What absorbs at 1392 cm⁻¹ in an FTIR spectrum?
A band near 1392 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 1392 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 | 5 | 5 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| Methoxy (OCH3) | 4 | 4 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Carbonate | 3 | 3 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| C-O single bond | 3 | 3 | 1.0 |
| Fatty acid | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| N n bond | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Carbohydrate | 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 |
|---|---|---|---|
| nanotubes | 1392, 1735, 1630 | Methacrylate, Acetate, Methoxy (OCH3) | 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 1392 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
-
Carbohydrate confidence 1.0
“The vibration 1392 is assigned to C stretching of carbohydrates, fatty acids, or amino acid side chains.”
Fourier transform infrared microspectroscopy detects biochemical changes during C. elegans lifespan DOI: 10.1016/j.vibspec.2019.04.005 -
Carboxyl (COOH) confidence 1.0
“Sodium salicylate 1597cm-1 The peak at 1392 and are due to the s(-COOas(-COOν ν ) and ) vibrations (Fig.”
Das 等 - 2004 - Kinetics and adsorption behaviour of salicylate on DOI: 10.1016/j.colsurfa.2004.02.010 -
N-O bond confidence 1.0
“There cm-1, 235 is no signal can be seen on blank 4-ATP capped mHNTs-AgNPs at 1143 1392 cm-1 cm-1”
4-Aminothiophenol capped Halloysite Nanotubes/Silver Nanoparticles as Surface-enhanced Raman Scattering Probe for In-situ Derivatization and Selective Determination of Nitrite Ions in Meat Product DOI: 10.1016/j.talanta.2020.121366 -
Amide confidence 1.0
“cm-1 were demonstrated at 1521 (amide I), 1457 (amide II), and 1392 (amide III) From the observed data, the areas of amide absorption of the treated samples were for the hydrolysate obtained at DH 16.56%, while the absorbance bands of the h”
Influence of the Enzymatic Hydrolysis Using Flavourzyme Enzyme on Functional, Secondary Structure, and Antioxidant Characteristics of Protein Hydrolysates Produced from Bighead Carp (Hypophthalmichthys nobilis) DOI: 10.3390/molecules28020519 -
Acetate confidence 1.0
“The Raman spectra are cm-1 displayed in Figure 5 and are normalized to the band at 1618 (C-O asymmetric stretching), cm-1 while the FTIR spectra, displayed in Figure 6, are normalized to the band at 1392 (C=C- (COO) asymmetric stretching).”
Iodine Uptake by Zr/Hf-Based UiO-66 Materials: The Influence of Metal Substitution on Iodine Evolution DOI: 10.1016/S0167-8140(02)00374-2. -
N n bond confidence 1.0
“starching mode of the functional groups on the hybrid CNTs surface, originating from the hybridized cm-1 N-N CH-CH Obviously, peaks at 1392 and 1241 cm-1 might also be attributed to N-N and CH-CH3 bonds from carbon [40].”
Basheer 等 - 2020 - Synthesis, Characterization, and Analysis of Hybri DOI: 10.3390/polym12061305 -
Carboxyl (COOH) confidence 1.0
“The two intense bands at 1580 and 1392 cm-1 are attributed to asymmetric and symmetric stretching vibrations of terephthalate linker carboxylate groups, respectively”
Butova 等 - 2023 - In Situ FTIR Spectroscopy for Scanning Accessible DOI: 10.3390/nano13101675 -
C c single bond confidence 1.0
“Biochemical results C-- C-- O (Amide I, O stretching) was located at 1392 The vibration of”
Development of novel spectroscopic and machine learning methods for the measurement of periodic changes in COVID-19 antibody level DOI: 10.1016/j.measurement.2022.111258
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