What absorbs at 717 cm⁻¹ in an FTIR spectrum?
A band near 717 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 717 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 | 5 | 5 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| N h | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| CNTs | 717, 3465, 2941 | Alkyl C-H, Aromatic ring | 1 |
| HDPE | 717, 1369, 1216 | Alkyl C-H, Aromatic ring | 1 |
| LDPE | 717, 1720, 1737 | Alkyl C-H, 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 717 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
-
Metal oxygen confidence 1.0
“USC cm-1 The characteristic sharp bands for Fe-O stretching were found at 717, 623,557 and 443 which confirmed the formation of magnetite nanoparticles.”
Mesoporous magnetite nanoparticles synthesis using the Peltophorum pterocarpum pod extract, their antibacterial efficacy against pathogens and ability to remove a pollutant dye DOI: 10.1016/j.molstruc.2018.10.042 -
Hydroxyl (O-H) confidence 1.0
“Description (cm-1) 717 As-OH vibration Symmetry stretch of As-OH As(III) As(OH) 3 2)- 721 As-O vibration Symmetry stretch of As-O AsO(OH”
The effect of electrocoagulation (EC) on total arsenic, arsenite (As3+) and arsenate (As5+) species removal from model groundwater investigating toxicity and sludge characteristic DOI: 10.1007/s13201-022-01660-0 -
Hydroxyl (O-H) confidence 1.0
“Polarized FTIR spectra of cm-1 films axially stretched CC PPO/carvacrol show that the guest peak at 717 is not dichroic, while the guest peak at cm-1 cm-1 confirms O-H 698 is markedly dichroic.”
Golla 等 - 2021 - Isolated and aggregated carvacrol guest molecules DOI: 10.1038/s41428-021-00511-0 -
Aromatic ring confidence 1.0
“The corresponding aromatic stretching 717 and 1614cm(cid:5)1”
A study on the characteristics of Algerian Hassi-Messaoud asphaltenes: solubility and precipitation DOI: 10.1080/10916466.2021.2017457 -
Alkyl C-H confidence 1.0
“The 717 absorption band is designated to the C-H stretching vibration of the CH 3/CH groups.”
Almousa 等 - 2021 - Paraffin Wax [As a Phase Changing Material (PCM)] DOI: 10.3390/cryst11080951 -
Metal oxygen confidence 1.0
“One visible shoulder peak at ~717 emerged, which is the absorption band of the Fe-O in the FH [26], at the expense of the shoulder peak located at”
Effects of Potassium Loading over Iron–Silica Interaction, Phase Evolution and Catalytic Behavior of Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis DOI: 10.3390/catal12080916 -
Chlorine confidence 1.0
“Explicit assignment in text”
Fabrication of Chitosan Nanofibers Containing Some Steroidal Compounds as a Drug Delivery System DOI: 10.3390/polym14102094 -
Alkyl C-H confidence 1.0
“The production and packaging of LDPE, the peak wavelength at represents the CH bend, 3 730cm-1, 719cm-1 717cm-1”
Hossain 等 - 2023 - First evidence of microplastics and their characte DOI: 10.3389/fenvs.2023.1232931
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