What absorbs at 2722 cm⁻¹ in an FTIR spectrum?
A band near 2722 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 |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 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
-
Alkyl C-H confidence 1.0
“Aldehydic (C-H) stretch at 2722 In fingerprint region For qualitative assessment of microbial biofilms, viable showed the presence of asymmetric and symmetric biofilm cells staining by acridine orange was used.”
Hamdoon 等 - 2022 - Evaluation of biofilm formation on different clear DOI: 10.4103/jos.jos_7_22 -
Alkyl C-H confidence 1.0
“Moreover, the cm-1, saturated aldehyde citronellal caused the vibrations at 2722 and 1725 due to the C-H aldehydic and C=O stretches [11,25].”
Rapid Classification and Recognition Method of the Species and Chemotypes of Essential Oils by ATR-FTIR Spectroscopy Coupled with Chemometrics DOI: 10.3390/molecules27175618 -
Alkyl C-H confidence 1.0
“The spectra showed that the characteristic absorption peak of NCO groups cm-1 vibrations, 2700-3000 for C-H asymmetric and symmetric stretching vibrations of methyl groups was at 2722 cm-1.”
Wu - 2020 - Synthesis and Properties of Moisture-Cured Reactiv DOI: 10.3390/polym12081838 -
Alkyl C-H confidence 1.0
“Cáceres and Canevarolo 2009), respectcontaining d 2w® (PP 3, PP and PP 7) there was a reduction 5 cm-1 ively, and the absorbance peak at 2722 in Tc that was proportional to the d was related to 2w® concentration, angular molecular vibration”
de Carvalho 等 - 2013 - A study of the controlled degradation of polypropy DOI: 10.1186/2193-1801-2-623
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