Triphenylphosphine, substitute

Birch and Pearson22 have studied electrophilic substitution of a triphenylphosphine-substituted system, [Fe(cyclohexadiene)(CO)2PPh3], (8 equation 7). Several features of their results are instructive. First, substitution of CO by the better o-donor, poorer ir-acceptor PPh3 ligand renders the complex more reac-... 

The structure of the triphenylphosphine substitution product is known (29). The square pyramidal Ru6C core is retained, and the phosphine replaces one carbon monoxide from a basal Ru(CO)3 group in 10. The carbide carbon atom is situated 0.19 A below the square face of the pyramid (cf. 0.11 A in 10). 

Chlorotris(triphenylphosphine)rhodium(I) is also the precursor of numerous chloro complexes which may be obtained by exchanging PPh3 for other ligands. The main use of this reaction, however, is to prepare [RhXL2L ] complexes (see Section 48.4.3.1 below). The triphenylphosphine substitution reactions of [RhCl(PPh3)3] are shown in Scheme 6. 

Scheme 6 Triphenylphosphine substitution reactions of [RhCl(PPh3)3]...

The reactions of allyliron tricarbonyl halides with donor molecules were studied. Triphenylphosphine substituted only one carbonyl, that trans-oriented with respect to the halogen of the form (XIX) [432). The phosphine derivatives of (XX) were not isolated as pure compounds. The complexes were decomposed entirely by dimethyl sulfoxide, giving [(0113)280] jFeX2 [435). Thermal decomposition of C3H5Fe(CO)3X depended on the medium and gave either diallyl, or diallyl ketone, together with propene, allyl ether, Fe(CO)5, and FeX2 [436). 

Colton s work with the tricarbonylbisdithiocarbamatomolybdenum series (9) and McDonald s success in studying the triphenylphosphine-substituted tungsten analogs (8) led us to attempt the synthesis and characterization of an analogous tungsten tricarbonyl complex since ... 

The bis(triphenylphosphine)-substituted complexes readily undergo phosphine substitution, allowing a variety of phosphine complexes to be prepared (Scheme 2) [35]. By varying the phosphine, heterocycle, and R a large number of new complexes are available and Aose shown in Schemes 1 and 2 are only representative examples of the range of possible complexes. 

Some triphenylphosphine-substituted anionic derivatives of vanadium carbonyl are known. Treatment of vanadium hexacarbonyl with tri-phenylphosphine in hexane solution gives the orange air-sensitive [(C6H5)jP]2V(CO)4 in 61.2% yield 39). 

The rates of chloride dissociation for triphenylphosphine substitution have been measured for a series of cyclometalated [Pt(N-N-C)Cl] complexes containing terdentate N-N-C anionic ligands derived from deprotonated alkyl-, phenyl-and benzyl-6-substituted 2,2 -bipyridines. The main factor controlling the rate is... 

---