What absorbs at 1050 cm⁻¹ in an FTIR spectrum?
A band near 1050 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 1050 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 | 56 | 53 | 1.0 |
| Methoxy (OCH3) | 51 | 48 | 1.0 |
| Methacrylate | 51 | 48 | 1.0 |
| Acetate | 51 | 47 | 1.0 |
| Hydroxyl (O-H) | 18 | 18 | 1.0 |
| Carbohydrate | 18 | 17 | 1.0 |
| Silicon-oxygen (Si-O) | 17 | 15 | 1.0 |
| Silicon (Si) | 14 | 11 | 1.0 |
| Phosphate (PO4) | 11 | 10 | 1.0 |
| Siloxane (Si-O-Si) | 9 | 7 | 1.0 |
| C c single bond | 8 | 8 | 1.0 |
| Metal oxygen | 7 | 7 | 1.0 |
| Amide | 7 | 7 | 1.0 |
| Secondary amine | 5 | 5 | 1.0 |
| Carboxyl (COOH) | 4 | 4 | 1.0 |
| Phosphorus | 4 | 4 | 1.0 |
| C n single bond | 4 | 4 | 1.0 |
| Ester | 4 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Alkene (C=C) | 3 | 3 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Water (H2O) | 3 | 2 | 1.0 |
| Silicate | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Hydrogen bond | 2 | 2 | 1.0 |
| Lignin | 2 | 2 | 1.0 |
| Chlorine | 2 | 1 | 1.0 |
| Protein alpha helix | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| Silicon silicon | 1 | 1 | 1.0 |
| Silicon hydride | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| Sulfonate | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Sulfate (SO4) | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 0.7 |
| S eq o | 1 | 0 | 0.7 |
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 |
|---|---|---|---|
| calcium phosphate | 1050, 1070, 1149 | C-O single bond, Methoxy (OCH3), Methacrylate | 1 |
| lignin | 1050, 1035, 1510 | Methacrylate, Acetate, 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 1050 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
“cm-1 467 and 588 are due to vibrations stretching metal-oxygen Due to the high temperature cm-1 heating at 1050 ºC, peaks at 1481-1484, 1642, 2917, 3416 disappeared and as a result no absorption band was appeared in Fig.”
Effect of rare earth and transition metal La-Mn substitution on electrical properties of co-precipitated M-type Ba-ferrites nanoparticles DOI: 10.1016/j.jre.2018.08.005 -
Lignin confidence 1.0
“These peaks were overlapped with the large and intense For sample L-PS4, the intensity of the -OH groups cm-1 lignin stretching bands at 1050 (Azhar et al.”
Azhar 等 - 2020 - Lignin-Coated PolystyreneTrichloromethylsilane Ab DOI: 10.17576/jsm-2020-4909-12 -
Silanol (Si-OH) confidence 1.0
“curve c - T In the insert, IR absorption spectra in the region of Si-OH stretching curve b - T d¼1050(cid:3)C,dopedwithdifferentamountofGd:curve1-1%m.f.Gdandcurve modefortwosamplesdensifiedatT Fraser 2 - 8% m.f.”
Baraldi 等 - 2002 - Vibrational spectroscopy of OH-defects in sol-gel DOI: 10.1080/10420150215814 -
Acetate confidence 1.0
“cm-1 cm-1 cm-1 stretching), 2894 (aliphatic C-H stretching), 1160 (bridge O stretching), 1050 (C-O stretching), also the usual characteristic pattern of cellulose can be seen in the fingerprint region.”
Surface modification of bacterial cellulose membrane by oxygen plasma treatment DOI: 10.1016/j.surfcoat.2016.06.035 -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
Development of Composite Scaffolds Based on Cerium Doped-Hydroxyapatite and Natural Gums—Biological and Mechanical Properties DOI: 10.3390/ma12152389 -
Water (H2O) confidence 1.0
“decomposition desorption of the residual organic this band for the samples calcinated at 1000 and 1050 cm-1 °C, compounds and occluded water during BTO heat treatment For the sample calcinated at 1000 the band at 1435 3”
Calcination temperature effect on dielectric, structural and morphology properties of BaTiO3 nano-structure prepared by modified sol—gel technique DOI: 10.1088/2043-6254/ab798d -
Amide confidence 1.0
“This increase films grown at 200 °C, the band located at approximately could explain the shift of the phenyl radical toward high 1050 cm-1 could be attributed to C-N vibrations [16] or C-O energies with respect to the phenyl species in the”
Galeano-Osorio 等 - 2014 - Carbon nitride films grown by cathodic vacuum arc DOI: 10.1126/science.245.4920.841 -
confidence 1.0
“a cool-stable chamber, to avoid the influence of the temlocalization of the band), partially ascribable to Si-O stretching 1050cm-1 perature changes [29] improving the sample reproducibility;”
Giovannozzi 和 Rocchia - 2008 - Effect of the reaction time, reagent concentration DOI: 10.1016/j.snb.2007.10.043
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