KINETICS STUDIES ON THE TAUTOMERIC REACTION OF 4-AMINO-5-METHYL-2,4-DIHYDRO-3H-1,2,4- TRIAZOLE-3-THIONE IN THE GAS PHASE: DFT AND CBS-QB3 METHODS USING TRANSITION STATE THEORY

Kazeminejad, Zahra; Shiroudi, Abolfazl; Pourshamsian, Khalil; Hatamjafari, Farhad; Reza Oliaey, Ahmad

dc.creator	Kazeminejad, Zahra
dc.creator	Shiroudi, Abolfazl
dc.creator	Pourshamsian, Khalil
dc.creator	Hatamjafari, Farhad
dc.creator	Reza Oliaey, Ahmad
dc.date	2019-03-27
dc.date.accessioned	2019-11-13T15:11:50Z
dc.date.available	2019-11-13T15:11:50Z
dc.identifier	http://www.jcchems.com/index.php/JCCHEMS/article/view/1037
dc.identifier.uri	https://revistaschilenas.uchile.cl/handle/2250/112736
dc.description	The isomerization reactions of the 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione have been studied theoretically using density functional theory (DFT) along with various exchange-correlation functionals (B3LYP and M06-2x) as well as the benchmark CBS-QB3 quantum chemical approach. The calculated energy profile has been supplemented with calculations of kinetic rate constants by means of transition state theory (TST).Based on the optimized isomers geometries using the CBS-QB3 method, a natural bond orbital analysis reveals that the electronic delocalization from non-bonding lone-pair orbitals [LP(e)S7] to the neighboring σ* N2-C3 antibonding orbital increase from isomer 1 to isomer 2. Also, the LP(e)S7→σ* N2-C3 delocalizations could fairly explain the increase of occupancies of LP(e) non-bonding orbitals in the ring of isomers 1 and 2 (2 > 1). The electronic delocalization from LP(e)S7 non-bonding to σ* N2-C3 antibonding orbitals increase the ground state structure stability, Therefore, the increase of LP(e)S7→σN2-C3 delocalizations could fairly explain the kinetics of the isomerization reactions 1 and 2 (k2 > k1). NBO results also suggest that the kinetics of these processes are controlled by LP→σ resonance energies.	en-US
dc.format	application/pdf
dc.language	eng
dc.publisher	Sociedad Chilena de Química	en-US
dc.relation	http://www.jcchems.com/index.php/JCCHEMS/article/view/1037/291
dc.rights	Copyright (c) 2019 Journal of the Chilean Chemical Society	en-US
dc.rights	https://creativecommons.org/licenses/by-nc-sa/4.0	en-US
dc.source	Journal of the Chilean Chemical Society; Vol 64 No 1 (2019): Journal of the Chilean Chemical Society	en-US
dc.source	0717-9707
dc.source	0717-9324
dc.subject	Isomerization	en-US
dc.subject	Rate constant	en-US
dc.subject	Reaction mechanism	en-US
dc.subject	Chemical kinetics	en-US
dc.subject	DFT	en-US
dc.subject	NBO	en-US
dc.title	KINETICS STUDIES ON THE TAUTOMERIC REACTION OF 4-AMINO-5-METHYL-2,4-DIHYDRO-3H-1,2,4- TRIAZOLE-3-THIONE IN THE GAS PHASE: DFT AND CBS-QB3 METHODS USING TRANSITION STATE THEORY	en-US
dc.type	info:eu-repo/semantics/article
dc.type	info:eu-repo/semantics/publishedVersion

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