Assessment of methyl ester as a green carrier solvent in pesticide emulsifiable concentrate formulation

The conventional pesticide emulsifiable concentrate (EC) formulations usually contain a large amount of aromatic solvents. This causes adverse effects to environment and human health due to the toxicity of such organic solvents. In this study, a cypermethrine 25EC formulation was developed using methyl ester as a green solvent. The physicochemical characterizations, emulsion properties and storage stabilities of the methyl ester EC formulations were investigated and compared with those of the EC formulation using naphtha A100 as a solvent, evidencing excellent emulsion properties and storage stabilities of such methyl ester EC formulations.

EXPRESS: Solvent Effect on Assembling and Interactions in Solutions of Phenol: Infrared Spectroscopic and DFT Study

This work provides new insight into assembling and competition between different kinds of interactions for phenol in various solvents. To examine both weak and strong interactions, we selected a series of non-aromatic and aromatic solvents. IR spectra were measured at low (0.05 M) and high (2 M) phenol concentrations. In addition, we calculated (DFT) the structures and harmonic vibrational spectra of 1:1 complexes of phenol with the solvents and the associates of phenol from dimer to tetramer. Based on these results, we divided the solvents into three groups. The first group consists of non-aromatic solvents weakly interacting with phenol. Depending on the concentration, molecules of phenol in these solvents remain non-bonded or self-associated. In diluted solutions of phenol in chlorinated non-aromatic solvents do not appear free OH groups, since they are involved in a weak OH···Cl interaction. The second group consists of aromatic solvents with methyl or chlorine substituents. At low concentrations molecules of phenol are involved in the phenol-solvent OH···π interaction and the strength of these interactions depends on the solvent. At a higher phenol content exists an equilibrium between the phenol-solvent OH···π and phenol-phenol OH···OH interactions. It is of note that in diluted solutions of phenol in tetramethylethylene both the non-bonded and bonded OH coexists. Finally, the third group includes both the aromatic and non-aromatic solvents having highly polar groups like CN. In this case, regardless of the concentration all molecules of phenol are involved in the solute-solvent OH···NC interaction. Comparison of the experimental and theoretical band parameters reveals that molecules of phenol in non-aromatic solvents prefer to create the cyclic associates, while in the aromatic solvents they tend to form the linear associates.

Copolymerization of Butadiene with Ethylene in the Presence of Ni-containing Organometallic Catalytic Systems and Different Modifiers

Copolymerization of ethylene with butadiene was carried out in the presence of nickel diethyldithiocarbamate and various modifiers. Triphenylphosphines were selected as modifiers. Solutions of nickel diethyldithiocarbamates and said modifiers in aromatic solvents of various concentrations have been prepared. Their physicochemical parameters, particle sizes in solutions, as well as mutual solubility were determined. It was demonstrated that these complexes are readily soluble in aromatic solvents, and the particle size in solution is in the nanometer range. These complexes were tested in the processes of copolymerization of ethylene with butadiene in combination with various cocatalysts - (tri-, diethylaluminum chloride). The products synthesized in their presence were analyzed by various physicochemical methods and their structure was confirmed. It has been shown that oligomeric and copolymer products with the required structure can be in fact synthesized in the presence of these catalytic systems. The activity and selectivity of catalytic systems have been comparatively tested in liquid phase (co) polymerization processes. The composition and conditions have been found to have a significant effect on the activity and structure of the resulting products.

Oligomerization of ethylene to linear α-olefins in the presence of complex catalytic systems based on zirconium carboxylates

The study considers the process of ethylene oligomerization in a medium of aliphatic and aromatic solvents in the presence of complex catalytic systems based on zirconium carboxylates, which were obtained from the fractions of naphthenic acids recovered from Baku oils and individual carboxylic acids. It was found that the catalytic activity and the molecular weight distribution (MWD) of the produced oligomeric products depend mostly on the solvent nature and the composition of zirconium complex. The ethylene oligomerization rate in the presence of catalytic systems based on zirconium carboxylates is 2–3 times lower in a medium of aliphatic solvents as compared to aromatic solvents; the obtained product has a narrow MWD and consists predominantly of С4-С10 fractions. Oligomeric products obtained in a medium of aromatic solvents have a broad MWD and in the presence of zirconium carboxylates comprise mostly С4-С18, while in the presence of zirconium naphthenates, С12-С18 and С20 fractions.

Fluorescence Quenching of 3,5-Diphenyl-8-CF3-BODIPY Luminophores Bearing Aminophenyl Substituents by Aromatic Molecules

It has been found that the fluorescence quantum yield of 3,5-diphenyl-8-CF3-BODIPY luminophores with aminophenyl substituents in aromatic solvents strongly depends on the position of the aniline amino group with respect to the position of attachment to the core of the BODIPY molecule. It has been suggested and substantiated that the reason for quenching of BODIPY meta-isomers is the specific interaction of luminophore molecules with aromatic molecules.

A peptidomimetic based thixotropic organogel showing syneresis-induced anti-adhesion for water and ice

The self-assembly, organogelation, syneresis, and anti-adhesion properties of a Peptidomimeticcontaining L-phenylalanine and 2,6-dimethylpyridine 3,5-dicarboxylic acid have been studied in detail. The peptidomimetic forms a transparent gel in aromatic solvents such...