The synthesis, reactivity, and spectroscopic properties of a series of triangular phosphido-bridged rhodium, iridium, palladium and platinum clusters are described. Throughout the project, X-ray diffraction and 31P{1H} NMR spectroscopy are the main techniques for characterizing compounds. In the first part of this report, the lability of μ-X and terminal phosphines in [M3(μ-X)(μ-PPh2)2(PPh3)3)[BF4](M= Pd, X= Cl; M=Pt, X= H) is utilized to prepare a number of compounds where the integrity of the triangular framework is maintained. The molecular structures of three representative examples: [Pd3(μ-SCH2Ph)(μ-PPh2)2(PEt3)3][BF4] [Pt3(μ-Cl)(μ-PPh2)2(PR3)3][BF4) (R= Ph, Et) were determined and are described. Reaction of these palladium and platinum trinuclear clusters with chelating ligands, R’2PYPR”2 (Y= O, CH2), results in unusual cluster fragmentation to give novel dinuclear monocations, [M2(μ-PP2)(μ-R’2PYPR”2) (PR3)2)+ (M= Pd, Pt) in which a metal-metal bond is supported by both dppm and phosphido bridges. These dimers are very inert failing to react with a number of reagents including C4H6, HCCCO2Me, CH2N2, CO, CH3I (when M= Pd), H2, HBF4 and CH2I2. The cluster, [Pt3(μ-H)(μ-PPh2)2(PPh3)3] [BF4], also reacts with ButNC to afford the dinuclear species (Pt2(μ-PPh2)2(ButNC)(PPh3)3]+. The crystal structures of fragmentation products [Pd2(μ-PPh2)( μ-Pri2PCH2PPh2)(PPh3)2] [BF4], (Pt2(μ-PPh2)( μ-Me2PCH2PMe2)(PPh3)2]2 [C2O4] and (Pt2(μ-PPh2)(ButNC)(PPh3)3]2(C2O4) are reported and discussed.
In the last part, the synthesis of a novel trinuclear iridium cluster, [Ir3(μ-PPh2)3(CO)5], is described, and the reactions of this cluster and its previously reported rhodium analogue, [Rh3(μ-PPh2)3(PPh3)2(CO)3], with dppm afford not fragmentation, but substitution products. The complex (Ir3(μ-PPh2)3(CO)5] also reacts with ButNC to yield [Ir3(μ-PPh2)3(CO)5(ButNC)2]. The crystal structures of the compounds, [M3(μ-PPh2)3(μ-dppm)(CO)3] (M= Rh, Ir) and (Ir3(μ-PPh2)3(CO)5(ButNC)2], are also reported. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/9475 |
| Date | 19 June 2018 |
| Creators | Dehghan, Khashayar |
| Contributors | Dixon, Keith R. |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Available to the World Wide Web |
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