What absorbs at 1788 cm⁻¹ in an FTIR spectrum?
A band near 1788 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 5 cited sources
Quick answer
A band near 1788 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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l＇appui | Sources citées | Confiance maximale |
|---|---|---|---|
| Methacrylate | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Methoxy (OCH3) | 2 | 2 | 1,0 |
| C-O single bond | 2 | 2 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Aldehyde (CHO) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| N-O bond | 1 | 1 | 1,0 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
Possible materials
| Matériel | Pics de support | Overlapping groups | Sources citées |
|---|---|---|---|
| chitosan | 1788, 1650, 1655 | Acetate, Methacrylate, 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 1788 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.
Bibliographie derrière ces attributions
-
N-O bond confiance 1,0
“1200cm-1 1788cm-1 900 and No peak at and the C-O-C and C-O ring vibrations also indicates the remaining aldehyde final in various polysaccharides in the cell wall [32].”
Sukprasert 等 - 2020 - Synchrotron FTIR Light Reveals Signal Changes of B DOI: 10.1155/2020/6149713 -
Alkyl C-H confiance 1,0
“The presence of peak at 2516 θθ θθ 2θ (º) cm-1 cm-1 and 1788 is C-H stretching vibration.”
Ding 和 Ni - 2013 - Preparation and Characterization of Biomorphic CaC DOI: 10.14233/ajchem.2013.OH50 -
Acetate confiance 1,0
“Furthermore, two prominent absorption peaks were observed at 1080 and cm-1 cm-1 1788 associated with C-O stretching, respectively.”
Thermomechanical characterization of bioplastic films produced using a combination of polylactic acid and bionano calcium carbonate DOI: 10.1038/s41598-022-20004-1 -
Hydroxyl (O-H) confiance 1,0
“1788 cm the O-H stretching vibrations of CMC chains.”
Development of hydrogel based on Carboxymethyl cellulose/poly(4-vinylpyridine) for controlled releasing of fertilizers DOI: 10.1186/s13065-022-00846-6 -
Carbonyl (C=O) confiance 1,0
“when The carbonyl stretching of "free" propylene carbonate falls at 1788 cm-1 The carbonyl stretching of "free" propylene carbonate falls at 1788 C=O);”
Plasticizers and Salt Concentrations Effects on Polymer Gel Electrolytes Based on Poly (Methyl Methacrylate) for Electrochemical Applications DOI: 10.3390/gels8060363
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