Keywords: Iron / Cluster compounds / S ligands / Hydrogenase / Electrocatalysis / DihydrogenThe reactions of 1,2,4-trithiolane (1), 1,2,5-trithiepane (6), 1,2,5-trithiocane (12) and 1,2,6-trithionane (10) with nonacarbonyldiiron (2) have been investigated. A novel diiron model complex, which can serve as a model complex of the active site of [Fe-only]-hydrogenase, was formed from the reaction with 1. In contrast, the reaction of 6 with 2 afforded the trinuclear iron cluster 7. Interestingly, the diiron compound 11 was obtained with 1,2,6-trithionane (10), which can be attributed to the more flexible dithiolato ligand 10. Furthermore, the reaction with 1,2,5-trithiocane (12) yielded the trinuclear