´
C. GODOY-ALCANTAR, A. K. YATSIMIRSKY AND J.-M. LEHN
984
regression line for points shown as solid squares follows
Eqn (9) with R2 ¼ 0.957 and SD ¼ 0.375.
program and for providing the facilities for using
the Bruker Avance 400 MHz spectrometer and to O.
Ramstrom and S. Lohmann for the synthesis of some
aldehydes. C.G.-A. thanks UAEM for a sabbatical year
(2000–01), PROMEP-UAEM for a post-doctoral fellow-
ship and CONACyT for financial support provided
log K ¼ ꢀ0:03 ꢄ 0:13 þ ð0:96 ꢄ 0:05Þlog Kcalc ð9Þ
Hence Eqn (8) allows one to predict the imine forma-
tion constant for a given pair of amine and aldehyde
within limits of a twofold variation. Significant positive
deviations are observed with aldehyde 6 bearing an o-
hydroxyl group and can be attributed to intramolecular
hydrogen bonding with the imine nitrogen. Also, signifi-
´
through the program of Estancias Sabaticas en Institu-
ciones del Extranjero por Demanda Libre 2000, Ref.
000023, and by the Project CONACyT Ref. 39574-Q.
t
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Supplementary material
The following tables are available in Wiley Interscience:
Table 1S, selected data for imine formation in D2O at
25 ꢅC together with chemical shifts for aldehyde and
imine CH protons; Tables 2S and 3S, HOMO and
LUMO energies and Fukui indices for some amines and
aldehydes studied; Table 4S, observed and calculated
imine formation constants in water at 25 ꢅC and para-
meters of Eqn (8).
´
´
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Acknowledgments
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26. Blaquez M, Pineda T, Sevilla J-M, Domınguez M, Garcıa-Blanco
We are grateful to Dr F. Medrano of the University of
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Sonora, Mexico, for all calculations made in the Gaussian
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27. Vazquez MA, Donoso J, Mun˜oz F, Garcıa-Blanco F, Garcıa del
Vado MA, Echevarria G. Helv. Chim. Acta 1990; 73: 1991–1998.
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Copyright # 2005 John Wiley & Sons, Ltd.
J. Phys. Org. Chem. 2005; 18: 979–985