Thallium complexes ligand substitutions

Cationic complexes of Tl3+ with oxygen donors are known, and can be regarded as substitution products of [T1(C)H2)6]3+ (c/. Section 25.2.8.3.1). The DMSO product has been characterized with various anions,403 and there seems no reason to suppose that similar compounds cannot be prepared with donor ligands which are resistant to oxidation. The cation [Tl(pyNO)8]3+ (prepared as the perchlorate) may be an indication that eight-coordinate compounds are also accessible in thallium(III) chemistry.404... 

The mixed complex CpCp TiCl2 (Scheme 445) containing one carbohydrate-substituted Cp ring has been synthesized by reaction of the thallium salt of the carbohydrate-derived Cp ligand with CpTiCl3 in THF.1060... 

As a consequence, it is not surprising that there appears to be only one isolated structure claimed. This is of the indium(I) and thallium(I) complexes with a single M—C bond from a o--bonded benzene anion that carries two bulky tri-substituted benzene substituents in ortho positions these partially block approach of other potential donors to the metal cation (Figure 4.3). An X-ray crystal structure has been determined, defining the shape. It is a rare observation, as other complexes (such as Mn(I) and Fe(I)) of the same ligand bind another ligand at the open side of the molecule, as expected. In any case, this coordination number is trivial in the sense that it can have only one shape - a linear M—L arrangement. 

The mixed anhydrides of diphenylphosphinous acid and heavily substituted alkenoic acids displace one PPh3 ligand from [RhCl(PPh3)3] to form a complex where the anhydride is coordinated through phosphorus. If these products are treated with thallium(I) or silver(I) salts, the anhydride coordinates additionally through the carbonyl oxygen and the chloro ligand is displaced. 

The oxidation of the hydrazinium ion by Tl + probably involves substitution of hydrazine for water in the hydrated thallium(iii) species. The kinetics of complex formation between thallium(iii) and 4-(2-pyridylazo)resorcinol in aqueous solutions have been studied. Two pathways have been identified, involving Tl and [T10H] + reacting with the protonated ligand. The similarity in rate to that of the corresponding reaction of thallium(iii) with Semi-xylenol Orange indicates that the rate is controlled by loss of water from the hydrated thallium cation. ... 

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