The reaction of realgar with [Cp′ 2 MH 3 ] in boiling toluene gave [Cp′ 2 M 2 As 2 S 6 ] (Cp′=t-BuC 5 H 4 ; M=Nb: 1; Ta: 2), while [Cp 2 WH 2 ] (Cp=C 5 H 5 ) reacted with As 4 S 4 to give [Cp 2 W(H)(η 1 -As 5 S 2 )] (6). The structures were determined by X-ray crystallography. Compounds 1 and 2 are dimers in which two Cp′M units are symmetrically bridged by a μ,η 2:2 -AsS 3 ligand, a sulfide ligand and a heteroallylic μ,η 2:2 -AsS 2 ligand. The structure of 6 belongs to the type of bent metallocenes in which tungsten is surrounded tetrahedrally by two Cp ligands, a crystallographically found hydride atom and the new As 5 S 2 cage. The reaction of 1 with W(CO) 5 THF gave [Cp′ 2 Nb 2 As 2 S 6 ·W(CO) 5 ] (3) and [Cp′ 2 Nb 2 As 2 S 6 W(CO) 3 ·W(CO) 5 ] (4). Compound 3 is a monoadduct of 1 bearing the W(CO) 5 fragment at the As atom of the AsS 3 ligand. The structure of 4 contains a distorted cubane-like Nb 2 WS 4 As cluster with an integrated W(CO) 3 unit. A similar cluster 5 containing a CuI fragment instead of W(CO) 3 was prepared from 1 and CuI. The structure is completed by an attached As 4 S 3 cage, the As 3 basis of which is oriented towards iodide. Electrochemical investigations of 1, 3, and 4 shows for each compound quasi-reversible one-electron reductions with E 1/2 =−0.73V (1), −0.55V (3) and −0.67V (4), respectively.