화학공학소재연구정보센터
Inorganic Chemistry, Vol.55, No.16, 7997-8002, 2016
An Unusual Cobalt Azide Adduct That Produces a Nitrene Species for Carbon-Hydrogen Insertion Chemistry
A family of Co(II) complexes supported by the bulky, dianionic bis(pyrrolyl)pyridine pincer ligand pyrr(2)py [pyrr(2)py(2) = 3,5-Bu-t(2)-bis(pyrrolyl)pyridine] are reported in this work. These compounds include 1-OEt2, 1.toluene, and 1-N(3)Ad (Ad = 1-adamantyl), the latter which is prepared via addition of N(3)Ad to 1-OEt2 [1 = (pyrr2py)Co]. While complexes 1-OEt2 and 1-N(3)Ad are four-coordinate systems having a Co(II) ion confined in a cis-divacant octahedral geometry, complex 1toluene possesses a Co(II) ion in a T-shaped environment where the toluene is interstitial and intercalated between two (pyrr(2)py)Co molecules. Complex 1-N(3)Ad is notable in that the organic azide binds to the metal through gamma-N in a kappa(1) fashion. Photolysis of 1-N(3)Ad results in N-2 extrusion and formation of CH insertion product [(pyrrpypyrrNHAd)Co] (2). We propose complex 2 form via insertion of the nitrene (NAd) into one Bu-t CH bond, thus resulting in a pincer ligand having a pendant secondary amine. Complexes 1-OEt2, 1.toluene, and 1-N(3)Ad and CH insertion product 2 have been structurally characterized, and in the case of 1-OEt2, we also present electrochemical data.