Supramolecular Pt and Pd Complexes of 4,4-Dipyridylditelluride/Diselenide Ligands through Self-Assembly

The self-assembly of 4,4-dipyridylditelluride/diselenide and M(OTf)(2) {M = cis-[Pt(PEt3)(2)](2+) or cis-[Pd(dppe)](2+); dppe = 1,2-bis(diphenylphosphino)ethane} yields [M(mu(2)-4,4-py(2)E(2))](n)(OTf)(2n) (E = Se, Te). The major and minor products, indistinguishable by simple proton NMR and phosphorus NMR spectroscopy, can be detected by heteronuclear (Se-77, Te-125, and Pt-195) NMR spectroscopy. The respective dimeric and trimeric structures are assigned by ESI and MALDI-TOF mass spectrometry, and for the first time, their equilibria have been established. The rhomboid shape of the dimeric complex containing the Pt-N bond is confirmed by its X-ray diffraction structure. The formation of the cluster-type minor product [Pd-3(mu-E)(2)(dppe)(3)](OTf)(2) has also been identified in the reactions of the Pd complexes.