What absorbs at 2652 cm⁻¹ in an FTIR spectrum?
A band near 2652 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
Quick answer
A band near 2652 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Carboxyl (COOH) | 2 | 2 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Thiol | 1 | 1 | 0,9 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 2652 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Литература, лежащая в основе этих назначений
-
Carboxyl (COOH) достоверность 1,0
“It is also observed the characteristic pattern of the overtone region of (2500-2700cm-1), carboxylic group showing a weak peak at 2652cm-1.”
Font 等 - 2007 - Fourier transform infrared spectroscopy as a suita DOI: 10.1016/j.aca.2007.07.021 -
Water (H2O) достоверность 1,0
“Relaxation of helical structural changes in the transition cm-1 spectra, but disappearance of the positive band at 2652 from Batho to BL takes place together with relaxation of resulted in the broad negative water band at 270046 Biophysics”
Hanai 等 - 2021 - Light-induced difference FTIR spectroscopy of prim DOI: 10.2142/biophysico.bppb-v18.005 -
Alkyl C-H достоверность 1,0
“ethyl acetate extract of The peak at 2652.15 corresponds to the stretching Methyl Red Negative Indole”
Isolation and Characterization of a Novel Actinomycete Isolated from Marine Sediments and Its Antibacterial Activity against Fish Pathogens DOI: 10.3390/antibiotics11111546 -
Carboxyl (COOH) достоверность 1,0
“peaks at 2652 and 2536 This band corresponds to the overtone stretching of the group.[35] carboxyl The characteristic band of carboxylic acid bonding ν(C=O) is observed at cm-1.[9],[33]”
Pavon 等 - 2022 - Comparative characterization of gum rosins for the DOI: 10.1002/app.51734
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