What absorbs at 2127 cm⁻¹ in an FTIR spectrum?
A band near 2127 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 4 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Acetate confidence 1.0
“The peaks at 2127 correspond to C=O stretching vibrations of”
Hieu 等 - 2022 - Microorganism-mediated green synthesis of silver n DOI: 10.15251/DJNB.2022.171.359 -
Carboxyl (COOH) confidence 1.0
“HPMC showed peaks at 1516 cm-1 and 1055 cm-1 due to pluronic acid spectra showed peaks at 2127 1516 and 1102 due to the absorption band of C-O ether linkage and stretching of the C-O-C group [29].”
Nanocrystals of Mangiferin Using Design Expert: Preparation, Characterization, and Pharmacokinetic Evaluation DOI: 10.3390/molecules28155918 -
confidence 1.0
“Obviously, a high-frequency band at observed on the calcined 5%Cu-5%Fe/SiO sample, which corresponds to CO linearly 2127 cm-1 was observed on the calcined 5%Cu-5%Fe/SiO2 sample, which corresponds to 2”
CuO-Fe2O3 Nanoparticles Supported on SiO2 and Al2O3 for Selective Hydrogenation of 2-Methyl-3-Butyn-2-ol DOI: 10.3390/catal11050625 -
confidence 0.9
“Explicit assignment in text.”
The Influence of Base Metal (M) Oxidation State in Au-M-O/TiO2 Systems on Their Catalytic Activity in Carbon Monoxide Oxidation DOI: 10.3390/catal2010038
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