The Effect of Substituent, Pressure and Temperature on the Dissociation Constants of Organic Acids. (2) Dissociation Constants of Some Substituted Naphthols in Aqueous Solution

유기산의 해리평형에 미치는 치환기 효과와 그의 온도 및 압력의 영향. (2) 수용액중에서 몇가지 치환나프톨류의 해리상수

  • Jung-Ui Hwang (The Research Institute for Physics and Chemistry, Kyungpook National University) ;
  • Zun-Ung Bae (The Research Institute for Physics and Chemistry, Kyungpook National University) ;
  • Jong-Jae Chung (The Research Institute for Physics and Chemistry, Kyungpook National University) ;
  • Jae-Won Jung (The Research Institute for Physics and Chemistry, Kyungpook National University) ;
  • Kyung-Hee Chang (The Research Institute for Physics and Chemistry, Kyungpook National University)
  • 황정의 (경북대학교 물리화학연구소) ;
  • 배준웅 (경북대학교 물리화학연구소) ;
  • 정종재 (경북대학교 물리화학연구소) ;
  • 정재원 (경북대학교 물리화학연구소) ;
  • 장경희 (경북대학교 물리화학연구소)
  • Published : 1986.04.20

Abstract

The dissociation constants of 4-Cl-1-naphthol, 6-Br-2-naphthol and $8-NH_2-2-naphthol$ in aqueous solution were measured by spectroscopic method in the temperature range from 25 to 40${\circ}C$ and pressure up to 2000bar. The dissociation constants were decreased as the substituents were inserted in naphthol f rom $4.4{\times}10^{-10}\;to\;5.82{\times}10^{-11}$ as chloride compound and $2.5{\times}10^{-10}\;to\;3.44{\times}10^{-11}\;or\;4.21{\times}10^{-11}$ as bromine or amino compounds, respectively. This decrease can be explained with the I-or R-effects of substituents. From the dissociation constants various thermodynamic properties were calculated and discussed the characteristics of the dissociation reaction.

치환나프톨류(4-Cl-1-naphthol, 6-Br-2-naphthol and $8-NH_2-2-naphthol)$의 해리상수를 온도(25 ~ 40${\circ}C$)와 압력(1~2000bar)을 변화시키면서 분광학적 방법으로 측정했다. 이들의 해리상수는 치환기가 들어가므로서 모두 감소했다. 이것은 치환기의 I-효과로서 설명이 가능했으며 또 온도와 압력이 증가하면 해리상수도 증가하였다. 이들 해리상수로부터 반응의 열역학적 성질을 계산하여 반응의 성질을 알아보았다.

Keywords

References

  1. Trans. Am. Geoghys. Un. R.E. Gibson;O.H. Loeffler
  2. J. Research Natl. Bur. Standard v.45 E.E. Sager;I.J. Siewers
  3. Helv. Chim. Acta. v.37 R.G. Bates;S.F. Schwarzenbah
  4. Trans. Farad. Soc. v.51 R.A. Robinson;A.I. Biggs
  5. J. Chem. Soc. A.I. Biggs
  6. J. Phys. Chem. v.66 G.F. Allen;R.A. Robinson;V.E. Vower
  7. J. Redearch Natl. Bur. Standard v.65A R.C. Bates;R. Gary
  8. J. Phys. Chem. v.79 R.C. Neuman;U.W. Kauzmann;A. Zipp
  9. J. Chem. Soc. Trans. Farad. 1 v.71 S.D. Hamann;M. Linton
  10. J. Chem. Soc. Trans. Farad. 1 v.70 S.D. Hamann;M. Linton
  11. Handbook of chemistry and physics R.C. Weastand;M.A. Astle
  12. J. Phys. Chem. v.29 Stenstrom;Reinhard
  13. J. Am. Chem. Soc. v.57 L.A. Flexser;L.P. Hammett;A. Dingwall
  14. Chem. Rev. v.78 T. Asano;W.J. Le Noble
  15. J. Am. Chem. Soc. v.94 R.C. Neuman Jr.;M.J. Amrich