What absorbs at 1222 cm⁻¹ in an FTIR spectrum?
A band near 1222 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 1222 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 |
|---|---|---|---|
| Methacrylate | 8 | 8 | 1.0 |
| Acetate | 8 | 8 | 1.0 |
| Methoxy (OCH3) | 7 | 7 | 1.0 |
| C-O single bond | 7 | 7 | 1.0 |
| Hydroxyl (O-H) | 6 | 5 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Urethane | 1 | 1 | 1.0 |
| N eq o | 1 | 1 | 1.0 |
| Nitro (NO2) | 1 | 1 | 1.0 |
| Lignin | 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 |
|---|---|---|---|
| water | 1222, 1018, 2945 | Methoxy (OCH3), Methacrylate, C-O single bond | 1 |
| CS | 1222, 1645, 1720 | Methacrylate, C-O single bond, Acetate | 1 |
| lignin | 1222, 1035, 1510 | Methacrylate, Acetate, C-O single bond | 1 |
| silver nanoparticles | 1222, 1636, 1631 | Methacrylate, Acetate, C-O single bond | 1 |
| DNA | 1222, 1712, 1660 | 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 1222 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
-
Lignin confidence 1.0
“LLM confirmed rule peak-group candidate”
Liang 等 - 2020 - Thermal Kinetics of a Lignin-Based Flame Retardant DOI: 10.3390/polym12092123 -
Phosphate (PO4) confidence 1.0
“The estimated 1222 is due to P=O stretchings [24].”
Rada 等 - 2009 - Structural and electronic properties of tellurite DOI: 10.1007/s10853-009-3433-8 -
Acetate confidence 1.0
“the peak at 1222 indicates the presence of the stretching vibration of the C-O vibration of nitro groups (N=O);”
Eucalyptus globulus and Salvia officinalis Extracts Mediated Green Synthesis of Silver Nanoparticles and Their Application as an Antioxidant and Antimicrobial Agent DOI: 10.3390/plants11081085 -
Acetate confidence 1.0
“The peak at 1222 was attributed to the =C-O-C stretching vibration of the carbamate.”
Jin 等 - 2021 - Preparation of Microspheres and Microfiber Membran DOI: 10.1002/app.39967 -
Carboxyl (COOH) confidence 1.0
“The most dominant ones appear at 1713 and 1222 and can be assigned to the 1222 cm-1, and can be assigned to the carboxylic acid groups [32].”
Infrared Spectroscopy as Molecular Probe of the Macroscopic Metal-Liquid Interface DOI: 10.3390/app7121229 -
Phosphate (PO4) confidence 1.0
“Specbands including the antisymmetric as) and symmetric s) p53PBM4 p531-355 tra of and were subtracted from spectra phosphate vibrations of the DNA backbone at 1222 and cm-1, p53WT, of respectively, resulting in positive bands for sec1086 r”
Krueger 等 - 2019 - Interactions of p53 with poly(ADP-ribose) and DNA DOI: 10.1093/nar/gkz175 -
C c single bond confidence 1.0
“C-C-Cinplanebend CH3twist 98 1188.306 1147.9 39.6 159 427.2545 412.7 5.5 C-C-Cinplanebend CH3twist 99 1159.176 1119.8 1.8 160 416.7383 402.6 3.0 C-C-Cinplanebend CH3twist 1246.5 100 1159.099 1119.7 2.7 161 400.3562 386.7 6.8 C-C-Cinplaneben”
Computational and spectral studies of 3,3'-(propane-1,3-diyl)bis(7,8-dimethoxy-1,3,4,5-tetrahydro-2H-benzo[d]azepin-2-one) DOI: 10.1016/j.heliyon.2019.e02420 -
Hydroxyl (O-H) confidence 1.0
“In these PEM spectra, the increasing overall intensity and the changes of both the Amide I and (cm-1) Assignment Component Wavenumber Amide II bands at around 1640 and 1550 cm-1 due to PLL and of ν(SO2) band at 1248/1222 cm-1 ν(OH) 3700-310”
Mueller - 2020 - Anomalous Influence of Salt Concentration on Depos DOI: 10.3390/molecules25102336
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