Anharmonic IR spectra of solvated ammonium and aminium ions: resemblance between water and bisulfate solvations
Journal
Physical Chemistry Chemical Physics
Journal Volume
24
Journal Issue
34
Pages
20318-20325
Date Issued
2022
Author(s)
Kuo J.-L.
Abstract
In this work, we analyze the vibrational spectra of ammonium, methylammonium, and dimethylammonium ions solvated by either water molecules or bisulfate anions using anharmonic vibrational algorithms. Rich and complicated spectral features in the 2700-3200 cm?1 region of the experimental spectra of these clusters are attributed to originate from strong Fermi resonance between hydrogen-bonded NH stretching fundamentals and NH bending overtones. Additional weaker bands around 2500-2600 cm?1 in solvated aminium ions are assigned to the combination tones involving the CH-NH (methyl-amino) rocking modes. Furthermore, the qualitative resemblance in band positions and spectral patterns between two-water-solvated and two-bisulfate-solvated cations suggest a common vibrational coupling scheme beneath the two seemingly different micro-solvation environments. ? 2022 The Royal Society of Chemistry.
Other Subjects
Hydrogen bonds; Ions; Molecules; Anharmonic; Band position; Dimethylammonium; Experimental spectra; Fermi resonances; In-band; IR spectrum; Rocking modes; Spectral feature; Water molecule; Solvation; ammonium derivative; cation; water; hydrogen bond; infrared spectrophotometry; Ammonium Compounds; Cations; Hydrogen Bonding; Spectrophotometry, Infrared; Water
Type
journal article