Pd-catalyzed synthesis of 1-(hetero)aryl-2,2,2-trichloroethanols using chloral hydrate and (hetero)arylboroxines

1-(Hetero)aryl-2,2,2-trichloroethanols are useful key intermediates for the synthesis of various bioactive compounds. Herein, we describe N-heterocyclic carbene (NHC)-coordinated cyclometallated palladium complex (CYP)-catalyzed (hetero)aryl addition of chloral hydrate using (hetero)arylboroxines, providing a new approach to 1-(hetero)aryl-2,2,2-trichloroethanols. Notably, PhS-IPent-CYP which coordinated the bulky yet flexible 2,6-di(pentan-3-yl)aniline (IPent)-based NHC showed good catalytic activities and promoted the transformation in 24-97% yields.

Effect of Anatase Synthesis on the Performance of Dye-Sensitized Solar Cells

Anatase nanoparticles were synthesized from a titanium isopropoxide solution using a hydrothermal process at different pressures in an autoclave system while keeping the volume of the solution constant. As the autoclave pressure was increased from 1 to 71 atm (23 to 210 °C), the crystal size in the nanoparticles increased from 9 to 13.8 nm. The anatase nanoparticles were used to build dye-sensitized solar cells (DSSC). Mesoporous films of this oxide were deposited over conducting SnO2:F substrates using the screen-printing technique and then annealed at 530 °C at 1 atm of air pressure. The morphology of the mesoporous film surface of anatase, studied using scanning electron microscopy, revealed that the crystal size and pore distribution were functions of the pressure conditions. The energy band gap of the films as a function of the crystal size exhibited quantum effects below 11.8 nm. The effects of the anatase synthesis conditions and properties of the mesoporous film on the DSSC-type solar cell parameters, η%, V OC, J SC, and FF, were also investigated: the mesoporous anatase films prepared at 200 °C (54 atm of pressure in the autoclave) and annealed at 530 °C in air generated the best solar cell, having the highest conversion efficiency.

Synthesis, Fungicidal Activity, Structure–Activity Relationship and Density Functional Theory Studies of Novel Oxime Ether Derivatives Containing 1-Aryl-3-Oxypyrazoles

A series of 16 oxime ether derivatives containing 1-aryl-3-oxypyrazoles were synthesised, and the structure of one of them, (E)-methyl 2-(2-({(1-(4-chlorophenyl)-1H-pyrazol-3-yl)-oxy}methyl)phenyl)-2-(methoxyimino)acetate was determined by X-ray diffraction crystallography. Preliminary bioassays indicated that some of these compounds exhibited very good fungicidal activities against Rhizoctonia solani, especially the ester 2-(2-({(1-(4-chlorophenyl)-1H-pyrazol-3-yl)-oxy}methyl)phenyl)-2-(methoxyimino)acetate, which displayed greater activity than control compound pyraclostrobin at a dosage of 0.1 μg mL-1. The relationship between structure and fungicidal activity was discussed. Density functional theory studies of the 3-methyl heterocyclic ester and the 4-chorophenyl heterocyclic N-methylamide were carried out and the results discussed in terms of the wide difference in fungicidal activity shown by each compound.

A semi-empirical analysis of dye adsorption and electron transport in dye sensitized solar cells (DSSCs)

Experiments and modeling of dye adsorption and electron transport characteristics with respect to photoanode thickness were performed to elucidate the dye adsorption parameters and their relation with the structural and transport properties of DSSCs.

Molecular scale characterization of the titania-dye-solvent interface in dye-sensitized solar cells

Charge separation at the dye/titania interface in dye sensitized solar cells is strongly influenced by the thickness and homogeneity of the sensitizing dye layer, as this controls the potential drop across the interface, and the probability of an excited electron being transferred from the dye to the titania. In this study we use atomic force microscopy and the depth profiling method neutral impact collision ion scattering spectroscopy (NICISS) to investigate the thickness and homogeneity of N719 dye adsorbed to titania before and after rinsing with pure acetonitrile. Both experimental methods show that the dye layers are closed but inhomogeneous. Inhomogeneity is more pronounced for unrinsed samples.