What absorbs at 1273 cm⁻¹ in an FTIR spectrum?
A band near 1273 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 1273 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 | 9 | 7 | 1.0 |
| Methoxy (OCH3) | 8 | 6 | 1.0 |
| Methacrylate | 8 | 6 | 1.0 |
| Acetate | 8 | 6 | 1.0 |
| Amide | 4 | 3 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Secondary amine | 3 | 2 | 1.0 |
| C n single bond | 3 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 0.9 |
| Hydrogen bond | 1 | 0 | 1.0 |
| Methyl | 1 | 0 | 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 |
|---|---|---|---|
| ZnO | 1273, 1400, 3430 | Acetate, Methacrylate, C-O single bond | 1 |
| CuO | 1273, 453, 1000 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| polyaniline | 1273, 1565, 1570 | 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 1273 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
-
Carbohydrate confidence 1.0
“microfibrils.Thepreferred pulpcharacteristicsfor paper productionare Moreover, the characteristic bands for amorphous cellulose at the presence of long fibres with a large diameter that provide me897cm-1, 1273cm-1, 1370cm-1 1430cm-1 and in”
Exploring the lignolytic potential of a new laccase producing strain Kocuria sp. PBS-1 and its application in bamboo pulp bleaching DOI: 10.1016/j.ibiod.2019.104726 -
Alkene (C=C) confidence 1.0
“cm-1 (iv) The absorption peak at 1273 can be ---- ---- 3 Fluconazole related to PO vibrations and stretching of 2 the double bond (P=O).”
Helmy 等 - 2021 - Preparation and Characterization of some Composite DOI: 10.21608/EJCHEM.2021.80482.3986 -
Amide confidence 1.0
“cm-1 1273 as stretching vibration of C-N.”
International Conference on Innovation on Polymer Science and Technology DOI: 10.1088/1757-899X/223/1/012051 -
Alkyl C-H confidence 1.0
“The C-H bending vibration at 1273”
Xiao 等 - 2020 - Preparation and characterization of broken-rice st DOI: 10.1016/j.ijbiomac.2020.05.182 -
Acetate confidence 1.0
“(cid:0)1 The peak at 1273 cm corresponds to the C-O stretch vibrations of carboxylic acids and ethers [37].”
Adeniyi 等 - 2022 - Evaluating the nature of captured exhaust soot fro DOI: 10.24200/sci.2021.57008.5017 -
Acetate confidence 1.0
“And the 1273 band represents the C-O stretchThe cotton fraction on PETco was the one carboxylated since ing from the carboxylic acids of the free linker, which after it is well known that the PET structure in textiles is highly forming the”
Alejandro Torres-Cortes 等 - 2022 - Ex situ synthesis of MOF@PETcotton textile fibers DOI: 10.1007/s10965-022-03216-x -
Acetate confidence 1.0
“The dispersion (EDXRF) cm-1 peak at 1504 is attributed to the carbonyl functional group (C=O), the peak attributed to enol (C-O) is displayed The presence of metallic elements is common in all cm-1, cm-1 at 1273 the peak at 1026 refers to t”
Boscariol 等 - 2022 - Characterization of Commercially Available Turmeri DOI: 10.21577/0103-5053.20220073 -
C-O single bond confidence 1.0
“cm-1), stretching bands corresponding to the O-H stretching vibrations (3432 cm-1), vibrations from C=O (1724 skeletal vibrations from non-oxidized gracm-1), cm-1), C-OH stretching vibrations (1273 and the phitic domains (1621 cm-1).”
Jitaru 等 - 2016 - Polymer-graphene composites by the photocuring of DOI: 10.2298/JSC151218040J
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