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

• Type: Article in International Scientific Journal
• Date: 2014

Authors

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

Journal

Title: Computational and Theoretical Chemistry

Vol. 1033

Pages: 67-73

ISSN: 2210-271X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 4 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7