Volume 92, Issue 12, December 2019

The distribution of ferric chloro complexes was investigated by factor analysis of UV-Vis absorption spectra, followed by fitting analysis of a theoretical model to individual molar attenuation coefficients. As the result, [Fe^III]³⁺, [Fe^IIICl]²⁺, [Fe^IIICl₂]⁺, [Fe^IIICl₃]⁰, and [Fe^IIICl₄]⁻ were identified. The thermodynamic parameters of the four cumulative formation constants and a Setchénow coefficient for neutral species of [Fe^IIICl₃]⁰ were determined.

Distribution of ion-exchange sites in zeolite frameworks affects the oxidation state distribution and coordination environment of ionic Cu sites on the zeolites, and plays a role on the formation of ionic Cu active sites for nitric oxide (NO) direct decomposition.

Zn(OAc)₂ and 1,10-phenanthroline, a commercially available catalyst, could catalyze carbon dioxide hydrosilylation to silyl formate, bis(silyl)acetal, methoxysilane, and methane. With isotope labelled chemical, ¹³CH₄ was fully characterized by NMR spectroscopy. In addition to Zn(OAc)₂, other first-row transition metals (Mn, Fe, Co, Ni, and Cu) also served as Lewis acid catalysts for CO₂ hydrosilylation, regardless of the nature of the metal.

The stable structure and the electron density of the spinels MgCo₂O₄ and MgCo_1.5Mn_0.5O₄, as Mg secondary battery cathode materials, was investigated by first-principles calculations. The electron density between Mg and O in MgCo_1.5Mn_0.5O₄ was lower than those in MgCo₂O₄, suggesting the Mg could easily move from the crystal by the substitution of Mn.

The first 21 geometries of a pair of tetracene molecules for which the highest rate of singlet fission is predicted are identified using a simplified frontier orbital model and a complete search of the six-dimensional space of all rigid pair geometries, excluding the subspace where the two molecules would interpenetrate.

The formation, structure, and thermal transformation of MA₂Pb₃I₈·2DMSO intermediate complex to MAPbI₃ is examined. Small, orientated intermediate crystallites in the precursor films are found to be critically important in driving the thermal transformation to dense and flat perovskite layers. Optimized fabrication methods were developed, resulting in MAPbI₃ perovskite solar cells with high power conversion efficiency (maximum ∼20.3%) and high reproducibility.

We found that cobalt nanoparticle catalysts supported on nitrogen-doped carbon could facilitate oxygenation of olefins in a heterogeneous manner. Both the nitrogen dopant and cobalt species were essential to promote the reactions. Based on several mechanistic studies, the formation of radical intermediates on cobalt nanoparticles is proposed.

We successfully developed a novel time-resolved synchrotron-radiation X-ray diffraction measurement system with high temporal resolution (50 ms) at the BL02B2 facility at SPring-8, and used it to monitor crystal structure changes of layered double hydroxides during anion-exchange reaction in nitrate aqueous solution of various concentrations.

The anharmonic vibrational wavenumbers of dihalogenomethanes and 1,2-dihalogenoethanes were calculated by using density-functional methods. The double-hybrid-type B2PLYP functional method with carefully chosen sets of basis functions gave molecular structures and anharmonic vibrational wavenumbers in good agreement with the published experimental values. The B2PLYP functional method may become a realistic approach for anharmonic vibrational analyses of relatively large molecules in general.

A convenient and versatile plasma-assisted droplet evaporation-rigid crosslinking method has been developed for the fabrication of gold nanoparticle array film. This 2D structure with rigid sulfurated crosslinkers can serve as an environmentally friendly catalyst for the CO₂ cycloaddition, which offers a novel strategy for the fabrication and application of 2D Au-based hybrid materials.

A MIL-125 is employed as a template to produce TiO₂ with high specific surface area and well-controlled porosity. Annealing under a hydrogen atmosphere results in an oxygen deficient TiO_2−δ, which is black in appearance, enhanced photocatalytic properties are observed, importantly including a significant visible light response in the degradation of RhB.

Polycyclic aromatic hydrocarbons (PAHs) were synthesized from two methylarene molecules. Trimethyl[2-(trifluoromethyl)allyl]silane was treated with Ar¹CH₂Br derived from Ar¹CH₃ to afford 2-trifluoromethyl-1-alkenes, which underwent an S_N2′-type reaction with Ar²CH₂Li generated from Ar²CH₃ to produce 1,1-difluoro-1-alkenes (cyclization precursors); their FSO₃H·SbF₅-promoted domino cyclization followed by dehydrogenation yielded PAHs. The combination of even a limited number of methylarenes resulted in various higher order PAHs.

The synthesis and characterization of a series of thiophene-thiazole hybrid macrocyclic compounds through the Pd-catalyzed direct couping are described. The coupling products form characteristic helical assemblies, and among them, the new tetraheteroarylene specifically affords chiral crystals. Additionally, the first synthesis of a tetraarylene composed of four different heteroaryl fragments is achieved.

By incorporating PTFE particles into the cathode catalyst layer, a large increase of current density was obtained mainly due to the improvement of hydrophobicity. Owing to the improvement of the hydrophobicity, addition of the PTFE was effective especially during low humidity operations.

When biomaterials come into contact with biological fluids, water molecules immediately adsorb onto the surface of the materials. Here, advances of the intermediate water concept are reviewed. This account provides an overview of the progress made in the design of multi-functional biomedical polymers by controlling the bio-interfacial water states.