Synthesis of Carbosilane Dendrimers Containing up to Four Metal Layers

Metallodendrimers are an important class of materials with valuable properties and applications in a large number of areas. Herein, we report a highly efficient route for the synthesis of carbosilane dendrimers containing multimetal layers. The procedure involves the use of heteroditopic and tritopic PN ligands as connectors of the metal layers. The synthetic strategy is based on the ability of the latter ligands to react selectively with the metal complexes [AuCl(tht)] (tht: tetrahydrothiophene). [{RuCl2)(p-cymene)}(2)] and [Pd(eta(3)-2-MeC3H4)-(cod)](OTf) (cod: 1,5-cyclooctadiene; OTf: triflate). In this way, metallodendrimers containing trimetallic Ru-Au-Pd or tetrametallic Ru-Au-Au'-Pd layers have been formed and characterized. The trimetallic dendrimer 9 can be selectively deconstructed by cleavage of the Ru-N or Au-N bonds by reaction with chloride or iodide salts, respectively.