Trifunctional phosphane ligands and their application in the synthesis of novel cage-structured platinacyclophanes and trinuclear chain-like platinacycles by self-assembly

The synthesis of the 1,3,5-tris[(diphenylphosphoryl)alkyl]-benzenes 7-10 su cceeds by reaction of the corresponding 1,3,5-tris(bromoalkyl)benzenes 3-6 with ethyl diphenylphosphinite in an Arbusov-type reaction. Reduction of th ese phosphane oxides leads to the trifunctional phosphane ligands 11-14. Th eir potency of self-assembly was examined by the employment of platinum(II) complex fragments. A five-component self-assembly consisting of 3 equiv, o f the platinum complex Cl2Pt(NCPh)(2) and 2 equiv. of the ligands 11-14 und er high-dilution conditions led to the formation of the nanoscaled triplati nacyclophanes 1 and 15-17. Polymers were formed as by-products from the rea ctions between 11-13 and Cl2Pt(NCPh)2, whereas in the case of 14 three othe r platinacyles 18-20 with a chain-like structure were formed. The structure s of the metallacycles 1 and 15-17 as well as 18-20 were elucidated by P-31 (H-1), C-13{H-1}, and Pt-195{H-1} NMR spectroscopic investigations.