LIF excitation spectrum of cyclohexylmethoxy and 2-cyclohexylethoxy

Abstract

1-Alkoxy and its cyclohexyl substituted variants play an important role in atmospheric chemistry. Spectroscopic and conformational studies can provide convenient methods to monitor these species and help to understand the reaction mechanism in the atmosphere. In this work, we report the LIF excitation spectrum following photolysis of cyclohexylmethyl and 2-cyclohexylethyl nitrites. The rotationally resolved LIF formaldehyde spectrum appeared in the narrow wavelength region of 28 290 to 28 350 cm⁻¹ in the photolysis precursor cyclohexylmethyl and 2-cyclohexylethyl nitrites. Furthermore, for the first time, a nicely resolved vibrational structure LIF spectrum of 2-cyclohexylethoxy was acquired in the wavelength region of 28 800 to 29 800 cm⁻¹. This spectrum was assigned preliminarily to G₁G₂ and G₁G′₂ conformers of 2-cyclohexylethoxy. The spectrum of 2-cyclohexylethoxy was similar to 1-propoxy that no ν >1 C–O stretch was observed in the jet-cooled spectrum. By a combination of experimental spectrum and computational results, we can learn the stabilization effects depending on molecular geometry, due to the substitution of the α H of CH₃O and β H of CH₃CH₂O by the big cyclohexyl group.