CAS; H. Iwamura and N. Koga, Acc. Chem. Res., 1993, 26, 346 CrossRef CAS; J. A. Crayston, A. Iraqi and J. C. Walton, Chem. Soc. Rev., 1994, 147 RSC; P. M. Lahti, Polymeric Materials Encyclopedia, CRC Press, Boca Raton, New York and London, 1996, vol. 2, pp. 1484–1494 Search PubMed; Y. Miura, ibid., vol. 9, pp. 6686–6695 Search PubMed; Proceedings of the Symposium of the 5th International Conference on Molecule-based Magnets, Mol. Cryst. Liq. Cryst., 1997, 305, 1; 306, 1 Search PubMed.
  2. N. Mataga, Theor. Chim. Acta, 1968, 10, 372 CrossRef CAS; A. A. Ovchinnikov, Theor. Chim. Acta, 1978, 47, 297 CrossRef CAS.
  3. S. Kato, K. Morokuma, D. Feller, E. R. Davidson and W. T. Borden, J. Am. Chem. Soc., 1983, 105, 1791 CrossRef CAS; P. M. Lahti and A. S. Ichimura, J. Org. Chem., 1991, 56, 3030 CrossRef CAS; R. C. Fort, Jr., S. J. Getty, D. A. Hrovat, P. M. Lahti and W. T. Borden, J. Am. Chem. Soc., 1992, 114, 7549 CrossRef.
  4. P. S. Zuev and R. S. Sheridan, Tetrahedron, 1995, 51, 11337 CrossRef CAS; Y. Teki, I. Fujita, T. Takui, T. Kinoshita and K. Itoh, J. Am. Chem. Soc., 1994, 116, 11499 CrossRef CAS and references cited therein.
  5. A. Rajca, Chem. Rev., 1994, 94, 871 CrossRef CAS.
  6. N. Miyaura and A. Suzuki, Chem. Rev., 1995, 95, 2457 CrossRef CAS.
  7. Y. Miura, H. Oka and M. Momoki, Synthesis, 1995, 1419 CrossRef CAS.
  8. Y. Miura, H. Oka and M. Morita, Macromolecules, 1998, 31, 2041 CrossRef CAS.
  9. A. Fujii, T. Ishida, N. Koga and H. Iwamura, Macromolecules, 1991, 24, 1077 CrossRef CAS; Y. Miura, M. Matsumoto and Y. Ushitani, Macromolecules, 1993, 26, 2628 CrossRef CAS; Y. Miura, M. Matsumoto, Y. Ushitani, Y. Teki, T. Takui and K. Itoh, Macromolecules, 1993, 26, 6673 CrossRef CAS; H. Nishide, T. Kaneko, M. Igarashi, E. Tsuchida, N. Yoshioka and P. M. Lahti, Macromolecules, 1994, 27, 3082 CrossRef CAS and references cited therein.
  10. Y. Miura, Y. Ushitani, K. Inui, Y. Teki, T. Takui and K. Itoh, Macromolecules, 1993, 26, 3698 CrossRef CAS; Y. Miura and Y. Ushitani, Macromolecules, 1993, 26, 7079 CrossRef CAS; Y. Miura, T. Issiki, Y. Ushitani, Y. Teki and K. Itoh, J. Mater. Chem., 1996, 6, 1745 RSC and references cited therein.
  11. H. Nishide, T. Kaneko, T. Nii, K. Katoh, E. Tsuchida and P. M. Lahti, J. Am. Chem. Soc., 1996, 118, 9695 CrossRef CAS and references cited therein.
  12. W. T. Borden and E. R. Davidson, J. Am. Chem. Soc., 1977, 99, 4587 CrossRef CAS.
  13. E. R. Biehl, R. Patrizi and P. C. Reeves, J. Org. Chem., 1971, 36, 3252 CrossRef CAS.
  14. S. Kajigaeshi, T. Kakinami, H. Tokikawa, T. Hirakawa and T. Okamoto, Bull. Chem. Soc. Jpn., 1987, 60, 2667 CAS; S. Kajigaeshi, T. Kakinami, K. Inoue, M. Kondo, H. Nakamura, M. Fujikawa and T. Okamoto, Bull. Chem. Soc. Jpn., 1988, 61, 597 CAS.
  15. M. Remmers, M. Shultze and G. Wegner, Macromol. Rapid. Commun., 1996, 17, 239 CAS; F. E. Goodson, T. I. Wallow and B. M. Novak, Macromolecules, 1998, 31, 2047 CrossRef CAS.
  16. A. B. Charette and A. Giroux, J. Org. Chem., 1996, 61, 8718 CrossRef.
  17. A. R. Forrester, J. M. Hay and R. H. Thomson, Organic Chemistry of Stable Free Radicals, Academic Press, London and New York, 1968, pp. 202–203 Search PubMed.
  18. S. Kajigaeshi, T. Kakinami, H. Yamasaki, S. Fujisaki and T. Okamoto, Bull. Chem. Soc. Jpn., 1988, 61, 600.
  19. R. M. Washburn, E. Levens, C. F. Albright and F. A. Billig, Org. Synth., 1963, Coll. Vol. IV, 68.
  20. D. R. Coulson, Inorg. Synth., 1972, 13, 121.
  21. All calculations were performed using the Molecular Structure Corporation's TEXSAN crystallographic software package.
Click here to see how this site uses Cookies. View our privacy policy here.