Thiocarbonyl complexes synthesis

Several diatomic ligands similar to CO are worth brief mention. Two of these, CS (thio-carbonyl) and CSe (selenocarbonyl), are of interest in part for purposes of comparison with CO. In most cases, synthesis of CS and CSe complexes is somewhat more difficult than for analogous CO complexes, because CS and CSe do not exist as stable, free molecules and do not, therefore, provide a ready ligand source.Therefore, the comparatively small number of such complexes should not be viewed as an indication of their stability. Thiocarbonyl complexes are also of interest as possible intermediates in certain sulfur transfer reactions in the removal of sulfur from natural fuels. In recent years, the chemistry of complexes containing these ligands has developed more rapidly as avenues for their synthesis have been devised. 

Liganded cobalt complexes react with carbon disulfide by addition across one of the C=S bonds to give relatively stable complexes 10. The same complex reacts with carbonyl sulfide to give a liganded carbonyl complex 11 andMesPS. In the reaction of carbon sulfose-lenide at -20 °C the adduct 12 as well as the thiocarbonyl complex 13 are formed, indicating that carbon sulfoselenide can be used for the synthesis of thiocarbonyl compounds. 

The orange thiocarbonyl is air stable (IR i/(C=S) 1332 cm-1) its synthesis proceeds via an isolable C2S5 complex that is desulphurized by refluxing with PPh3 [144] ... 

Other hand, electrophilic addition to thiocarbonyl ligands is a well-established method for the synthesis of thiocarbyne complexes (5). Doyle and Angelici synthesized the cationic thiocarbyne complex 42 according to Eq. 

On the other hand, when R = 3-allyl, the product [PdL2Cl2] is obtained, which i.r. studies show to contain an unco-ordinated olefinic group and unidentate bonding via the thiocarbonyl S. Also described is the synthesis of the new ligand H2(sacac)2(en), together with the preparation of the stable palladium complex... 

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