Stability and structure of mono- and dinuclear Cu(ii), Ni(ii) and Zn(ii) complexes of pyrazole and triazole bridged bis-macrocyclesElectronic supplementary information (ESI) available: titration curves and species distribution curves. See http://www.rsc.org/suppdata/dt/b2/b212113a/
作者:Michael Raidt、Markus Neuburger、Thomas A. Kaden
DOI:10.1039/b212113a
日期:2003.3.24
The two ligands L1 and L2, consisting of two 1,4,7-triazacyclononane rings bridged by a pyrazole or a triazole group, form with Cu2+, Ni2+ and Zn2+ a series of mononuclear [MLHn](n
+ 2)+
(n
=
−3, −2, −1, 0, 1, 2) and dinuclear species [M2LHm](m
+ 4)+
(m
= 0, −1, −2, −3), the stabilities of which have been determined by potentiometric titrations. The triazole bridged ligand L1 forms complexes which are more stable than those of the pyrazole bridged system L2. It also shows a higher tendency to form dinuclear species compared to L2. In addition two dinuclear species [Cu2(L2H−1)(μ-Ph2PO2)](ClO4)2·MeCN and [Cu4(L2H−1)2(μ4-PO4)](ClO4)3·MeCN·H2O have been isolated as solids and their X-ray structures have been determined. In the first complex we find a dinuclear Cu2+ species which is bridged by the pyrazolide group as well as by the exogenous diphenyl phosphinate. In the second case a μ4-phosphate ion bridges two dinuclear units, resulting in a tetranuclear species.
这两个配体L1和L2,由两个1,4,7-三氮杂环壬烷环通过吡唑或三唑基团桥接而成,与Cu2+、Ni2+和Zn2+形成一系列单核[MLHn](n + 2)+ (n = -3, -2, -1, 0, 1, 2)和双核物种[M2LHm](m + 4)+ (m = 0, -1, -2, -3),其稳定性通过电位滴定法确定。三唑桥接的配体L1形成的络合物比吡唑桥接的系统L2更稳定。与L2相比,L1显示出更高的形成双核物种的倾向。此外,还分离出两个双核物种[Cu2(L2H−1)(μ-Ph2PO2)](ClO4)2·MeCN和[Cu4(L2H−1)2(μ4-PO4)](ClO4)3·MeCN·H2O作为固体,并确定了它们的X射线结构。在第一个络合物中,我们发现一个由吡唑基团和外源性二苯基磷酸盐桥接的双核Cu2+物种。在第二种情况下,一个μ4-磷酸根离子桥接两个双核单元,形成一个四核物种。