Photothermal Oxidation of Cinnamyl Alcohol with Hydrogen Peroxide Catalyzed by Gold Nanoparticle/Antimony-Doped Tin Oxide Nanocrystals

Gold nanoparticles with different mean sizes were formed on antimony-doped tin oxide nanocrystals by the temperature-varied deposition-precipitation method (Au/ATO NCs). Au/ATO NCs possess strong absorption in the near-infrared region due to Drude excitation in addition to the localized surface plasmon resonance (LSPR) of AuNPs around 530 nm. Au/ATO NCs show thermally activated catalytic activity for the oxidation of cinnamyl alcohol to cinnamaldehyde by hydrogen peroxide. The catalytic activity increases with a decrease in the mean Au particle size (d_Au) at 5.3 nm≤d_Au≤8.2 nm. Light irradiation (λ_ex >660 nm, ∼0.5 sun) of Au/ATO NCs increases the rate of reaction by more than twice with ∼95 % selectivity. Kinetic analyses indicated that the striking enhancement of the reaction stems from the rise in the temperature near the catalyst surface of ∼30 K due to the photothermal effect of the ATO NCs.     

Effect of increasing pressure on the structure and temperature-induced changes in magnetic properties of heterospin complexes

Russian Chemical Bulletin - The study is concerned with structural rearrangements in the crystals of heterospin complexes Cu(hfac)2 with nitroxide radicals LR (hfac is hexafluoroacetylacetonate, LR...     

Control of Axial Chirality by Planar Chirality Based on Optically Active [2.2]Paracyclophane

Optically active X-shaped molecules based on the planar chiral [2.2]paracyclophane building block were prepared, in which di(methoxy)terphenyl units were stacked on the central benzene rings. At 25 °C, anisolyl rings freely rotate in solution, while in the crystal form, they are fixed by intramolecular CH–π interactions, thereby leading to the expression of the axial chirality, i.e., propeller chirality was exhibited by the planar chiral [2.2]paracyclophane moiety. The X-shaped molecule exhibited good circularly polarized luminescence (CPL) profiles with moderate Φ_PL and a large g_lum value in the order of 10⁻³ at 25 °C, in solution. In contrast, at −120 °C, dual CPL emission with opposite signs was observed. According to the theoretical studies, the rotary motion of the anisolyl units is suppressed in the excited states, and so emission from two isomers could be observed. These results demonstrate that the axial chirality was controlled by the planar chirality, leading ultimately to propeller chirality.     

A dipping method for radioactivity measurement in water using plastic scintillator

Journal of Radioanalytical and Nuclear Chemistry - A new dipping method was studied for the measurement of radioactive solution using plastic scintillator sheets and pellets (PSs) and a liquid...     

Crystal structures and magnetic properties of nitroxide radical-coordinated copper(II) and cobalt(II) complexes

Transition Metal Chemistry - The crystal structures and magnetic properties of three coordination compounds constructed from various nitroxide radicals L and MII(hfac)2(H2O)2 building blocks...     

Highly bent crystals formed by restrained π-stacked columns connected via alkylene linkers with variable conformations

A reproducible formation of strongly bent crystals was accomplished by structurally restraining macrocyclic π-conjugated molecules. The model π-units consist of two 9,10-bis(2-thienylethynyl)anthracenes with a strong propensity for stacking, which are connected in a macrocyclic fashion via two alkylene linkers. The correlation between the crystalline morphology and the macrocyclic structures restrained by a variety of flexible alkylene linker combinations was systematically studied. Bent crystals were obtained only with specific alkylene linkers of appropriate chain length. The alkylene linkers can adopt different conformations in the crystal packing, so as to fill voids within the macrocycle. The ability to form several similar molecular structures with different alkylene conformations gives rise to contaminations of different crystalline phases within a single crystal, and it is these phase contaminations which are responsible for the bending of the crystals.