The impact of Metal–Ligand Cooperation in Hydrogenation of Carbon Dioxide Catalyzed by Ruthenium PNP Pincer

Abstract

The metal−ligand cooperative activation of CO 2 with pyridine-based ruthenium PNP pincer catalysts leads to pronounced inhibition of the activity in the catalytic CO 2 hydrogenation to formic acid. The addition of water restores catalytic performance by activating alternative reaction pathways and leads to unprecedented Rucatalyzed CO 2 hydrogenation activity. The mechanism of the underlying chemical transformations is proposed on the basis of DFT calculations, kinetic experiments, and NMR reactivity studies.

Reduction of CO2 by Pyridine Monoimine Molybdenum Carbonyl Complexes: Cooperative Metal–Ligand Binding of CO2

“…For example, Braunstein et al in 1981 obtained a similar result to ours by activation of CO 2 at a square planar Pd diphenylphophinoacetate complex. [23] Similar binding patterns of carbon dioxide have recently been reported for PNN-Ru [24] and PNP-Ru/Re [25] pincer complexes as well as β-diketiminate Sc [26] complexes.…”

Ruthenium(II) Complexes Containing Lutidine‐Derived Pincer CNC Ligands: Synthesis, Structure, and Catalytic Hydrogenation of CN bonds

“…Alternatively, Dub, Gordon et al 40. as well as Pidko et al 5f. 6i have recently proposed a role for the coordination of a second molecule of hydrogen to Ru prior to a second hydrogen transfer in related asymmetric hydrogenation of ketones and CO 2 hydrogenation, respectively (Figure 10), albeit in those reactions, higher H 2 pressures than in this work were used.…”

Hydrogenation of CO2 to formic acid with iridiumIII(bisMETAMORPhos)(hydride): the role of a dormant fac-IrIII(trihydride) and an active trans-IrIII(dihydride) species

“…The conversion did not increase significantly between 90 to 180 minutes and a final concentration of 0.015 M HCOOH was obtained. Similar differences in catalytic performance with NEt 3 and DBU were observed with system C. 5 The formation of HDBU + ·•HCOO -was monitored in time by the appearance of the HCOO -formate signal at 8.60 ppm in consecutive 1 H NMR spectra (see ESI). The concentration of H 2 increases over time, but is barely detectable in the first 30 minutes of reaction.…”