Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media

PM3 semiempirical method was used for quantum chemical investigation in order to investigate the electronic properties and to determine the protonation centre in 1,2,4-triazoline-3-thione molecule. Confirmation of protonation center in acid media of investigated compounds was made using the values o...

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Main Authors: Mirjana S. Jankulovska, Vesna Dimova, Ilinka Spirevska, Milena Jankulovska
Format: Article
Language:English
Published: Engineering Society for Corrosion, Belgrade 2021-03-01
Series:Zaštita Materijala
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Online Access:https://www.zastita-materijala.org/index.php/home/article/view/230
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author Mirjana S. Jankulovska
Vesna Dimova
Ilinka Spirevska
Milena Jankulovska
author_facet Mirjana S. Jankulovska
Vesna Dimova
Ilinka Spirevska
Milena Jankulovska
author_sort Mirjana S. Jankulovska
collection DOAJ
description PM3 semiempirical method was used for quantum chemical investigation in order to investigate the electronic properties and to determine the protonation centre in 1,2,4-triazoline-3-thione molecule. Confirmation of protonation center in acid media of investigated compounds was made using the values of atomic charges, as well as, proton affinity values. The results from semiempirical calculations indicated that the protonation center in the thione molecule was the sulphur atom. The behavior of thiones was investigated in mineral acid media using UV spectroscopy. The influence of the strength of the acid and its anion on the protonation process was discussed using three different mineral acids (perchloric, hydrochloric and phosphoric acid) for protonation. The protonation process in perchloric and hydrochloric acid took place in one step, while in phosphoric acid was not finished even when its concentration was to the highest degree. The dissociation constants of protonated forms (pKBH + ) and the solvation parameter m* values were calculated in accordance with "excess acidity" function method (Cox and Yates) using the absorbance data from the experimental and reconstructed spectra (Characteristic Vector Analysis (CVA)). The determined pKBH + values in hydrochloric acid had more negative value than those obtained in perchloric acid media. The pKBH + values were in agreement with the literature data for this class of compounds.
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institution Kabale University
issn 0351-9465
2466-2585
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publishDate 2021-03-01
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record_format Article
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spelling doaj-art-e3bc4e6eea6443308f976ac8869a46fd2025-08-20T03:25:07ZengEngineering Society for Corrosion, BelgradeZaštita Materijala0351-94652466-25852021-03-0162192110.5937/zasmat2101009J229Comparison of theoretical and experimental investigation of protonation process of some thiones in acid mediaMirjana S. Jankulovska0Vesna Dimova1Ilinka Spirevska2Milena Jankulovska3Ss.Cyril and Methodius University, Faculty of Agricultural Sciences and Food, Skopje, North MacedoniaSs.Cyril and Methodius University, Faculty of Technology and Metallurgy, Skopje, North MacedoniaSs.Cyril and Methodius University, Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Skopje, North MacedoniaUniversity St. Kliment Ohridski, Faculty of Veterinary Medicine, Skopje, North MacedoniaPM3 semiempirical method was used for quantum chemical investigation in order to investigate the electronic properties and to determine the protonation centre in 1,2,4-triazoline-3-thione molecule. Confirmation of protonation center in acid media of investigated compounds was made using the values of atomic charges, as well as, proton affinity values. The results from semiempirical calculations indicated that the protonation center in the thione molecule was the sulphur atom. The behavior of thiones was investigated in mineral acid media using UV spectroscopy. The influence of the strength of the acid and its anion on the protonation process was discussed using three different mineral acids (perchloric, hydrochloric and phosphoric acid) for protonation. The protonation process in perchloric and hydrochloric acid took place in one step, while in phosphoric acid was not finished even when its concentration was to the highest degree. The dissociation constants of protonated forms (pKBH + ) and the solvation parameter m* values were calculated in accordance with "excess acidity" function method (Cox and Yates) using the absorbance data from the experimental and reconstructed spectra (Characteristic Vector Analysis (CVA)). The determined pKBH + values in hydrochloric acid had more negative value than those obtained in perchloric acid media. The pKBH + values were in agreement with the literature data for this class of compounds.https://www.zastita-materijala.org/index.php/home/article/view/2301,2,4-triazoline-3-thionesprotonationdissociation constantsproton affinityuvspectrophotometrypm3 semiempirical method
spellingShingle Mirjana S. Jankulovska
Vesna Dimova
Ilinka Spirevska
Milena Jankulovska
Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
Zaštita Materijala
1,2,4-triazoline-3-thiones
protonation
dissociation constants
proton affinity
uvspectrophotometry
pm3 semiempirical method
title Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
title_full Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
title_fullStr Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
title_full_unstemmed Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
title_short Comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
title_sort comparison of theoretical and experimental investigation of protonation process of some thiones in acid media
topic 1,2,4-triazoline-3-thiones
protonation
dissociation constants
proton affinity
uvspectrophotometry
pm3 semiempirical method
url https://www.zastita-materijala.org/index.php/home/article/view/230
work_keys_str_mv AT mirjanasjankulovska comparisonoftheoreticalandexperimentalinvestigationofprotonationprocessofsomethionesinacidmedia
AT vesnadimova comparisonoftheoreticalandexperimentalinvestigationofprotonationprocessofsomethionesinacidmedia
AT ilinkaspirevska comparisonoftheoreticalandexperimentalinvestigationofprotonationprocessofsomethionesinacidmedia
AT milenajankulovska comparisonoftheoreticalandexperimentalinvestigationofprotonationprocessofsomethionesinacidmedia