Photochemistry of Alkylidyne Complexes

Only a few alkylidyne complexes have had their photochemical properties examined and this is clearly an area in need of further development. The reported studies involve both mononuclear and polynuclear alkylidyne complexes. 

The title complex has been shown to be photosensitive in the presence of acetylacetone (Hacac) [Eq. (154)] (792). The hydroxyarylacetylene ligand 

Vogler et al. (193) reported that irradiation of either (CO)2-(PPh3)20s=CPh (160) or (CO)(PPh3)2(Cl)Os=CPh (161) in the presence of HCl gives protonation of the alkylidyne ligand and formation of the alkylidene complex 162 [Eq. (155)]. Both starting complexes show 

Emax = 4700 cm ). Irradiation into these bands led to the observed 

Of the large number of /u.3-alkylidyne clusters known, only the title complexes have had their photochemical properties reported (194). The structure of CH3CCo3(CO)9 (163) consists of a triangle of metal-metal 

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The photochemistry of this class of compounds was reviewed in the 1979 book Organometallic Photochemistry (9) which reviewed the literature comprehensively through 1977. In the years since that review, a number of significant advances have been made. Indeed, the general conclusions that can now be drawn concerning the photochemistry of alkyl complexes are quite different from those given in that earlier review. Then, few alkylidene and alkylidyne complexes had been studied, but that too has changed. A comprehensive review on this subject is thus timely. 

Photochemistry of Alkyl, Alkylidene, and Alkylidyne Complexes of the Transition Metals... 

In this chapter Cp represents C5H4Me and Cp indicates C5Me5. There is material of general relevance in a number of reviews including that in articles on transition metal complexes in organic synthesis, complexes with heteronuclear metal-metal bonds, C-H activation the photochemistry of metal alkyls, alkylidenes and alkylidynes, u.v. photoelectron spectroscopy of metal alkyls , reactive intermediates derived from metallocenes, and M-C bond energies for organometallies . Some other material appears in a... 

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