A double cubane structure in organoplatinum(Ⅳ) chemistry

摘要

The reaction of [PtMe_2(dpe)], dpe = 1,2-di-2-pyridylethane, with hydrogen peroxide occurs with ligand loss to give [{PtMe_2(OH)_2}_n], but the reaction mixture then slowly yields crystals of [{PtMe_3OH·PtMe_2(OH)_2}_2][PtMe_2(CO_3)(dpe)]_2, in which the central cluster has an unexpected structure based on a face-bridged double cubane.rnThe trimethylplatinum(iv) complexes [(PtMe_3X)_4], X = Cl, Br, I, OH etc., were among the first alkyl complexes of transition metals to be prepared, and so they have a particularly important place in organometallic chemistry. They have the cubane structure A, Scheme I. There are also complexes of formula [{(PtMe_3X)(PtMe_2X_2)}_n] and [(PtMe_2X_2)_n] whose compositions are well-established but whose structures are less certain. The compounds [{(PtMe_3X)(PtMe_2X_2)}_n] are proposed to have cubane structures, B or C in Scheme 1, based mostly on vibrational spectroscopy and by analogy to A. This paper shows that the complex [{(PtMe_3X)(PtMe_2X_2)}_n], X = OH, actually has the structure D, Scheme 1, which is based on a face-bridged double cubane with two vertices missing.