Oxy-tethered Cp*Ir(iii) complex as a competent catalyst for selective dehydrogenation from formic acid

Abstract

A bifunctional tethered iridium catalyst containing a 1,2-diphenylethylenediamine framework was synthesised for the first time. The ethereal tether chain was easily constructed via the intramolecular oxydefluorination of a perfluorophenylsulfonyl substituent...

Pressurized formic acid dehydrogenation: an entropic spring replaces hydrogen compression cost

“…Notably, Shvo's cyclopentadienone-ligated catalyst 14 is much more reactive than Cp*Ir systems under pressurizing condition. The Shvo system is known to rest in its dimeric form 14 in the presence of H 2 , 40–42 so we reason that the availability of CO to trap the system's oxidized monomer and prevent formation of 14 could account for its rate advantage upon pressurization, because it is known that H 2 pressure will drive the system back to dimer 14 . 41–43…”

Metal–Ligand Cooperation in Cp*Ir-Pyridylpyrrole Complexes: Rational Design and Catalytic Activity in Formic Acid Dehydrogenation and CO2 Hydrogenation under Ambient Conditions

“…Obviously, the hydrogenation of CO 2 in basic aqueous solution is more feasible thermodynamically. However, in most cases of CO 2 hydrogenation, harsh conditions including high temperature, high pressure, and the use of organic solvents as well as catalyst are still required. , Although homogeneous catalysts based on Ru, − Ir, − Co, − Fe, − and so on , have been extensively investigated, reports of metal complexes under ambient conditions are still quite rare. For example, for Cp*Ir complexes (Scheme ), [Cp*Ir­(4-(1 H -pyrazol-1-yl-κN 2 )­benzoic acid-κC 3 )­(H 2 O)] 2 ­SO 4 reported by Fukuzumi and [Cp*Ir­(dhbp)­(H 2 O)]­SO 4 (dhbp = 4,4′-di­hydroxy-2,2′-bipyridine) reported by Fujita achieved respective 6.8 and 70 h –1 TOFs for CO 2 hydrogenation to produce formate under atmospheric pressure (CO 2 /H 2 = 0.05 MPa/0.05 MPa) at 25 °C.…”