What absorbs at 1335 cm⁻¹ in an FTIR spectrum?
A band near 1335 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 1335 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 |
|---|---|---|---|
| Alkyl C-H | 11 | 11 | 1.0 |
| Hydroxyl (O-H) | 6 | 6 | 1.0 |
| Carbohydrate | 5 | 5 | 1.0 |
| C-O single bond | 3 | 3 | 1.0 |
| Ring structure | 3 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 0.8 |
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 |
|---|---|---|---|
| cellulose | 1335, 1735, 1650 | Alkyl C-H, C-O single bond, Hydroxyl (O-H) | 2 |
| chitosan | 1335, 1650, 1655 | Alkyl C-H, Hydroxyl (O-H), C-O single bond | 1 |
| goethite | 1335, 1470, 696 | Hydroxyl (O-H), 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 1335 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
-
Carbohydrate confidence 1.0
“LLM confirmed rule peak-group candidate”
A Microscopic Study of Paper Decayed by Trichoderma harzianum and Paecilomyces variotii DOI: 10.1007/s10924-017-1147-6 -
C-O single bond confidence 1.0
“calculation of band areas d d 1238 6.6 CH ? OH in plane m d stretching vibrations, d d 1335 10.8 CCH ? OCH bending vibrations”
Pemmaraju 等 - 2016 - Modulation of Candida albicans Biofilm by Differen DOI: 10.1007/s11046-016-9992-8) -
Alkyl C-H confidence 1.0
“(3437cm-1), 167 one can see the O-H stretching due to the physisorbed water molecules N-H (3067cm-1), (2822cm-1and 2883cm-1), (1642cm168 stretching C-H stretching OH bending vibration 1), (1335cm-1),14”
Removal of hazardous pollutants from wastewater: Catalytic applications of Mg nanoparticle functionalized aminoclay DOI: 10.1016/j.molliq.2019.112005 -
Alkyl C-H confidence 1.0
“The band at 1335 due to methyl”
Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization DOI: 10.1002/app.26838 -
confidence 1.0
“12a), both for the blanks (brometric O-C-O stretch vibration and the one at 1335 the symmetric stretch.”
Surface Complexation Modeling and FTIR Study of Carbonate Adsorption to Goethite DOI: 10.1006/jcis.2000.7341 -
Alkyl C-H confidence 1.0
“2021, 35(3) Optical characteristics of poly(vinyl alcohol)/carboxymethyl cellulose/curcumin nanocomposites 619 cm-1 stretching vibrations and (iv) the band at 1335 has been assigned to the combination frequencies of (CH·OH).”
Ahmed 等 - 2021 - STRUCTURAL AND OPTICAL CHARACTERISTICS OF POLY(VIN DOI: 10.4314/bcse.v35i3.12 -
Alkyl C-H confidence 1.0
“Other spectral bands, such as, 1335 (CH rocking vibration 2 188 cm-1 cm-1 at C6), 1381 (CH in-plane bending), 1418 (HCH in plane bending vibration, CH 2 189 scissoring motion, CH symmetric bending at C6) are also attributed to alkyl units o”
Barzic 等 - 2022 - Cellulose derivativebarium titanate composites wi DOI: 10.21203/rs.3.rs-467926/v1 -
Hydroxyl (O-H) confidence 1.0
“Amide II (NH) wagging 1058 CO stretching 1335 CH and OH wagging”
Application of Vibrational Spectroscopic Techniques in the Study of the Natural Polysaccharides and Their Cross-Linking Process DOI: 10.3390/ijms24032630
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