1:1 Cross-Assembly of Two beta-Diketonate Complexes through Arene-Perfluoroarene Interactions

摘要

Closely arranged metal-metal systems have been investigated in efforts to obtain new magnetic and conductive materials of nanometer size to exploit innovative functions. How to construct the systems in order to make use of the metal-metal interactions is a crucial issue for many chemists. The most popular strategy for this purpose is direct construction of coordination compounds from metals and organic frames through coordination bonds. On the other hand, in an example of an indirect method, hydrogen bonds were used to arrange discrete metal complexes. Electrostatic interactions are also frequently used to control the systems as they are weaker, though it is difficult to control the directionality of the self-assembled system in many cases. The arene-perfluoroarene interaction as an example of electrostatic interactions is a promising approach to control the direction and position of intermolecular interactions by quadrupole moments. For example, two different organic molecules are regularly arranged by such interactions between arene- and perfluoroarene-functionalized moieties. This idea prompted us to cross-assemble different metal complexes through arene-perfluoroarene interactions. Here, we demonstrate the one-dimensional arrangement of metal complexes, namely, the arene-functionalized Cu~(II) complex 1a and the perfluoroarene-functionalized Cu~(II) complex 2 (Scheme 1). The metal-metal distance is close to that of the van der Waals contact. This is the first application of the simple and unique construction strategy through arene-perfluoroarene interactions between different complexes to obtain a metal-metal arrangement. Furthermore, the analogous cross-assembled architectures have also been achieved with Pd~(II) and Pt~(II) complexes, which suggests a great utility of this method for obtaining metal cross-assemblies.