Relative stabilities of metal complexes of 4-(2-pyridylazo)resorcinol and 4-(2-thiazolylazo)resorcinol
1986; Elsevier BV; Volume: 5; Issue: 6 Linguagem: Inglês
10.1016/s0277-5387(00)81387-x
ISSN1873-3719
Autores Tópico(s)Electrochemical sensors and biosensors
ResumoThe stability constants of 1:1 complexes of 4-(2-pyridylazo)resorcinol (PAR) and 4-(2-thiazolylazo)resorcinol (TAR) with Mn(II), Ni(II), Cu(II) and Zn(II) have been determined spectrophotometrically at μ = 0.1 and 25°C. The method is based on indirect estimation of the protonated and normal complexes by measuring the ligand absorption peak. Both protonated and normal complexes of these metals with PAR are more stable than those with TAR. The reverse order was previously observed for the pronated complexes of the lanthanides(III). The different behaviour of the 3d transition metals(II) compared to the lanthanides(III) is discussed. The proton dissociation constants of the protonated complexes of PAR or TAR with various metals are also discussed.
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