In this research work we present the synthesis and characterization of asymmetrical [FeFe]‐hydrogenase mimic, [Fe2(CO)5P(OMe)3{μ‐(SCH2)2SnPh2}] (2), obtained from replacing one of the CO ligands of the parent hexacarbonyl complex [Fe2(CO)6{μ‐(SCH2)2SnPh2}] (1) with the monodentate phosphite P(OMe)3. The molecular structure of complex 2 was confirmed by X‐ray diffraction analysis. Moreover, the electrochemistry of complexes 1 and 2 was investigated to explore the influence of the steric bulk of the Ph‐ring at the bridgehead Sn atom with the nearby P(OMe)3 ligand. In addition, both complexes show their potentials toward hydrogen formation in the presence of weak acid, such as acetic acid (AcOH), suggesting an ECEC (E=electron transfer, C=chemical process) mechanism for hydrogen production.