Synthesis of Tetrahedral Shape-Persistent Tetranuclear Metal-salphens

The synthesis of two novel tetrakis(salicylaldehydes) based on a rigid tetraphenylmethane core is presented. These salicylaldehydes were used as precursors for the construction of three-dimensional multimetallic salphens, as exemplified by the synthesis of rigid and shape-persistent tetranuclear zinc-, nickel- and palladium-salphens with defined geometries and distances between the metal sites. The UV/Vis measurements of the tetranuclear metal complexes are presented.