What absorbs at 1244 cm⁻¹ in an FTIR spectrum?
A band near 1244 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 1244 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| C-O single bond | 15 | 14 | 1.0 |
| Methoxy (OCH3) | 14 | 13 | 1.0 |
| Methacrylate | 14 | 13 | 1.0 |
| Acetate | 14 | 13 | 1.0 |
| Amide | 13 | 13 | 1.0 |
| Secondary amine | 7 | 7 | 1.0 |
| C n single bond | 7 | 7 | 1.0 |
| Aromatic ring | 5 | 5 | 1.0 |
| Phosphate (PO4) | 4 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| N h | 3 | 3 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Lignin | 2 | 2 | 1.0 |
| N-O bond | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| C=n | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Ammonium | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PMMA | 1244, 1722, 1383 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| SiO2 | 1244, 1739, 699 | Methoxy (OCH3) | 1 |
| protein | 1244, 1650, 1640 | Methacrylate, Acetate | 1 |
| PVC | 1244, 834, 1195 | Methoxy (OCH3), Methacrylate, Acetate | 1 |
| plasma | 1244, 1656, 1650 | Methacrylate, Acetate | 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 1244 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.
Literature behind these assignments
-
N-O bond confidence 1.0
“In the low wavenumber region, 20 wt % Cr/TiO that temperatures below 273 K are required to study 2 cm-1 complexes,35-36 has peaks at 1244, 1425, 1607, and 1669 that correspond NO the nitrate species observed in this work 4+) sites,33 s(NH 3”
Pena 等 - 2004 - Identification of surface species on titania-suppo DOI: 10.1021/jp0313122 -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
Petibois 等 - 2004 - Determination of stress-induced changes in plasma DOI: 10.1002/bip.20002 -
Alkyl C-H confidence 1.0
“1244cm-1, The peak at assigned to the CH-rocking vibrationofPVCinPVC-PMMAblendisobservedtohaveshiftedto 847cm-1 1256cm-1 1438, 1168, 988 and are shifted to 2874, 1734, 1460, in the PVC-PMMA-LiCF 3SO complex.”
Ramesh 等 - 2007 - FTIR studies of PVCPMMA blend based polymer elect DOI: 10.1016/j.saa.2006.06.012 -
confidence 1.0
“- - Aldehydic C-H bending vibration 1366 C-N stretching and N-H bending vibration - - - - - 1244 of amide III P=O asymmetric stretching of”
Sukprasert 等 - 2020 - Synchrotron FTIR Light Reveals Signal Changes of B DOI: 10.1155/2020/6149713 -
Amide confidence 1.0
“The 1298cm-1 peaks at 1244 and originate from the C-N stretching vibrations associated with the doped”
Suneetha 和 Vedhi - 2013 - Synthesis, Characterisation and Voltammetric behav DOI: 10.4028/www.scientific.net/AMR.678.258 -
Carboxyl (COOH) confidence 1.0
“cm-1(-)/1228 cm-1(+) cm-1is consistent with a protein origin, and its frequency is The bands at 1244 and 1107 cm-1(+) (-)/1099 15N characteristic for an aspartic or glutamic acid that remains in are also sensitive to labeling of the state.2”
van Thor 等 - 2005 - Assignments of the Pfr-Pr FTIR difference spectrum DOI: 10.1021/jp052323t -
Amide confidence 1.0
“Six leaves were ground and transferred into two amino groups (aromatic primary C-N stretch) at 1244 cm(cid:2)1, flasks 1000-1100 separate 100-mL conical having screwcaps with a silprimary and secondary alcohol stretch at”
Acharya 等 - 2022 - Phytochemical profiling of spiny coriander (Eryngi DOI: 10.1556/1326.2021.00909 -
Aromatic ring confidence 1.0
“At the same time, in the fingerprint region, the absorption peaks around 1244 cm-1 were ascribed to the aromatic C-H in-plane bending vibrations, while those located”
Evaluation of Water Sorption and Solubility and FTIR Spectroscopy of Thermoplastic Orthodontic Retainer Materials Subjected to Thermoforming and Thermocycling DOI: 10.3390/app13085165
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