The Hydrogen-Bond Basicity pKHB Scale of Peroxides and Ethers
FULL PAPER
[11]
[12]
[13]
237 l molϪ1 cmϪ1) and the other equilibrium concentrations were
deduced from Ca. The maximum error in pKHB is estimated to be
± 0.04.
F. Besseau, C. Laurence, M. Berthelot, J. Chem. Soc., Perkin
Trans. 2 1994, 485Ϫ489.
J.-Y. Le Questel, C. Laurence, A. Lachkar , M. Helbert, M.
Berthelot, J. Chem. Soc., Perkin Trans. 2 1992, 2091Ϫ2094.
F. Besseau, M. Lucon, C. Laurence, M. Berthelot, J. Chem.
¸
In the case of polyethers, we must maintain the ether concen-
tration at least in tenfold excess, in order to favor the formation of
1:1 complexes over n:1 complexes. The constancy of the equilib-
rium constants determined at different ether concentrations on the
basis of 1:1 complex formation, indicates that the 1:1 complex is
the primary species formed (Table 5).
Soc., Perkin Trans. 2 1998, 101Ϫ107.
[14] [14a]
C. Laurence, M. Berthelot, M. Lucon, D. G. Morris, J.
¸
Chem. Soc., Perkin Trans. 2 1994, 491Ϫ 493. Ϫ [14b] A. Chardin,
C. Laurence, M. Berthelot, D. G. Morris, Bull. Soc. Chim. Fr.
1996, 133, 389Ϫ393.
[15]
[16]
[17]
A. Chardin, C. Laurence, M. Berthelot, D. G. Morris, J. Chem.
Soc., Perkin Trans. 2 1996, 1047Ϫ1051.
A. Chardin, M. Berthelot, C. Laurence, D. G. Morris, J. Phys.
Org. Chem. 1994, 7, 705Ϫ711.
0
Table 5. Variation of Kf (l molϪ1) as a function of Cb0/Ca for the
E. Lippert, H. Prigge, Justus Liebigs Ann. Chem. 1962, 659,
81Ϫ89.
4-fluorophenol/18-crown-6 complex; Kf is constant when the ratio
0
Cb0/Ca is over 10
[18]
[19]
T. Gramstad, Spectrochim. Acta 1963, 19, 497Ϫ508.
E. S. Hanrahan, F. Deskins, Proc. West Va. Acad. Sci. 1967,
39, 371Ϫ374.
R. West, D. L. Powell, M. K. T. Lee, L. S. Whatley, J. Am.
Chem. Soc. 1964, 86, 3227Ϫ3229.
T. M. Barakat, M. J. Nelson , S. M. Nelson, A. D. E. Pullin,
Trans. Faraday Soc. 1966, 62, 2674Ϫ2684.
R. West, L. S. Wilson, D. L. Powell, J. Organomet. Chem. 1979,
178, 5Ϫ9.
T. Iijima, H. Kakiuchi, Tetrahedron 1979, 35, 299Ϫ302.
L. Bellon, R. W. Taft, J.-L. M. Abboud, J. Org. Chem. 1980,
45, 1166Ϫ1168.
H. Fritzsche, Spectrochim. Acta 1965, 21, 799Ϫ813.
C. Laurence, M. Berthelot, M. Helbert, Spectrochim. Acta 1985,
41A, 883Ϫ892.
A. Massat, P. Guillaume, J. P. Doucet , J. E. Dubois, J. Mol.
Struct. 1991, 244, 69Ϫ86
J. L. E. Erickson, W. J. Ashton, J. Am. Chem. Soc. 1941, 63,
1767Ϫ1771.
J.-Y. Le Questel, Ph. D. Thesis, University of Nantes, 1991.
D. Clotman, D. Van Lerberghe, T. Zeegers-Huyskens, Spectro-
chim. Acta 1970, 26A, 1621Ϫ1631.
M. Berthelot, C. Laurence, unpublished work.
R. M. Badger, S. H. Bauer, J. Chem. Phys. 1937, 5, 839Ϫ851.
R. M. Badger , J. Chem. Phys. 1940, 8, 288Ϫ289.
T. Gramstad, S. Husebye, K. Maartmann-Moe, Acta Chem.
Scand. 1985, B39, 767Ϫ771.
A.C. Legon, D. J. Millen , Chem. Soc. Rev. 1987, 16, 467Ϫ498.
A.C. Legon, J. C. Thor, Chem. Phys. Lett. 1994, 227, 472Ϫ479.
