Biphasic Behaviors of Nd Bound with Cyanex272, Cyanex301, and Cyanex302: A Molecular Dynamics Simulation Study.

By means of molecular dynamics simulations, this work addresses the conformational flexibility and migration of trivalent neodymium (Nd) coordinated with three or six titled (thio)phosphinic ligands and shows that the fluxionality of the complexes enables them to adapt to the solvent environment during the migration. Cyanex272 forms a more compact complex than the other two types of ligands and screens more significantly the interaction between the water solvent and the metal ion in the complex, which weakens the detainment of the aqueous environment. This results in faster motion of the Nd(C272) complex both in its translation and rotation than the other complexes when migrating to the organic phase and wins over the other two ligands in transporting the metal ions from the aqueous phase to the organic phase.

Understanding the Unique Antioxidation Property of Boron-Based Catalysts during Oxidative Dehydrogenation of Alkanes.

Boron-based catalysts show excellent performance in oxidative dehydrogenation (ODH) of light alkanes to alkenes with high selectivity and extremely good antioxidation properties. However, the anti-deep-oxidation mechanism remains unclear. Herein, we chose -BN and BO as representative boron-based catalysts to investigate their reactions with two important intermediates in the light alkane ODH, Et· (evolving to ethene) and EtO· (evolving to ethene or CO), to elucidate the origin of the antioxidation of alkanes.

The proximity of the G-quadruplex to hemin impacts the intrinsic DNAzyme activity in mitochondria.

The DNAzyme activity of G-quadruplex/hemin in mitochondria has not been characterized. Herein, we report an unexpected difference in the DNAzyme activity between in vitro assays and in mitochondria. Molecular dynamic simulations illustrate how the interaction of the G-quadruplex with hemin may modulate the DNAzyme activity.

Tracing the driving forces responsible for the remarkable infectivity of 2019-nCoV: 1. Receptor binding domain in its bound and unbound states.

The pandemic of COVID-19 has posed an urgent need to learn the dynamics of the virus and the mechanism of its contagion of host cells. By means of molecular dynamics simulations, this work addressed the behavior of 2019-nCoV in two aspects: the binding affinity of its receptor binding domain (RBD) with ACE2, and its potential conformation preferences in its unbound state. The results showed that the RBD of 2019-nCov bound much stronger with ACE2 than that of SARS-CoV due to a better organized hydrogen bond network between the former pair with most of the residues at the contact interface sharing the responsibility to hold the pair tightly.

Stronger Hydration of Eu(III) Impedes Its Competition against Am(III) in Binding with N-donor Extractants.

The significance of understanding the interaction between actinide(III)/lanthanide(III) (An(III)/Ln(III)) and N-donor extractants lies in the importance of efficient An/Ln separation in advanced nuclear fuel cycles and the high expectation of the application of N-donor extractants. This work reports a density functional theory study aiming at a plausible explanation of the origin of the selectivity of the ligands in An/Ln separation and an evaluation of the influence of the bridging groups of typical N-donor extractants. Five bis(triazine) N-donor ligands were considered, differing in their denticity dictated by their bridging groups and in the flexibility of these bridging groups.

Polarizable and Non-Polarizable Force Field Representations of Ferric Cation and Validations.

The AMOEBA polarizable force field of ferric ion was optimized and applied to study the hydration of ferric ion and its complexation with porphine in the aqueous phase. The nonpolarizable force field was also optimized for comparison. The AMOEBA force field was found to give a more accurate hydration free energy than the nonpolarizable force field with respect to experimental data, and correctly predict the most stable electronic state of hydrated Fe, which is the sextet state, and of the Fe-Por complex, which is the quartet state, consistent with the literature that was carried out using the DFT method.

Phosphine-Catalyzed Enantioselective [4 + 3] Annulation of Allenoates with C,N-Cyclic Azomethine Imines: Synthesis of Quinazoline-Based Tricyclic Heterocycles.

With the use of a commercially available chiral phosphine as the catalyst, the first catalytic enantioselective [4 + 3] annulation of allenoates with C,N-cyclic azomethine imines is developed. The reaction works efficiently under mild reaction conditions to afford seven-membered ring-fused quinazoline-based tricyclic heterocycles in high yields with good to excellent diastereo- and enantioselectivities.