Metal‐Assisted Assembly of Chain and Macrocyclic As–S Ligands from Ethylcycloarsathiane (C 2 H 5 AsS) n

Treatment of cyclo ‐(EtAsS) n with [RuCl 2 (Ph 3 P) 3 ] and [Re‐Br(CO) 5 ] affords the respective complexes [RuCl 2 { cyclo ‐(EtAsS) 4 }(Ph 3 P)] ( 1 ) and [{Re(CO) 3 } 2 {μ‐(Et 4 As 4 S 5 )}] ( 2 ). Whereas 1 contains a η 3 As coordinated intact cyclotetramer (EtAsS) 4 , ring cleavage leads to the chain anion Et 4 As 4 S 5 2− , stabilised as a bridging hexadentate ligand in 2 . Reaction of MCl 3 with cyclo ‐(EtAsS) n in toluene in a Carius tube enables the metal‐mediated temperature controlled assembly of the novel 16‐ and 14‐membered macrocyclic hexadentate As–S ligands in (M{ cyclo ‐(Et 6 As 8 S 10 )}] ( 3 : M = Os; 4 : M = Ru) and [Ru{ cyclo ‐(Et 4 As 6 S 10 )}] ( 5 ). The structures of the products were established by X‐ray crystallography.