What absorbs at 1283 cm⁻¹ in an FTIR spectrum?
A band near 1283 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 1283 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 |
|---|---|---|---|
| Methacrylate | 7 | 6 | 1.0 |
| Acetate | 7 | 6 | 1.0 |
| Amide | 6 | 5 | 1.0 |
| C-O single bond | 5 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Carboxyl (COOH) | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 4 | 3 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Protein alpha helix | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 0.9 |
| Protein | 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 |
|---|---|---|---|
| quercetin | 1283, 1745, 1612 | Methacrylate, Acetate, C-O single bond | 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 1283 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
-
Protein alpha helix confidence 1.0
“At lower wavenumber, the bands at cm-1 α-helices 1283 is assigned to of the amide III absorption band owing to in-phase combination of CH stretching and NH bending vibrations [42].”
Gupta 等 - 2022 - In vitro cell composition identification of wood d DOI: 10.1098/rsos.201935 -
Acetate confidence 1.0
“7 of 11 Bioengineering 2016, 3, 34 7 of 11 cm-1 Infra red (IR) spectra (Figure 4) showed intense peaks at 1724 and 1283 corresponding to Infra red (IR) spectra (Figure 4) showed intense peaks at 1724 and 1283 cm-1 corresponding to - -C=O an”
Biodegradable Polymeric Substances Produced by a Marine Bacterium from a Surplus Stream of the Biodiesel Industry DOI: 10.3390/bioengineering3040034 -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
Chen 等 - 2021 - Synthesis of Novel Arginine-Based Flame Retardant DOI: 10.3390/molecules26123588 -
Phosphate (PO4) confidence 1.0
“The absorption band at cm-1 1283 is assigned to the asymmetric stretching vibration mode of the O-P-O bonding, cm-1 denoted by ν (PO 2).”
El-Damrawi 等 - 2023 - STRUCTURE AND PROPERTIES OF STRONTIUM PHOSPHATE GL DOI: 10.4314/bcse.v37i3.9 -
Acetate confidence 1.0
“However, a strong band at ~1283 cm-1 assigned Slurry evaporation and ethyl acetate”
Garbacz 等 - 2020 - Structural Characterization of Co-Crystals of Chlo DOI: 10.3390/pharmaceutics12070648 -
Carboxyl (COOH) confidence 1.0
“Thus, for instance, the band assigned to the hydroxyl group of p-aminobenzoic acid is shifted from p-aminobenzoic Thus, for instance, the band assigned to the hydroxyl group of acid is shifted from ~1283 cm-1 in the spectra of physical mixt”
Garbacz 和 Wesolowski - 2018 - DSC, FTIR and Raman Spectroscopy Coupled with Mult DOI: 10.3390/molecules23092136 -
Acetate confidence 1.0
“The TEM and 1283 cm-1 corresponding to C=O and C-N of PVP, respectively (Figure 2b).”
Graphene Oxide-Gold Nanorods Nanocomposite-Porphyrin Conjugate as Promising Tool for Cancer Phototherapy Performance DOI: 10.3390/ph14121295 -
Alkyl C-H confidence 1.0
“In addition, absorption bands at 1283 and 1465 attributed to the cm-1 vibration of-CH and at 964 corresponds to the CH out-of-plane vibration [18].”
The Fine-Tuned Release of Antioxidant from Superparamagnetic Nanocarriers under the Combination of Stationary and Alternating Magnetic Fields DOI: 10.3390/antiox10081212
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