1 research outputs found
Dependence of Adenine Raman Spectrum on Excitation Laser Wavelength: Comparison between Experiment and Theoretical Simulations
We
acquired the Raman spectra of adenine in powder and aqueous
phase using excitation lasers with 532, 633, and 785 nm wavelengths
for the region between 300 and 1500 cm<sup>–1</sup>. In comparison
to the most distinct peak at 722 cm<sup>–1</sup>, the peaks
between 1200 and 1500 cm<sup>–1</sup> exhibited a characteristic
increase in cross-section with decreasing excitation wavelength in
both phases. This trend can be reproduced by different density functional
theory (DFT) calculations for the adenine molecule in the gas phase
as well as in the aqueous phase. Furthermore, from the calculation
on the π-stacked dimer, hydrogen-bonded dimer, and trimer, we
find that this trend toward excitation laser wavelength is not sensitive
to the packing. When comparing the Raman spectra given by different
excitation wavelength, one should take care in analyzing the cross-section,
and present day DFT calculations are able to capture general trends
in the excitation laser wavelength dependence of the Raman activity