Post-coordination functionalisation of pyrazolyl-based ligands as a route to polynuclear complexes based on an inert Ru<sup>II</sup>N<sub>6</sub>core
作者:Qiao-Hua Wei、Stephen P. Argent、Harry Adams、Michael D. Ward
DOI:10.1039/b708572a
日期:——
The simple mononuclear complex [Ru(H2bpp)2][PF6]2 [H2bpp = 2,6-bis(pyrazol-3-yl)pyridine] contains four coordinated pyrazolyl ligands which each have a reactive NH site at the position adjacent to the coordinated N atom. Alkylation of these with either 2-[1-4-(bromomethyl)benzyl}-1H-pyrazol-3-yl]pyridine or 4′-[(4-bromomethyl)phenyl]terpyridine allows attachment of four additional chelating groups, either bidentate pyrazolyl–pyridine and terdentate terpyridyl units, respectively, which are pendant from the central kinetically inert RuIIN6 complex core. These functionalised mononuclear complexes [Ru(L1)2][PF6]2 (with four pendant pyrazolyl–pyridine bidentate sites) and [Ru(L2)2][PF6]2 (with four pendant terpyridyl sites) can be used as the starting point for polynuclear assemblies by attachment of additional labile metal ions as the secondary sites. As examples of this we prepared and structurally characterised the trinuclear complex [RuAg2(L1)2][ClO4]4, an unusual example of a polynuclear helicate containing a kinetically inert metal centre, and the pentanuclear complex [RuCu4(MeCN)5(H2O)1.5(L2)2](SbF6)6(BF4)4 in which each of the pendant terpyridyl sites of the [Ru(L2)2]2+ core is coordinated to a Cu(II) ion.
简单的单核配合物 [Ru(H2bpp)2][PF6]2 [H2bpp = 2,6-双(吡唑-3-基)吡啶]包含四个配位的吡唑基配体,每个配体在与配位的N原子。用 2-[1-4-(溴甲基)苯甲基}-1H-吡唑-3-基]吡啶或 4'-[(4-溴甲基)苯基]三联吡啶将它们烷基化,可以连接四个额外的螯合基团,分别是二齿吡唑基-吡啶和三齿三联吡啶单元,它们悬挂在中心动力学惰性 RuIIN6 复合物核心上。这些功能化单核配合物 [Ru(L1)2][PF6]2(具有四个侧挂吡唑基-吡啶二齿位点)和 [Ru(L2)2][PF6]2(具有四个侧挂三联吡啶位点)可用作起始材料通过连接额外的不稳定金属离子作为第二位点进行多核组装。作为例子,我们制备并表征了三核配合物 [RuAg2(L1)2][ClO4]4(包含动力学惰性金属中心的多核螺旋的不寻常例子)和五核配合物 [RuCu4(MeCN)5(H2O) )1.5(L2)2](SbF6)6(BF4)4,其中 [Ru(L2)2]2+ 核心的每个侧联三联吡啶位点均与 Cu(II) 离子配位。