What absorbs at 1800 cm⁻¹ in an FTIR spectrum?
A band near 1800 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) | 8 | 6 | 0.9 |
| Carboxyl (COOH) | 2 | 0 | 0.8 |
| Carbonate | 1 | 1 | 0.9 |
| Hydroxyl (O-H) | 1 | 1 | 0.8 |
| Protein | 1 | 1 | 0.7 |
| C-O single bond | 1 | 0 | 0.6 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
confidence 0.9
“Text: 'bands assigned to carbonate phases (1800 cm-1)'”
Ion 等 - 2023 - Archaeometric Investigations of the Chalcolithic P DOI: 10.3390/coatings13030488 -
confidence 0.9
“Explicit assignment: symmetric stretching mode.”
Jarmelo 等 - 2008 - Matrix-Isolated Diglycolic Anhydride Vibrational DOI: 10.1021/jp805603b -
Carbonate confidence 0.9
“Same attribution as above.”
Ouallal 等 - 2019 - Kinetic, isotherm and mechanism investigations of DOI: 10.1016/j.heliyon.2019.e01616 -
Carbonyl (C=O) confidence 0.9
“carbonyl peak (C=O stretching at 1800 cm-1) indicating anhydrides and lactones”
Stehlik 等 - 2016 - Water interaction with hydrogenated and oxidized d DOI: 10.1016/j.diamond.2014.09.013. -
Carbonyl (C=O) confidence 0.9
“C=O stretch around 1800-1650 cm-1.”
Waskow 等 - 2021 - Advantages and Limitations of Surface Analysis Tec DOI: 10.3389/fmats.2021.642099 -
Carbonyl (C=O) confidence 0.9
“Absorption signals between 1800 and 1700 cm-1 attributed to carbonyl groups”
Wu 等 - 2015 - Fourier transform infrared spectroscopy for the di DOI: 10.1186/s12967-015-0468-2 -
Hydroxyl (O-H) confidence 0.8
“Region between 1500-1800 attributed to O-H stretching”
Cebi 等 - 2020 - An evaluation of FTIR spectroscopy for prediction DOI: 10.1080/00218839.2019.1707009 -
Carbonyl (C=O) confidence 0.8
“Mentioned as carbonyl stretching region.”
Choe 等 - 2019 - Characterization of cotton fabric scouring by Four DOI: 10.1177/0040517518790976
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