Original scientific paper

Spectrophotometric Studies of Some Novel Deri vati ves of Pyridinium Chloride

Jasna Lovrić ; Department of Chemistry and Biochemistry, Faculty of Medicine, University of Zagreb, Šalata 3, 10000 Zagreb, Croatia
Nicoletta Burger ; Department of Chemistry and Biochemistry, Faculty of Medicine, University of Zagreb, Šalata 3, 10000 Zagreb, Croatia
Vjera Deljac ; Department of Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, 10000 Zagreb, Croatia
Zlatko Mihalić ; Department of Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, 10000 Zagreb, Croatia

Abstract

The UV-Vis and IR characteristics of five novel aralkyl derivatives of pyridinium chloride, found to be reversible inhibitors of acetyl-cholinesterase, are reported. The dissociation constants of the individual keto and oxime functional groups were determined spectrophotometrically and discussed in terms of the known pK values of compounds with similar structures. The three examined derivatives of the phenacylpyridinium type contain in solution a considerable proportion of the enol form while their next higher homologues are present predominately in their keto forms. AM1 molecular-orbital calculations show that the much higher acidity of α-CH₂ group of benzoylethylpyridinium type compounds is a consequence of an anomeric effect.

Keywords

Hrčak ID:

132141

URI

https://hrcak.srce.hr/132141

Publication date:

1.3.1999.

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