(E)-2-(2-(2-hydroxyphenyl)hydrazono)-1-phenylbutane-1,3-dione: Tautomery and coordination to copper(II)

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• 作者：Maximilian N. Kopylovich^a ; ^{radivil2000@mail.ru"" rel=""nofollow} ; Kamran T. Mahmudov^a ; Matti Haukka^b ; Konstantin V. Luzyanin^a ; Armando J.L. Pombeiro^a ; ^{pombeiro@ist.utl.pt"" rel=""nofollow}
• 关键词：(E)-2-(2-(2-hydroxyphenyl)hydrazono)-1-phenylbutane-1 ; 3-dione ; Azoderivatives of β ; -diketones ; Copper(II) complexes ; X-ray structural analysis
• 刊名：Inorganica Chimica Acta
• 出版年：2011
• 出版时间：1 August 2011
• 年：2011
• 卷：374
• 期：1
• 页码：175-180
• 全文大小：505 K

文摘

(E)-2-(2-(2-hydroxyphenyl)hydrazono)-1-phenylbutane-1,3-dione (H₂L) was synthesized by azocoupling of diazonium salt of 2-hydroxyaniline with 1-phenylbutane-1,3-dione and characterized by IR, ¹H and ¹³C NMR spectroscopies and X-ray diffraction analysis. In solution, H₂L exists as a mixture of the enol-azo and hydrazone tautomeric forms and a decrease of temperature and of solvent polarity shifts the tautomeric balance to the hydrazone form. In the solid state, H₂L crystallizes from ethanol–water in the monohydrate hydrazone form, as shown by X-ray analysis. The dissociation constants of H₂L (pK₁ = 5.98 ± 0.04, pK₂ = 9.72 ± 0.03) and the stability constants of its copper(II) complex (log β₁ = 11.01 ± 0.07, log β₂ = 20.19 ± 0.08) were determined by the potentiometric method in aqueous-ethanol solution. The copper(II) complex [Cu₂(μ-L)₂]_n was isolated in the solid state and found by X-rays to be a coordination polymer of a binuclear core with a distorted square pyramidal metal coordination geometry.