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Your search keyword '"Halasz, Ivan"' showing total 9 results
Start Over Author "Halasz, Ivan" Journal croatica chemica acta
9 results on '"Halasz, Ivan"'

2. Acid-Base Catalysis in the Mechanochemical Formation of a Reluctant Imine

Author

Vugrin, Leonarda, Cvrtila, Ivica, Juribašić Kulcsár, Marina, and Halasz, Ivan

Subjects
imine, mechanochemistry, acid-base catalysis, mechanism, Raman monitoring
Abstract

Understanding the mechanism of action of catalytic amounts of additives on mechanochemical reactions is a growing and increasingly important topic in mechanochemistry, because it allows a significant level of control over the course and selectivity of mechanochemical reactions. Here, we investigate catalysis in the mechanochemical formation of an imine derived from p-nitrobenzaldehyde and p-nitroaniline, which did not occur by neat grinding at room temperature. Based on in situ reaction monitoring and DFT computations, we explain efficient catalysis observed for carboxylic acids, which suitably position the reacting partners and facilitate proton transfer. We also observe the formation of an aminal intermediate and conclude that the final elimination step in imine formation may proceed from either the hemiaminal or the aminal.

Published
2022

3. Supramolecular Isomerism of Coordination Compounds Based on the in Situ Formed [V2O3]4+ Core: Discrete and Chain-like Architectures.

Author

Rubčić, Mirta, Halasz, Ivan, Pavlović, Gordana, Pajić, Damir, Topić, Edi, and Cindrić, Marina

Subjects
*COORDINATION compounds, *ISOMERISM, *INFRARED spectroscopy, *ISOMERS, *X-ray diffraction, *SUPRAMOLECULAR chemistry
Abstract

Flexible 1,5-bis(salicilydene)carbohydrazone ligand in combination with an in situ formed divanadium [V2O3]4+ core afforded one discrete tetranuclear complex and two polymeric chain-like architectures, mutually related as supramolecular isomers. The occurrence of a particular isomer was controlled through the reaction conditions. All isolated products were structurally characterized via X-ray diffraction and infrared spectroscopy, while the relative stability of the architectures was assessed via competitive slurry and thermal experiments. This study highlights the adaptability of oxovanadium species towards the coordination "inventory" of building blocks present in the environment, while at the same time it unveils the richness of assembly modes of the related structural units. [ABSTRACT FROM AUTHOR]

Published
2022
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9. Investigation of Mechanochemical Thianthrene-Mediated Aryl C-H Functionalization.

Author

Vugrin, Leonarda, Cvrtila, Ivica, Geneste, Hervé, and Halasz, Ivan

Subjects
*COUPLING reactions (Chemistry), *BALL mills, *ORGANIC solvents, *MECHANICAL chemistry, *SALT
Abstract

We report an efficient solvent-free approach for palladium-catalyzed coupling reactions exploiting S-aryl-thianthrenium salts as intermediates. All reaction steps -- thianthrene oxidation, arene thianthrenation, and thianthrenium salt functionalization -- can be achieved with high yields mechanochemically, without the need for inert conditions, thus offering significant savings in time, energy, and organic solvents. [ABSTRACT FROM AUTHOR]

Published
2024
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