What absorbs at 890 cm⁻¹ in an FTIR spectrum?
A band near 890 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 890 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 | 8 | 7 | 1.0 |
| Carbohydrate | 7 | 7 | 1.0 |
| C-O single bond | 6 | 6 | 1.0 |
| Phosphate (PO4) | 5 | 4 | 1.0 |
| Methoxy (OCH3) | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Metal oxygen | 3 | 2 | 1.0 |
| Silicon hydride | 3 | 2 | 1.0 |
| Alkene (C=C) | 3 | 2 | 1.0 |
| Hydroxyl (O-H) | 3 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Phosphorus | 2 | 2 | 1.0 |
| Silicon carbon | 2 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 0 | 1.0 |
| Water (H2O) | 1 | 0 | 0.9 |
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 |
|---|---|---|---|
| Al2O3 | 890, 1722, 1383 | Alkyl C-H | 1 |
| polysaccharide | 890, 1637, 1320 | Alkyl C-H, C-O single bond | 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 890 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
-
Acetate confidence 1.0
“2 cm-1: jugated ketone (phenyl-carbonyl) in lignin, 1160 C-O-C asymmetrical stretching in cellulose and hemicm-1: cm-1: celluloses, 1030 C-O, C=C, and C-C-O stretching in wood, and 890 glycosidic linkage.”
Physicochemical characterisation of barley straw treated with sodium hydroxide or urea and its digestibility and in vitro fermentability in ruminants DOI: 10.1038/s41598-022-24738-w -
Carbohydrate confidence 1.0
“acid.44 illustrated both IOP and Se-IOP contained 1000 to 1200 the presence of β-galactopyranose and β-galacturonic ring.12 cm-1 The absorption peak at 889.51 or 889.1 Four carbon signal peaks in the region of 80.0-70.0 ppm and pyranoid sho”
Hu 等 - 2017 - Effects of Selenizing Modification on Characterist DOI: 10.1007/s13233-017-5030-z -
C-O single bond confidence 1.0
“cm-1 890 The bands of the mushrooms at about 1023, 1000, 930, 920, and 850 are assigned to α-glycosidic bond.”
Liu 等 - 2006 - A study of the mushrooms of boletes by Fourier tra DOI: 10.1117/12.667136 -
confidence 1.0
“The broad cm-1 band centered at 890 is clearly observed which is assigned to the Non-bridging oxygen hole centers (NBOHC) formed by Si-O-Si vibration [20, 22].”
Lu 等 - 2013 - Red Light Emission from Silicon Created by Self-io DOI: 10.4028/www.scientific.net/AMM.320.109 -
Hydroxyl (O-H) confidence 1.0
“Nowe01017 Article Ce ascribed to OH stretching vibrations, whereas the bands with maxima at 890 and cm(cid:1)1 1411 appeared caused by the in-plane and out-of-plane bending vibrations of OeH CeH bonds, respectively [28].”
Interactions between polyols and wheat biopolymers in a bread model system fortified with inulin: A Fourier transform infrared study DOI: 10.1016/j.heliyon.2018. -
C-O single bond confidence 1.0
“Moreover, the band cm-1 - C=O Distinctively, the weak absorption peak at 890 cm indicated the existing of β-type glycosidic bond 1 at 1640 was due to (-COOH) stretching vibration, which was the proof of the presence”
Song 等 - 2020 - Acetylated Polysaccharides From Pleurotus geestera DOI: 10.3390/ijms21082810 -
Acetate confidence 1.0
“trabeum fungus also yielded an increase in the band at 1150 cm-1 (vibration of C-O-C bonds from cellulose and hemicelluloses [22]), accompanied by the disappearance of the band at 890 cm-1 (out-of-plane bending of the exomethylene groups fr”
Acosta 等 - 2022 - Alumina as an Antifungal Agent for Pinus elliottii DOI: 10.3390/jof8121299 -
Alkyl C-H confidence 1.0
“Agar specific peak at 890 α-galactose (AnGal-units) whereas agar is less sulfated polydue to anomeric CH in the β-galactose residues and a band”
Antioxidant and cytotoxic activities of sulfated polysaccharides from five different edible seaweeds DOI: 10.1007/s11694-020-00661-4
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