Helical and higher structural ordering in poly(3-methyl-4-vinylpyridine)

ACS Symposium Series

Volumn 812, Issue , 2002, Pages 55-65

  Ortiz, Lisandra J ^a   Pratt, Lawrence ^b   Smitherman, Kimberly ^b   Sannigrahi, Biswajit ^b   Khan, Ishrat M ^a  

^a CLARK ATLANTA UNIVERSITY   (United States)

^b FISK UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0041866359     PISSN: 00976156     EISSN: None     Source Type: Book Series    
DOI: 10.1021/bk-2002-0812.ch005     Document Type: Article

References (28)

1. Fujiki, M. J. Am. Chem. Soc. 2000, 122, 3336-3343.
2. Okamoto, Y.; Nakano, T. Chem. Rev. 1994, 94, 349-372.
3. (a) Corley, L.S.; Vogl, O. Polym. Bull. 1980, 3, 211-217.
4. (b) Kamer, P.C.J.; Nolte, R.J.M.; Drenth, W. J. Am. Chem. Soc. 1988, 110, 6818-6825.
5. Green, M.M.; Peterson, N.C.; Sato, T.; Teramoto, A.; Cook, R.; Lifson, S. Science, 1995, 268, 1860-1865.
6. Okamoto, Y.; Mohri, H.; Nakano, T.; Hatada, K. J. Am. Chem. Soc. 1989, 111, 5952-5954.
7. (e) Vogl, O., J. Poly. Sci. Poly. Chem, 2000, 2623-2634.
8. (a) Okamoto, Y.; CHEMTECH, 1987, 144.
9. (b) Okamoto, Y.; Honda, S.; Okamoto, I.; Yuki, H.; J. Am. Chem. Soc. 1981, 103, 6971-6973.
10. 3 may penetrate the swollen polymer and form the polymeric reagent, the larger acetophenone molecule may not do so, thus directly affecting the chemical yield. Secondly, while workup for isolation of the product is relatively easy, it is not possible to effectively regenerate the polymer reagent after one cycle. This is because the optical activity of the polymer decreases during the reduction process and after 20 hours the optical activity is negligible Most likely this is due to the helix-helix interconversion resulting in racemization and/or side reactions that may be taking place during reduction. For details see, Yun Liu, "Asymmetric Reduction of Porchiral Ketone by Optically Active Polymeric Reagents", MS Thesis, Clark Atlanta University, 1995.
11. Cornelissen, J.J.L.M.; Fischer, M.; Sommerdijk, N.A.J.M.; Nolte, R.J.M. Science 1998, 280, 1427-1430.
12. Hirschberg, J.H.K.K.; Brunsveld, L.; Ramzi, A.; Vekemans, J.A.J.M.; Sijbesma, R.P.; Meijer, E.W. Nature 2000, 407, 167-170.
13. Ortiz, L.J.; Khan, I.M. Macromolecules 1998, 31, 5927-5929.
14. Habaue, S.; Ajiro, H.; Okamoto, Y. J. Polym. Sci. Poly. Chem. 2000, 38, 4088-4094.
15. (a) Bovey, F. A.; Jelinski, L. W., "Chain Structure and Conformation of Macromolecules", Academic, Press, 1992.
16. (b) Natta, G.; Danusson, F.; Sianesi, D. Makromol. Chem. 1958, 28, 253.
17. Khan, I. M.; Hogen-Esch, T. E. Macromolecules 1987, 20, 2335-2340.
18. The composites were prepared using PEO (MW 600,000) and PEG (MW 3000) to obtain a thermoplastic elastomeric material. Elastomeric materials are easy to fabricate for CD measurements. Temperature dependent racemization studies were not carried out but since segmental motion seems to be necessary for helix-to-helix interconversion, the racemization in the solid state should be possible above the glass transition temperature of the polymer matrix. Rate of racemization should increase with increasing temperature. Detailed DSC studies have not been undertaken, PEG is a good plasticizing agent, and additionally because PEO has a melting temperature around 60°C, the crystalline content of the composite at this temperature is small.
19. Alchemy 32 Version 2.05, Tripos, Inc. St. Louis, MO, USA
20. (a) Maeda, K.; Yamamoto, N.; Okamoto, Y.; Macromolecules 1998, 31, 5924-5926.
21. (b) Schlitzer, D.; Novak, B.M. J. Am. Chem. Soc., 1998, 120, 2196-2197.
22. Yashima, E.; Matsushima, T.; Okamoto, Y. J. Am. Chem. Soc. 1995, 117, 11596-11957.
23. (e) Yashima, E.; Nimura, T.; Matsushima, T.; Okamoto, Y. J. Am. Chem. Soc. 1996, 118, 9800-9801.
24. (f) Yashima, E.; Matsushima, T.; Okamoto, Y. J. Am. Chem. Soc, 1997, 119, 6345-6359.
25. (g) Yashima, E.; Maeda, K.; Yamanaka, T. J. Am. Chem. Soc., 2000, 122, 7813.
26. The usage of the term "chaperoning" is appropriate in this system. Starting with a racemic helical poly(3-methyl-4-vinylpyridine), an optically active chaperone is utilized to carry out a helicity selection process.
27. The complexes were prepared by mixing 5 mg of P3M4VP and the appropriate amount of the MA in 5 ml of THF and stirred for 6 hour at room temperature.
28. 2O. In figure 2, the Cotton effect signals may due to the absorption of the carbonyl of MA.