Computational design of a renewable organic reagent for photochemical reduction of CO2 with visible light

Abstract

Density functional calculations have been used to design an organic molecule that should be capable of reducing carbon dioxide to formic acid, using the energy from visible light. The compound combines the functions of photocatalyst and reducing agent, and is designed to be renewable by hydrogenation of its oxidation product. The keys to the design are the photochemical generation of a zwitterion in a form that is kinetically inhibited from return to the ground state, and the reduction of CO 2 by direct hydride addition rather than separate electron and proton additions.

Status and perspectives of CO2 conversion into fuels and chemicals by catalytic, photocatalytic and electrocatalytic processes

“…A recent, conceptually very different approach is using purely organic solar light absorbing materials. 220,221 That comes with an added benet that, somewhat auspiciously, organic molecules mostly cannot operate under UV light conditions due to their stability; thus, visible light organic molecules need to be used which is favourable for any practical purpose. A very elegant approach was reported by Carpenter and Rose 221 where the B3LYP hybrid functional combined with 6-31+G(d, p) basis sets and IEFPCM simulated acetonitrile solvent were used to design an organic compound for the conversion of CO 2 to formic acid circumventing the generation of CO 2 _ À .…”

“…220,221 That comes with an added benet that, somewhat auspiciously, organic molecules mostly cannot operate under UV light conditions due to their stability; thus, visible light organic molecules need to be used which is favourable for any practical purpose. A very elegant approach was reported by Carpenter and Rose 221 where the B3LYP hybrid functional combined with 6-31+G(d, p) basis sets and IEFPCM simulated acetonitrile solvent were used to design an organic compound for the conversion of CO 2 to formic acid circumventing the generation of CO 2 _ À . Instead, hydride generating organic molecules based on substituted naphthalene were devised, which aer the initial photon absorption undergo series of elementary intramolecular reaction steps, involving intersystem crossing from S1 to T3, enabling hydride transfer to CO 2 to form formic acid.…”

Photolysis of Tertiary Amines in the Presence of CO2: The Paths to Formic Acid, α-Amino Acids, and 1,2-Diamines

“…Triethylamine ( 1a ) has been used as a sacrificial electron donor in the oligo­( p -phenylenes) photocatalyzed reduction of CO 2 to formic acid and carbon monoxide, and this reaction has been explored theoretically in order to design a task-specific recyclable amine for selective CO 2 reduction to formic acid . Recently, this reaction has been applied to the α-carboxylation of tertiary amines .…”