What absorbs at 761 cm⁻¹ in an FTIR spectrum?
A band near 761 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 6 cited sources
Quick answer
A band near 761 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 |
|---|---|---|---|
| Metal oxygen | 3 | 3 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PANI | 761, 2930, 1300 | Ring structure | 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 761 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
-
Metal oxygen confidence 1.0
“The strong peak at 761 is due to the stretching frequency of V-O band in cm-1 YVO 4[17].”
Rajendra 等 - 2018 - Luminescence properties of dysprosium doped YVO4 p DOI: 10.1016/j.jre.2018.07.001 -
Aromatic ring confidence 1.0
“The characteristic bands of vitamin A were the aromatic ring vibration at 761 cm-1, =C-H, and the C=C Figure 7a shows the Raman spectrum for a 10% STS solution in water for the spectral range vibrations for the aromatic ring.”
Spectroscopic Characterization of Emulsions Generated with a New Laser-Assisted Device DOI: 10.3390/molecules25071729 -
Metal oxygen confidence 1.0
“3 cm-1 and the distinctive bands at 823 932, 823 and 761 cm-1 and 761 are recognized as the W-O-W stretching [41].”
He 等 - 2020 - Flexible fabric gas sensors based on PANIWO(3)p-n DOI: 10.1007/s40843-020-1364-4 -
Silicon (Si) confidence 1.0
“cm-1 cm-1, Peaks of Si-O-T asymmetric and symmetric stretching of BA appear at 1089 and 761 Peaks of Si-O-T asymmetric and symmetric stretching of BA appear at 1089 cm-1 and 761 cm-1, respectively.”
Licciulli 等 - 2020 - Thermally Aerated Geopolymers as Lightweight Const DOI: 10.3390/app10196697 -
N-O bond confidence 1.0
“(𝜈 cm-1 cm-1 cm-1 2) The IR bands at 708.47 and 761.38 𝑠NO and at 910.98 (ring stretching bands) are 𝛾-HMX.Thepeaksat713.88 (𝜈 cm-1,761.19 cm-1 cm-1 2) characteristicof 𝑠NO and1031 (ringstretching 𝛼-HMX.”
Thakur 等 - 2022 - SUPERCRITICAL ANTISOLVENT METHOD FOR RECRYSTALLIZA DOI: 10.24425/cpe.2022.140819 -
confidence 0.9
“Explicit assignment: 'peak at 761 (S-Au)'”
Svorcik 等 - 2011 - Soft and rigid dithiols and Au nanoparticles gra DOI: 10.1186/1556-276X-6-607
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