Light scattering in a finite multi-particle system

We use the discrete dipole approximation (DDA) to perform electromagnetic scattering calculations of particles in a 3D volume. We adjust the spacing between the particles to change the volume densities of the scattering systems from approximately 10% to 100%. For very large volume densities, e.g. >50%, it is difficult to assign unambiguously whether the system is composed of a single heterogeneous particle or of multiple particles. Our calculations demonstrate optical effects attributable to multiple scattering in systems having volume densities as high as ～90%. This suggests that heterogeneities within naturally occurring particle systems can produce multiple-scattering effects. We also see evidence of very deep negative polarization branches (NPBs) (～?6%) that may have implications in interpreting polarization phase curves of cometary circumnuclear halos.     

Efficient synthesis of chalcone-4′-sulfonyl chlorides and fluorides

A library of 4′-chloro- and 4′-fluorosulfonyl-substituted chalcones was prepared via the aldol-type condensation reactions of 4-acetylbenzene-1-sulfonyl halides with various aromatic aldehydes, either in absolute ethanol or glacial acetic acid, in the presence of dry HCl. This represents the first examples of chalcone sulfonyl halides in which the phenone ring bears one of these functional groups. The reactivity of the chalcone sulfonyl halides were strongly dependent on the styrene ring substituents; sulfonyl chlorides reacted with most nucleophiles (e.g. amines, alcohols), while sulfonyl fluorides reacted only with charged nucleophiles (e.g. phenolates).     

Synthesis of Fluorine-Containing Derivatives of 5-Arylisoxazoles and 4,5-Dichlorothiazole

Alkylation of fluorophenols and phenolic aldehydes with 5-phenyl(p-tolyl)-3-chloromethylisoxazole under the Williamson reaction conditions afforded the corresponding ethers. Condensation of the resulting phenolic aldehyde derivatives and 5-phenyl(p-tolyl)isoxazole-3-carbaldehydes with p-fluoroaniline resulted in fluorine-containing azomethines. Acylation of fluorinated amines with 5-(p-tolyl)isoxazole- and 4,5- dichloroisothiazole-3-carbonyl chlorides gave rise to fluorinated amides bearing isoxazole and isothiazole fragments, representatives of which showed a synergistic effect in compositions with insecticides.     

Synthesis of bis[2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[a]acridin-12-yl)phenyl] succinates

Reactions of succinyl chloride with 4-hydroxy-3-methoxybenzaldehyde and 3-ethoxy-4-hydroxybenzaldehyde gave the corresponding succinates which were brought into the condensation with naphthalen-2-amine to obtain Schiff bases. The latter reacted with CH acids (cyclohexane-1,3-dione and 5,5-dimethylcyclohexane-1,3-dione) to form bis[2-alkoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[a]acridin-12-yl)phenyl]-succinates which can also be obtained by three-component heterocyclization of naphthalen-2-amine with bis-(2-alkoxy-4-formylphenyl)succinates and CH acid.     

Spectral localization in the hierarchical Anderson model

We prove that a large class of hierarchical Anderson models with spectral dimension has only pure point spectrum.

     

Environment‐Adopting Surfaces with Reversibly Switchable Morphology

Two‐component polymer brushes (polystyrene and poly(2‐vinylpyridine)) were synthesized by grafting from the surface of Si‐wafers. The brushes are sensitive to the surrounding medium, and their morphology and composition of the top of a brush can be switched upon exposure to different solvents. Thus surface energetic states and roughness of the film can be precisely tuned.     

A representative of p,p,p-trihalogenylides: synthesis and structure

The representative of P,P,P-trichloroylides-5-methyl-2-phenyl-4-(trichlorophosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one-was synthesized. Its constitution was confirmed by 1H, 13C, and 31P NMR spectroscopy and by X-ray analysis. Some chemical properties were studied and compared with ones of P,P,P-trimethylylide-5-methyl-2-phenyl-4-(trimethylphosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one. DFT calculations of the model molecules were carried out.     

Effect of the orientation of the optic axis on simulated scattering matrix elements of small birefringent particles

We study how the orientation of the optic axis affects single-scattering properties for small, birefringent calcite particles simulated using DDSCAT 7.1.1. We consider two irregular model particles, a flake and a rhomboid, in either a (i)?fixed or (ii)?random orientation. Simulations are performed for three volume-equivalent radii of 0.1, 0.45, and 1.0?μm. For each target, we repeat the computations for three sets of orientations of the optic axis. When a fixed spatial orientation of the target is considered, the simulations are significantly affected by the orientation of the optic axis. However, the effect is considerably weaker when assuming the same targets in random spatial orientation.     

Synthesis of 1,3-dioxolanes from substituted benzaldehydes of the vanillin series

Condensation of substituted benzaldehydes of the vanillin series with propane-1,2-diol and 3-chloropropane-1,2-diol in boiling benzene in the presence of FIBAN K-1 sulfonated cation exchanger as catalyst gave the corresponding substituted 1,3-dioxolanes.     

Synthesis of hydroxybenzaldehyde derivatives containing an isoxazole heteroring

5-Phenyl(p-tolyl)isoxazole-3-carboxylic acids were synthesized starting from 3-hydroxyiminomethyl-5-phenyl(p-tolyl)isoxazoles, and their reactions with p-hydroxybenzaldehyde, vanillin, isovanillin, o-vanillin, and ethyl vanillin gave the corresponding esters. The latter were brought into condensation with aromatic amines to obtain Schiff bases which were reduced to amines.