Molecular dynamics simulations of cinchonidine-modified platinum in ethanol: comparisons with surface studies

Surface-level mechanistic studies of adsorbate–adsorbate interactions in heterogeneous catalysis by metals

“…Furthermore, analysis of the interactions between chiral molecules and reactants at the metal surface is hampered in part by the complexity of chiral modifiers such as CD. CD has been found to adsorb on surfaces such as Pt (111) through multiple coordination with the metal surface, and in a variety of orientations that depend on surface coverage and temperature [62][63][64][65][66][67][68]. At conditions of low (room) temperature, CD has been found to adsorb with its quinoline ring lying more or less flat on the surface at low coverage, though significant tilt becomes obvious at higher temperatures and coverage.…”

“…The flat-lying geometry is generally assumed to be the structure that imparts enantioselectivity, in part because the modifier is most effective in conferring enantioselectivity at moderate coverages. Tilted structures are generally assumed to be spectators [62][63][64][65][66][67][68]. Interestingly, the presence of hydrogen on the surface appears to affect the binding of CD on metal surfaces.…”

Conformational Behavior of Cinchonidine Revisited: A Combined Theoretical and Experimental Study

“…9 The conformational behavior of CD is rather complex; it is remarkably influenced by various parameters, such as solvents, 7 solutes, 10,17,18 self-interactions, 14,19 protonation, 12 and the presence of metallic surfaces. 11,20,21 Knowledge on the conformation is critical, because the conformation in solution and on surface can directly influence its chiral interactions with substrates, hence the resulting chemistry. NMR, nuclear Overhauser enhancement spectroscopy (NOESY), IR, vibrational circular dichroism, and theoretical modeling have been applied to study the dynamic aspects of its structure.…”

Towards a rational design of enantioselective heterogeneous catalysts: Modeling of chiral organotin precursors

“…Despite the extense work done by the groups of Vargas at ETH (Zurich) and the group of Murzin at Turku in Finland on enantioselective catalytic systems based on the adsorption of a chiral modifier on a supported transition metal catalyst [11,12,18,[37][38][39], the mechanism of enantioselective hydrogenation reactions employing catalytic systems prepared through SOMC/M techniques is far from being known in detail, so any contribution leading to the knowledge of the structure of the transition-state complex in the key step of enantiodifferentiation may provide an important guide for the rational development of new catalytic systems. In this regard, as a first step towards designing a chiral heterogeneous catalyst we propose modeling the organotin precursor compound that would optimize the catalyst that would finally be obtained.…”