What absorbs at 3026 cm⁻¹ in an FTIR spectrum?
A band near 3026 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 3026 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 | 8 | 8 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| C=n | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
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 3026 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
“LLM confirmed rule peak-group candidate”
60MeV Ni ion induced modifications in nano-CdS/polystyrene composite films DOI: 10.1016/j.radphyschem.2013.06.022 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Rahmalia 等 - 2022 - Simple Green Routes for Metal-Bixin Complexes Synt DOI: 10.22146/ijc.76759 -
Alkyl C-H confidence 1.0
“3026cm-1 can be assigned to the C-H peak at wavenumber”
Chen 等 - 2015 - Determination of the Degree of Degradation of Fryi DOI: 10.1155/2015/185367 -
Aromatic ring confidence 1.0
“aromatic vibrations vibrations St-homo 3026 2921 - 1600 1450”
Fila 等 - 2018 - Thermal and spectral analysis of copolymers with s DOI: 10.1007/s10973-017-6833-z -
Alkyl C-H confidence 1.0
“For Benzene the peak is at 3035.86 BA shows two C-H stretching vibration bands at cm-1 3026.06 & 2911.54 due to the aromatic C-H and CH groups.”
Hema 等 - 2022 - Structural and vibrational study of molecular inte DOI: 10.21203/rs.3.rs-649250/v1 -
Alkyl C-H confidence 1.0
“A new C-H stretching mode of cm-1 mode of the methyl group at 3026 cm-1 is visible in the spectra of TMePyP, which conthe methyl group at 3026 is visible in the spectra of TMePyP, which confirmed the methylation of TPyP.”
Graphene Oxide-Gold Nanorods Nanocomposite-Porphyrin Conjugate as Promising Tool for Cancer Phototherapy Performance DOI: 10.3390/ph14121295 -
Alkyl C-H confidence 1.0
“Finally, other bands in this spectrum were associated with cm-1, cm-1, vibration of the aliphatic CH 2, at 2914 and aromatic CH, at 3026 and the medium intensity the stretching vibration of the aliphatic CH2, at 2914 cm-1, and aromatic CH,”
Ramirez-Gomez 等 - 2019 - Synthesis and Characterization of Clay Polymer Nan DOI: 10.3390/polym11040721 -
Alkyl C-H confidence 1.0
“The solution was stretching of methyl groups shows a peak at 3026 and C - H stretching of the methylene group gives two peaks at slowly evaporated at room temperature to obtain free-standing cm-1”
Siddaiah 等 - 2018 - DOI: 10.1590/1980-5373-MR-2017-0987
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