Trapping atmospheric CO₂ with gold

Abstract

The ability of gold-hydroxides to fix CO2 is reported. [Au(IPr)(OH)] and [{Au(IPr)}2(μ-OH)][BF4] react with atmospheric CO2 to form the trigold carbonate complex [{Au(IPr)}3(μ(3)-CO3)][BF4]. Reactivity studies revealed that this complex behaves as two basic and one cationic Au centres, and that it is catalytically active. DFT calculations and kinetic experiments have been carried out.

Reactivity of Gold Hydrides: O2 Insertion into the Au–H Bond

“…The cation consists of three (NHC)Au ions coordinated to the carbonate oxygen atoms (see the Supporting Information ); the anion, most probably HO, was disordered and could not be reliably located. The cation is identical with that prepared recently by Sadighi by a different route, 15 as well as by Nolan et al 16 …”

“…The cation consists of three (NHC)Au ions coordinated to the carbonate oxygen atoms (see the Supporting Information); the anion, most probably HO, was disordered and could not be reliably located. The cation is identical with that prepared recently by Sadighi by a different route, 15 as well as by Nolan et al 16 A second reaction pathway of gold hydrides is through H radical abstraction by radical acceptors. We have previously shown that the Au(III) hydride (C ∧ N ∧ C)AuH reacts with galvinoxyl to give the Au(II) compound (C ∧ N ∧ C)Au− Au(C ∧ N ∧ C), whereas there was no reaction with TEMPO.…”

Main Avenues in Gold Coordination Chemistry

“…A mixture of [Au(IPr)(OH)] and [Au(IPr) 2 (μ− OH)]BF 4 reacted with atmospheric CO 2 to give the trigold carbonate complex [Au 3 (IPr) 3 (μ 3 -CO 3 )]BF 4 (35) process was found to be reversible and the presence of water had an important role in the equilibrium of the reaction. 112 Exploiting the knowledge acquired on the use of weak inorganic bases to form M−C bonds, a large number of Au(I)−aryl complexes stabilized by NHC ligands were synthesized in high yields by reaction between [AuCl(NHC)] and aryl boronic acids in the presence of K 2 CO 3 . 110 These reaction conditions are far milder and sustainable than the classical arylation or alkylation pathways.…”

“…A mixture of [Au­(IPr)­(OH)] and [Au­(IPr) 2 (μ–OH)]­BF 4 reacted with atmospheric CO 2 to give the trigold carbonate complex [Au 3 (IPr) 3 (μ 3 -CO 3 )]­BF 4 ( 35 ). The process was found to be reversible and the presence of water had an important role in the equilibrium of the reaction …”

Hydroxide complexes of the late transition metals: Organometallic chemistry and catalysis

“…The hydroxide species can also trap CO2 (even at relatively low pressures), leading to a nickel carbonate complex (Scheme 19 (c)). This carbonate complex remains monomeric, unlike NHCirdium(I) 43 (vide supra) and NHC-gold(I) 58 examples (vide infra), which dimerise or trimerise, respectively. Other nickel complexes, with bridging hydroxide moieties, have also been reported to trap CO2 in the form of carbonate ligands.…”