What absorbs at 1735 cm⁻¹ in an FTIR spectrum?
A band near 1735 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 1735 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 |
|---|---|---|---|
| Carbonyl (C=O) | 99 | 89 | 1.0 |
| Ester | 78 | 76 | 1.0 |
| Acetate | 71 | 67 | 1.0 |
| Methacrylate | 70 | 66 | 1.0 |
| Carboxyl (COOH) | 68 | 66 | 1.0 |
| Ketone | 60 | 59 | 1.0 |
| Amide | 59 | 58 | 1.0 |
| Carbohydrate | 17 | 14 | 1.0 |
| Alkyl C-H | 16 | 15 | 1.0 |
| Methoxy (OCH3) | 14 | 11 | 1.0 |
| C-O single bond | 14 | 11 | 1.0 |
| Acetyl | 8 | 7 | 1.0 |
| Hydroxyl (O-H) | 7 | 6 | 1.0 |
| Lipid | 6 | 5 | 1.0 |
| Alkene (C=C) | 3 | 3 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| N-O bond | 2 | 2 | 1.0 |
| Water (H2O) | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Lignin | 2 | 1 | 1.0 |
| Thiol | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| N c o | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| Azide | 1 | 1 | 0.9 |
| Phosphate (PO4) | 1 | 0 | 1.0 |
| Methyl | 1 | 0 | 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 |
|---|---|---|---|
| nanotube | 1735, 1540, 1080 | Methacrylate, Acetate | 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 1735 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
-
Acetate confidence 1.0
“The new peak appears cm-1 at 1735 which indicates the presence of a C=O bond from carboxylic acid.”
Arizka 等 - 2019 - Synthesis and Physical Properties Characterization DOI: 10.1088/1757-899X/546/4/042004 -
Carbohydrate confidence 1.0
“The peak at approximately 1735 tion and ball milling) is directly dissolved in the NMR solvent, represent is typically associated with xylan and has also been”
Bryant 等 - 2023 - Variable lignin structure revealed in Populus leav DOI: 10.1039/d3ra03142j -
Acetate confidence 1.0
“cm-1 characteristic peak at 1735 (acetyl groups in xylan and other nonconjugated carcm-1 cm-1 bonyls), C=O stretch in xylan (hemicelluloses) and the peaks at 1508 and 1427 cm-1 cm-1 show the aromatic skeletal vibration of lignin.”
n-Heptadecane-Impregnated Wood as a Potential Material for Energy-Saving Buildings DOI: 10.3390/f13122137 -
Acetate confidence 1.0
“Another characteristic peak at 1735 cm-1, including acetyl groups in xylan and other non-conjugated carbonyls, a C=O stretch in xylan (hemicelluloses), a lignin aromatic skeletal vibration at 1508 cm-1, a lignin aromatic skeletal vibra-”
Can 等 - 2023 - Choline Chloride-Based Deep Eutectic Solvent-Treat DOI: 10.3390/f14030569 -
Ester confidence 1.0
“stretching vibration at 1735.2 cm-1 The peak region at 10001300 is assigned to the ester (C-O) functionalities due to the presence of acetic acid in the composites.”
Dahham 等 - 2018 - The Influences of Zirconium Dioxide on ENR-25ZrO2 DOI: 10.1088/1742-6596/1019/1/012055 -
Carboxyl (COOH) confidence 1.0
“The small peaks at 2352 and acteristic peaks of CO oxidation products at 2347 due to cm(cid:3)1 cm(cid:3)1 CO235 1651 physisorbed were observed and characterized for adsorbed CO2 and and a peak at 1735 due to carboxylate (CO32(cid:3)”
CO oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSM-5 zeolite DOI: 10.1016/j.jre.2021.07.009 -
Lipid confidence 1.0
“The shift in the peak at 1082 22 nificant differences among primary cells, cell lines and malignant the environment near the PO group underwent a series of cm21, cells in the shapes of the band at 1735 which may be alterations during malign”
Erukhimovitch 等 - 2002 - Spectroscopic characterization of human and mouse DOI: 10.1562/0031-8655(2002)076 -
Hydroxyl (O-H) confidence 1.0
“DS that reached at those condition is 0.22 and has the same tipe as cm-1 native starch (tipe A).The result of FTIR shown that there's a new peak at 1735 which is a part of carbonyl group and the weakening of hydroxyl group peak of acetate s”
Fiqtinovri 等 - 2020 - Physical, Amilograph and Morphological Properties DOI: 10.22146/agritech.33809
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