Ruthenium metallodendrimers based on Nitrile-functionalized Poly(alkylidene imine)s

The preparation of the first- and second-generation of nitrilefunctionalized poly(alkylidene imine) dendrimers with the organometallic ruthenium complex [Ru(η5-C5H5)(PPh3)2Cl] peripherally attached is described. The reaction of N,N -bis(cyanomethyl)piperazine (1), N,N -bis[N ,N -bis(cyanoethyl)aminoethyl]piperazine (2), or N,N,N ,N -tetrakis(cyanoethyl)ethylenediamine (3) with [Ru(η5-C5H5)(PPh3)2Cl] (4) in the presence of TlPF6 gives the new air-stable ruthenium metallodendrimers 5, 6, and 7, respectively. These stable metallodendrimers are easily prepared and represent a novel quantitative method to solidify and chromatographically purify the otherwise semi-liquid nitrile-functionalized poly(alkylidene imine) dendrimers. The compounds were fully characterized by IR and 1H, 13C, and 31P NMR spectroscopy, and mass spectrometry. These dendrimers represent the first example of the utilization of nitrile-functionalized poly(alkylidene imine)s as cores in the preparation of metallodendrimers.