Sulfur donors thiolates

Figure 4 compares the relative a- and 7c-donor ability of three distinct sulfur donors thiolate, sulfinate, and thioether 17, 23, 24, 26-28). Based on simple charge considerations, both the thiolate and sulfinate donors are anionic, while the thioether is neutral. In terms of a-donor ability, the thiolato sulfur should be stronger than the sulfinate since the oxygen atoms of the latter withdraw significant electron density away from sulfur. The neutral thioether is the poorest a-donor. In terms of 7c-donor ability, only the thiolate sulfur possess the... 

Cyclometallated gold(III) dihalide complexes also act as useful precursors for the synthesis of gold(III) complexes with thiolate and other sulfur donor ligands. The cyclometallated ligand stabilises the gold(III) centre towards reduction, which is important due to the reducing potential of sulfur-based ligands. 

We have explored both water-free and water-assisted routes to the cleavage of the H-H bond in certain r 2-H2 species of Fig. 3. For the former route, the bridging thiolate sulfur donor and the bridging hydride were considered as possible internal bases for the heterolytic cleavage of H2 from each of the dihydrogen species, Fig. 7. In the water-assisted routes, H20 is used as an external base to deprotonate H2, Fig. 8. 

The reactivity of the iron centre is linked to the thiolate ligand which means that any enzyme model must contain both an iron(II)-porphyrin centre and a sulfur donor. This combination is hard to achieve under aerobic conditions as both the iron and the sulfur are readily oxidized. Furthermore both are light sensitive to a degree. 

Barriers of 12.5-15.5 kcal/mol for neutral CpMo(CO)(MeC=CMe)-(SR) complexes are quite similar to rotational barriers in cationic complexes (74). Given the 7r acidity of CO and the tt basicity of SR-, these barriers are surprisingly small. Sulfur donor ligands tend to be electronically flexible, and the soft thiolate may facilitate alkyne rotation by simultaneous rotation of the thiolate substituent. 

Efforts to optimize rhodium-based systems for methanol carbonylation led to the development of new supporting ligands containing phosphorus and sulfur donor atoms, both thiolates and thioethers, such as those used in the preparation of complexes (20) and (21). Ligands such as 2-diphenylphosphinothiolate have been shown to give rise to complexes that exhibit higher activities, up to four times faster, for the carbonylation of methanol compared to [Rh(CO)2l2] . ... 

Ooi and co-workers adopted an elegant synthetic approach to the mixed-metal complexes of 4-methylpyridine-2-thiolate (4-mpyt). This approach includes the initial preparation of mononuclear complexes [M(4-mpytH)4]Cl2 (M = Pt, Pd), in which all four 4-mpytH ligands coordinate to with sulfur-donor atoms (84,102). The structure of the mononuclear Pd(II) complex with nonsubstituted pyridine-2-thiolate, [Pd(pytH)4]Cl2, is shown in Fig. 16 (84). These mononuclear complexes can be further reacted with the second metal ion to give mixed-metal dinuclear complexes. 

Driven in part by interest in potential materials applications,the number of i-block complexes containing ligands with sulfur donors has increased tremendously since the 1980s. The structures of hundreds of such compounds are now known, even though the first crystal structure of a lithium thiolate did not appear until 1985. ... 

Instead of a phosphide, a thiolate may be used in the first substitution step, such that tripod ligands with one Cp, one phosphorus, and one sulfur donor are available (116). Compounds obtained following Scheme 1C have a CH2OH group at the backbone which may be silylated, but could not by now be transformed into an ether function.48... 

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