Hydride complexes of rhenium

Table 6 Some Mononuclear Hydride Complexes of Rhenium(III) and Their Spectroscopic Properties... 

Gusev D, Llamazares A, Artus G, Jacobsen H, Berke H (1999) Classieal and nonclassieal nitrosyl hydride complexes of rhenium in various oxidation states. Organometallies 18 75-89... 

Hieber and coworkers first prepared the pentacarbonyl hydride complex of rhenium by protonation of tte corresponding pentacarbonyl anion, [Re(CO)5]. Modified versions of the original syntheses have been reported, but these procedures still require extensive vacuum-line manipulations. Furthermore, the yield of ReH(CO)5 is only < 30% based on pure Na[Re(CO)5], which means that the overall yield from Re2(CO)io is much lower. 

Carbonyl Complexes of the Transition Metals Electronic Sfructme of Organometalhc Compounds Hydride Complexes of the Transition Metals Ligand Field Theory Spectra Manganese Organometalhc Chemistry Photochemistry of Transition Metal Complexes Rhenium Organometalhc Chemistry Rutheiuum Organometalhc Chemistry. 

These complexes have been used as starting materials in the preparation of other alkoxy and phenoxy complexes, phenylimido complexes, analogous amine complexes, dioxotetrapyridinerhenium(V) salts and dioxobis(ethylene-diamine) rhenium (V) salts, cyano complexes of rhenium-(V), acetylacetone complexes, hydrides, carbonyls, and isonitrile complexes. The products of reactions using the materials described here as sources are normally easier to purify than those obtained by other methods. 

Compared to manganese, little work has been carried out on analogous alkyl complexes of rhenium, although that which has may be divided into the same categories, namely, (1) reaction with transition metal hydrides, for example [CpW(H)(CO>3] (2) reaction with Lewis acids, for example, AlCUEt (3) orthometallation reactions (4) reaction with cationic species, for example, (5) reaction with anionic nucleophiles, for example, BF4" (6) reaction with neutral nucleophiles, for example, PPh3-... 

The acetylide complex [Co2(CO)6 U-PhC=CRe(CO)5 ] (256) (obtained by the treatment of the binuclear acetylide-hydride carbonyl complex of rhenium [Re2(CO)g( -H)( -C CPh)] with [Co2(CO)g] undergoes nondestructive reaction with oxygen resulting in the net loss of one acetylide carbon atom together with a CO ligand and formation of the carbyne cluster complex [Co2Re(CO)io(/i3-CPh)] (257) (Scheme 68), ... 

Compounds of the formulas Re(CR]), ReO(CH3)4, Li2[Re2(CH3)g] [60975-25-9], Re02(CH3)3 [56090-011-8], and Re03CH3 [70197-13-6] have been prepared. The first two compounds were obtained from reaction of rhenium hahdes or oxyhahdes and methyllithium the last three were formed from the species by oxidation or reduction reactions. The use of these hydride and alkyl complexes as catalysts is under investigation. 

Finally, whilst rhenium hydride complexes have not been reported to hydrogenate alkenes, there are several reports of the dehydrogenation of alkanes in the presence of tBuCH=CH2 as an hydrogen acceptor (Scheme 6.14) [136-142]. For example, cycloalkanes are transformed catalytically into the corresponding cyclic alkene, which shows that, in principle, a Re-based catalyst could be designed. 

Although some hydride complexes have been included in the chemistry of rhenium already described the main discussion of their chemistry is referred to this point due to the ambiguities... 

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