A Terminal Imido Complex of an Iron–Sulfur Cluster
Arun Sridharan, Alexandra C. Brown, Daniel L. M. Suess
Abstract
Abstract We report the synthesis and characterization of the first terminal imido complex of an Fe–S cluster, (IMes) 3 Fe 4 S 4 =NDipp ( 2 ; IMes=1,3‐dimesitylimidazol‐2‐ylidene, Dipp=2,6‐diisopropylphenyl), which is generated by oxidative group transfer from DippN 3 to the all‐ferrous cluster (IMes) 3 Fe 4 S 4 (PPh 3 ). This two‐electron process is achieved by formal one‐electron oxidation of the imido‐bound Fe site and one‐electron oxidation of two IMes‐bound Fe sites. Structural, spectroscopic, and computational studies establish that the Fe–imido site is best described as a high‐spin Fe 3+ center, which is manifested in its long Fe−N(imido) distance of 1.763(2) Å. Cluster 2 abstracts hydrogen atoms from 1,4‐cyclohexadiene to yield the corresponding anilido complex, demonstrating competency for C−H activation.