Indium complexes sulfur compounds

R Tl compounds react readily with acids, halocarbons, or sulfur dioxide to form R2TIX. They also form neutral complexes (R3TI L) with Lewis bases (L), eg, amines and phosphines, in a similar manner as the gaHium and indium analogues. 

Sulfur complexes of Al, Ga, and In are less common, but the tris(dithiocarba-mates), M(dtc)3, and thiolato anions, Ga(SR)4, are known. The gallium and indium compounds differ structurally from most other tris(dithiocarbamates) in their close approach to a prismatic arrangement of S atoms. 

Sulfur forms three binary compounds with indium, In2S, InS, and In2S3. The latter is prepared by direct union of the elements, by heating ln208 with sulfur or H2S or by passing H2S into the weakly acid solution of an indium salt. The precipitated form is yellow, and the salt formed by dry methods varies from yellow to brown. It is soluble in mineral acids, readily forms colloidal solutions, and gives complex salts with the alkali sulfides, such as K2In2S . 

The insertion of sulfur dioxide between the metal atom and the alkyl or aryl group of indium gallium and iron porphyrins of the form M(Por)(R) gives rise to M(Por)S02R sulfinato derivatives (Eq. 18). The iron sulfinato compounds are air stable at room temperature, but can easily be oxidized by a stream of oxygen to give the corresponding sulfonato complexes. 

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