What absorbs at 772 cm⁻¹ in an FTIR spectrum?
A band near 772 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 772 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.
Attributions possibles de groupes fonctionnels
| Groupe fonctionnel | Faits à l'appui | Sources citées | Confiance maximale |
|---|---|---|---|
| Alkyl C-H | 2 | 2 | 1,0 |
| Borate | 2 | 2 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.
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 772 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.
Bibliographie derrière ces attributions
-
confiance 1,0
“In Fourier-transform infrared spectra, a Cr O peak newly cm¡1 Cr-O cm¡1 appeared at 897 after Cr(VI) removal, whereas a peak was detected at 772 due to the association of Cr(VI) ions with ion-exchange sites.”
Modacrylic anion-exchange fibers for Cr\(VI\) removal from chromium-plating rinse water in batch and flow-through column experiments DOI: 10.1080/10934529.2017.1356192 -
C-S single bond confiance 1,0
“cm-1 cm-1, S-OH [15] and the C-S stretching peaks were obtained at 907 and 772 respecOH [15] and the C-S stretching peaks were obtained at 907 cm-1 and 772 cm-1, respectively cm-1 tively [16,17].”
Anis 等 - 2023 - Studies on Polybenzimidazole and Methanesulfonate DOI: 10.3390/polym15132821 -
Phosphate (PO4) confiance 1,0
“The band around 772 cm-1 frequency of (PO and the harmonics of P=O bending vibrations [21,22].”
The Influence of CoO/P2O5 Substitutions on the Structural, Mechanical, and Radiation Shielding of Boro-Phosphate Glasses DOI: 10.3390/ma14216632 -
Acetate confiance 1,0
“1,6-Bis[4-(naphthyliminomethylidene)-phenoxy]-hexane cm-1): ν, FTIR (KBr, 3047 (=C-H stretch of the aromatic rings), 2941-2856 (C-H stretch of aliphatic chains), 1618 (-N=CHstretch), 1605, 1565, 1513 (C-C ring stretch), 1246, 1H-NMR 1166 (C”
Mesomorphic Behavior of Symmetric Azomethine Dimers Containing Different Chromophore Groups DOI: 10.3390/molecules26082183 -
confiance 1,0
“bands observed at 772 and 809 were assigned to the OCO Nucleophilicity is a measure of the molecule to contribute the electrons.”
Growth, spectral, optical, electrical and computational analysis of sodium oxalate single crystals DOI: 10.1016/j.heliyon.2021.e06527 -
Borate confiance 1,0
“For the C-PVA/PAN composite fiber, new absorption peaks located at cm-1 cm-1 772 and 653 were assigned to the stretching vibration of B-O-C and O-B-O [17,18].”
Ren 等 - 2018 - Polyvinyl Alcohol Reinforced Flame-Retardant Polya DOI: 10.3390/ma11122391 -
Alkyl C-H confiance 1,0
“The cm-1 (peak 12) is assigned to methylene absorption at 772”
The Synthesis and Characterization of Novel Bis-cationic Asphalt Emulsifier DOI: 10.1051/matecconf/201713004004 -
Alkyl C-H confiance 1,0
“The GNPs with good biocompatibility could bring modes of in-plane C-C stretching vibrations of The cm-1 new opportunities for ultrasensitive detection, molecular Raman band at 772 was assigned to the C-H out-of-”
IJN-24785-one-pot-green-synthesis-of-gold-nanoparticles-using-plant-ch DOI: 10.2147/IJN.S24785
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