What absorbs at 1758 cm⁻¹ in an FTIR spectrum?
A band near 1758 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 1758 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.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Carbonyl (C=O) | 3 | 3 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Possible materials
| Материал | Поддерживающие пики | Overlapping groups | Цитируемые источники |
|---|---|---|---|
| SiO2 | 1758, 1739, 699 | Alkyl C-H | 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 1758 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.
Литература, лежащая в основе этих назначений
-
Carbonyl (C=O) достоверность 1,0
“The peak cm-1 cm-1 positioned 1758 is assigned to the carbonyl group of the branched polylactide.”
Saetae 和 Magaraphan - 2015 - Synthesis and study of sericin-g-PLA DOI: 10.1063/1.4918510 -
Alkyl C-H достоверность 1,0
“cm-1, (carbonil) absorption band at 1758 the bands corresponding to the asymmetric and symmetric bending cm-1, cm-1 the vibration peak of methane (-CH) groups at 1270 are vibrations of methyl groups at 1451 and 1383 cm-1 characteristic poly”
Ceyhan 等 - 2008 - Analysis of degradation failure of poly L-lactic a DOI: 10.3944/AOTT.2008.284 -
Acetate достоверность 1,0
“The absorption band at 1758 corresponded cm-1 to the stretching modes of the C=O functional groups.”
Hagos 等 - 2022 - NEW ANALYTICAL METHODS FOR THE DETERMINATION OF AS DOI: 10.4314/bcse.v36i2.3 -
Carbohydrate достоверность 1,0
“After modification, new peaks occurred at 1758 showed that PPL contained cellulose, hemicellulose, lignin, and pectin.”
Pomelo Peel Modified with Citrate as a Sustainable Adsorbent for Removal of Methylene Blue from Aqueous Solution DOI: 10.3390/molecules23061342 -
Alkyl C-H достоверность 1,0
“enthalpy(Jg(cid:1)1)thatwas cm(cid:1)1 cm(cid:1)1 C]O calculatedfrom thefusionpeakinDSC Moreover, the 1758 and 2995 were assigned to DH* C-H -CH curve, and in ester bond and in is the theoretical enthalpy of completely crys3, which are well”
One-pot route to graft long-chain polymer onto silica nanoparticles and its application for high-performance poly(l-lactide) nanocomposites DOI: 10.1039/c9ra01360a
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