What absorbs at 656 cm⁻¹ in an FTIR spectrum?
A band near 656 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 5 cited sources
Quick answer
A band near 656 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.
Mogelijke functionele-groeptoewijzingen
| Functionele groep | Ondersteunende feiten | Geciteerde bronnen | Hoogste vertrouwen |
|---|---|---|---|
| Sulfonate | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Bromine | 1 | 1 | 1,0 |
| Carbon bromine | 1 | 1 | 1,0 |
| Carbon dioxide | 1 | 1 | 0,9 |
Ranglijst weerspiegelt cumulatief literatuurbewijs, niet één gezaghebbende regel. Bevestig altijd aan de hand van uw monsterecontext.
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 656 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.
Literatuur achter deze toewijzingen
-
Carbon bromine vertrouwen 1,0
“The antioxidant activity of crude extract of cm-1 ammi The peak at 655.80 shows C-Br stretching.”
Bawazeer 等 - 2021 - Synthesis, Characterization and Bioactivity Profil DOI: 10.22207/JPAM.15.2.11 -
vertrouwen 1,0
“The bending vibration of -OH and Si-O appeared at 656 cm-1 of bare chlorite showed peaks at 3744 3411 1000 indicating the stretching of Si-OH, cm-1 and 472 cm-1, respectively.”
The Effect of Sodium Alginate on Chlorite and Serpentine in Chalcopyrite Flotation DOI: 10.3390/min9030196 -
Sulfonate vertrouwen 1,0
“The bands with a peak at 1172 and 1156 cm-1 belong to the engine oil and worn engine oil in the area of fingerprint FTIR spectra, several changes can be observed sulfonate detergent tension bands [38,39], and the bands with a peak at 970 cm”
FTIR Spectrometry with PLS Regression for Rapid TBN Determination of Worn Mineral Engine Oils DOI: 10.3390/en13236438 -
Carbon dioxide vertrouwen 0,9
“CO2 band”
Galvez 等 - 2008 - Trapping and adsorption of CO2 in amorphous ice A DOI: 10.1016/j.icarus.2008.05.016 -
vertrouwen 0,8
“Text: '656cm-1 ... symmetric stretching peak'”
Khatamian 等 - 2010 - Synthesis, characterization and acidic properties DOI: 10.1016/j.powtec.2010.06.012
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