Rhenium dithiocarbamate complexes

Although relatively few oxo-bridged rhenium complexes have been characterized electrochemically, several studies have been conducted on Re(V) complexes containing a linear O=Re—O—Re=O unit (1, Chart 1). Dithiocarbamate complexes such as Re2O3(Et2dtc)4 exhibit a reversible Re Re reduction at... 

A synthetic route developed by Tsipis co-workers (201) involves the addition of electrophiles to anionic dithiocarbimato complexes of the group 10 (Vlll) elements the latter being prepared upon deprotonation of the corresponding primary amine derived dithiocarbamate complexes. In this way, Schwarz and Rauchfuss (202) also prepared the rhenium complexes [ReS(ri -S4)(S2CNMeR)] (Eq. 25). 

The first rhenium dithiocarbamate complexes, [ReClaCSaCNRa)], were not reported until 1960 (1181), and even then, it was not until the 1970s that substantial inroads were made. Now, dithiocarbamates are known to stabilize rhenium in oxidation states +1 to +5, with the latter being the most common, and the chemistry is dominated by strong jt-donor ligands such as oxo and imido, and especially prevalent are nitride complexes. 

Rhenium imido-dithiocarbamate complexes were first prepared by Rowbot-tom and Wilkinson in 1972 (1182) and considerable recent progress has been made in this area. Reaction of [ReCl3(NAr)(PPh3)2] (Ar = Ph, p-tol. Me) (240) with either Me3SiS2CNR2 or TIS2CNR2 (R = Me, Et) gives [Re(NAr)-... 

Only one report has appeared on related sulfido complexes reaction of [ReS(r -S4)(S2C=NMe)] with MeOTf giving the dithiocarbamate complex [ReS(r -S4)(S2CNMe2)] (202). The latter appears to be quite stable and it is somewhat surprising that other terminal sulfido complexes have not been reported. Stiefel and co-workers (184,185) reported the synthesis of a range of dimeric rhenium(lV) complexes with bridging sulfido ligands and these are discussed further below. 

Figure 142. Base-catalyzed interconversion of rhenium(I) dithiocarbamate complexes.

Pseudo-allyl compounds are formed from reactions of [Re(CO)2(PPh3)2(OCHNC6H4-4-Me)] with excess of PhNCO or PhNCS. Whereas carbamate compounds are formed in the former case, a mixture of monothio- and dithiocarbamate compounds is obtained with the sulfur analogue. The formation of the latter complex proceeds via the intermediate formation of the first. The related compounds show similar structural features with distorted octahedral rhenium atoms and... 

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