Herein it is shown that complexes [Cp*Ir(R-pica)Cl] {R-pica = R-picolinamidate = κ2-R-pyridine-2-carboxamide ion (–1), 1 R = H and 2 R = Me} catalyze the liberation of H2 from formic acid (FA) in water, at ambient temperature and pressure, in the absence of any addictive/promoter, with performances comparable with those of the best catalysts reported so far. TOF values approaching 30000 h–1 were observed for 1 and 2 (pH = 3.7, [HCOOH] + [HCOO–]=1 M, [Cat] = 250 μM, T = 60 °C), whereas the TON was only limited by the amount of HCOOH used and by the increase of pH with the progress of reaction, which makes the protonation of Ir–H less probable.
Hydrogen Liberation from Formic Acid Mediated by Efficient Iridium(III) Catalysts Bearing Pyridine-Carboxiamide Ligands
Gabriel Menendez Rodriguez;Chiara Domestici;Alberto Bucci;Cristiano Zuccaccia;Alceo Macchioni
2018
Abstract
Herein it is shown that complexes [Cp*Ir(R-pica)Cl] {R-pica = R-picolinamidate = κ2-R-pyridine-2-carboxamide ion (–1), 1 R = H and 2 R = Me} catalyze the liberation of H2 from formic acid (FA) in water, at ambient temperature and pressure, in the absence of any addictive/promoter, with performances comparable with those of the best catalysts reported so far. TOF values approaching 30000 h–1 were observed for 1 and 2 (pH = 3.7, [HCOOH] + [HCOO–]=1 M, [Cat] = 250 μM, T = 60 °C), whereas the TON was only limited by the amount of HCOOH used and by the increase of pH with the progress of reaction, which makes the protonation of Ir–H less probable.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
