What absorbs at 1744 cm⁻¹ in an FTIR spectrum?
A band near 1744 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Carbonyl (C=O) | 13 | 13 | 0.9 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Lipid | 2 | 1 | 0.9 |
| Ester | 1 | 1 | 0.9 |
| Nucleic acid | 1 | 1 | 0.8 |
| Carbohydrate | 1 | 1 | 0.8 |
| N h | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Carboxyl (COOH) confidence 1.0
“Adsorption of -COOH group peak”
Handayani 等 - 2018 - Synthesis and Characterization of Chitosan-p-t-But DOI: 10.1088/1757-899X/333/1/012011 -
Carbonyl (C=O) confidence 0.9
“Explicit assignment: 'vibration 1744 assigned to C=O stretching'”
Bouyanfif 等 - 2019 - Fourier transform infrared microspectroscopy detec DOI: 10.1016/j.vibspec.2019.04.005 -
Carbonyl (C=O) confidence 0.9
“Explicitly attributed to C=O”
Delaroza 等 - 2014 - Spectroscopic and Chromatographic Fingerprint Anal DOI: 10.5935/0103-5053.20140172 -
confidence 0.9
“Explicit assignment: stretching groups of cis-unsaturated fatty acid at 1744 cm-1.”
Gao 等 - 2017 - Technical note Characterization of lipid constitu DOI: 10.2527/jas2016.1332 -
Carbonyl (C=O) confidence 0.9
“Explicit assignment in table.”
Wille 等 - 2003 - Redox-triggered FTIR difference spectra of FAD in DOI: 10.1021/bi035219f -
Carbonyl (C=O) confidence 0.9
“Explicitly stated: 'absorption peaks representing C=O ... observed at 1744'”
Chang 等 - 2018 - Synthesis of Linseed Oil-Based Waterborne Urethane DOI: 10.3390/polym10111235 -
Carbonyl (C=O) confidence 0.9
“band at 1744 assigned to C=O stretching vibration of the carb”
Da Ros 等 - 2013 - Assessment of Chemical and Physico-Chemical Proper DOI: 10.3390/md11072365 -
confidence 0.9
“Explicit assignment: 'vibrational band at 1744'”
Gamulin 等 - 2022 - Fourier Transform Infrared Spectroscopy Reveals Mo DOI: 10.3390/biomedicines10123130
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