What absorbs at 1607 cm⁻¹ in an FTIR spectrum?
A band near 1607 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 1607 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 |
|---|---|---|---|
| Aromatic ring | 12 | 11 | 1.0 |
| Alkene (C=C) | 8 | 8 | 1.0 |
| Amide | 7 | 5 | 1.0 |
| N h | 6 | 5 | 1.0 |
| C c single bond | 5 | 5 | 1.0 |
| Carboxyl (COOH) | 5 | 4 | 1.0 |
| Ring structure | 4 | 4 | 1.0 |
| Secondary amine | 4 | 3 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| C n single bond | 2 | 2 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| C=n | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
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 1607 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
-
confidence 1.0
“Explicit assignment: '1590, 1607, 1635 (vibrational mode of furan)'”
Preparation and evaluation of nanocomposites of polyfuran with Al2O3 and montmorillonite clay DOI: 10.1002/pi.1562 -
Amino acid confidence 1.0
“The bands cm-1) originating from the amino acid side chains vibrations are also observed (1607 [21].”
A Preliminary Study of FTIR Spectroscopy as a Potential Non-Invasive Screening Tool for Pediatric Precursor B Lymphoblastic Leukemia DOI: 10.3390/molecules -
Hydroxyl (O-H) confidence 1.0
“The bands observed at 1607, 1391 and 238 cm-1 1018 were assigned to alcohol and phenolic groups, C-N stretching vibrations of aliphatic 239”
Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles DOI: 10.1016/j.micpath.2015.11.021 -
Alkene (C=C) confidence 1.0
“peak for poly (AAm) at 1649 However, C=C functional group still presented in both spectra at 1651 and 1607 cm-1.”
Characterization of ultraviolet-photocured acrylamide based polymer DOI: 10.1063/1.4966755 -
Acetate confidence 1.0
“OCOcm-1) stretching band (1607 of N-bentonite became stronger in the temperature interval metric 100-400◦C of as a result of binding via the C O group of the ligand to exchangeable cation and/or Keywords: cm-1) water molecule whereas the OH”
Tabak 等 - 2011 - Structural analysis of naproxen-intercalated bento DOI: 10.1016/j.cej.2011.09.027 -
C c single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Al-Hamdan 等 - 2020 - Influence of Hydroxyapatite Nanospheres in Dentin DOI: 10.3390/polym12122948 -
C c single bond confidence 1.0
“Aromatic (C-C) cm-1 cm-1 and aliphatic (C=C) reference peaks recorded at 1607 and 1638 were collected.”
Influence of Concentration Levels of -Tricalcium Phosphate on the Physical Properties of a Dental Adhesive DOI: 10.3390/nano12050853 -
C c single bond confidence 1.0
“Using an already recognized technique [19], the aromatic C-C cm-1) cm-1) characteristic peaks (1607 and aliphatic C=C absorbance peaks (1638 were”
Dentin Bond Integrity of Filled and Unfilled Resin Adhesive Enhanced with Silica Nanoparticles—An SEM, EDX, Micro-Raman, FTIR and Micro-Tensile Bond Strength Study DOI: 10.3390/polym13071093
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