What absorbs at 1419 cm⁻¹ in an FTIR spectrum?
A band near 1419 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 1419 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 |
|---|---|---|---|
| Carboxyl (COOH) | 9 | 8 | 1.0 |
| Alkyl C-H | 8 | 8 | 1.0 |
| Methacrylate | 6 | 6 | 1.0 |
| Acetate | 6 | 6 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 4 | 4 | 1.0 |
| Amide | 4 | 3 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Secondary amine | 1 | 0 | 1.0 |
| C n single bond | 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 |
|---|---|---|---|
| chitosan | 1419, 1650, 1655 | Alkyl C-H, Acetate, Methacrylate | 2 |
| starch | 1419, 1650, 1540 | Methacrylate, Acetate, Alkyl C-H | 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 1419 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
-
Alkyl C-H confidence 1.0
“C-H rocking of pure 2 cm(cid:3)1 ognized as the cause for the pure PVA absorption peak at PVA is considered the reason for absorption peak at 838 cm(cid:3)1, while C-H deformation vibration has been related 1419”
Metal framework as a novel approach for the fabrication of electric double layer capacitor device with high energy density using plasticized Poly(vinyl alcohol): Ammonium thiocyanate based polymer electrolyte DOI: 10.1016/j.arabjc.2020.08.006 -
Hydroxyl (O-H) confidence 1.0
“Additionally, peaks were found In the case of Riva Light Cure, an initial band was found at 3422 cm-1, indicative of cm-1, COO-, cm-1, near 1636 corresponding to followed by a peak at 1419 corresponding the presence of OH groups.”
Remineralization Potential of Three Restorative Glass Ionomer Cements: An In Vitro Study DOI: 10.3390/jcm12062434 -
Acetate confidence 1.0
“cm-1 cm-1 cm-1 (starch-water interaction), 1150 and 1078 (C-O in C-O-H stretching), 1015 cm-1 cm-1 (C-O in C-O-C stretching), and 1419 (C-O in carbonate stretching).”
Prapruddivongs 和 Wongpreedee - 2020 - Use of eggshell powder as a potential hydrolytic r DOI: 10.1016/j.powtec.2020.05.076 -
C c single bond confidence 1.0
“weak C-H stretching at 3.86.05 3810.57 3859.98 We further observed sharp asymmetric C = O cm-1, cm-1 carboxylate at 1691.28 C-C ring stretching at 1419.30 and C-N stretching of a tertiary amine at cm-1.”
Characterizing and demonstrating the role of Klebsiella SSN1 exopolysaccharide in osmotic stress tolerance using neutron radiography DOI: 10.1038/s41598-023-37133-w -
Alkyl C-H confidence 1.0
“The bands at 1419 belonged to CH deformation vibrations in the CH 2OH groups and the signals 2”
Production and physicochemical characterization of chitosan for the harvesting of wild microalgae consortia DOI: 10.1016/j.btre.2020.e00554 -
Amide confidence 1.0
“be noticed (Figure 3a), the main bands of neat CS are recorded at 3000-3600 cm-1 (a broad band attributed to -OH with maximum at 3457 cm-1 and a shoulder at 3200-3270 cm-1 due to -NH 2 stretching, area a), 1659 cm-1 (amide I), 1585 cm-1 (am”
Microencapsulation of Fluticasone Propionate and Salmeterol Xinafoate in Modified Chitosan Microparticles for Release Optimization DOI: 10.3390/molecules25173888 -
Acetate confidence 1.0
“sharp peaks at and 601 to the triply bending vibrations of PO in 926cm-1 32The characteristic bands of CO identified at correspond to the C-O bending, and the bands at 1419, 1481cm-1 32-17,24-25.”
Asmi 等 - 2016 - Synthesis and Characterisation of Composite based DOI: 10.1063/1.4945463 -
Alkyl C-H confidence 1.0
“Further changes are denoted in the hydroxyl ZnS nanocrystals measured in water and chitosan group attributed to the OH and CH vibrations present cm-1 in the ring (from 1419 and 1316 to 1408 and cm-1, 1341 and their transfer into the water.”
Mechanochemistry of Chitosan-Coated Zinc Sulfide (ZnS) Nanocrystals for Bio-imaging Applications DOI: 10.1186/s11671-017-2103-z
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