Understanding the role of aliovalent cation substitution on the li-ion diffusion mechanism in Li6+xP1-xSixS5Br argyrodites.

Due to their high ionic conductivity, lithium-ion conducting argyrodites show promise as solid electrolytes for solid-state batteries. Aliovalent substitution is an effective technique to enhance the transport properties of Li6PS5Br, where aliovalent Si substitution triples ionic conductivity. However, the origin of this experimentally observed increase is not fully understood. Our density functional theory (DFT) study reveals that Si4+ substitution increases Li diffusion by activating Li occupancy in the T4 sites. Redistribution of Li-ions within the lattice results in a more uniform distribution of Li around the T4 and neighboring T5 sites, flattening the energy landscape for diffusion. Since the T4 site is positioned in the intercage jump pathway, an increase in the intercage jump rate is found, which is directly related to the macroscopic diffusion and bulk conductivity. Analysis of neutron diffraction experiments confirms partial T4 site occupancy, in agreement with the computational findings. Understanding the aliovalent substitution effect on interstitials is crucial for improving solid electrolyte ionic conductivity and advancing solid-state battery performance.

Intramolecular amination via acid-catalyzed rearrangement of azides: a potent alternative to intermolecular direct electrophilic route.

Although acid-catalyzed intramolecular rearrangement of organic azides is an attractive route to amines, its mechanism and synthetic prospective are still debated. Herein, through computational and experimental studies, we demonstrated that azide intramolecular rearrangement could serve as a potent synthetic route to a sought-after amine functionality including preparation of difficult to access and valuable heterocyclic amines. Using quantum chemical calculations at MP2/aug-cc-pVTZ and B3LYP/aug-cc-pVDZ levels, we discovered that this reaction proceeds via a concerted transition state with nitrogen elimination and alkyl/aryl migration occurring at the same time. Two conformers of protonated azides - syn- and anti- - were shown to precede corresponding transition states. It was shown that the reaction follows Curtin-Hammett scenario as the energy gap required for conformer interconversion was substantially lower than activation barrier of either transition state. Intramolecular amination via azide rearrangement was predicted to be a selective process with migratory aptitude increasing in a row alkyl

Poly(ε-caprolactone) Scaffolds Doped with c-Jun N-terminal Kinase Inhibitors Modulate Phagocyte Activation.

The modulation of phagocyte responses is essential for successful performance of biomaterials in order to prevent negative outcomes associated with inflammation. Herein, we developed electrospun poly(ε-caprolactone) (PCL) scaffolds doped with the novel potent c-Jun N-terminal kinase (JNK) inhibitors 11H-indeno[1,2-b]quinoxalin-11-one oxime (IQ-1) and 11H-indeno[1,2-b]quinoxalin-11-one O-(O-ethylcarboxymethyl) oxime(IQ-1E) as a promising approach for modulating phagocyte activation. Optimized electrospinning parameters allowed us to produce microfiber composite materials with suitable mechanical properties. We found that embedded compounds were bound to the polymer matrix via hydrophobic interactions and released in two steps, with release mostly controlled by Fickian diffusion. The fabricated scaffolds doped with active compounds IQ-1 and IQ-1E effectively inhibited phagocyte inflammatory responses. For example, they suppressed human neutrophil activation by the biomaterials, as indicated by decreased neutrophil reactive oxygen species (ROS) production and Ca2+ mobilization. In addition, they inhibited lipopolysaccharide (LPS)-induced NF-κB/AP-1 reporter activity in THP-1Blue cells and interleukin (IL)-6 production in MonoMac-6 cells without affecting cell viability. These effects were attributed to the released compounds rather than cell-surface interactions. Therefore, our study demonstrates that doping tissue engineering scaffolds with novel JNK inhibitors represents a powerful tool for preventing adverse immune responses to biomaterials as well as serves as a platform for drug delivery.