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

摘要

Reduction of the {Co(NO)}(8) cobalt-nitrosyl N-confused porphyrin (NCP) [Co(CTPPMe)(NO)] (1) produced electron-rich {Co(NO)}(9) [Co(CTPPMe)(NO)][Co(Cp*)(2)] (2), which was necessary for NO-to-N2O conversion. Complex 2 was NO-reduction-silent in neat THF, but was partially activated to a hydrogen-bonded species 2MeOH in THF/MeOH (1:1, v/v). This species coupling with 2 transformed NO into N2O, which was fragmented from an [N2O2]-bridging intermediate. An intense IR peak at 1622cm(-1) was ascribed to (NO) in an [N2O2]-containing intermediate. Time-course ESI(-) mass spectra supported the presence of the dimeric [Co(NCP)](2)(N2O2) intermediate. Five complete NO-to-N2O conversion cycles were possible without significant decay in the amount of N2O produced.