What absorbs at 1208 cm⁻¹ in an FTIR spectrum?
A band near 1208 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 1208 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 |
|---|---|---|---|
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Aromatic ring | 3 | 3 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
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 |
|---|---|---|---|
| hemicellulose | 1208, 1730, 897 | Methacrylate, Acetate | 1 |
| TiO2 | 1208, 1700, 1093 | Methacrylate, Acetate, Carboxyl (COOH) | 1 |
| TiO | 1208, 1730, 1699 | Methacrylate, Acetate, Carboxyl (COOH) | 1 |
| citric acid | 1208, 1725, 1732 | Methacrylate, Acetate, Carboxyl (COOH) | 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 1208 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
-
Hydroxyl (O-H) confidence 1.0
“1203cm-1 cm-1 The band at of the glucose spectra and the band at 1208 of the sucrose spectra, respectively, represent OH peaks.”
Hauswirth 等 - 2022 - Spectroscopic Investigation of the Impact of Cold DOI: 10.3390/foods11182786 -
Alkene (C=C) confidence 1.0
“transmittance was the stretching vibration peak at 1208.32 modified cm-1 Compared with the control group, ZDMA PMMA The generation of IR peak at 1208.32 was due to the open of confirmed groups have shown higher Ra values, 108.8 ± 2.59 nm, 1”
Antifungal efficiency and cytocompatibility of polymethyl methacrylate modified with zinc dimethacrylate DOI: 10.3389/fcimb.2023.1138588 -
C c single bond confidence 1.0
“The bands at 1497 and 1455 can be readily assigned to cm-1 to the C-C stretching skeletal vibrations of the aromatic ring and the band centred at 1208 cm-1 vibration.”
Augugliaro 等 - 2008 - Photocatalytic oxidation of aromatic alcohols to a DOI: 10.1016/j.apcata.2008.07.038 -
Carboxyl (COOH) confidence 1.0
“cm(cid:3)1 thaninCA30-Cfilm,indicatingthatSHPcouldhavepromotedcitric films increased peak at 1208 in with citric acid is ascribed to CeO acid decarboxylation on curing, as suggested by Yao, Wang, Ye, and stretching of formed ester bonds (Ba”
Azeredo 等 - 2015 - Wheat straw hemicellulose films as affected by cit DOI: 10.1016/j.foodhyd.2015.04.005 -
Aromatic ring confidence 1.0
“1453 -C=Caromatic stretching 1411 -S=O anti-symmetric stretching overlapping 1208 -C=Cwith aromatic bending”
Benbow 等 - 2018 - A Novel Soft Contact Piezo-Controlled Liquid Cell DOI: 10.1038/s41598-018-34673-4 -
Aromatic ring confidence 1.0
“= the O P-O bridging phosphorous, and confirm the presence of phosphate In the FTIR spectrum of the kanamycin-Cu 3(PO 4) hybrid flowers (red line), while the characteristic peaks at 1153, 1095, 1000, 635 2 cm-1 cm-1 and 564 demonstrate the”
Self-assembled kanamycin antibiotic-inorganic microflowers and their application as a photocatalyst for the removal of organic dyes DOI: 10.1038/s41598-019-57044-z -
confidence 1.0
“The ring oxygen stretching the salt concentration increases, a new shoulder grew up at 1208 The ring oxygen cm-1 stretching is located at 1074 at the lowest concentration (0.1 M), while at the highest is located at 1074 cm-1 at the lowest c”
Plasticizers and Salt Concentrations Effects on Polymer Gel Electrolytes Based on Poly (Methyl Methacrylate) for Electrochemical Applications DOI: 10.3390/gels8060363 -
Hydroxyl (O-H) confidence 1.0
“cm(cid:3)1 C-C centered at 3456 at 1494 and 1452 and ring bending at 698 The remained in the spectrum but was less Ouro cm(cid:3)1 O-H shied C-O peaks assigned to bending at 1208 intense and to higher wavelengths due the decrease in and to”
Insight into magnetite nanoparticle phase evolution in solvothermal synthesis through a simple method based on iron chloride and metallic iron DOI: 10.1039/c4ra06620k
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.