Spectrophotometric study of binary and ternary systems involving metal ions and benzylidenepyruvates: Equilibria in aqueous solutions
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
26/05/2014
26/05/2014
01/12/1984
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Resumo |
The protonation of 4-dimethylaminobenzylidenepyruvate (DMBP) and 2-chloro-4-dimethylaminobenzylidenepyruvate (2-CI-DMBP) and their complex formation with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and Al(III) have been studied by potentiometric and spectrophotometric methods at 25 °C and ionic strength 0.500 M, held with sodium perchlorate. The stability order found for 1 :1 complexes of both ligands is Al(III) > Cu(II) > Pb(II) > Ni(II) > Zn(II) > Co(II) > Cd(II) > Mn(II). The stability changes move in the same direction as the pKa of the ligands. The results are compared with literature values reported for metal ion pyruvate systems. Thermodynamic stabilities of ternary complexes formed in Cu(II)-B-L- systems, where B = 2,2′-bipyridyl (bipy), ethylenediamine or glycinate and L = DMBP or 2-CI-DMBP, were also determined. The Cu(bipy)L+ species are more stable than would be expected on purely statistical grounds. The importance of the :t system associated with bipy on the enhanced stability of its mixed ligand complexes is stressed. Analytical applications of the investigated ligands are outlined. |
Formato |
385-389 |
Identificador |
http://dx.doi.org/10.1039/AN9840900385 The Analyst, v. 109, n. 3, p. 385-389, 1984. 0003-2654 http://hdl.handle.net/11449/63684 10.1039/AN9840900385 2-s2.0-0001037091 |
Idioma(s) |
eng |
Relação |
The Analyst |
Direitos |
closedAccess |
Palavras-Chave | #Benzylidenepyruvates #Binary and ternary metal ion complexes #Equilibria #Spectrophotometry |
Tipo |
info:eu-repo/semantics/article |