Modifying the energy term and considering the entropic contribution by IE method significantly improve the accuracy of predicted binding free energy in MM/PBSA method.

Based on a metal-templated approach using a rigid and globular structural scaffold in the form of a bis-cyclometalated octahedral iridium complex, an exceptionally active hydrogen-bond-mediated asymmetric catalyst was developed and its mode of action investigated by crystallography, NMR, computation, kinetic experiments, comparison with a rhodium congener, and reactions in the presence of competing H-bond donors and acceptors. Relying exclusively on weak forces, the enantioselective conjugate reduction of nitroalkenes can be executed at catalyst loadings as low as 0.004 mol% (40 ppm), representing turnover numbers of up to 20 250. A rate acceleration by the catalyst of 2.5 × 10(5) was determined. The origin of the catalysis is traced to an effective stabilization of developing charges in the transition state by carefully orchestrated hydrogen-bonding and van der Waals interactions between catalyst and substrates. This study demonstrates that the proficiency of asymmetric catalysis merely driven by hydrogen-bonding and van der Waals interactions can rival traditional activation through direct transition metal coordination of the substrate.

Molecular dynamics (MD) simulations were performed employing the polarized protein-specific charge (PPC) to explore the origin of the cooperativity in streptavidin–biotin systems (wild type, two single mutations and one double-mutation).

Electrode/electrolyte interfacial water is one of the most interesting systems studied by surface-enhanced Raman spectroscopy (SERS) in the past two decades, and is brieÑy reviewed. It has been shown that the SERS characteristics of water are very di †erent from those of other surface species. Strong libration bands and the abnormal enhancement of the bending mode of water on Cu and Ag electrodes have been observed in the hydrogen evolution reaction (HER) potential region (AEÔ1.0 V SCE). The observations may be attributed to the special interfacial ¿s. structure of water molecules, which is in favor of the deprotonation of water and mass transfer of the proton and the reaction product OH-from the surface to the bulk through the hydrogen bonding net during HER. A new enhancement mechanism for SERS involving charge transfer (CT) from metal to water is suggested by the correlation of HER current density and SERS band intensity. The generality of this CT enhancement is brieÑy discussed.

An asymmetricF riedel-Crafts alkylation of indoles with (Z)-1-bromo-1-nitrostyrenes, which is efficiently catalyzed by an umber of hydrogenb ond interactions with the ligand sphere of bis-cyclometalated iridium complexes, has been reported. The proposed transition state exploits ah ydrogen bond network, which is illustrated by the co-crystal structure of am odel catalyst with an analog of the nitro substrate. The bromof unctional group not only plays an important role for achieving ah igh asymmetric induction but also affords chiral indole-containing products, which can be readily converted to ar ange of useful intermediates for the creation of chiral indole building blocks.