title: Heteroleptic Chini-Type Platinum Clusters: Synthesis and Characterization of Bis-Phospine Derivatives of [Pt3n(CO)6n]2-(n = 2-4).
abstract: The reactions of [Pt3n(CO)6n]2-(n = 2-4) homoleptic Chini-type clusters with stoichiometric amounts of Ph2PCH2CH2PPh2(dppe) result in the heteroleptic Chini-type clusters [Pt6(CO)10(dppe)]2-, [Pt9(CO)16(dppe)]2-, and [Pt12(CO)20(dppe)2]2-. Their formation is accompanied by slight amounts of neutral species such as Pt4(CO)4(dppe)2, Pt6(CO)6(dppe)3, and Pt(dppe)2. A similar behavior was observed with the chiral ligand R-Ph2PCH(Me)CH2PPh2(R-dppp), and two isomers of [Pt9(CO)16(R-dppp)]2-were identified. All the new species were spectroscopically characterized by means of IR and31P NMR, and their structures were determined by single-crystal X-ray diffraction. The results obtained are compared to those previously reported for monodentate phosphines, that is, PPh3, as well as more rigid bidentate ligands, that is, CH2═C(PPh2)2(P^P), CH2(PPh2)2(dppm), and o-C6H4(PPh2)2(dppb). From a structural point of view, functionalization of anionic platinum Chini clusters preserves their triangular Pt3units, whereas the overall trigonal prismatic structures present in the homoleptic clusters are readily deformed and transformed upon functionalization. Such transformations may be just local deformations, as found in [Pt9(CO)16(dppe)]2-, [Pt9(CO)16(R-dppp)]2-, [Pt12(CO)22(PPh3)2]2-, and [Pt9(CO)16(PPh3)2]2-; an inversion of the cage from trigonal prismatic to octahedral, as observed in [Pt6(CO)10(dppe)]2-and [Pt6(CO)10(PPh3)2]2-; the reciprocal rotation of two trigonal prismatic units with the loss of a Pt-Pt contact as found in [Pt12(CO)20(dppe)2]2-.
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Cesari
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Iacopo
authors.initials: I
authors.lastname: Ciabatti
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Femoni
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Maria Carmela
authors.initials: MC
authors.lastname: Iapalucci
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Mancini
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Stefano
authors.identifier: http://orcid.org/0000-0003-0739-0518
authors.initials: S
authors.lastname: Zacchini