What absorbs at 2011 cm⁻¹ in an FTIR spectrum?
A band near 2011 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 2011 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 | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
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 2011 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
-
C-O single bond confidence 1.0
“cellulose C O C bridges (1165 C O bond stretching 2011;”
Avila Ramirez 等 - 2014 - Surface esterification of cellulose nanofibers by DOI: 10.1016/j.carbpol.2014.08.020 -
Alkyl C-H confidence 1.0
“Librando et al., 2900 CH stretching Cellulose 2011).”
Water-Based Aerosol for Book Deacidification: Experimental Apparatus and Theoretical Interpretation of Results DOI: 10.3390/molecules26144249 -
confidence 1.0
“cm-1 with N-H bending at 1618 (University of Colorado Oxidative stress effects of zinc oxide nanoparticles on cm-1 2011a), acid with C-O stretching at 1299 (Silverstein fresh water microalga Haematococcus pluivalis.”
Djearamane 等 - 2022 - Sensitivity of Proteus vulgaris to Zinc Oxide Nano DOI: 10.17576/jsm-2022-5105-07 -
Acetate confidence 1.0
“2011) 2 1740 C-O vibrations from lipids (Wrobel et al.”
Koziorowska 等 - 2020 - Electromagnetic field of extremely low frequency h DOI: 10.24425/pjvs.2020.134703 -
Hydroxyl (O-H) confidence 1.0
“2 provides an overview of the OH stretching region of the 2011”
Nedic 等 - 2011 - A combined Ramanand infrared jet study of mixed DOI: 10.1039/C1CP20182D -
Alkyl C-H confidence 1.0
“Hauser (Ed.), Textile Dyeing, InTech, ment ric and symmetric C H stretching vibration bands as well as the 2011, pp.”
Oliveira 等 - 2014 - Dyeing mechanism and optimization of polyamide 6,6 DOI: 10.1016/j.apsusc.2013.12.126 -
Ring structure confidence 1.0
“cm-1, due to the in-plane C-O stretching vibration combined with band at 1728 which appears due to the C=O stretching et al., from lipids, we can conclude that lipids are found in higher the ring stretch of phenyl (Lu 2011).”
Pop 等 - 2014 - Untargeted Metabolomics for Sea Buckthorn (Hippoph DOI: 10.15835/nbha4229654 -
Amide confidence 1.0
“Collagen type I amide I band 2011;42:283-289.”
Rodrigues 等 - 2018 - Evaluation of inflammatory processes by FTIR spect DOI: 10.1080/03091902.2018.1470691
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