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Understanding lithium solvation and transport in ionic liquids is important due to their possible application in electrochemical devices. Using first-principles simulations aided by a metadynamics approach we study the free-energy landscape for lithium ions at infinite dilution in ethylammonium nitrate, a protic ionic liquid. We analyze the local structure of the liquid around the lithium cation and obtain a quantitative picture in agreement with experimental findings. Our simulations show that the lowest two free energy minima correspond to conformations with the lithium ion being solvated either by three or four nitrate ions with a transition barrier between them of 0.2 eV. Other less probable conformations having different solvation pattern are also investigated. [ABSTRACT FROM AUTHOR]

A novel strategy for post-synthesis amine borane functionalization of MOFs under gas-solid phase transformation, utilizing gaseous diborane, is reported. The covalently confined amine borane derivative decorated on the framework backbone is stable when preserved at low temperature, but spontaneously liberates soft chemical hydrogen at room temperature, leading to the development of an unusual borenium type species (-NH=BH2+) ion-paired with a hydroborate anion. Furthermore, the unsaturated amino borane (-NH=BH2) and the μ-iminodiborane (-μ-NHB2H5) were detected as final products. A combination of DFT based molecular dynamics simulations and solid state NMR spectroscopy, utilizing isotopically enriched materials, were undertaken to unequivocally elucidate the mechanistic pathways for H2 liberation. [ABSTRACT FROM AUTHOR]

The electrophilic N-trifluoromethylation of MeCN with a hypervalent iodine reagent to form a nitrilium ion, that is rapidly trapped by an azole nucleophile, is thought to occur via reductive elimination (RE). A recent study showed that, depending on the solvent representation, the S N2 is favoured to a different extent over the RE. However, there is a discriminative solvent effect present, which calls for a statistical mechanics approach to fully account for the entropic contributions. In this study, we perform metadynamic simulations for two trifluoromethylation reactions (with N- and S-nucleophiles), showing that the RE mechanism is always favoured in MeCN solution. These computations also indicate that a radical mechanism (single electron transfer) may play an important role. The computational protocol based on accelerated molecular dynamics for the exploration of the free energy surface is transferable and will be applied to similar reactions to investigate other electrophiles on the reagent. Based on the activation parameters determined, this approach also gives insight into the mechanistic details of the trifluoromethylation and shows that these commonly known mechanisms mark the limits within which the reaction proceeds. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

In this study we have used density functional theory calculations to investigate the stability, structure and catalytic properties of Ni clusters supported on CeO2. We have found Ni clusters to be stabilized with increasing cluster size up to ten atoms both as isolated clusters and adsorbed on CeO2(1 1 1). Analysis of the structural properties showed an opening of the Ni particles when deposited on CeO2(1 1 1) indicating facilitated accessibility for reacting molecules. The reactivity of the functionalized surface has been examined on the example of CO2 adsorption and activation and compared to the one on pristine CeO2(1 1 1) and isolated Ni clusters. Furthermore, the effect of Ni cluster deposition on the formation and characteristics of surface and subsurface oxygen vacancies in CeO2 has been investigated. The oxygen vacancy position is found to significantly affect the stability and electronic structure of the Ni/CeO2 system. [ABSTRACT FROM AUTHOR]

Aminoglycosides containing a 2,3- trans carbamate group easily undergo anomerization from the 1,2- trans glycoside to the 1,2- cis isomer under mild acidic conditions. The N-substituent of the carbamate has a significant effect on the anomerization reaction; in particular, an N-acetyl group facilitated rapid and complete α-anomerization. The differences in reactivity due to the various N-substituents were supported by the results of DFT calculations; the orientation of the acetyl carbonyl group close to the anomeric position was found to contribute significantly to the directing of the anomerization reaction. By exploiting this reaction, oligoaminoglycosides with multiple 1,2- cis glycosidic bonds were generated from 1,2- trans glycosides in a one-step process. [ABSTRACT FROM AUTHOR]

cp2 k has become a versatile open-source tool for the simulation of complex systems on the nanometer scale. It allows for sampling and exploring potential energy surfaces that can be computed using a variety of empirical and first principles models. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern and massively parallel hardware. This review briefly summarizes the main capabilities and illustrates with recent applications the science cp2 k has enabled in the field of atomistic simulation. WIREs Comput Mol Sci 2014, 4:15-25. doi: 10.1002/wcms.1159 The authors have declared no conflicts of interest in relation to this article. For further resources related to this article, please visit the WIREs website. [ABSTRACT FROM AUTHOR]

The Car-Parrinello (CP) method made molecular dynamics simulation with on-the-fly computation of interaction potentials from electronic structure theory computationally feasible. The method reformulates ab initio molecular dynamics (AIMD) as a two-component classical dynamical system. This approach proved to be valuable far beyond the original CP molecular dynamics method. The modern formulation of Born-Oppenheimer (BO) dynamics is based on the same basic principles and can be derived from the same Lagrange function as the CP method. These time-reversible BO molecular dynamics methods allow higher accuracy and efficiency while providing similar longtime stability as the CP method. AIMD is used in many fields of computational physics and chemistry. Its applications are instrumental in fields as divers as enzymatic catalysis and the study of the interior of planets. With its versatility and predictive power, AIMD has become a major approach in atomistic simulations. © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Back Cover picture shows the free energy landscape for Li+ solvation in ethyleammonuim nitrate (EAN). Using first‐principle simulations aided by a metadynamics approach, the solvation and transport of lithium in EAN was investigated. We identified different lithium solvation scenarios that were explored by the metadynamics and quantified their free energy barriers. The lowest free‐energy barrier appears to be consistent with what has been observed experimentally. More details can be found in the Full Paper by Kachmar et al. on page 3083 in Issue 15, 2017 (DOI: 10.1002/cssc.201700510). [ABSTRACT FROM AUTHOR]