Tungsten complexes mononuclear

Consequently, these topics are not specifically discussed in this article, which focuses primarily on the chemistry of mononuclear tungsten complexes containing organic ligands. 

Figure 27 Isolated mononuclear tungsten complexes (a) [LW(CO)3](PF6) (L= l,4,7-tribenzyl-l,4,7-...

Surface-catalyzed isomerization of mononuclear alkynyl tungsten complexes to allyl derivatives has also been reported it occurs on silica gel. ... 

The electrosynthesis of hydride complexes directly from molecular hydrogen at atmospheric pressure by reduction of Mo(II) and W(II) tertiary phosphine precursors in moderate yield has been described as also the electrosynthesis of trihydride complexes of these metals by reduction of M(IV) dihydride precursors [101,102]. Hydrogen evolution at the active site of molybdenum nitrogenases [103] is intimately linked with biological nitrogen fixation and the electrochemistry of certain well-defined mononuclear molybdenum and tungsten hydrido species has been discussed in this context [104,105]. 

Bis(adamantylimido) compounds, with monomeric chromium(VI) complexes, 5, 348 Bis(alkene) complexes conjugated, Rh complexes, 7, 214 mononuclear Ru and Os compounds, 6, 401 -02 in Ru and Os half-sandwich rj6-arenes, 6, 538 with tungsten carbonyls and isocyanides, 5, 685 Bis(u-alkenylcyclopentadienyl) complexes, with Ti(II), 4, 254 Bis(alkoxide) nitrogen-donor complexes, with Zr(IV), 4, 805 Bis(alkoxide) titanium alkynes, in cross-coupling, 4, 276 Bis(alkoxo) complexes, with bis-Cp Ti(IV), 4, 588 Bis[alkoxy(alkylamino)carbene]gold complexes, preparation, 2, 288... 

I should like to propose that all the types of reactions which have been established for mononuclear transition metal complexes will also occur for dinuclear transition metal complexes, and furthermore, that the latter will show additional modes of reactivity which are uniquely associated with the metal-metal bond. In this article, I shall support this proposal by illustrations taken from the reactions of dinuclear compounds of molybdenum and tungsten, two elements which enter into extensive dinuclear relationships (J ). 

The intraligand bond distances in 11a are similar to those in several mononuclear tungsten diazoalkane complexes (39., 40), and the N-N (1. 35A) and C=N (1. 28A) distances are compatible with the assignment of bond orders of 1.3 and 1.9, respectively, to these bonds. Similar bond length/bond order relations suggest bond orders of ca. 1.0 for Mo2-Nl and 1.7 for Mol-Nl. The Mo-Mo bond... 

Bildstein et al. have previously shown that Fc functionalised NHC (annulated and nonan-nulated) can be successfully employed to synthesise a broad range of transition metal complexes [166]. These include palladium, tungsten and mercury. Interestingly, two different species of mercury NHC complexes could be synthesised and structurally characterised (see Figure 4.49), with the dinuclear complex being the precursor for the mononuclear one. 

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