Ligand-induced substrate steering and reshaping of [Ag2(H)](+) scaffold for selective CO2 extrusion from formic acid.
Metalloenzymes preorganize the reaction environment to steer substrate(s) along the required reaction coordinate. Here, we show that phosphine ligands selectively facilitate protonation of binuclear silver hydride cations, [LAg2(H)](+) by optimizing the geometry of the active site. This is a key step in the selective, catalysed extrusion of carbon dioxide from formic acid, HO2CH, with important applications (for example, hydrogen storage). Gas-phase ion-molecule reactions, collision-induced dissociation (CID), infrared and ultraviolet action spectroscopy and computational chemistry link structure to reactivity and mechanism. [Ag2(H)](+) and [Ph3PAg2(H)](+) react with formic acid yielding Lewis adducts, while [(Ph3P)2Ag2(H)](+) is unreactive. Using bis(diphenylphosphino)methane (dppm) reshapes the geometry of the binuclear Ag2(H)(+) scaffold, triggering reactivity towards formic acid, to produce [dppmAg2(O2CH)](+) and H2. Decarboxylation of [dppmAg2(O2CH)](+) via CID regenerates [dppmAg2(H)](+). These gas-phase insights inspired variable temperature NMR studies that show CO2 and H2 production at 70 °C from solutions containing dppm, AgBF4, NaO2CH and HO2CH.
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, 30 Flemington Road, Parkville, Victoria 3010, Australia.
Athanasios
0000-0003-2797-9303
A
Zavras
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, 30 Flemington Road, Parkville, Victoria 3010, Australia.
George N
GN
Khairallah
Center of Excellence for Science and Technology - Integration of Mediterranean region (STIM) at Interdisciplinary Center for Advanced Science and Technology (ICAST), University of Split, Meštrovićevo šetalište 45, 21000 Split, Croatia.
Marjan
M
Krstić
Institut des Sciences Analytiques, Université de Lyon, Université Lyon 1-CNRS-ENS Lyon, 69100 Villeurbanne, France.
Marion
M
Girod
Institut Lumière Matière, Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne Cedex, France.
Steven
S
Daly
Institut Lumière Matière, Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne Cedex, France.
Rodolphe
R
Antoine
Laboratoire de Chimie Physique, Bâtiment 349, Université Paris-Sud, CNRS, Université Paris-Saclay, F-91405 Orsay, France.
Philippe
P
Maitre
CSIRO Manufacturing, Bayview Avenue, Clayton, Victoria 3168, Australia.
Roger J
RJ
Mulder
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, 30 Flemington Road, Parkville, Victoria 3010, Australia.
Stefanie-Ann
SA
Alexander
Center of Excellence for Science and Technology - Integration of Mediterranean region (STIM) at Interdisciplinary Center for Advanced Science and Technology (ICAST), University of Split, Meštrovićevo šetalište 45, 21000 Split, Croatia.|Humboldt-Universität Berlin, Institut für Chemie, 12489 Berlin, Germany.
Vlasta
V
Bonačić-Koutecký
Institut Lumière Matière, Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne Cedex, France.
Philippe
P
Dugourd
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, 30 Flemington Road, Parkville, Victoria 3010, Australia.
Richard A J
RA
O'Hair
D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003653:Decarboxylation; D005561:Formates / Q000737:chemistry*; D007477:Ions; D008024:Ligands; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry*; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D005561:Formates; D007477:Ions; D008024:Ligands; D012996:Solutions; C030544:formic acid; D002245:Carbon Dioxide; D012834:Silver