Comparative vibrational study between two imidazolium zwitterionic ionic liquids by FTIR-ATR and Raman spectroscopies
Year: 2026
Type: article
Abstract: In this study, two imidazolium-based zwitterionic ionic liquids, 3-(1,3-diethyl-1H-imidazol-3-ium-4-yl)propanoate ( ZIL2 ) and 3-(1,3-dipentyl-1H-imidazol-3-ium-4-yl)propanoate ( ZIL5 ), were synthesized and characterized using FTIR/ATR and Raman spectroscopy to evaluate the influence of alkyl chain length on their structural and vibrational properties. FTIR-ATR analysis reveals similar overall spectral profiles, with subtle shifts in band positions and variations in intensity in the C–H stretching, C=N stretching, and CH₂ bending regions. Raman spectroscopy highlights more pronounced differences between ZIL2 and ZIL5, particularly in the 1700–200 cm⁻¹ region, indicating the sensitivity of the imidazolium ring and C–N bonds to alkyl substitution. ZIL5 exhibits a higher degree of molecular ordering, as suggested by sharper C–H stretching bands around 2930 cm⁻¹, narrower CH₂ bending bands near1465 and 1440 cm⁻¹, and a more intense C=C stretching band around 1605 cm⁻¹ compared with ZIL2. Deconvolution of the Raman and FTIR- ATR spectra using Lorentzian functions was employed to identify spectroscopic differentiation markers between ZIL2 and ZIL5.
Source: Next Materials
Institution: Université IBN Khaldoun Tiaret
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,280
OpenAlex ID: W7213982620