Conversion of Nitric Oxide into Nitrous Oxide as Triggered by the Polarization of Coordinated NO by Hydrogen Bonding

Reduction of the {Co(NO)} 8 cobalt–nitrosyl N‐confused porphyrin (NCP) [Co(CTPP Me )(NO)] ( 1 ) produced electron‐rich {Co(NO)} 9 [Co(CTPP Me )(NO)][Co(Cp*) 2 ] ( 2 ), which was necessary for NO‐to‐N 2 O conversion. Complex 2 was NO‐reduction‐silent in neat THF, but was partially activated to a hydrogen‐bonded species 2 ⋅⋅⋅ MeOH in THF/MeOH (1:1, v/v). This species coupling with 2 transformed NO into N 2 O, which was fragmented from an [N 2 O 2 ]‐bridging intermediate. An intense IR peak at 1622 cm −1 was ascribed to ν(NO) in an [N 2 O 2 ]‐containing intermediate. Time–course ESI(−) mass spectra supported the presence of the dimeric [Co(NCP)] 2 (N 2 O 2 ) intermediate. Five complete NO‐to‐N 2 O conversion cycles were possible without significant decay in the amount of N 2 O produced.