A. Filarowski et al. / Journal of Molecular Structure 484 (1999) 75–89
89
[3] T. Sekikawa, T. Kobayashi, T. Inabe, J. Phys. Chem. A 101
(1997) 644.
[4] A. Grabowska, K. Kownacki, Ł. Kaczmarek, Acta. Phys.
Polon. A 88 (1995) 1081.
[5] A. Grabowska, K. Kownacki, J. Karpiuk, S. Dobrin, Ł. Kacz-
marek, Chem. Phys. Lett. 267 (1997) 132.
[6] A. Filarowski, A. Koll, T. Głowiak, E. Majewski, T. Dziem-
bowska, Phys. Chem. Ber. Bunsenges. 102 (1998) 393.
[7] A. Filarowski, A. Koll, T. Głowiak, J.Chem.Cryst. 27 (1997) 707.
[8] F. Kristek, J. Klicnar, P. Vetesnik, Collect. Czech. Chem.
Commun. 38 (1971) 3608.
[9] International Tables for X-ray Crystallography, vol. 4,
Kynoch. Press: Birmingham, UK, 1974.
[10] G.M. Sheldrick, Acta Crystallogr. A 46 (1990) 467.
[11] SHELIXL 93, Crystal structure Refinement, Department of
hydrogen bond strength owing to change of pKa of the
basic part of the hydrogen bridge.
Very large liability of the potential for the proton
movement within the hydrogen bridge was demon-
strated in temperature studies of IR spectra. Radical
decrease of the energy of PT forms of I–III
compounds was stated in comparison to related
compounds without alkyl substituents in the central
part of a molecule. Steric modification of the potential
for the proton movement discussed in this paper, can
be a source of the compounds with desirable physico-
chemical properties, including potential practical
applications resulting from thermochromic and photo-
chromic properties of Schiff bases.
¨
Inorganic Chemistry, University of Gottingen, German.
[12] G. Gilli, F. Bellucci, V. Ferretti, V. Bertolasi, J. Am. Chem.
Soc. 111 (1989) 1023.
[13] P. Gilli, V. Bertolasi, V. Ferretti, G. Gilli, J. Am. Chem. Soc.
116 (1994) 909.
Acknowledgements
[14] A. Bondi, J. Phys. Chem. 68 (1964) 441.
[15] S. Kevran, A. Elmali, Y. Elerman, Acta Cryst. C 52 (1996)
3256.
[16] J.-H. Lii, N.L. Allinger, J. Am. Chem. Soc. 111 (1989) 8576.
[17] S. Scheiner, Acc. Chem. Res. J. Am. Chem. Res. 116 (1994)
402.
Authors acknowledge the financial support of KBN
grant No 3TO9A04210. We would also like to
´
acknowledge Mr. Jerzy Janski for the help in
performing quantum mechanical calculations.
[18] P. Camilleri, C.A. Marby, B. Odell, H.S. Rzepa, R.N. Shep-
pard, J.J.P. Stewart, D.J. Williams, J. Chem. Soc. Chem.
Commun. (1989) 1722.
References
[19] A. Koll, Bull. Soc. Chim. Belg. 92 (1983) 313.
[20] S. Mukherjee, D. Majumar, A., Koll, A. Filarowski,
submitted.
[1] W.-H. Fang, Y. Zhang, X.-Z. You, J. Mol. Struct. (Theochem)
334 (1995) 81.
[2] G.M.J. Schmidt, in: D. Ginsburg (Ed.), Solid State Photo-
chemistry, Verlag Chemie, Weinheim, New York, 1976.
[21] D.D. Perrin, Dissociation Constants of Organic Bases in
Aqueous Solutions, Butterworths, London, 1972.