What absorbs at 1288 cm⁻¹ in an FTIR spectrum?
A band near 1288 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 1288 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 |
|---|---|---|---|
| Amide | 7 | 7 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| C n single bond | 5 | 5 | 1.0 |
| Methoxy (OCH3) | 4 | 4 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Ammonium | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Metal oxygen | 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.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PVP | 1288, 2983, 1648 | Amide, Methacrylate, Secondary amine | 1 |
| ZnO NPs | 1288, 1664, 875 | Amide, Methacrylate | 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 1288 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
-
Amide confidence 1.0
“1422 2 C-N stretching 1288 1293 1293 1293”
Investigations of biodegradable polymer blend electrolytes based on Cornstarch: PVP: NH4Cl and its potential application in solid-state batteries DOI: 10.1007/s10854-021-05266-1 -
Acetate confidence 1.0
“For PDA-NPs, cm-1 the peak at 1288 is related to C-O tensile vibration.”
Synthesis and characterization of Gd3+-loaded hyaluronic acid-polydopamine nanoparticles as a dual contrast agent for CT and MRI scans DOI: 10.1038/s41598-023-31252-0 -
Alkyl C-H confidence 1.0
“The peaks at 1288 and 1025 4.80x10-2 may be due to a combination of C-H in-plane ring bending 1.0”
In-Situ Chemical Synthesis, Microstructural, Morphological and Charge Transport Studies of Polypyrrole-CuS Hybrid Nanocomposites DOI: 10.1007/s10904-020-01747-8 -
Hydroxyl (O-H) confidence 1.0
“The band at 1288 corresponds to the primary alcohol (hydroxyethyl group) O-H in-plane bending vibration.”
Aktas 等 - 2020 - A Novel Ag-N-Heterocyclic Carbene Complex Bearing DOI: 10.3390/cryst10030171 -
Alkyl C-H confidence 1.0
“Peaks at 904 to Transmittance 70 1288cm-1 were generally associated with C-H bending,”
Du 等 - 2019 - Authenticating Raw from Reconstituted Milk Using F DOI: 10.1155/2019/5487890 -
Metal oxygen confidence 1.0
“For due to interactions with anatase TiO 2 example,thebandsat1585cm-1,1504cm-1,and1288cm-1, and nanocomposites were performed by using an Iviumstat C=N, C=C, electrochemical working station (Ivium Technologies BV).”
Guo 等 - 2012 - Preparation of a Novel Nanocomposite of Polyanilin DOI: 10.1155/2012/202794 -
Acetate confidence 1.0
“As the concentration of increased, it caused (C-H bending), 887.26 bending), cm-1 cm-1 increase in absorption and shaper peaks were obtained 1091.71 (C-O stretching), 1288.45 (C-O cm-1 and growth of nanoparticles was also enhanced but stret”
Iqtedar 等 - 2020 - Biosynthesis, optimization and characterization of DOI: 10.24275/rmiq/Bio1605 -
Acetate confidence 1.0
“The peak for C-O at cm-1 1288 can also be assigned to C=O of carboxylic acids in HTC-PLs.”
Recovery and Reuse of Valuable Chemicals Derived from Hydrothermal Carbonization Process Liquid DOI: 10.3390/en16020732
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