What absorbs at 1396 cm⁻¹ in an FTIR spectrum?
A band near 1396 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 1396 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 |
|---|---|---|---|
| N h | 9 | 8 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Amide | 6 | 6 | 1.0 |
| Alkyl C-H | 5 | 5 | 1.0 |
| Carboxyl (COOH) | 4 | 4 | 1.0 |
| Protein | 3 | 3 | 1.0 |
| Secondary amine | 3 | 3 | 1.0 |
| Amino acid | 3 | 3 | 1.0 |
| Carbonate | 3 | 3 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| C n single bond | 2 | 2 | 1.0 |
| Borate | 2 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| Nitro (NO2) | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 0.9 |
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 |
|---|---|---|---|
| silver nanoparticles | 1396, 1636, 1631 | Hydroxyl (O-H), Alkyl C-H, Amide | 2 |
| AgNPs | 1396, 1232, 1048 | Alkyl C-H, N h, Hydroxyl (O-H) | 1 |
| CuO | 1396, 453, 1000 | Hydroxyl (O-H), Amide | 1 |
| calcite | 1396, 2850, 2864 | Hydroxyl (O-H), Alkyl C-H, Amide | 1 |
| apatite | 1396, 3053, 1640 | Amide, Hydroxyl (O-H), 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 1396 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
-
Carbonate confidence 1.0
“The peak in the area of 1396 attributes to carbonate.”
Chaber 等 - 2017 - Fourier Transform Infrared (FTIR) spectroscopy of DOI: 10.1016/j.infrared.2017.07.017 -
N h confidence 1.0
“FTIR spectra showed that the main absorption bands of biomolecules capping AgNPs appeared at avercm-1 cm-1 cm-1 age wave numbers of 3435 [ν(N-H) of amide A overlapped by ν(O-H)], 1631 [(ν(C=O) of amide I], 1396 cm-1 cm-1 [ν(C-N) of amide I]”
Multi-bioactive silver nanoparticles synthesized using mosquitocidal Bacilli and their characterization DOI: 10.1007/s00203-019-01718-9 -
Carboxyl (COOH) confidence 1.0
“0.14 0.01** Amide II 1542.34±1.54 1545.34±0.46 0.05* COO symmetric stretching 1396.38±2.09 1398.45±1.27 0.01** PO2 asymmetric stretching 1235.51±1.74 1250.20±0.57 0.01** C-O-C symmetric stretching 1156.29±1.22 1150.96±1.48 PO2 symmetric str”
Use of Fourier transform infrared spectroscopy for rapid comparative analysis of Bacillus and Micrococcus isolates DOI: 10.1016/j.foodchem.2008.08.063 -
confidence 1.0
“Experimental data of apparent viscosity were fitted cm-1 as a decrease at 1153 (N-H, amide II) and an increase (R2 > 0.97) to the Ellis model (Equation 2) and the values cm-1 in the peak at 1396 (C-N, amide III).”
Garcia-de la Rosa 等 - 2023 - Rheological and structural properties of complex c DOI: 10.24275/rmiq/Alim3003 -
Carbonyl (C=O) confidence 1.0
“The peak at 1396 of the carbonyl group stretching vibration of the carboxyl (-COO) group shifted inside the calcite band cm-1.”
Abdel-Halim 等 - 2023 - Apatite-Calcite Flotation Separation Using Sodium DOI: 10.3390/min13070970 -
Hydroxyl (O-H) confidence 1.0
“cm-1, cm-1, cm-1, cm-1, cm-1, cm-1 1736 1621 1560 1396 1215 and 1045 related to OH cm-1, 1736 cm-1, 1621 cm-1, 1560 cm-1, 1396 cm-1, 1215 cm-1, and 1045 cm-1 related to OH sp2-hybridized groups, the stretching of carboxylic acid groups, C g”
Effect of rGO wt.% on the Preparation of rGO/CuO Nanocomposites at Different Test Periods and Temperatures DOI: 10.3390/cryst12101325 -
Alkyl C-H confidence 1.0
“In particular, the second derivative spectra of NI cells are characterized by a band at ~1468 cm-1 due to CH2/CH3 deformations of lipid hydrocarbon chains, two components at cm-1 ~1468 due to CH 2/CH deformations of lipid hydrocarbon chains”
Pathological ATX3 Expression Induces Cell Perturbations in E. coli as Revealed by Biochemical and Biophysical Investigations DOI: 10.3390/ijms22020943 -
Hydroxyl (O-H) confidence 1.0
“Furthermore, the OH bending vibration of the phenol group was detectable at 1396 and 1371 cm-1 in the Agrimonia eupatoria L.”
In Situ Gel with Silver Nanoparticles Prepared Using Agrimonia eupatoria L. Shows Antibacterial Activity DOI: 10.3390/life13020573
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