What absorbs at 1271 cm⁻¹ in an FTIR spectrum?
A band near 1271 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
Mabilis na sagot
A band near 1271 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.
Mga posibleng pagtatalaga ng functional-group
| Grupong functional | Mga sumusuportang katotohanan | Mga nasiping sanggunian | Pinakamataas na kumpiyansa |
|---|---|---|---|
| C-O single bond | 5 | 4 | 1.0 |
| Methoxy (OCH3) | 4 | 3 | 1.0 |
| Methacrylate | 4 | 3 | 1.0 |
| Acetate | 4 | 3 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
Ang pagraranggo ay sumasalamin sa naipon na ebidensya ng literatura, hindi isang solong awtoritatibong tuntunin. Palaging kumpirmahin laban sa konteksto ng iyong sample.
Mga posibleng materyales
| Materyal | Sumusuportang mga peak | Mga overlapping na grupo | Mga nasiping sanggunian |
|---|---|---|---|
| polyimide | 1271, 1720, 1778 | Methacrylate, Acetate | 1 |
| PVC | 1271, 834, 1195 | Methoxy (OCH3), Methacrylate, Acetate | 1 |
| cellulose | 1271, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 1 |
| HDPE | 1271, 1369, 1216 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
Ang mga materyales ay ipinapakita lamang kapag ang parehong literatura pool ay sumusuporta sa banda na ito at hindi bababa sa isang karagdagang katangian na tuktok.
Logic ng spectrum
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 1271 cm⁻¹ is usually not enough for material identification by itself.
Paggamit sa totoong mundo
Ang uri ng query na ito ay karaniwan sa pagtukoy ng polymer, screening ng hindi kilalang plastic, pag-troubleshoot ng QC, pag-verify ng recycled na materyal, at pagsusuri ng pagtatalaga ng peak na may suporta ng literatura.
Mga karaniwang pagkakamali
- Pagtrato sa isang nakahiwalay na banda bilang patunay ng isang materyal nang hindi sinusuri ang hindi bababa sa isa o dalawang sumusuportang peak.
- Hindi pinapansin ang overlap: maraming functional group ang maaaring mag-ambag malapit sa parehong wavenumber.
- Pag-laktaw sa pagpapatunay kapag ang mga additives, blends, oxidation, o contamination ay maaaring mag-distort ng spectrum.
Payo sa pagpapatunay
Kapag nananatili ang kalabuan, patunayan ang hypothesis gamit ang DSC, GC-MS, o TGA, lalo na para sa mga blend, degraded na sample, at filled polymers.
Literatura sa likod ng mga pagtatalagang ito
-
Lignin kumpiyansa 1.0
“The most characteristic vibrations of lignin correspond to thoseofaromaticringsatapproximately1599and1509cm(cid:2)1.Thetypicalbandsassignedto identifiedat1271and1216cm(cid:2)1(guaiacylringbreathing) guaiacyl(G)moietieswere and cm(cid:2)1 cm”
Synthesis and characterization of lignin–melamine–formaldehyde resin DOI: 10.1177/0892705716632856 -
Hydroxyl (O-H) kumpiyansa 1.0
“The peak at about 1271 and 3478 were due in CP2, TP1, to OH stretching vibration of free acid groups and N-H TP2 and TP3 was assigned to C-F vibration.”
Purushothaman 和 Bilal - 2014 - Development and characterization of homo, co and t DOI: 10.1515/polyeng-2013-0167 -
Acetate kumpiyansa 1.0
“(10/90) 10/90 6/94 0.18 cm-1, teristic of ester groups, and another typical band at 1271 assigned to the C-O-C (20/80)”
Isosorbide and 2,5-Furandicarboxylic Acid Based (Co)Polyesters: Synthesis, Characterization, and Environmental Degradation DOI: 10.3390/polym14183868 -
Acetate kumpiyansa 1.0
“The band at 1123 cm-1 corresponds to planar cm-1 at 1327 belongs to the skeletal vibrations of the syringyl ring with the C-O stretching bending vibrations of the C-H syringyl aromatic rings, and the C-O stretching vibrations bands around 1”
An Efficient Method of Birch Ethanol Lignin Sulfation with a Sulfaic Acid-Urea Mixture DOI: 10.3390/molecules27196356 -
Ester kumpiyansa 1.0
“Furthermore, the bands at cm-1 cm-1 cm-1 1271 and 1724 are characteristic of the ester group and the band at 729 represents the cm-1 aromatic ring of the phthalate group [37].”
Nolasco 等 - 2022 - Morphology, Chemical Characterization and Sources DOI: 10.21203/rs.3.rs-1166452/v1 -
Acetate kumpiyansa 1.0
“the C-O stretching vibration peak at 1271 and cm-1, the aromatic skeleton (=C-H) stretching vibration at 3000-3020 which was coincided with decrease of O and H”
Xu 和 Li - 2017 - Effect of High-pressure on Pine Sawdust Pyrolysis DOI: 10.1063/1.4992933 -
kumpiyansa 0.9
“Explicit assignment: '1271 (s, ester stretch C-O)'”
Rezende 等 - 2020 - Efficient internal plasticization of poly(vinyl ch DOI: 10.1016/j.polymer.2020.122473 -
C-O single bond kumpiyansa 0.7
“Band at approx. 1271 cm-1 assigned to C-C(=O)-O.”
Chemometric approach to characterization of the selected grape seed oils based on their fatty acids composition and FTIR spectroscopy DOI: 10.1038/s41598-021-98763-6
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