What absorbs at 1341 cm⁻¹ in an FTIR spectrum?
A band near 1341 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 1341 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 |
|---|---|---|---|
| Alkyl C-H | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Carbonate | 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 |
|---|---|---|---|
| PET | 1341, 1408, 800 | Methacrylate, Alkyl C-H, Methoxy (OCH3) | 2 |
| collagen | 1341, 1408, 1660 | Methacrylate, Alkyl C-H, Methoxy (OCH3) | 2 |
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 1341 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
-
Alkyl C-H confidence 1.0
“-1, C-H stretching At wavelengths 1341, 1365 and 1467cm -1 𝜃𝜃 was observed due to methyl group.”
Ankamwar 和 Thorat - 2013 - Rod-Shaped Magnetite NanoMicroparticles Synthesis DOI: 10.1155/2013/537976 -
Carbonate confidence 1.0
“cm-1) 32cm-1 ν collagen (~1341 and carbonate band 2(CO ) of a wavenumber of ~1407 was observed.”
Simultaneous FTIR and Raman Spectroscopy in Endometrial Atypical Hyperplasia and Cancer DOI: 10.3390/ijms21144828 -
Hydroxyl (O-H) confidence 1.0
“Strong stretching O=C--O 2361 Carbon dioxide Strong stretching C=C 1634 Conjugated alkene Medium stretching O-H 1341 phenol”
Chowdhury 等 - 2023 - Green synthesis and characterization of zirconium DOI: 10.1016/j.heliyon.2022.e12711 -
Alkyl C-H confidence 1.0
“In this study, PET and 1341 refer to C-H bond stretching (methylene powder was only the sole carbon source and energy of the group), which becomes less intense for both samples of culture medium of PET incubated with VT3.12, VT3.15, PET wit”
Biological degradation of polyethylene terephthalate by rhizobacteria DOI: 10.1007/s11356-022-20324-9 -
Alkyl C-H confidence 1.0
“LLM confirmed rule peak-group candidate”
Drobota 等 - 2019 - INVESTIGATION OF PROPERTIES OF NANOFIBERS FROM COL DOI: 10.1021/bm050086u -
Alkyl C-H confidence 1.0
“The structure presents signals at 1373 and 1341 cm-1 attributed to from cm-1 ɷ(CH2-CH2) vibration bands.”
Drobota 等 - 2020 - Preparation and Characterization of Electrospun Co DOI: 10.3390/ma13183961 -
Acetate confidence 1.0
“FTIR spectrum of IPNs after grafting with SP exhibits a cm-1 band at 1341 assigned to the C-O ester group which”
Ghani 等 - 2021 - Molecular-Gated Drug Delivery Systems Using Light- DOI: 10.1021/acsabm.0c01458 -
Protein confidence 1.0
“cm-1 A distinctive peak is also observed at 1341 (assigned to proteins) and it is present”
Infrared Spectroscopy as a Potential Diagnostic Tool for Medulloblastoma DOI: 10.3390/molecules28052390
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.