What absorbs at 1456 cm⁻¹ in an FTIR spectrum?
A band near 1456 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 1456 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 |
|---|---|---|---|
| Alkyl C-H | 43 | 42 | 1.0 |
| Methyl | 9 | 8 | 1.0 |
| Amide | 8 | 8 | 1.0 |
| Aromatic ring | 7 | 7 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 6 | 6 | 1.0 |
| Methacrylate | 6 | 6 | 1.0 |
| Acetate | 6 | 6 | 1.0 |
| Carbonate | 6 | 6 | 1.0 |
| Carboxyl (COOH) | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| N h | 5 | 5 | 1.0 |
| C n single bond | 4 | 4 | 1.0 |
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Alkene (C=C) | 4 | 3 | 1.0 |
| Fatty acid | 3 | 3 | 1.0 |
| Phosphate (PO4) | 3 | 3 | 1.0 |
| Protein | 3 | 3 | 1.0 |
| Phosphorus | 2 | 2 | 1.0 |
| Phospholipid | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Lewis acid site | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 0.95 |
| Silanol (Si-OH) | 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 |
|---|---|---|---|
| Starch | 1456, 1650, 1540 | Alkyl C-H, Amide | 1 |
| cellulose | 1456, 1735, 1650 | Alkyl C-H, Amide | 1 |
| asphalt | 1456, 1600, 1376 | Alkyl C-H, Aromatic ring | 1 |
| chitosan | 1456, 1650, 1655 | Alkyl C-H, Amide | 1 |
| chitin | 1456, 1650, 1655 | Amide, 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 1456 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
-
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
XRD and FTIR study of A&B type carbonated hydroxyapatite extracted from bovine bone DOI: 10.1063/1.5089399 -
Alkyl C-H confidence 1.0
“T P cm-1 The vibration around 1456 is assigned to CH bending and deformation of 2 E methylene and could originate from lipids, proteins or cholesterol esters.”
Fourier transform infrared microspectroscopy detects biochemical changes during C. elegans lifespan DOI: 10.1016/j.vibspec.2019.04.005 -
Alkyl C-H confidence 1.0
“LLM confirmed rule peak-group candidate”
Variable-temperature Fourier-transform infrared spectroscopy study of asphalt binders from the SHRP Materials Reference Library DOI: 10.1016/j.fuel.2021.120819 -
Alkyl C-H confidence 1.0
“There was a cm(cid:0) 1 (H-C-H peak at 1455.74 in the influent wastewater for alkanes Table 1c C-C-- C asymmetric stretch for aromatic rings which was bend) and Fourier-transform infrared spectroscopy (FTIR) spectra results for L.”
Greenhouse gases emissions from duckweed pond system treating polyester resin wastewater containing 1,4-dioxane and heavy metals DOI: 10.1016/j.ecoenv.2020.111253 -
Water (H2O) confidence 1.0
“Its that the water clusters with moderate strong hydrogen existence indicate that the O-H vibrations in the plane of bonding and the increase of the free water population occoupled with the rocking vibrations of the C-H vibrator out cm-1 cu”
Studies of the behavior of reverse nonionic surfactant Pluronic 31R1 in aqueous and Propylammonium acetate (PAAc) ionic liquid solutions DOI: 10.1007/s10965-020-02315-x -
Alkyl C-H confidence 1.0
“The strong peaks at 1456 and 1346 are related to the -CH scissoring and -OH bending vibrations, respectively.”
Cellulose‐reinforced starch biocomposite: optimization of the effects of filler and various plasticizers using Design‐Expert method DOI: 10.1002/star.202000028. -
Amide confidence 1.0
“2 cm-1 differences The spectral signature were less evident in the from lipids and proteins resulted in a main peak at 1456 cm-1 amide II peaks compared to the amide I peak vibrations.”
Shi 等 - 2018 - Biochemical alterations of Candida albicans during DOI: 10.1039/c8an01452c -
Amide confidence 1.0
“cm-1 FTIR spectrum of the demineralized chitin showed a strong absorption band at 3427 (amide cm-1 cm-1 A), 2932 corresponding to [CH-CH] stretching (amide B), 1456 (amide I & II) and n cm-1 cm-1”
Tiburu 等 - 2017 - Formation of Chitosan Nanoparticles Using Deacetyl DOI: 10.4028/www.scientific.net/JNanoR.48.156
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