Triphosphines

Only a few studies are known concerning the application of triphosphines as ligands in hydroformylation. Their behavior resembles in principle the effect of three monodentate phosphines coordinated to rhodium. For 

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Bardaji, M., Laguna, A., Orera, V.M. and Villacampa, M.D. (1998) Synthesis, Structural Characterization, and Luminescence Studies of Gold(l) and Gold(lll) Complexes with a Triphosphine Ligand. Inorganic Chemistry, 37(20), 5125-5130. 

Bardaji, M., Laguna, A., Vicente, J. and Jones, P.G. (2001) Synthesis of luminescent gold(I) and gold(III) complexes with a triphosphine ligand. Inorganic Chemistry, 40, 2675-2681. 

Related to these diphosphine dichalcogenides are the triphosphine trisulfides [R2P(S)]3CH (12) which can be prepared from lithiated methylene diphosphine disulfides upon treatment with thiophosphinic chlorides (Equation 9). Deprotonation of 12 with tBuLi gives a resonance-stabilised anion 13 containing a planar central carbanion whose charge is delocalised onto the three neighbouring phosphorus and sulfur atoms.32... 

Triphosphine reacted with carbon tetrabromide to form an organic salt [13]. This reactive species then reacted with alcohol to form the corresponding bromide. Kinetics results showed that there is no significant difference in reaction rate when resin beads of different sizes were used. This demonstrated that the diffusion of the organic salt into bead was not rate hmiting compared with the reaction rate. 

Triphosphine, P3H5, has been identified as a product from the hydrolysis of CaaPj or Mg3P2 in acidic media by mass spectroscopy In addition, using mass spectroscopic analysis Baudler and her co-workers 436.437) able to identify the following higher phosphines formed during the hydrolysis or the disproportionation of diphosphine ... 

Figure 2.35 Trinuclear gold compound with bridging thiolate and triphosphine ligands.

The use of both di- or triphosphines and chalcogenolates as building blocks in the same molecule leads to different species. The trinuclear derivative shown in Figure 2.35 is an example [167]. A more complicated structure is that of Au9(p.-p-tc)6(p.-dppm)4]3+ (p-tc = p-thiocresolate) which exhibits short gold-gold interactions. An emission at 540 nm is observed upon excitation at 450 nm in the solid state at room temperature that increases in intensity at 77 [168]. 

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