Preparation and study of amino acid (DL-leucine, L-isoleucine, L-histidine) Schiff bases with ethyl-α-ketocyclopentylcarboxylate and the corresponding copper(II) complexes
1992; Elsevier BV; Volume: 195; Issue: 1 Linguagem: Inglês
10.1016/s0020-1693(00)83848-7
ISSN1873-3255
AutoresA. Angoso, J.M. Martín-Llorente, J.L. Manzano, Maria Luisa Martín, Robert Martin, E. Rodríguez, J. Soria,
Tópico(s)Protein Interaction Studies and Fluorescence Analysis
ResumoAmino acid Schiff bases with ester function K(Rleu)·2H2O (1), K(Rile)·2H2O (2), K(Rhis)·H2O (3) (Rleu, Rile and Rhis represent the Schiff base of DL-leucine, L-isoleucine and L-histidine, and ethyl-α-ketocyclopentylcarboxylate) were synthesized. Compounds 1, 2 and 3 were characterized by 1H NMR spectroscopy. The copper(II) complexes, Cu(Rleu′)·H2O (4), Cu[Rile′]·H2O (5) andCu(Rhis′)·2H2O (6), were obtained with the N-deprotonated Schiff bases (Rleu′, Rile′ and Rhis′). The COO stretching bands in their IR spectra suggest that the carboxylate acts as a monodentate group when binding with copper. The temperature dependence of the susceptibility for 6 may be fit to the Curie-Weiss expression χ=O.32/(T-26.2) emu mol−1 K−1 The dehydration process of 6 leads to the anhydrous compound, enthalpy (53±2kJ mol−1) and activation energy (82±5 kJ mol−1).
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