What absorbs at 1309 cm⁻¹ in an FTIR spectrum?
A band near 1309 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 1309 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.
Possibili assegnazioni di gruppi funzionali
| Gruppo funzionale | Fatti di supporto | Fonti citate | Affidabilità massima |
|---|---|---|---|
| Amide | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| Protein alpha helix | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Protein | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Oxalate | 1 | 1 | 0,9 |
La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.
Possible materials
| Materiale | Picchi di supporto | Overlapping groups | Fonti citate |
|---|---|---|---|
| polyurethane | 1309, 2270, 1700 | Methacrylate, Acetate, Amide | 1 |
| polyester | 1309, 1700, 1250 | Methacrylate, Acetate, Amide | 1 |
| blood | 1309, 2965, 1117 | Amide, Hydroxyl (O-H), Methacrylate | 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 1309 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.
Letteratura dietro queste assegnazioni
-
Hydroxyl (O-H) affidabilità 1,0
“The band around 1309 could cm-1, be due to aryl OH deformations while 1284 and 1191 which were among the strongest peaks in the spectra, may be due to C-O stretching vibrations.”
Synthesis, crystal structures, quantum chemical studies and corrosion inhibition potentials of 4-(((4-ethylphenyl)imino)methyl)phenol and (E)-4-((naphthalen-2-ylimino) methyl) phenol Schiff bases DOI: 10.1016/j.molstruc.2017.06.104 -
Amide affidabilità 1,0
“(cm-1), samples, additional peaks were observed at 1309 and 1240 which were attributed to amide III (C-N stretching mode of proteins).”
Low-Vacuum Filtration as an Alternative Extracellular Vesicle Concentration Method: A Comparison with Ultracentrifugation and Differential Centrifugation DOI: 10.3390/pharmaceutics12090872 -
C c single bond affidabilità 1,0
“cm-1 cm-1, FTIR spectra display intense absorption bands at 1309 and 1308 respectively ν(C-C) (Figure 3b,c), which are related to the coupled vibrations of the ring and the carν(C=O), δ(C-H) δ(C-OH) bonyl together with the contribution from”
Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks DOI: 10.3390/molecules27010279 -
Alkyl C-H affidabilità 1,0
“The peaks at 1309 1166 and 1082 reflected the CH bending, Biomolecules2022,12,1815 6of15 PO2C-O-C stretching and stretching vibrations, respectively, linked to the characteristics”
Fast and Deep Diagnosis Using Blood-Based ATR-FTIR Spectroscopy for Digestive Tract Cancers DOI: 10.3390/biom12121815 -
Acetate affidabilità 1,0
“2 article cm(cid:3)1 cm(cid:3)1 (C-O (C-O-H 1124 namely the twisting or wagging and rocking vibrations, stretch) and 1309 bend) are Article.”
Hydroxylation and self-assembly of colloidal hydrogenated nanodiamonds by aqueous oxygen radicals from atmospheric pressure plasma jet DOI: 10.1039/c8ra07873d -
Protein alpha helix affidabilità 1,0
“The remaining two minor peaks at 1309 and 1247 demonstrate the C-N 2 stretching of proteins, referring to the α-helical conformation of amide III peak.”
Extracellular vesicles derived from microgreens of Raphanus sativus L. var. caudatus Alef contain bioactive macromolecules and inhibit HCT116 cells proliferation DOI: 10.1038/s41598-022-19950-7 -
Oxalate affidabilità 0,9
“Aqueous oxalate species peak.”
Yoon 等 - 2004 - Adsorption of organic matter at mineralwater inte DOI: 10.1016/j.gca.2004.04.025 -
Carbonyl (C=O) affidabilità 0,7
“Explicit assignment: '1309 (C=O' (likely C=O related).”
ATR-FTIR Analysis of Orthodontic Invisalign® Aligners Subjected to Various In Vitro Aging Treatments DOI: 10.3390/ma14040818
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