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Phosphine complexes cyclometallation

In an account of his forty years work on metal carbonyl-liquid ammonia systems, Behrens includes information on [M(CO) Lj,] complexes (L=NH3, bipy, phen, or terpy). Reviews have also appeared on alkylaminobis(difluoro-phosphine) complexes, cyclometallations involving phosphorus donor ligands, and optically active species/... [Pg.177]

A series of cyclometalated platinum(II) phosphine complexes [Pt(bzq)(P-P)](Pp6) (P-P = dppm, dppe, dppp) has been synthesized and stracturally characterized. The absorption bands at ca. 300nm (e... [Pg.5441]

Cyclometallation and RE of the cyclopropane should give PtHClL2 the phosphine must cyclometallate in the -CH2Nb case, which would release CHsNb and leave a cyclometalated Pd complex. [Pg.483]

The formation of rings that contain a thioether linkage does not appear to be catalyzed efficiently by Ru, even when terminal olefins are present. On the other hand, molybdenum appears to work relatively well, as shown in Eqs. 30 [207] and 31 [208]. Under some conditions polymerization (ADMET) to give poly-thioethers is a possible alternative [26]. Aryloxide tungsten catalysts have also been employed successfully to prepare thioether derivatives [107,166,169]. Apparently the mismatch between a hard earlier metal center and a soft sulfur donor is what allows thioethers to be tolerated by molybdenum and tungsten. Similar arguments could be used to explain why cyclometalated aryloxycarbene complexes of tungsten have been successfully employed to prepare a variety of cyclic olefins such as the phosphine shown in Eq. 32 [107,193]. [Pg.34]

The preparation of carbonyl-lr—NHC complexes (Scheme 3.1) and the study of their average CO-stretching frequencies [7], have provided some of the earliest experimental information on the electron-donor power of NHCs, quantified in terms of Tolman s electronic parameter [8]. The same method was later used to assess the electronic effects in a family of sterically demanding and rigid N-heterocyclic carbenes derived from bis-oxazolines [9]. The high electron-donor power of NHCs should favor oxidative addition involving the C—H bonds of their N-substituents, particularly because these substituents project towards the metal rather than away, as in phosphines. Indeed, NHCs have produced a number of unusual cyclometallation processes, some of which have led to electron-deficient... [Pg.40]

Mdssbauer spectra of bonding and structure in, 15 184-187 reactions with diborane, 16 213 stabilization of, 5 17, 18-19 cyanates, 17 297, 298 cyanide complexes of, 8 143-144 cyclometallated bipyridine complex, 30 76 diazene complexes, 27 231-232 dinitrogen complexes, 27 215, 217 diphosphine complexes of, 14 208-219 dithiocarbamates, 23 253-254 -1,2-dithiolene complexes, 22 323-327 hydrogen bonding, 22 327 halide complexes with phosphine, etc., 6 25 hexaflouride, structure, 27 104 hydride complexes, 20 235, 248-281, see also Transition metal-hydride complexes... [Pg.147]

This chapter is concerned with the effects of nonbonded interactions in tertiary phosphine-transition-metal complexes on (a) cyclometallation and C-H activation and (b) the stability and conformations of large chelate rings. It also deals with how nonbonded interactions might be used in other areas of chemistry. [Pg.106]


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See also in sourсe #XX -- [ Pg.274 ]




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