Complexation behaviour and stability of Schiff bases in aqueous solution. The case of an acyclic diimino(amino) diphenol and its reduced triamine derivative
作者:P. Di Bernardo、P. L. Zanonato、S. Tamburini、P. Tomasin、P. A. Vigato
DOI:10.1039/b604211b
日期:——
a maximum formation percentage at pH approximately 9. In addition, the involvement of imine nitrogens in the complexes markedly stabilises the azomethylene linkage, so that the metal complexes of H(2)L(A), particularly those of copper(II), are the species largely prevailing in solutions with pH >3.5. The stability constants of the complexes formed by metal ions with H(2)L(A) and H(2)L(B) follow the
无环席夫碱H(2)L(A)的铜(II),镍(II)和锌(II)配合物,是通过[1 + 2]缩合1,2-乙二胺,N-(2)获得的-氨基乙基)-N-甲基与3-乙氧基-2-羟基苯甲醛和H(2)L(B)(H(2)L(A)的还原衍生物)的制备,并通过IR,NMR研究了它们的性质和SEM-EDS。在这些络合物中,金属离子始终位于配体的配位室内,该配位室由两个酚氧和氮原子(胺或亚胺)界定。H(2)L(A)和H(2)L(B)在298 K水溶液中对H(+),Cu(2 +),Ni(2+)和Zn(2+)的配位行为mu = 0.1 mol dm(-3)(Na)ClO(4)也通过电位法,NMR和UV-VIS测量进行了研究。特别是,电位平衡研究表明,H(2)L(A)不够稳定,无法具有pH范围,在pH范围内它是水溶液中的唯一物质。在这样的溶液中,席夫碱在有限的pH范围(6到10)之间形成,在pH约为9时最大形成百分数。