CO2 hydrogenation to methanol, a renewable fuel, under benign conditions and without the use of sacrificial agents is a rarity and certainly a much sought after goal of present-day research. Herein, we report using well calibrated computational tools the viability of hydrogenating CO2 to CH3OH and pyridine to 1,2-dihydropyridine, a renewable organohydride which can also reduce CO2 to CH3OH sustainably, using hydrogens chemisorbed on Au(111) surface of Au20 by photo-excitation. Our studies predict that these hydrogenations can occur at appreciable rates at room temperature. Thus, we reveal the untapped potential of the chemisorbed hydrogens on Au(111) surface, achieved by hot-electron generation through photo-excitation, in facilitating endoergic hydrogenations akin to those enabled by NADPH.

Molecular solar thermal storage (MOST) systems have been largely limited to three classes of molecular motifs: azo-benzene, norbornadiene, and transition metal based fulvalene-tetracarbonyl systems. Photodimerization of anthracene has been known for a century; however, this photoprocess has not been successfully exploited for MOST purposes due to its poor energy storage. Using well-calibrated theoretical methods on a series of [n.n](9,10)bis-anthracene cyclophanes, we have exposed that they can store solar energy into chemical bonds and can release in the form of heat energy on demand under mild conditions. The storage is mainly attributed to the strain in the rings formed by the alkyl linkers upon photoexcitation. Our results demonstrate that the gravimetric energy storage density for longer alkyl-chain linkers (n > 3) are comparable to those for the best-known candidates; however, it lacks some of the deleterious attributes of known systems, thus making the proposed molecules desirable targets for MOST applications.

Density functional calculations have been performed to elucidate the mechanism of formation of N-phenylbenzylamine (Am) from alkylation of aniline (An) with benzaldehyde (Bz), with the intermediacy of the imine, N-benzylideneaniline (Im), catalyzed by the triaryl borane (BAr 3), B(2,6-Cl 2 C 6 H 3)(p-HC 6 F 4) 2 , and utilizing H 2 as the reductant. Our computational investigation reveals that H 2 activation by BAr 3 /LB (LB = Lewis Base; An, Im, THF or Bz) frustrated Lewis pairs (FLPs) proceeds through a stepwise mechanism consisting of initial H 2 capture followed by heterolytic HÀ H cleavage, via a 3c-2e H 2 coordinated borane species. H 2 activation subsequently leads to a H 2 dissociated ion pair, overcoming energy barriers (31 kcal/mol at M06-2X/6-311 + + G(d,p)) accessible at the experimental temperature (100°C). Consequently, the iminium hydridoborate ion pair, [BAr 3-H] À [Im-H] + , undergoes hydride transfer from boron (À BH) to the imine carbon (À C=NÀ) and develops the targeted amine. Furthermore, we also identify the crucial role of an unbound aniline and imine which actively participates in proton shuttle mechanism from a coordinated aniline to À C=O of benzaldehyde to generate the desired imine, along with the release of water.

Hydrogen Storage is an indispensable component of hydrogen based fuel economy. Chemical hydrogen storage relies on development of lightweight compounds which can deliver high weight percentage of H2 at moderate...

Metal free catalysis has emerged as a viable alternative for transition metal based catalysts for enabling different chemical processes, particularly for de/hydrogenation reactions. Herein, employing theoretical studies we reveal the unexpected Frustrated Lewis Pair like reactivity of a boron based catalyst, 9,10-dichlorodiboraanthracene and the ethereal solvent to enable dehydrogenation of ammonia-borane (NH 3 BH 3 , AB) under moderate conditions. The mechanistic channels thus uncovered reveal that the boron catalyst abstracts a hydride from NH 3 BH 3 followed by crucial stabilization of the NH 3 BH 2 + moiety by the nucleophilic action of the solvent. H 2 is released by the combination of hydride and proton from the borohydride moiety and the solvated NH 3 BH 2 + respectively. Catalysis becomes unfeasible if the Lewis base-like action of the ethereal solvent is not taken into consideration. Thus, it is suggested that the clandestine partnership of the Lewis Acid, Boron catalyst and the Lewis Base, ethereal solvent, i. e. FLP like action enables dehydrogenation of NH 3 BH 3 in the instant case.[a] M. Sultana, I.