What absorbs at 1281 cm⁻¹ in an FTIR spectrum?
A band near 1281 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 1281 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.
Iespējamie funkcionālo grupu piešķīrumi
| Funkcionālā grupa | Atbalstošie fakti | Citētie avoti | Augstākā pārliecība |
|---|---|---|---|
| Methoxy (OCH3) | 3 | 3 | 1,0 |
| Methacrylate | 3 | 3 | 1,0 |
| C-O single bond | 3 | 3 | 1,0 |
| Acetate | 3 | 3 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Nitrogen heterocycle | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 0,8 |
| Phosphate (PO4) | 1 | 1 | 0,8 |
Rangs atspoguļo uzkrātos literatūras pierādījumus, nevis vienu autoritatīvu noteikumu. Vienmēr apstipriniet atbilstoši parauga kontekstam.
Possible materials
| Materiāls | Atbalstošie pīķi | Overlapping groups | Citētie avoti |
|---|---|---|---|
| cellulose | 1281, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 2 |
| montmorillonite | 1281, 1637, 523 | Methacrylate, Acetate | 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 1281 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.
Literatūra aiz šiem piešķīrumiem
-
Alkyl C-H pārliecība 1,0
“20 C-O stretching vibration 1107,1053,1031 Control cm-1 C-H bending in cellulose and hemicelluloses 895-899 0 cm-1 3900 3400 2900 2400 1900 1400 900 400 CH2 vibrations 1281”
A Microscopic Study of Paper Decayed by Trichoderma harzianum and Paecilomyces variotii DOI: 10.1007/s10924-017-1147-6 -
Acetate pārliecība 1,0
“cm-1 stretching) present in hemicellulose composent, 1639 (frequency of deformation cm-1 cm-1 vibration of CH and CH groups are located), 1371 (C-H band),1318 (CH 2 cm-1 bending mode), 1281 (C-O stretching mode of ester group) stretch of th”
Boudjema 等 - 2020 - Green composites based on Atriplex halimus fibers DOI: 10.1515/polyeng-2020-0068 -
Amide pārliecība 1,0
“(C-O stretch of ester) disaphemihydrate (methoxyl group) and 1229 peared,andthepeaksat1281,1097,1009and925cm-1assigned As the temperature of the sample was increased, all the to C-N and lactam ring stretchings of DKP gradually apFTIR spectr”
Non-isothermal dehydration kinetic study of aspartame hemihydrate using DSC, TGA and DSC-FTIR microspectroscopy DOI: 10.1016/j.ajps.2017.12.001 -
pārliecība 1,0
“The band at 1281 (cid:4)(CH), is assigned to pyridine in-plane deformation while the 3.3.”
Adsorption of picloram herbicide on montmorillonite: Kinetic and equilibrium studies DOI: 10.1016/j.colsurfa.2014.02.038 -
Amide pārliecība 1,0
“For the amide III bands there are in the scanned FTIR spectrum, is that the intensity of two bands assigned at 1241 and 1281 cm-1.”
Radev 等 - 2009 - OrganicInorganic bioactive materials Part II in DOI: 10.2478/s11532-009-0076-1 -
Acetate pārliecība 1,0
“Castor oil showed a wide 430 band at 3450 cm-1 for hydroxyl groups, 2920 and 2850 cm-1 for CH2 and CH3 scissoring, 1743 cm-1 for 431 C-O ester groups, 1711 cm-1 for the stretching of C-O in free fatty acids, 1281 cm-1 for asymmetric C-O 432”
Vazquez-Gonzalez 等 - 2021 - Electrosprayed cashew gum microparticles for the e DOI: 10.1016/j.carbpol.2016.08.031 -
Alkyl C-H pārliecība 1,0
“In cm-1), addition, bands corresponding to C-H bending vibration (1371 to O-H or C-H cm-1) cm-1) bending vibration (1281 in arabinoxylan, to C-O stretching vibration (1032 in cm-1) the cellulose, and to β-glycosidic linkage (893 connecting”
Wang 等 - 2021 - Molecular Structure of Poplar Lignin Obtained by p DOI: 10.3390/ijms19020428 -
Phosphate (PO4) pārliecība 0,8
“Asymmetric stretching vibrations of PO groups (Q2 structural units)”
El-Hezzat 等 - 2021 - Structure - Properties study of Na2O-CaO-PbO-P2O5 DOI: 10.1016/j.solidstatesciences.2021.106666
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