What absorbs at 1379 cm⁻¹ in an FTIR spectrum?
A band near 1379 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 1379 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 | 12 | 12 | 1.0 |
| Methoxy (OCH3) | 11 | 9 | 1.0 |
| Methacrylate | 10 | 8 | 1.0 |
| C-O single bond | 10 | 8 | 1.0 |
| Acetate | 10 | 8 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Methyl | 4 | 4 | 1.0 |
| Secondary amine | 4 | 3 | 1.0 |
| Amide | 4 | 3 | 1.0 |
| C n single bond | 3 | 2 | 1.0 |
| N h | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
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 1379 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 h confidence 1.0
“It isevidentthatseveralcharacteristicabsorptionbandsat3202(NH stretching), 3098, 2928, 2871 (CH stretching), 2845, 1699 (C O stretchingcyclic),1678,1492,1452(CHbending),1420,1379,1330 cm-1 were observed in the IR spectra of and 1273 (CN str”
Hsu 和 Lin - 2009 - Rapid examination of the kinetic process of intram DOI: 10.1016/j.tca.2008.12.008 -
C-O single bond confidence 1.0
“[24], this peak at the near region (1520-1500 cm-1) could be derived from any other aromatic or phenolic compounds due to C = C stretching of aromatic rings, with contributions at 1379 cm-1 which may be due to overlapping C-OH deformation o”
Specific Mycoparasite-Fusarium Graminearum Molecular Signatures in Germinating Seeds Disabled Fusarium Head Blight Pathogen’s Infection DOI: 10.3390/ijms22052461 -
Acetate confidence 1.0
“We suggest that the relative peak area of the bandwith cm-1 change of the intensity of C-O-C band as function of peaks at 1379 and 1371 cannot represents the exact (1-3 concentration.”
Studies of the behavior of reverse nonionic surfactant Pluronic 31R1 in aqueous and Propylammonium acetate (PAAc) ionic liquid solutions DOI: 10.1007/s10965-020-02315-x -
Amide confidence 1.0
“Strong peak at 1379 may refer to C-N stretching amine due to the M”
Cytotoxicity and antibacterial activities of plant-mediated synthesized zinc oxide (ZnO) nanoparticles using Punica granatum (pomegranate) fruit peels extract DOI: 10.1016/j.molstruc.2019.04.026 -
Acetate confidence 1.0
“If deprotonation occurs during DES-BA coamorphous salt formation, the carboxylic anion (-COO-) has only a single stretch (C-O) at 1379.16 cm-1.”
A Novel Desloratadine-Benzoic Acid Co-Amorphous Solid: Preparation, Characterization, and Stability Evaluation DOI: 10.3390/pharmaceutics10030085 -
Acetate confidence 1.0
“Figure 4c shows areas of these cm-1 C-H peaks of adsorbed n-pentane integrated within 3000-2820 for each spectrum Nanomaterials 2023, 13, x FOR PEER REVIEW 8 of 18 can see in Figure S4b the peaks at 1460 and 1379 cm-1, which correspond to t”
Sorption and Desorption of Vapor of n-Pentane by Porphyrin Aluminum Metal–Organic Framework: Mechanism of Bonding, Kinetics and Stoichiometry by Complementary In-Situ Time-Dependent and Ex-Situ Methods DOI: 10.3390/nano13091529 -
Alkyl C-H confidence 1.0
“In this sample, Alkyl group is represented by Bhasmas a tool to differentiate the prepared by different four peaks raised due to C-H stretching vibrations at 1379.25, techniques.”
Chaudhari 等 - 2015 - Fourier transform infrared analysis of Tamra Bhasm DOI: 10.4103/0974-8520.169013 -
Alkyl C-H confidence 1.0
“The bands at 1452 1379 cm-1 and 760 can be attributed to the bending vibrations of the C-H bonds.”
Chylinski 等 - 2022 - Effectiveness of Curing Compounds for Concrete DOI: 10.3390/ma15072699
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