Fragmentation reactions ofN-sulfinylaniline PhNSO by the dinuclear complex [Fe2(CO)7{μ-C(R)C(NEt2)}]: Nitrene and sulfur insertions into iron carbene bonds. Synthesis and x-ray structures of [Fe2(CO)6{μ-N(Ph)C(NEt2)C(Me)S}] [Fe2(CO)6{μ-N(Ph)C(NEt2)C(Ph)S}] · 0.5C6H14 and [Fe2(CO)6{μ-C(C3H5)C(NEt2)N(Ph)SO}] · 0.5CH2Cl2

The diiron ynamine complexes [Fe₂(CO)₇{μ-C(R)C(NEt₂)}] (1) (R=Me, Ph, C₃H₅, SiMe₃) react with theN-sulfinylaniline, PhNSO, in refluxing hexane to yield the complexes [Fe₂(CO)₆{μ-N(Ph)C(Me)S}] (2), [Fe₂(CO)₆{μ-N(Ph)C(NEt₂)C(Ph)S}] · 0.5C₆H₁₂ (3), [Fe₂(CO)₆{μ-C(C₃H₅)C(NEt₂)N(Ph)SO}] · 0.5CH₂Cl₂ (4), and [Fe₂(CO)₆{μ-C(SiMe₃)C(NEt₂)S)}] (5). Compound 5 was found to be identical to the previously reported product obtained from the reaction of 1 with sulfur. Compounds 2, 3, and 4 were characterized by single crystal X-ray diffraction analyses. Crystal data: for 2: space group = P2₁/n,a=9.533(1) Å,b=18.830(4) Å,c=12.705(4) Å, β=107.01(2)°,Z=4, 2687 reflections,R=0.027; for 3: space group=P2₁/n,a=13.660(2) Å,b=19.096(8) Å,c=10.972(2) Å, β=90.62(1)°,Z=4, 2821 reflections,R=0.036; for 4: space group=P2₁/a,a=18.098(5) Å,b=16.564(4) Å,c=18.548(2) Å, β=115.44(2)°,Z=4, 3569 reflections,R=0.041. Complexes 2 and 3 result from fragmentation of theN-sulfinylaniline ligand and insertion of the nitrene grouping into the Fe=C(aminocarbene) bond, whereas the sulfur atom inserts into one Fe-C bond of the bridging carbene. Compound 4 is formed by insertion of the entireN-sulfinyl aniline ligand into the Fe=C(aminocarbene) bond. All three complexes have basket-like arachno structure isolobal to the benzvalene one.     

Radical Polymerization of Vinyl Acetate with Bis(tetramethylheptadionato)cobalt(II): Coexistence of Three Different Mechanisms

Poly(vinyl acetate) by OMRP : Increasing the steric encumbrance of the β‐diketonate R substituents in vinyl acetate (VAc) polymerization mediator [Co{OC(R)CHC(R)O}₂] from Me to tBu sufficiently weakens the Co^III? PVAc bond of the polymer chain to allow it to operate by both associative (degenerative transfer) and dissociative (organometallic radical polymerization, OMRP) mechanisms (see scheme). The Co^III? PVAc species also acts as a transfer agent in the absence of Lewis bases, whereas the Co^II complex shows catalytic chain transfer (CCT) activity.