Chemistry of bridging phosphanes: a comparative study within Cu(I)-Ag(I)-Au(I) triad-based homonuclear dimers.
Chemistry of bridging phosphanes: a comparative study within Cu(I)-Ag(I)-Au(I) triad-based homonuclear dimers.
复制标题
桥膦化学：基于 Cu(I)-Ag(I)-Au(I) 三联体的同核二聚体的比较研究。
作者：
S. Welsch;Brigitte Nohra;E. Peresypkina;C. Lescop;M. Scheer;R. Réau
Ag(I)和Au(I)双金属络合物中的桥联配体：在Ag(I)二聚体中，双(2-吡啶)膦的P部分作为对称、半或非桥联供体(见图)。在相关的Au(I)络合物中，只观察到非桥联模式。用不饱和的Ag(I)二聚体作为自适应分子剪切剂合成了pi堆叠的金属环钯化合物，双(2-吡啶基)膦C与AgPF(6)和dppm反应生成了阳离子二聚体1，其中C作为1kappaN：1，2kappaP：2kappaN-供体，对称桥联P-中心。这个配合物给出了第一个基于带有桥联sigma(3)、lambda(3)-膦配体的三角平面金属中心的二聚体的例子。C的两个等价物与AgPF(6)和Ag{Al[OC(CF(3))(3)](4)}反应，分别得到通式为Ag(2)(C)(2)(2+)的阳离子二聚体2和3。X-射线衍射仪研究表明，1个配体C作为1kappaN：1，2kappaP：2kappaN-施主对称桥联P-中心，另一个配体C作为1kappaN：2kappaP-螯合物。在化合物3中，一个甲苯分子与一个银中心相互作用，给出了第一个具有桥联P-给体的混合配位二聚体的例子。用不同的方法合成了通式为Ag(2)(C)(3)(2+)，2X(-)(X=Pf(6)，BF(4)，Al[OC(Cf(3))(3)](4))的Ag(I)-二聚体4a-c，并用X射线衍射法进行了表征。在这些衍生物中，C表现出不同的配位模式，这取决于反阴离子和不对称单元中包含的溶剂分子的性质。这些复合体可以具有0、1或2个桥联P-供体。这些结果明确地证明了膦配体的P中心可以很容易地从桥联模式切换到半桥联和非桥联配位模式。二聚体2被用作与重位连接物反应合成pi堆叠的金属环状化合物7a、b和8的“适应性”分子夹子。X-射线衍射研究表明，这些超分子物种是反阴离子(PF(6)、BF(4))的受体，阴离子的性质影响超分子金属环番的立体化学。制备了含两个配体C的Au(I)-二聚体10a，b作为1kappaN：2kappaP-螯合物，并在固态下进行了表征。
Bridging ligands in Ag(I) and Au(I) bimetallic complexes: The P moiety of bis(2-pyridyl)phosphole acts as a symmetrically, semi-, or non-bridging donor in Ag(I) dimers (see figure). In related Au(I) complexes, only the non-bridging mode is observed. An unsaturated Ag(I) dimer is used as an adaptive molecular clip for the synthesis of pi-stacked metallocyclophanes.Bis(2-pyridyl)phosphole C reacted with AgPF(6) and dppm giving rise to dicationic dimer 1 in which C acts as a 1kappaN:1,2kappaP:2kappaN-donor with a symmetrically bridging P-centre. This complex gives the first example of dimers based on trigonal planar metal centres bearing a bridging sigma(3),lambda(3)-phosphane ligand. The reaction of two equivalents of C with AgPF(6) and Ag{Al[OC(CF(3))(3)](4)} afforded dicationic dimers 2 and 3 of general formula Ag(2)(C)(2) (2+), respectively. X-ray diffraction studies showed that one ligand C acts as a 1kappaN:1,2kappaP:2kappaN-donor with a symmetrically bridging P-centre and one behaves as a 1kappaN:2kappaP-chelate. In complex 3, one toluene molecule interacts with an Ag centre, giving the first example of a mixed coordination dimer featuring a bridging P-donor. Ag(I)-dimers 4 a-c of the general formula Ag(2)(C)(3) (2+), 2 X(-) (X=PF(6), BF(4), Al[OC(CF(3))(3)](4)) have been prepared according to different routes and characterised by X-ray diffraction study. In these derivatives, C exhibits a variety of coordination modes depending on the nature of the counteranion and of the solvent molecules included in the asymmetric units. These complexes can feature 0, 1, or 2 bridging P-donors. These results definitively demonstrate that the P-centre of phosphane ligands can easily switch from a bridging to a semi-bridging and a non-bridging coordination mode. Dimer 2 is used as an "adaptive" molecular clip for the synthesis of pi-stacked metallocyclophanes 7 a, b and 8 upon reaction with ditopic linkers. X-ray diffraction studies revealed that these supramolecular species behave as receptors for the counteranions (PF(6), BF(4)) and that the nature of the anion impacts the stereochemistry of the supramolecular metallocyclophanes. Au(I)-Dimers 10 a, b bearing two ligands C acting as 1kappaN:2kappaP-chelates are prepared and characterised in the solid-state.