Hybrid Pigments Based on Montmorillonite and Anionic Dyes for Leather Finishing

The work is focused on obtaining hybrid pigments by adsorption of anionic dyes on positively charged montmorillonite. Modification of the sodium form of montmorillonite by chromium hydroxocomplexes was provided to ensure effective adsorption of anionic dyes on the surface of mineral particles. A high level of adsorption of anionic dyes as a result of steric factor was revealed. It was shown that the adsorption of dyes depended on the pH of the medium and was characterized by a maximum level at pH 4.5 – 6.0. The scheme of obtaining hybrid pigments, which were characterized by good сovering ability, resistance to stratification, especially saturated and intense colour was proposed.

Structure-Astringency Relationship of Anacardic Acids from Cashew Apple (Anacardium Occidentale L.)

<p>Cashew apple presents a characteristic astringency. However, the compounds responsible for this characteristic were not described yet. A cashew apple extract was added to a BSA solution and the compounds before and after precipitation were analyzed by UPLC-QTOF/MS^E. The extract astringency was measured on a 5-point scale (0: non astringent and 4: extremely astringent). Among the phenolics detected anacardic acids were identified and evaluated for their astringent effect. In the sensorial tests the cashew apple extract was considered very astringent (average of 2.5). A mixture of anacardic acids, had an average of 1.76 (astringent). The three isolated anacardic acids were evaluated. The <i>in silico</i>experiments were performed to analyze mainly the steric factor associated to the binding. The sensory results were confirmed by <i>in silico</i> analysis, indicating that a higher unsaturation degree of the aliphatic chain leads to an astringency increase.</p>

Structure-Astringency Relationship of Anacardic Acids from Cashew Apple (Anacardium Occidentale L.)

<p>Cashew apple presents a characteristic astringency. However, the compounds responsible for this characteristic were not described yet. A cashew apple extract was added to a BSA solution and the compounds before and after precipitation were analyzed by UPLC-QTOF/MS^E. The extract astringency was measured on a 5-point scale (0: non astringent and 4: extremely astringent). Among the phenolics detected anacardic acids were identified and evaluated for their astringent effect. In the sensorial tests the cashew apple extract was considered very astringent (average of 2.5). A mixture of anacardic acids, had an average of 1.76 (astringent). The three isolated anacardic acids were evaluated. The <i>in silico</i>experiments were performed to analyze mainly the steric factor associated to the binding. The sensory results were confirmed by <i>in silico</i> analysis, indicating that a higher unsaturation degree of the aliphatic chain leads to an astringency increase.</p>

Living β-selective cyclopolymerization using Ru dithiolate catalysts

Herein, we demonstrate the first example of living β-selective CP by rational engineering of the steric factor on monomer or catalyst structures, along with a mechanistic investigation by in situ kinetic studies using 1H NMR spectroscopy.

Chloranilate bridged dinuclear copper(ii) complexes: syn–anti geometry tuned by the steric factor and supramolecular interactions

The anti-conformation of chloranilate bridged di-copper complexes of NNO donor Schiff-base ligands is more stable than the syn-conformation, but the latter is stabilised by CH⋯π and hydrogen bonding interactions between solvent of crystallisation and chloranilate moieties.

Ultrasonic and solvent free Synthesis of Regioselective Diastereomeric Adducts and Heterocyclic Products as antibacterial agent

Oxirane ring containing the carboxylic group in the α,β-position are useful intermediates in the synthesis of biologically active compounds. Epoxidation of 4-(4-acetylamino and/or bromophenyl)-4-oxo-but-2-enoic acids via ultrasound condition afforded α-oxirane carboxylic acid followed by regioselective diastereomeric adducts of camphor. The steric factor plays an important role in regioselectivity. Formation of oxirane and furan derivatives via ultrasonic condition was considered as key steps for synthesis of some important heterocyclic compounds. The structure of new synthesized compounds 2-9a,b were elucidated by elemental analysis and spectroscopic data. The antibacterial activity for the synthesized compounds was evaluated.

Emergence through delicate balance between the steric factor and molecular orientation: a highly bright and photostable DNA marker for real-time monitoring of cell growth dynamics

A bright and biostable molecular fluorogenic material for real-time monitoring of in vitro cellular growth dynamics.

Pyramidalization/twisting of the amide functional group via remote steric congestion triggered by metal coordination

The distortion of the planar structure of amides is manifested by taking advantage of the temporary increase of the peripheral steric factor.

The cyclopropanation of [60]fullerobenzofurans via electrosynthesis

The regioselective cyclopropanation of dianionic [60]fullerobenzofurans by diethyl dibromomalonate is dominantly controlled by steric factor.