What absorbs at 1614 cm⁻¹ in an FTIR spectrum?
A band near 1614 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 1614 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) | 11 | 10 | 1.0 |
| Aromatic ring | 10 | 9 | 1.0 |
| Alkene (C=C) | 9 | 7 | 1.0 |
| Methacrylate | 7 | 6 | 1.0 |
| Carboxyl (COOH) | 7 | 6 | 1.0 |
| Acetate | 7 | 6 | 1.0 |
| Amide | 7 | 5 | 1.0 |
| Ring structure | 5 | 5 | 1.0 |
| Ketone | 5 | 4 | 1.0 |
| Ester | 5 | 4 | 1.0 |
| Water (H2O) | 4 | 4 | 1.0 |
| N h | 4 | 3 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Protein beta sheet | 3 | 3 | 1.0 |
| C=n | 3 | 3 | 1.0 |
| Nitrogen heterocycle | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Sulfur heterocycle | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| Lewis acid site | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Sulfur | 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 |
|---|---|---|---|
| graphene oxide | 1614, 1150, 3400 | Methacrylate, Carbonyl (C=O) | 1 |
| TiO2 | 1614, 1700, 1093 | Methacrylate | 1 |
| microplastics | 1614, 1643, 1760 | Alkene (C=C), Carbonyl (C=O), 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 1614 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
“In the spectra related to the PE fragments and pellets, new weathering bands from cm-1 cm-1 1510 to 1770 of absorbance, with centred peaks at about 1614 (corresponding to C=O stretching), are also evident.”
Campanale 等 - 2023 - Fourier Transform Infrared Spectroscopy to Assess DOI: 10.3390/polym15040911 -
Protein beta sheet confidence 1.0
“The line at 1614 cm-1 corresponds to the intermolecular β-sheets and 1685 cm-1”
A Preliminary Study of FTIR Spectroscopy as a Potential Non-Invasive Screening Tool for Pediatric Precursor B Lymphoblastic Leukemia DOI: 10.3390/molecules -
C=n confidence 1.0
“In the salicylidene-phenylhydrazine Schiff base, a characteristic strong cm-1 peak at 1614 due to azomethine functionality (-C=N) confirmed its formation.”
Synthesis, Characterization, Theoretical and Experimental Anticancer Evaluation of Novel Cocrystals of 5-Fluorouracil and Schiff Bases against SW480 Colorectal Carcinoma DOI: 10.3390/pharmaceutics15071929 -
Aromatic ring confidence 1.0
“Bands at 1614, 1584 and 1510 are related to the in the benzene ring or the C-C elongation bond of the aromatic ring in the epoxy [62,63].”
Pereira 等 - 2020 - Ballistic Performance of Ramie Fabric Reinforcing DOI: 10.3390/polym12112711 -
C=n confidence 1.0
“C≡N 2341 2224 stretching C=N stretching 1614 1604”
Yusoff 等 - 2018 - Theoretical and Experimental Approach Towards P-Cy DOI: 10.1088/1757-899X/374/1/012086 -
C c single bond confidence 1.0
“highest values of linearity (TZD=0.954 and TmH=0.951), C-N The FTIR spectrum of TZD showed the amide cm-1) stretching peaks (1566, 1507, 1560 and 1513 and the C-C aromatic stretching peaks (1614, 1507, 1442, 1626, 1513”
Aamir 和 Ahmad - 2010 - Production and Stability Evaluation of Modified-Re DOI: 10.1208/s12249-010-9392-1 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
A novel gallium oxide nanoparticles-based sensor for the simultaneous electrochemical detection of Pb2+, Cd2+ and Hg2+ ions in real water samples DOI: 10.1038/s41598-022-24558-y -
Water (H2O) confidence 1.0
“cm-1 time in the intensity of the absorption band centred at 1640 through two parallel reaction routes active since the start of due to the bending vibration mode of adsorbed molecular water, irradiation: the first one determines the MBA pa”
Augugliaro 等 - 2009 - Home-prepared anatase, rutile, and brookite TiO2 f DOI: 10.1039/b818353h
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