Sulphur donor ligands

The absence of S—H vibrational bands in the i.r. spectrum of [RhL2(H20)2]-C1 (L = dimethylaminoethanethiol) has shown that L is bidentate. Comparison of calculated force constants with those found for other noble metal complexes suggests the stability order Pt Rh Co Ni .  

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Sulphur donor ligands. Dialkyl- and diphenyl-thioethane complexes have been synthesized via the route shown in Scheme 8 I.r. and magnetic studies... 

Group VI Donors. Oxygen and sulphur donor ligands. Oxidative addition of tetrachloro-l,2-benzoquinone to rrans-[Ir(CO)Cl(PR3)2] (R3 — Ph3 or Ph2Me) has been shown to give the Ir ° products [Ir(02CgCl4)(C0)Cl(PR3)2], whose structures (45) were confirmed from far-i.r. and H n.m.r. data. Comparison... 

Mossbauer spectroscopy has proved useful in investigating the series of complexes [FeBr(NO)2L] in which L is a sulphur donor ligand. A distinctly different Mossbauer isomer shift for the o-aminothiophenol (atp) compounds, compared with the monodentate thioester complexes (Table II), is evidence for a change from 4- to 5-coordination in the former (97). 

Table 12. Mo NMR data for Mo(0) compounds containing sulphur donor ligands.

Stability to high temperature processing, e.g. some nickel chelates containing sulphur donor ligands will decompose above 250°C and turn black due to nickel sulphide. 

A full paper by Alper and Chan, describing in detail the formation of sulphur-donor ligand ortho-metallated complexes (74) by the reaction of substituted thiobenzophenones with di-iron enneacarbonyl, Fe2(CO)>, has appeared. The complexes (74) appeared to be valuable starting materials in the synthesis of the little-known isobenzothiophen heterocycles. Related ortho-metallated thiobenzophenone complexes of ruthenium were found to have a different structure (75). Some non-aromatic thioketones also react with di-iron enneacarbonyl, but these reactions appear to be more complicated. Thus adamantanethione yielded no less than four different complexes, of which (76) was the prevailing one (71%). Thiocamphenilone (77) formed a complex analogous with (76), but such a complex could not be obtained with thiofenchone (78), presumably for steric reasons. Two... 

Metal Complexes.—In order to determine the effect of the presence of a nitrogen donor on the ortho-metallation of the thiobenzoyl function, Alper and Chan treated NN-dimethylthiobenzamide with di-iron enneacar-bonyl. However, no sulphur-donor ligand ortho-metallated complex was obtained, as happens in the case of thiobenzophenone, but instead the complexes (245) and (246) were formed. - NN-Dimethylthioacetamide similarly yielded the complexes (247) and (248), whereas the unsubstituted thiobenzamide on treatment with di-iron enneacarbonyl gave the complexes (249) and (250). The synthesis and properties of metal complexes of dithio-oxamides, dithiomalonamides, 2-thiocarbamoyl-l,10-phenan-throlines, thiomorpholine-3-thione, and 2,4-dithiouracil have also been described recently. 

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