A systematic approach to methyl cinnamate photodynamics. (17th January 2021)

• Record Type: Journal Article
• Authors: Krokidi, Konstantina M.; Turner, Matthew A. P.; Pearcy, Philip A. J.; Stavros, Vasilios G.
• Is Part Of: Molecular physics. Volume 119:Number 1/2(2021)
• Publication Date: 2021-01-17
• Subjects: Sunscreen -- photochemistry -- ultrafast laser spectroscopy -- photoisomerisation -- triplet state; Molecules -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Molécules -- Périodiques; Chimie physique et théorique -- Périodiques; 539.6.05
• DOI: 10.1080/00268976.2020.1811910
• Languages: English
• ISSNs: 0026-8976

Abstract

ABSTRACT: Methyl cinnamate (MC) is an ester within the cinnamate family. Recent time-resolved gas-phase studies have suggested that upon excitation to its first singlet ππ* (1 1 ππ*) state, there is initial decay to the lowest lying singlet 1 nπ* (1 1 nπ*) state within 10 ps, en route to trans – cis isomerisation. In the present study, we have implemented time-resolved ion yield (TR-IY) and time-resolved photoelectron spectroscopy (TR-PES) experiments in the gas-phase to precisely determine the lifetime of the 1 1 ππ* state. We found this lifetime to be ∼ 4.5 ps using both TR-IY and TR-PES. MC was also studied in a more complex cyclohexane solution environment, using transient electronic absorption spectroscopy. Along with complementary steady-state irradiation and 1 H NMR studies, these studies demonstrate that trans–cis isomerisation is preserved in the more complex, cyclohexane solution environment. GRAPHICAL ABSTRACT: