Thallium-bound metal complexes

Thallium(i) salts have long been used in reactions with organic and organometallic halide complexes as a means of activating the halide by removal as insoluble T1X. However, the thallium ions proved not to be innocent bystanders, and numerous examples were reported in COMC (1995) where the metal-bound thallium complexes were formed. Deliberate reactions of thallium(i) and thallium(m) salts with metal carbonyl anions have yielded a variety of complexes of the form T1 MLJ3. In the past decade, new examples of metal carbonyl derivatives of thallium have been prepared (see Table 2). In addition, the propensity for Tl+ to form adducts with 16-electron noble metal complexes has been exploited. 

Various indium-metal - and thallium-metal o-bonded porphyrin complexes have been synthesized. These metalloporphyrins are represented by (P)InM (L) and (P)TIM (L) where P is OEP or TPP and M (L) is one of the following metallate ions Co(CO)4, Cr(C0)3Cp, Mn(CO)s, Mo(C0)3Cp or W(C0)3Cp. Detailed electrochemical studies involving both series of compounds have been carried out . The results of these studies indicate that the reduction of binuclear (P)MM (L) can occur by one or two electrons depending upon the specific porphyrin ring, the temperature, the nature of H and the nature of the bound metallate ion, H (L). Additional peaks are also observed for oxidation and reduction of (P)M and [(P)M] which are formed by cleavage of the reduced bimetallic species, as well as for [(P)M]+ when some decomposition of the neutral complex occurs. The generated stability of [(P)MM (L)]- and [(P)MM (L)]-2 is very low for complexes in both the T1 and In series. A low stability of electrooxidized [(P)InM (L)]+ is also observed but the singly and doubly oxidized [(P)TIM (Ii)]+ and [(P)TIM (L)] + 2 derivatives are quite stable and can be spectroscopically characterized . ... 

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