View source for DFT Study on the Photoisomerization of Carvone

{{DISPLAYTITLE:DFT Study on the Photoisomerization of Carvone}}{{#seo:
|title=DFT Study on the Photoisomerization of Carvone - Top Italian Scientists Journal
|description=A theoretical investigation of the photochemical isomerization of carvone was conducted using Density Functional Theory (DFT) and multiconfigurational methods.
|keywords=carvone; terpenes; photoisomerization; DFT calculation; CASSCF.
|citation_author=Emanuele,Lucia;Racioppi,Rocco;D’Auria,Maurizio
|citation_journal_title=Top Italian Scientists Journal 
|citation_publication_date=2026/01/24 
|citation_title=DFT Study on the Photoisomerization of Carvone
|citation_keywords=carvone; terpenes; photoisomerization; DFT calculation; CASSCF.
|citation_publisher=Top Italian Scientists
|citation_volume=3
|citation_issue=1
|citation_doi=10.62684/UHJS3297
|citation_issn=3033-5132
|}}
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| '''Published'''
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| January 24, 2026
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| '''Title''' 
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| style="width:200px;" | DFT Study on the Photoisomerization of Carvone
|- 
| '''Authors'''
|-
|   Lucia Emanuele, Rocco Racioppi and Maurizio D’Auria
|-
| '''DOI'''
|-
| [https://doi.org/10.62684/UHJS3297 10.62684/UHJS3297]
|-
| '''Keywords'''
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| carvone; terpenes; photoisomerization; DFT calculation; CASSCF.
|-
| '''Downloads'''
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|  style="text-align: center;" | [[File:PDF_file_icon.png|center|50px|'''Download PDF'''|link=https://journal.topitalianscientists.org/images/c/cd/DFT_Study_on_the_Photoisomerization_of_Carvone.pdf]]
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'''Lucia Emanuele''' <sup>(a)</sup>, '''Rocco Racioppi''' <sup>(b)</sup>, '''[https://www.topitalianscientists.org/tis/52759/Maurizio_D'Auria_-_Top_Italian_Scientist_in_Chemistry Maurizio D’Auria]''' <sup>(b)</sup>

<sup>(a)</sup> Department of Arts and Restoration, University of Dubrovnik, Branitelja Dubrovnika 41, 20000 Du-brovnik, Croatia; lemanuel@unidu.hr

<sup>(b)</sup> Dipartimento di Scienze di Base ed Applicate, Università della Basilicata, V.le dell’Ateneo Lucano 10, 85100 Potenza, Italy; rocco.racioppi@unibas.it;  maurizio.dauria53@gmail.com


''Correspondence to'': Maurizio D’Auria, maurizio.dauria53@gmail.com

==Abstract==
A theoretical investigation of the photochemical isomerization of carvone was conducted using Density Functional Theory (DFT) and multiconfigurational methods. Geometry optimizations, excited-state calculations, and reaction pathway analyses were performed at the B3LYP/6-311G+(d,p) level, supported by TD-DFT and CASSCF(6,6) calculations. The results provide strong computational evidence for the mechanism proposed by Büchi in 1957, in which the reaction proceeds through the first excited triplet state rather than a concerted singlet-state cycloaddition. After photoexcitation, intersystem crossing leads to a triplet state with pronounced radical character at the carbon atom β to the carbonyl group. Intramolecular coupling with the terminal olefinic carbon of the isopropenyl side chain generates a triplet biradical intermediate through a very low activation barrier (0.22 eV), which subsequently cyclizes to form the observed tricyclic terpene. Although the final product is thermodynamically less stable than the reactant, the process is kinetically feasible under photochemical conditions. CASSCF calculations did not reveal a conical intersection in the first excited singlet state, excluding a concerted [2+2] pathway. Solvent effects were also rationalized, with polar, hydrogen-bonding solvents significantly stabilizing the biradical intermediate, in agreement with experimentally observed variations in quantum yield.

==Declarations==
=== Conflict of Interest ===
The opinions expressed in this contribution are personal and do not in any way commit to the Ministry of Foreign Affairs and International Cooperation.
The Authors declare that there is no conflict of interest.

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[[Category:Open Access]]

[[Category:Research Article]]

[[Category:Chemistry]]