Reactions of Monoanions [(μ-RE)(μ-E)Fe₂(CO)₆]⁻ and Dianions [(μ-E)₂Fe₂(CO)₆]²⁻ (E = Se, S) with N-Substituted Benzimidoyl Chlorides, Leading to Novel Butterfly Fe/E Cluster Complexes

We have first studied the reactions of monoanions [(μ-RE)(μ-E)Fe2(CO)6]− (A, E = Se; B, E = S) with electrophile PhC(Cl)NPh or dianions [(μ-E)2Fe2(CO)6]2− (C, E = Se; D, E = S) with electrophiles PhC(Cl)NR′ (R′ = Ph, p-MeC6H4). While monoanion A was found to react with PhC(Cl)NPh to give expected complexes (μ-RSe)[μ-SeC(Ph)NPh]Fe2(CO)6 (1, R = Me; 2, R = Et; 3, R = m-MeC6H4), monoanion B was found to react with PhC(Cl)NPh to afford unexpected complexes (μ-RS)[η1-SC(Ph)NPh-η1]Fe2(CO)6 (4, R = Me; 5, R = Et). Furthermore, while dianion C reacted with PhC(Cl)NR′ (R′ = Ph, p-MeC6H4) to give expected complexes [μ-SeC(Ph)NR′]2Fe2(CO)6 (6, R′ = Ph; 7, R′ = p-MeC6H4), dianion D was found to react with PhC(Cl)NR′ (R′ = Ph, p-MeC6H4) to afford unexpected complexes [μ-SC(Ph)NR′][η1-C(Ph)NR′-η1]Fe2(CO)6 (8, R′ = Ph; 9, R′ = p-MeC6H4). All the new complexes 1−9 were characterized by elemental analysis and spectroscopy, and complexes 1 and 4−8 were further structurally confirmed by X-ray crystallography.