What absorbs at 836 cm⁻¹ in an FTIR spectrum?
A band near 836 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 836 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 | 7 | 7 | 1.0 |
| Methacrylate | 6 | 6 | 1.0 |
| Acetate | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Aromatic ring | 4 | 4 | 1.0 |
| N-O bond | 3 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Nitro (NO2) | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
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 836 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
-
Aromatic ring confidence 1.0
“santalinus only at 1594 cm-1, 1205 cm-1, 1155 cm-1 and 836 cm-1, corresponding to the stretching vibration of carbon atoms in the aromatic framework, C-O-C stretching vibration in extractives, C-O-”
Jin 等 - 2022 - Rapid Identification for the Pterocarpus Bracelet DOI: 10.3390/molecules27154793 -
Silanol (Si-OH) confidence 1.0
“The presence of silica in both ENR/PVC/SiO and ENR/PVC/ 2 SiAOASi TEOS membranes is shown by the presence of asymcm(cid:1)1.22 Furmetric stretching at the absorption peaks of 836 (SiAOH) thermore, the silanol absorption peak in both memCAOA”
Jon 等 - 2013 - Influence of silica addition on the properties of DOI: 10.1002/app.38997 -
N-O bond confidence 1.0
“Na+ and NO Moreover, in the RH range from formation of contact ion pairs between (cid:3)26%, (cid:2) 3cm-1 down to two peaks at 836 and 829 were observed in the 2-NO band region, 2008 American Institute of solid particles and droplets.”
Lu 等 - 2008 - Molecular events in deliquescence and efflorescenc DOI: 10.1063/1.2973623(cid:5) -
Alkyl C-H confidence 1.0
“The appearance of 2 cm-1 cm-1 peak at 836 is due to -CH stretching mode of PVA.”
Synthesis, Structural, Optical, Electrical and Thermal Studies of Poly(vinyl alcohol)/CdO Nanocomposite Films DOI: 10.1007/s10904-017-0662-1 -
Nitrate confidence 1.0
“The latter is apparent from the subsequent increase in γ = WSR cm-1, A the peak area at 836 which represents the signal of nitrate - (1) ν - NO 2 3 ions in the crystal state.”
Zhang 等 - 2014 - In Situ Observation on the Dynamic Process of Evap DOI: 10.1021/jp412073c -
Acetate confidence 1.0
“cm-1 (ring stretching), 1445 due to CH3 (stretching), 1303 and 1125 due to C-N cm-1 cm-1 (stretching), 1210 due to C-O-C (stretching), and 836, 755, and 693 due to C-H (out of plane bending of aromatic ring).”
Adam 等 - 2022 - Comparative Evaluation of Amlodipine Besylate Gene DOI: 10.14227/DT290422PGC2 -
Alkyl C-H confidence 1.0
“C-H rocking is considered cm-1 cm-1 to relate to the absorption bands at 836 and 839 [24].”
An Investigation into the PVA:MC:NH4Cl-Based Proton-Conducting Polymer-Blend Electrolytes for Electrochemical Double Layer Capacitor (EDLC) Device Application: The FTIR, Circuit Design and Electrochemical Studies DOI: 10.3390/molecules27031011 -
Aromatic ring confidence 1.0
“and the asymmetric bending vibration of C-H appears at the absorption of 1456 The cm-1 absorption peak at 1105 represents the in-plane bending vibration of C-H in the cm-1 syringyl group, and the absorption peak at 836 is the out-of-plane b”
Hu 等 - 2021 - Pyrolytic Characteristics and Kinetics of Guanzhon DOI: 10.1016/j.fuel.2014.01.014
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