Experimental Approach to the Study of Anharmonicity in the Infrared Spectrum of Pyrene from 14 to 723 K.

ABSTRACT: Quantifying the effect of anharmonicity on the infrared spectrum of large molecules such as polycyclic aromatic hydrocarbons (PAHs) at high temperatures is the focus of a number of theoretical and experimental studies, many of them motivated by astrophysical applications. We recorded the IR spectrum of pyrene C₁₆H₁₀ microcrystals embedded in KBr pellets over a wide range of temperatures (14-723 K) and studied the evolution of band positions, widths, and integrated intensities with temperature. We identified jumps for some of the spectral characteristics of some bands in the 423-473 K range. These were attributed to a change of phase from crystal to molten in condensed pyrene, which appears to affect more strongly bands involving large CH motions. Empirical anharmonici

SUBMITTER: Chakraborty S 

PROVIDER: S-EPMC6557715 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature