What absorbs at 1033 cm⁻¹ in an FTIR spectrum?
A band near 1033 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 1033 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 |
|---|---|---|---|
| C-O single bond | 21 | 21 | 1.0 |
| Methoxy (OCH3) | 17 | 17 | 1.0 |
| Methacrylate | 17 | 17 | 1.0 |
| Acetate | 17 | 17 | 1.0 |
| Carbohydrate | 10 | 10 | 1.0 |
| Silicon-oxygen (Si-O) | 9 | 8 | 1.0 |
| Phosphate (PO4) | 6 | 6 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Silicon (Si) | 6 | 5 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Siloxane (Si-O-Si) | 4 | 3 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Carbonate | 2 | 2 | 1.0 |
| Hydrogen bond | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Anhydride | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 0.8 |
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 1033 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
“The vibration at 1033 attributed [Australian tration in new roots of the seedlings, but B deficiency to C-O-C stretching particularly within cellulose was roots' evidently increased B concentration in new cell”
Changes in chemical composition and structure of root cell wall of citrus rootstock seedlings in response to boron deficiency by FTIR spectroscopy DOI: 10.1080/14620316.2017.1362327 -
Acetate confidence 1.0
“alkyl halides), 1107.09, 1054.90 and cm-1 1032.88 (C-O stretch;”
Govindasamy 等 - 2019 - Evaluation of Salmonella bongori derived biosurfac DOI: 10.1016/j.ijbiomac.2019.08.034 -
C c single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Guo 等 - 2018 - Observation of conformational changes in ethylene DOI: 10.1063/1.4995975 -
confidence 1.0
“(2019), the standard spectra of bentonbands in the spectra since marked at 1033 cm-1, cm-1, cm-1, 532 910 1033 denoted as the Si-O-Si vibrations (Taher et al., ite minerals are 470 cm-1, cm-1, cm-1,”
Hakim 等 - 2023 - Ammonium-Assisted Intercalation of Java Bentonite DOI: 10.12911/22998993/156665 -
Acetate confidence 1.0
“-b 19 1072-1043 -C-O Stretching 1033a 20 1043-1006 -C-O Stretching -HC@CH968a 21 1006-929 (trans)”
Rapid evaluation of oxidised fatty acid concentration in virgin olive oil using Fourier-transform infrared spectroscopy and multiple linear regression DOI: 10.1016/j.foodchem.2010.06.054 -
Hydroxyl (O-H) confidence 1.0
“peak at 1033 The adsorption peak vibration corresponded to the stretching of C6-O-H in the SHR (%) = [(G × 25 × 0.9)/200]100………….(6) t”
Li 等 - 2014 - Characterization of Digestion Resistance Sweet Pot DOI: 10.4314/tjpr.v13i9.3 -
C-O single bond confidence 1.0
“The The bands bands of of Termitomyces Termitomyces albuminosus albuminosus at at about about 1152, 1152, 1075, 1075, 1045, 1045, 1038, 1038, 950, 950, 896 896 cm1 cm1 are are attributed attributed to to 3-g1ycosidic 3-g1ycosidic bond, bond”
Liu 等 - 2006 - Characterization of the basidiomycetes Thelephora DOI: 10.1117/12.710905 -
confidence 1.0
“by Georges-IVO (2005) at 1033, 1032 and 1007 cm-1 The peaks 912-937 were ascribed to Al-OH bend-”
Preparation and characterization of adsorbents derived from bentonite and kaolin clays DOI: 10.1007/s13201-018-0827-2
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