What absorbs at 1248 cm⁻¹ in an FTIR spectrum?
A band near 1248 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
Quick answer
A band near 1248 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 |
|---|---|---|---|
| Methoxy (OCH3) | 8 | 8 | 1,0 |
| Methacrylate | 8 | 8 | 1,0 |
| C-O single bond | 8 | 8 | 1,0 |
| Acetate | 8 | 8 | 1,0 |
| Amide | 4 | 4 | 1,0 |
| Lignin | 3 | 3 | 1,0 |
| N h | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| C n single bond | 2 | 2 | 1,0 |
| Carbohydrate | 2 | 2 | 1,0 |
| Ammonium | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| C=n | 1 | 1 | 1,0 |
| Acetyl | 1 | 1 | 1,0 |
| Lipid | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
| Bromine | 1 | 1 | 1,0 |
| Carbon bromine | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Phosphorus | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| S eq o | 1 | 1 | 0,9 |
| Sulfate (SO4) | 1 | 1 | 0,9 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Possible materials
| Материал | Поддерживающие пики | Overlapping groups | Цитируемые источники |
|---|---|---|---|
| Cellulose | 1248, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 1 |
| DNA | 1248, 1712, 1660 | Methacrylate, Acetate, C-O single bond | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
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 1248 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
-
Acetate достоверность 1,0
“Our assignment of FTIR peaks 1248 C-O stretch (ether) of DGEBA (a)”
Probing deformation of double-walled carbon nanotube (DWNT)/epoxy composites using FTIR and Raman techniques DOI: 10.1016/j.compscitech.2010.04.025 -
Amide достоверность 1,0
“bution from the NH in-plane bending along with CN 23 cm-1 stretching), and 1248 (as a result of C-N-H in09:05 plane bending vibrations and CN stretching vibration) were assigned as amide II and III band (Kong at Figure 1.”
Changes in chemical composition and structure of root cell wall of citrus rootstock seedlings in response to boron deficiency by FTIR spectroscopy DOI: 10.1080/14620316.2017.1362327 -
Hydroxyl (O-H) достоверность 1,0
“The IR cm-1 band at 1248 is ascribed to the O-H bending vibrations.”
Gani 等 - 2017 - Physico-chemical, structural, pasting and thermal DOI: 10.1016/j.ijbiomac.2016.10.100 -
Phosphate (PO4) достоверность 1,0
“The peak at 1248 was ascribed to phosphate reticulata Lindl.”
Han 等 - 2018 - Insight into Rapid DNA-Specific Identification of DOI: 10.3390/molecules23112842 -
Acetate достоверность 1,0
“The peak for C-O-C (1248 cm-1 ascribable to the deformation of the C-H rocking Meanwhile, the peaks at 1161.72, 1104.35, and 1094.86”
Characterization of cellulose extracted from oil palm empty fruit bunch DOI: 10.1063/1.4931295 -
Ester достоверность 1,0
“Explicitly assigned to ester group vibrations.”
Biowaxes from Palm Oil as Promising Candidates for Cosmetic Matrices and Pharmaceuticals for Human Use DOI: 10.3390/ma16124402 -
Lignin достоверность 1,0
“Also being noted, decrease of peaks close to close to lignin (1505 and 1597 cm-1) and hemicellulose (1737 and 1248 cm-1) [15,31].”
Combined Treatment (Alkali + Thermal) of Calotropis procera Fiber for Removal of Petroleum Hydrocarbons in Cases of Oil Spill DOI: 10.3390/polym13193285 -
Carbohydrate достоверность 1,0
“The second LDA axis explained 31.3 % of the variation and segregated the samples mainly according to the ATR-FTIR spectrum peak at 1737 cm-1 connected with lipids, peaks at 1173 and 1248 cm-1 corresponded with carbohydrates and”
Highly Efficient Use of Infrared Spectroscopy (ATR-FTIR) to Identify Aphid Species DOI: 10.3390/biology11081232
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