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Zn 2+ complexes with N ‐(2‐pyridyl)cinnamides: Characterization and UV studies
Author(s) -
Duran H.,
Duran E.,
Gorrichon L.,
Perry M.
Publication year - 1993
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.610060104
Subject(s) - chemistry , stoichiometry , zinc , oxygen atom , crystallography , stereochemistry , medicinal chemistry , analytical chemistry (journal) , molecule , organic chemistry
Zinc(II) complexes of N ‐pyridylcinnamides (H, m ‐OCH 3 , p ‐OCH 3 and p ‐OH derivatives) were studied by spectrophotometric methods in aprotic media, and represent a chemical model inhibition by cinnamides of coniferyl alcohol dehydrogenase (CAD), a zinc enzyme involved in the lignification process. The complexation of N ‐pyridylcinnamide and m ‐methoxy‐ N ‐pyridylcinnamide with zinc ion is effected according to a 1 : 1 stoichiometry (ML), whereas a two‐step equilibrium (M + L ⇌ ML \documentclass{article}\pagestyle{empty}\begin{document}$ V_{\rm m} = 4 \cdot 45C_0 + 6 \cdot 44C_1 - 3 \cdot 33C_2 + 0 \cdot 46C_4 + 52 \cdot 9{\rm (}n = 300,r = 0 \cdot 999,s = 0 \cdot 81) $\end{document} ML 2 ) is preferred with p ‐methoxy and p ‐hydroxy compounds. These ligands are mainly bonded through the carbonyl oxygen atom and the nitrogen of the pyridyl ring. Molar absorptivities for these complexes, not directly available, were calculated from analysis of the experiemental data. The UV complexation results are also supported by the stoichiometry of the complexes, which were synthesized and characterized.