What absorbs at 1274 cm⁻¹ in an FTIR spectrum?
A band near 1274 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 1274 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 | 7 | 7 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.9 |
| Ester | 1 | 1 | 0.7 |
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 1274 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
-
C-O single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Shin 等 - 2002 - Structural comparison of Langmuir-Blodgett and spi DOI: 10.1021/la020135d -
Hydrogen bond confidence 1.0
“4-···HOH···BF 4BF hydrogen-bonding structure, while ii is C-H band,27 mentioned in the analysis of the the stronger force 4related to BF interacting with the cyclic water dimer structure, 42-H between BF and C should have a lower wavenumber”
Sun 等 - 2008 - Trace of the Interesting V-Shaped Dynamic Mechan DOI: 10.1021/jp806805r -
Hydroxyl (O-H) confidence 1.0
“A sharp cm1 cm1 peak at 1727.71 with a supporting peak at 1384.76 indicates O-H stretching/deformations of cm1 aromatic alcohols, while the peak at 1273.73 indicates O-H deformation of secondary alcohols.”
Agrawal 等 - 2023 - Biotreatment of azo dye containing textile industr DOI: 10.21203/rs.3.rs-1876766/v2 -
Acetate confidence 1.0
“cm-1 >NH peaks are recorded in 3494-3300, 2976-2888, 1732, 1645, 1248, and 1274 corresponding to the >CH >C=O, and -OH, 2, -C-O-C-, and -C-Ngroups of PTX, while in the case of the drug-loaded cm-1 nanoparticles the recorded 1274 peak, corre”
Paclitaxel Magnetic Core–Shell Nanoparticles Based on Poly(lactic acid) Semitelechelic Novel Block Copolymers for Combined Hyperthermia and Chemotherapy Treatment of Cancer DOI: 10.3390/pharmaceutics11050213 -
Alkyl C-H confidence 1.0
“The OCS-Silica, SOC-Silica and cm-1, cm-1, cm-1 -CH symmetric deformation vibration peaks at 1273.63 1265.25 and 1261.85 SCA-Silica produced -CH3 symmetric deformation vibration peaks at 1273.63 cm-1, 1265.25 cm-1, and 3”
Evaluating the Effect of Hydrophobic Nanosilica on the Viscoelasticity Property of Asphalt and Asphalt Mixture DOI: 10.3390/ma11112328 -
Alkyl C-H confidence 1.0
“The 2 cm-1 intensive absorption bands of 1274 and 875 deal with CH wagging and stretching 2 Membranes2023,13,520 8of11”
Copolymer of VDF/TFE as a Promising Polymer Additive for CsH2PO4-Based Composite Electrolytes DOI: 10.3390/membranes13050520 -
Hydroxyl (O-H) confidence 1.0
“The peak at 1274 cm-1 could be related to asymmetric stretching vibrations of the CO-C linkages in phenolic ethers (C-O stretch) and esters of phenolic hydroxyls [43].”
Characterisation of the Phenolic Profile of Acacia retinodes and Acacia mearnsii Flowers’ Extracts DOI: 10.3390/plants11111442 -
Fatty acid confidence 1.0
“The phosphate stretchcm-1 ing in 1274 and 1085 is attributed to the interaction of compounds in the EO and fatty acid chains or polar heads in the nanoliposome.”
Nanoliposomes containing three essential oils from the Artemisia genus as effective larvicides against Aedes aegypti and Anopheles stephensi DOI: 10.1038/s41598-023-38284-6
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