Dinuclear oxidative addition of N-H and S-H bonds at chromium. Reaction of •Cr(CO)₃(C₅Me₅) with {o-(HA)C₆H₄S-Cr(CO)₃ (C₅Me₅)} (A = S, NH) yielding [η²-o-(μ-A)C₆H₄S-Cr (C₅Me₅)]₂ and H-Cr(CO)₃(C₅Me₅)

Reaction of the 17-electron radical •Cr(CO)₃Cp* (Cp* = C₅Me₅) with 0.5 equiv of 2-aminophenyl disulfide [(o-H₂-NC₆H₄)₂S₂] results in rapid oxidative addition to form the initial product (o-H₂N)C₆H₄S-Cr(CO)₃Cp*. Addition of a second equivalent of •Cr(CO)₃Cp* to this solution results in the formation of H-Cr(CO)₃Cp* as well as 1/2[{η²-o-(μ-NH)C₆H₄S} CrCp*]₂. Spectroscopic data show that (o-H₂N)C₆H₄S-Cr(CO)₃Cp* loses CO to form {η²-(o-H₂N)-C₆H₄S} Cr(CO)₂Cp*. Attack on the N-H bond of the coordinated amine by •Cr(CO)₃Cp* provides a reasonable mechanism consistent with the observation that both chelate formation and oxidative addition of the N-H bond are faster under argon than under CO atmosphere. The N-H bonds of uncoordinated aniline do not react with •Cr-(CO)₃Cp*. Reaction of the 2 mol of •Cr(CO)₃Cp* with 1,2-benzene dithiol [1,2-C₆H₄(SH)₂] yields the initial product (o-HS)C₆H₄S-Cr(CO)₃Cp* and 1 mol of H-Cr(CO)₃Cp*. Addition of 1 equiv more of •Cr(CO)₃Cp* to this solution also results in the formation of 1 equiv of H-Cr(CO)₃Cp*, as well as the dimeric product 1/2[{η²-o-(μ-S)C₆H₄S}- CrCp*]₂. This reaction also occurs more rapidly under Ar than under CO, consistent with intramolecular coordination of the second thiol group prior to oxidative addition. The crystal structures of [{η²-o-(μ-NH)C₆H₄S} CrCp*]₂ and [{η²-o-(μ-S)C₆H₄S} CrCp*]₂ are reported.