Ambrosi Gianluca, Dapporto Paolo, Formica Mauro, Fusi Vieri, Giorgi Luca, Guerri Annalisa, Micheloni Mauro, Paoli Paola, Pontellini Roberto, Rossi Patrizia
Institute of Chemical Sciences, University of Urbino, Italy.
Dalton Trans. 2004 Nov 7(21):3468-74. doi: 10.1039/B408808E. Epub 2004 Sep 17.
The synthesis and characterization of two new macrocyclic ligands, the bis-macrocyclic compound 2,6-bis(1,4,13-triaza-7,10-dioxacyclopentadec-1-ylmethyl)phenol (L) and 38-methoxy-1,4,13,16,19,28-hexaaza-7,10,22,25-tetraoxatricyclo[14.14.7.1(32,36)]octatriconta-32,34,Delta(36,38)-triene (L1) are reported. Equilibrium studies of basicity and coordination properties toward metal ions such as Cu(II), Zn(II), Cd(II) and Pb(II) were performed for ligand by potentiometric measurements in aqueous solution (298.1 +/- 0.1 K, I= 0.15 mol dm(-3)). L behaves as a hexaprotic base (logK(1)= 10.93, logK(2)= 9.70, logK(3)= 8.79, logK(4)= 8.05, logK(5)= 6.83, logK(6)= 2.55). All metal ions form stable mono- and dinuclear complexes: logK(MLH(-1))= 25.61 for Cu(II), 15.37 for Zn(II), 12.58 for Cd(II) and 13.79 for Pb(II); logK(M(2)LH(-1))= 31.61 for Cu(II), 23.38 for Zn(II), 24.49 for Cd(II) and 23.68 for Pb(II). All these dinuclear species show a great tendency to add the OH(-) group: the equilibrium constant for the addition reaction was found to be logK(M(2)LH(-1)OH)= 4.77 for Cu(II), 5.66 for Zn(II), 2.8 for Cd(II) and 3.18 for Pb(II). In the case of Ni(II), kinetic inertness prevents the possibility of solution studies. The dinuclear solid adducts [Ni(2)H(-1)L(N(3))(3)].EtOH and Cu(2)H(-1)L(N(3))(2) were characterized by X-ray analysis.
报道了两种新型大环配体,双大环化合物2,6 - 双(1,4,13 - 三氮杂 - 7,10 - 二氧杂环十五烷基甲基)苯酚(L)和38 - 甲氧基 - 1,4,13,16,19,28 - 六氮杂 - 7,10,22,25 - 四氧杂三环[14.14.7.1(32,36)]三十八 - 32,34,Δ(36,38) - 三烯(L1)的合成与表征。通过在水溶液(298.1 ± 0.1 K,I = 0.15 mol dm⁻³)中进行电位测量,对配体与Cu(II)、Zn(II)、Cd(II)和Pb(II)等金属离子的碱性和配位性质进行了平衡研究。L表现为六元质子碱(logK₁ = 10.93,logK₂ = 9.70,logK₃ = 8.79,logK₄ = 8.05,logK₅ = 6.83,logK₆ = 2.55)。所有金属离子均形成稳定的单核和双核配合物:Cu(II)的logK(MLH⁻¹) = 25.61,Zn(II)的为15.37,Cd(II)的为12.58,Pb(II)的为13.79;Cu(II)的logK(M₂LH⁻¹) = 31.61,Zn(II)的为23.38,Cd(II)的为24.49,Pb(II)的为23.68。所有这些双核物种都表现出强烈的添加OH⁻基团的倾向:发现Cu(II)的加成反应平衡常数为logK(M₂LH⁻¹OH) = 4.77,Zn(II)的为5.66,Cd(II)的为2.8,Pb(II)的为3.18。对于Ni(II),动力学惰性使得无法进行溶液研究。通过X射线分析对双核固体加合物[Ni₂H⁻¹L(N₃)₃]·EtOH和Cu₂H⁻¹L(N₃)₂进行了表征。