The amide oxygen donor. Metal ion coordinating properties of the ligand nitrilotriacetamide. A thermodynamic and crystallographic study
作者:Laura A. Clapp、Chynthia J. Siddons、Donald G. VanDerveer、Joseph H. Reibenspies、S. Bart Jones、Robert D. Hancock
DOI:10.1039/b512017a
日期:——
of [Pb(ntam)(NO3)2]2 (1) and [Ca2(ntam)3(H2O)2](ClO4)4·3H2O (2) are reported. For 1: triclinic, space group P, a = 7.4411(16), b = 9.0455(19), c = 11.625(3) Å, α = 69.976(4), β = 79.591(4), γ = 67.045(3)°, Z = 2, R = 0.0275. For 2: monoclinic, space group P21/c, a = 10.485(2), b = 11.414(2), c = 38.059(8) Å, β = 92.05(3)°, Z = 4, R = 0.0634. Structure 1 is dimeric with two Pb atoms linked by bridging
ntam(次氮基三乙酰胺)的报告。在25°C下于0.1 M NaClO 4中,ntam的质子化常数(p K)为2.6 。在25°C下于0.1 M NaClO 4中的形成常数(log K 1)由下式确定:1 H NMR 和 紫外可见 光谱学分别为:Ca(II),1.28;镁(II),0.4;La(III),2.30;铅(II),3.69。Cd(II),3.78; m / z。Ni(II),2.38; N,2。铜(II),3.16。讨论了ntam配合物的实测log K 1值,如p K所证明的那样,是因为N供体的碱度较低,以及金属离子尺寸对配合物稳定性的影响。这酰胺相对于NH 3络合物的log K 1,ntam的O供体导致大型金属离子(Pb(II),Cd(II),La(III),Ca(II))的络合物的稳定化,而对于较小的金属离子金属离子(Ni(II),Cu(II))酰胺O型供体会导致不稳定。就