A.C. Legon, Chem. Phys. Lett. 1995, 247, 24Ϫ31.
P. Murray-Rust, J.P. Glusker, J. Am. Chem. Soc. 1984, 106,
1018Ϫ1025.
0
Cb0/Ca
Kf
0.42 0.85 1.73 3.36 7.15 10.7 13.7 15.8
142
131
122
114
97.1 95.9 95.7 95.8
[20]
[21]
[22]
1:1, 2:1, ... complexes[a]
1:1 complexes: Kf ϭ 95.8
[a] By assuming the presence of only a 1:1 complex and a 2:1 com-
plex (2 molecules of 4-fluorophenol for 1 crown ether), we obtain,
by the Huyskens method[30], Kf(1:1) ϭ 93.7 l molϪ1 in good
agreement with the value obtained when the crown ether is in ten-
to sixteenfold excess.
[23]
[24]
[25]
[26]
Infrared Shifts: The wavenumber shifts of the OH bands of meth-
[27]
[28]
anol at 3644 cmϪ1 and 4-fluorophenol at 3614 cmϪ1 are defined as
∆ν1(OH)
ϭ 3644 Ϫ ν1(OH···O) and ∆ν2(OH) ϭ 3614 Ϫ
ν2(OH···O), respectively. They are known to ± 2 cmϪ1 if the
ν(OH···O) band is almost symmetrical, but asymmetry and math-
ematical decomposition cause larger errors.
[29]
[30]
[31]
[32]
[33]
[34]
[1]
D. Gurka , R. W. Taft, J. Am. Chem. Soc. 1969, 91, 4794Ϫ4801.
[2]
E. M. Arnett, L. Joris , E. Mitchell , T. S. S. R. Murty, T. M.
Gorrie, P. v. R. Schleyer, J. Am. Chem. Soc. 1970, 92,
2365Ϫ2377.
[35]
[36]
[37]
[38]
[3]
M. D. Joesten, R. S. Drago, J. Am. Chem. Soc. 1962, 84,
2037Ϫ2039.
[4]
D. Gurka, R. W.Taft, L. Joris, P. v. R. Schleyer, J. Am. Chem.
Soc. 1967, 89, 5957Ϫ5958.
[5]
M. H. Abraham, P. L. Grellier, D. V. Prior, J. J. Morris, P. J.
[39]
[40]
[41]
J. A. Shea, S. G. Kukolich, J. Chem. Phys. 1983, 78, 3545Ϫ3551.
Z. Yoshida, E. Osawa, J. Am. Chem. Soc. 1966, 88, 4019Ϫ4026.
R.W. Taft, R. D. Topsom, Progr. Phys. Org. Chem. 1987, 16,
1Ϫ83.
Taylor, J. Chem. Soc. Perkin Trans. 2 1990, 521Ϫ529.
[6]
A. Chardin, Ph. D. Thesis, University of Nantes, 1997.
[7] [7a]
M. Berthelot, M. Helbert, C. Laurence, J.-Y. Le Questel, J.
[7b]
Phys. Org. Chem. 1993, 6, 302Ϫ 306. Ϫ
E. D. Raczynska,
[42]
[43]
[44]
[45]
R. W. Taft, F. Anvia, M. Taagepera, J. Catalan, J. Elguero, J.
Am. Chem. Soc. 1986, 108, 3237Ϫ3239.
C. Laurence, P. Nicolet, J. Chem. Soc., Perkin Trans. 2 1988,
1491Ϫ1494.
R. West, L. S. Whatley, K. J. Lake, J. Am. Chem. Soc. 1961,
83, 761Ϫ764.
[8]
[9]
C. Laurence, M. Berthelot, J.-Y. Le Questel, M. J. El Ghomari,
J. Chem. Soc., Perkin Trans. 2 1995, 2075Ϫ2079.
F. Besseau , C. Laurence, M. Berthelot, Bull. Soc. Chim. Fr.
1996, 133, 381Ϫ387.
M. Berthelot, C. Laurence, M. Safar, F. Besseau, J. Chem. Soc.,
Perkin Trans. 2, in press.
P. P. Graczyk, M. Mikoajczyk, Top. Stereochem. 1994, 31,
159Ϫ349.
[10]
C. Laurence, M. Berthelot, M. Helbert, K. Sraıdi, J. Phys.
¨
Chem. 1989, 93, 3799Ϫ3802.
[97356]
Eur. J. Org. Chem. 1998, 925Ϫ931
931