What absorbs at 1617 cm⁻¹ in an FTIR spectrum?
A band near 1617 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 1617 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) | 9 | 8 | 1.0 |
| Aromatic ring | 8 | 8 | 1.0 |
| Amide | 6 | 6 | 1.0 |
| Methacrylate | 6 | 5 | 1.0 |
| Acetate | 6 | 5 | 1.0 |
| Alkene (C=C) | 6 | 5 | 1.0 |
| Hydroxyl (O-H) | 5 | 5 | 1.0 |
| Ester | 5 | 4 | 1.0 |
| Ketone | 4 | 4 | 1.0 |
| Carboxyl (COOH) | 4 | 4 | 1.0 |
| Ring structure | 4 | 4 | 1.0 |
| N h | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 1 | 1.0 |
| C-O single bond | 2 | 1 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| N n bond | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Protein | 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 |
|---|---|---|---|
| activated carbon | 1617, 1575, 1210 | Methacrylate, Aromatic ring | 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 1617 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
-
Amide confidence 1.0
“However, these buffer bands are expected if the changes arise solely from amide I changes, broad in comparison to the underlying protein bands and 1617(+) cm-1, particularly the band at which is rather outside occur in only these two region”
Iwaki 等 - 2005 - Direct observation of redox-linked histidine proto DOI: 10.1021/bi047533v -
Amide confidence 1.0
“Peak Assignment of PAL and the Stretching According to the Spectrum of the PAL Casting Film in Figure 1 and the Spectrum of the Si Substrate in Figure 2 (cm-1) peak position assignment N-H 3348 asym stretching of NH2 ((cid:238)) N-H 3200 sy”
Lu 和 Mi - 2005 - Characterization of the interfacial interaction be DOI: 10.1021/ma0486896 -
Hydroxyl (O-H) confidence 1.0
“3411.84 3446 H-O-H bending vibration 1617.15 1617.36 1627.63 1634 Nitrate group stretching 1378.13 1384.4 1384.47 1385”
Investigation on structural, optical and electrical nature of pure and Cr-incorporated cobalt oxide nanoparticles prepared via co-precipitation method for photocatalytic activity of methylene blue dye DOI: 10.1007/s10854-020-04708-6 -
Ring structure confidence 1.0
“of LLC-GEN, at around 1617, 1062, 991, 887 and 789 For GEN, two characteristic cm-1, were assigned to the vibration of the C = C bond in ring peaks, centred at 1617 and 789 B and the C-C-C, C-C and C = O bonds in ring C of the isoflavonoid”
Balazs 等 - 2016 - ATR-FTIR and Raman spectroscopic investigation of DOI: 10.1364/BOE.7.000067 -
N n bond confidence 1.0
“assigned to stretching vibrations of O-H and cm-1 N-H bond, peak at 2890 corresponding to saturated cm-1 C-H stretching vibration, peak at 2325 assigned to cm-1 C=O, band at 1617 corresponding to N=N azo”
Biodegradation and decolorization of azo dyes by adherent Staphylococcus lentus strain DOI: 10.1007/s13765-016-0169-4 -
Alkene (C=C) confidence 1.0
“The peak around 1617 could be attributed to C=C stretching vibration from the aromatic ring and conjugated C=O bond [31].”
Modified Activated Carbon for Copper Ion Removal from Aqueous Solution DOI: 10.3390/pr10010150 -
Amino acid confidence 1.0
“cm-1 The bands at 1617 could be a combination of intermolecular turns sheet structure and the amino acid side chain residue vibration [16].”
Improvement of Functional Properties of Wheat Gluten Using Acid Protease from Aspergillus usamii DOI: 10.1371/journal.pone.0160101 -
Alkene (C=C) confidence 1.0
“Figure 2(c) indicates cm-1 the characteristic bands of pure GA at 3286 (acidic cm-1 O-H stretching), 1712 (presence of phenol group), cm-1 (C=C stretching vibration of aromatic ring), 1617 cm-1”
Dorniani 等 - 2016 - Graphene Oxide-Gallic Acid Nanodelivery System for DOI: 10.1186/s11671-016-1712-2
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