The Organometallic Chemistry of Carbon Dioxide

Activation of carbon dioxide and carbon disulfide by a scandium N-heterocyclic carbene complex

“…10 Such activation of CO 2 using FLPs has allowed subsequent reduction to methanol and methane. 11,12 There are few, but an increasing number, of transition metal FLP type systems which can activate CO 2 X-ray quality single crystals of 1 were grown by slow diffusion of hexane into a concentrated benzene solution at 298 K over five days. The molecular structure of the Λ-mer enantiomer of 1 is shown alongside equation 1 (the asymmetric unit contains both ∆-mer and Λ-mer enantiomers).…”

Self-Assembly Fabrication of Hollow Mesoporous Silica@Co–Al Layered Double Hydroxide@Graphene and Application in Toxic Effluents Elimination

“…3,4 Carbon disulfide (CS 2 ) is isoelectronic with CO 2 and has a more electrophilic carbon centre due to the weaker π-donor ability of the softer S, and is often studied as a comparator for CO 2 .…”

“…Neutral N-heterocyclic carbenes (NHCs) are highly nucleophilic and are known to react with both CO 2 and CS 2 to form zwitterionic imidazolium carboxylates (NHC·CO 2 ) and dithiocarboxylates (NHC·CS 2 ) respectively (A in Chart 1). 5 Imidazolium carboxylates have been shown to successfully catalyse reactions such as the coupling of epoxides and carbon dioxide to produce cyclic carbamates.…”

“…10 Such activation of CO 2 using FLPs has allowed subsequent reduction to methanol and methane. 11,12 There are few, but an increasing number, of transition metal FLP type systems which can activate CO 2 3 1 in a 67% yield, eqn (1). The 1 H NMR spectrum of 1 at room temperature shows one set of broad ligand resonances which would indicate either C 3 symmetry in solution or that a fluxional process between free and bound carbenes is occurring on the NMR timescale.…”

“…28,29 For comparison, reactions with one, two, and an excess of equivalents of CS 2 were studied. Treatment of 1 with one equivalent of CS 2 in toluene affords the microcrystalline red solid 2 ), which was shown by a single crystal X-ray study to contain a single dithiocarboxylated imidazolium group, coordinated to Sc through the alkoxide. The 1 H NMR spectrum of 3 shows two sets of ligand resonances in a 2 : 1 ratio and the 13 C NMR spectrum is in agreement, with the resonance at 226.7 ppm attributed to the dithiocarboxylate group and a resonance at 150.6 ppm attributed to the C 2 imidazolium carbon through which CS 2 is bound.…”