What absorbs at 3155 cm⁻¹ in an FTIR spectrum?
A band near 3155 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 3 cited sources
Quick answer
A band near 3155 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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| Water (H2O) | 2 | 2 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| N h | 1 | 1 | 0,9 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Possible materials
| Material | Stödjande toppar | Overlapping groups | Citerade källor |
|---|---|---|---|
| polypropylene | 3155, 1030, 1600 | Amide | 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 3155 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.
Litteratur bakom dessa identifieringar
-
Hydroxyl (O-H) förtroende 1,0
“O-H O-H between the overtone of the bending band and the (cid:24)3155 cm-1 4+, asymmetric stretching band at from (F 2)-NH (cid:238) O-H stretching band in the difference spectra;”
Wei 等 - 2005 - Observation of the first hydration layer of isolat DOI: 10.1021/jp0453865 -
Water (H2O) förtroende 1,0
“1 coordinated water, complex exhibited a wider absorption peak near 3155 The asymmetric cm-1 C(O)OC=O vibrational peaks near 1627 and 1587 show that the O atom in”
Cao 等 - 2020 - Synthesis and Effects of Two Novel Rare-Earth Ener DOI: 10.3390/ma13122811 -
Amide förtroende 1,0
“For MP, the following vibration peaks are recognized, such as stretching vibration of -NH at 2 cm-1, cm-1, cm-1, 3+ 3393 stretching vibration of -NH at 3155 stretching vibration of C-N at 1671 and”
He 等 - 2019 - Novel Intumescent Flame Retardant Masterbatch Prep DOI: 10.3390/polym11010050
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