AbstractThe heterolytic cleavage of molecular hydrogen by [Fe(H2O)6][BF4]2 and the chiral phosphane (+)‐1,2‐bis[(2R,5R)‐2,5‐dimethylphospholano]benzene [(R,R)‐Me‐DuPhos] or its enantiomer [(S,S)‐Me‐DuPhos] yields the (dihydrogen)(hydrido)iron complexes [FeH(η2‐H2){(R,R)‐Me‐DuPhos}2]BF4 ([R,R‐1]BF4) and [FeH(η2‐H2){(S,S)‐Me‐DuPhos}2]BF4 ([S,S‐1]BF4), respectively. These complexes are fluxional in solution at room temperature, and the trans isomers are observed at 200 K. The (Λ)‐cis‐[R,R‐1]BF4 complex was identified crystallographically as the only stereoisomer at room temperature. The energetic and structural differences between the cis (Λ and Δ) and trans isomers were analyzed from a computational (DFT) perspective. The coordinated dihydrogen is displaced by CO or CH3CN ligands to form a mixture of cis and trans isomers of FeH(L)[(R,R)‐Me‐DuPhos]2BF4 {L = CO ([R,R‐2]BF4), CH3CN ([R,R‐3]BF4)} or FeH(L)[(S,S)‐Me‐DuPhos]2BF4 {L = CO ([S,S‐2]BF4), CH3CN ([S,S‐3]BF4)} complexes, and the cis isomers are the major ones. The formation of trans‐[FeH(NMe3)(Me‐DuPhos*)2]BF4 is suggested for the reaction of [R,R‐1]BF4 and [S,S‐1]BF4 with NMe3 {Me‐DuPhos* = [(R,R)‐Me‐DuPhos] or [(S,S)‐Me‐Duphos]}.