Thallium—oxygen bonds sulfur

I,6-Dioxa-6a-thiapentalene (4).5 Addition of thallium(IU) trifluoroacetate in acetonitrile to a solution of 4//-pyrane-4-thione (1) in acetonitrile at room temperature gives the labile pyrylium salt (2), which on addition of water gives 1,6-dioxa-6a-thiapentalene (4) by sulfur-oxygen bond formation. The intermediate (3) is suggested. 

Polymeric ribbons of self-assembled chelate molecules, with participation of dative thallium-oxygen and secondary thallium-sulfur intermolecular bonds are present in dimethylthallium(III) diethylmonothiocarbamate, Me2Tl[S(0)CNEt2], 49 [170], and in diphenylthallium(III) diphenylmonothiophosphinate, Ph2Tl[S(0)-PPh2], 50 [171]. 

When oxygen, nitrogen, and sulfur bound to organic groups are also bound to Tl1, the Tl—X bond appears to be more covalent than the bond to alkali metal ions in similar compounds. Thallium compounds tend to be polymeric rather than ionic. Thus the acetylacetonate is a linear polymer with 4-coordinate Tl. 

Electrochemical oxidation of thallium in the presence of l-hydroxopyridine-2-thione (HPT) affords the thallium(I) adduct along with T1(PT)3 (103). The thallium atom is bonded to three oxygens and three sulfur atoms in an octahedral fashion, forming the mcr-isomer. The T1 NMR spectrum of T1(PT)3 exhibits the resonance due to thallium (III) at 8 2,968. The related thallium(I) adduct Tl(PT) displays the signal due to thallium(I) at 8 2,697. 

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