Intramolecular C−H Activation by Putative Terminal Two-Coordinate Manganese(III) Imido Intermediates: Hydrogen Abstraction from a Phenyl Group

Reactions of the Mn(I) inverted sandwich complex (η 6 -C 7 H 8 ){MnAr*-3,5- i Pr 2 } 2 (Ar*-3,5- i Pr 2 = C 6 H-2,6-(C 6 H 2 -2,4,6- i Pr 3 ) 2 -3,5- i Pr 2 ) with bulky terphenyl azides afforded the dimeric Mn(II) amido/aryl complex {CH 2 C 6 H 2 -2-(C 6 H 3 -2-(N(H)MnAr*-3,5- i Pr 2 )-3-(C 6 H 2 -2,4,6-Me 3 ))-3,5-Me 2 } 2 ( 1 ) and the binuclear Mn(II) complex (μ,η 1:η 1 -NH-C 6 H 3 -2-(C 6 H 2 -3,5- t Bu 2 )-6-(C 6 H 3 -3,5- t Bu 2 )){MnAr*-3,5- i Pr 2 } 2 ( 2 ). Complex 1 arises via methyl hydrogen abstraction by the nitrogen atom and dimerization via radical coupling with C−C bond formation. Complex 2 was formed by phenyl hydrogen abstraction by the imido nitrogen atom, followed by incorporation of a further MnAr*-3,5- i Pr 2 unit. In addition, complex 2 features two different manganese environments and is also the first structurally characterized heteroleptic two-coordinate diaryl Mn(II) species.