Gas-phase molecular structure and energetics of UVB filter 4-methylbenzylidene camphor: A computational study

• Tipo: Artigo em Revista Científica Internacional
• Data: 2014

Autores

Paulo J O Ferreira (Autor) Outra; Luis Pinto da Silva (Autor) Outra; Margarida S Miranda (Autor) Outra; Joaquim C G E Esteves da Silva (Autor) FCUP

Revista

Título: Computational and Theoretical Chemistry

Vol. 1033

Páginas: 67-73

ISSN: 2210-271X

Editora: Elsevier

Indexação

ISI Web of Knowledge - 3 Citações

Scopus - 4 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-009-6VQ

DOI: 10.1016/j.comptc.2014.02.010

Abstract (EN): 4-Methylbenzylidene camphor (4MBC) is an organic UV filter commonly used in sunscreens and many personal care products due to its ability to protect human skin against UVB solar radiation. 4MBC can exist as a (E)- or (Z)-isomer due to an exocyclic carbon-carbon double bond. In sunscreen formulations the (E) isomer predominates but under light exposure isomerization occurs from (E) to (Z). In this study we have performed density functional theory calculations with the B3LYP hybrid functional and two basis sets: 6-31G(d) and 6-311G(d,p) to obtain the gas-phase molecular structure and energetics of the (E)- and (Z)-isomers of 4MBC. For comparison and validation purposes this study has been extended to the parent molecule: camphor. To obtain more accurate energy values we have also used the G3(MP2)//B3LYP method. The standard molar enthalpy of formation of 4MBC in the gas-phase, at T = 298.15 K, was derived from these calculations using appropriately chosen reactions.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7