Homo- and heteropolynuclear Ni2+ and Cu2+ complexes of polytopic ligands, consisting of a tren unit substituted with three 12-membered tetraazamacrocycles
作者:Liselotte Siegfried、C. Niamh McMahon、Jan Baumeister、Markus Neuburger、Thomas A. Kaden、Sreekanth Anandaram、Cornelia G. Palivan
DOI:10.1039/b709422a
日期:——
Cu(2+) and Ni(2+) complexes with L3 (1-(N-methyl-2-aminoethyl-1,4,7,10-tetraazacyclododecane)) were also investigated. The crystal structures of [CuL3H(H(2)O)](ClO(4))(3) and [NiL3Cl](ClO(4)) were solved and show that the side chain in its protonated form is not involved in coordination, whereas deprotonated it binds to the metal ion. The thermodynamically stable 3:1 complexes of L1 or L2 have a metal
已经合成了两个新的多位配体L1和L2。它们由一个中央tren单元组成,三个1,4,7,10-四氮杂环十二烷环分别通过一个乙烯桥和一个三亚甲基桥连接到该中心。通过电位pH滴定,UV-Vis,EPR光谱和动力学技术研究了L1和L2对Cu(2+)和Ni(2+)的络合特性。作为比较,还研究了具有L3(1-(N-甲基-2-氨基乙基-1,4,7,10-四氮杂十二烷))的Cu(2+)和Ni(2+)配合物。解析[CuL3H(H(2)O)](ClO(4))(3)和[NiL3Cl](ClO(4))的晶体结构,结果表明质子化形式的侧链不参与配位,而去质子化它与金属离子结合。L1或L2的热力学稳定的3:1配合物在三个大环单元中具有金属离子。然而,当将三当量的Cu(2+)添加到L1或L2中时,金属离子首先结合到tren单元,然后才结合到大环。研究了不同络合步骤的动力学,并提出了机理。