Novel inorganic cage structures based on ass ligands and cyclopentadienylruthenium groups

Abstract

Abstract The reaction of [Cp (*) 2 Ru 2 ‐(CO) 4 ] [ a : Cp (*) = Cp * (η 5 ‐C 5 Me 5 ); b : Cp (*) = Cp x (η 5 ‐C 5 Me 4 Et)] with β‐realgar in boiling n ‐decane gives [Cp (*) 2 Ru 2 ‐As 4 S 4 ] ( 1a,b ). in good yields along with some [Cp (*) 2 Ru 2 ‐As 4 S 2 ] ( 2a,b ). According to X‐ray diffraction analyses of 1b and 2a , their structures belong to two different types of inorganic clusters. Whereas 1b has a cage structure in which the [Cp (*) 2 Ru 2 unit is inserted into the As 4 S 4 ] cradle, 2a has a sandwich structure in which two coplanar η 2 ‐As 4 S ligands and the Cp * ligands are oriented parallel to one another. Analysis of the As‐S connectivity in the core of 1 b reveals a structural relationship to the extremely rare form of arsenic sulfide As 4 S 4 (II), and not to the metastable high‐temperature form β‐As 4 S 4 used in the synthesis. At lower temperatures (60, 115°C) formation of CO‐containing products is observed.