What absorbs at 844 cm⁻¹ in an FTIR spectrum?
A band near 844 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 844 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 |
|---|---|---|---|
| Silicon (Si) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Sulfonate | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 0.9 |
| Hydroxyl (O-H) | 1 | 0 | 0.8 |
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 |
|---|---|---|---|
| PDMS | 844, 873, 1080 | Silicon-oxygen (Si-O), Silicon (Si) | 1 |
| SiO2 | 844, 1739, 699 | Silicon-oxygen (Si-O), Silicon (Si) | 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 844 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
-
C-O single bond confidence 1.0
“In addition, small shoulder peaks at 844 cm-1 (1→4) β and 1077 are related to the glycosidic link and linkages between the sugar cm-1, monomers.”
Biochemical and Structural Characterization of Ferulated Arabinoxylans Extracted from Nixtamalized and Non-Nixtamalized Maize Bran DOI: 10.3390/foods11213374 -
Carbonyl (C=O) confidence 1.0
“The PVA-metal salt complexes can be used as solid electrolytes in different energy conversion A 1733=A ð1Þ RI of carbonyl peak RI ¼ ¼ 844 ½C¼O=CH(cid:1) devices such as batteries/fuel cells, photo-electrochemical A 1578=A RI of terminal dou”
Parveen 等 - 2009 - Synthesis and characterizations of nano-sized Ni(O DOI: 10.1007/s10853-009-3826-8 -
Sulfonate confidence 1.0
“The peaks observed at 3373, 1221, 1037, 1157, 924 and 844 cm-1 can be attributed cm-1 1356-1374 attributed to sulphate (SO 3) group stretching in 1.5-3% CARR:SA (1:0) wafers.”
Akiyode 和 Boateng - 2018 - Composite Biopolymer-Based Wafer Dressings Loaded DOI: 10.3390/polym10080918 -
Oxygen heterocycle confidence 1.0
“In addition, after modification, FTIR peaks that assigned to the epoxy ring (844 cm-1 and 904 cm-1) were decreased.”
Mazlan 和 Abu Hanifah - 2014 - Synthesis and Effect of Modification On Methacylat DOI: 10.1063/1.4895206 -
confidence 1.0
“The (001) interplanar Furthermore, Si-O stretching of Al-Mg-OH (844”
Natkanski 等 - 2013 - Effect of Fe3+ ions present in the structure of po DOI: 10.1007/s10973-013-3225-x -
Ring structure confidence 1.0
“and possibly glycosidic bonds and cyclic structures of On the other hand, the negative cm-1, cm-1 cm-1 influence had peaks at 1152 1109 (C-O stretching and C-C stretching), and 844 (Ring vibration), indicating carbohydrates which might incl”
Spectroscopy and SEM imaging reveal endosymbiont-dependent components changes in germinating kernel through direct and indirect coleorhiza-fungus interactions under stress DOI: 10.1038/s41598-018-36621-8 -
Silicon (Si) confidence 1.0
“structures of PDMS The peaks at 844 and 796 attribute to SiOH-PDMS copolymerization Si-C23, 24.”
Determination of Phenols Isomers in Water by Novel Nanosilica/Polydimethylsiloxane-Coated Stirring Bar Combined with High Performance Liquid Chromatography-Fourier Transform Infrared Spectroscopy DOI: 10.1038/s41598-017-09050-2 -
C c single bond confidence 0.9
“Text: '844 (νCC, rCH)'”
Sodium montmorillonite/ureasil-poly(oxyethylene) nanocomposite as potential adsorbent of cationic dye DOI: 10.1016/j.clay.2017.11.009
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