Abstract [FeFe]-hydrogenase-active-site models containing larger chalcogens such as Se or Te have exhibited greater electron richness at the metal centers and smaller gas-phase ionization energies and reorganization energies relative to molecules containing S atoms. Diiron complexes related to the much-studied molecule [Fe 2 (μ-SC 3 H 6 S)(CO) 6](1) have been prepared with one S atom replaced either by one Se atom to give [Fe 2 (μ-SC 3 H 6 ...
