What absorbs at 1491 cm⁻¹ in an FTIR spectrum?
A band near 1491 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
Hiter odgovor
A band near 1491 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.
Možne dodelitve funkcionalnih skupin
| Funkcionalna skupina | Podporna dejstva | Citirani viri | Najvišje zaupanje |
|---|---|---|---|
| Aromatic ring | 5 | 5 | 1,0 |
| Carboxyl (COOH) | 3 | 2 | 1,0 |
| Alkene (C=C) | 2 | 2 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
Razvrstitev odraža zbrane literaturne dokaze, ne enega avtoritativnega pravila. Vedno preverite glede na kontekst vašega vzorca.
Možni materiali
| Material | Podporni vrhovi | Prekrivajoče se skupine | Citirani viri |
|---|---|---|---|
| methylene blue | 1491, 1745, 1739 | Carboxyl (COOH) | 1 |
| HCl | 1491, 1708, 1032 | Aromatic ring | 1 |
Materiali so prikazani le, ko ista literaturna podlaga podpira ta pas in vsaj en dodatni karakteristični vrh.
Logika spektra
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 1491 cm⁻¹ is usually not enough for material identification by itself.
Uporaba v resničnem svetu
Ta vrsta poizvedbe je pogosta pri identifikaciji polimerov, pregledovanju neznanih plastičnih mas, odpravljanju težav pri QC, preverjanju recikliranih materialov in literaturno podprtem pregledu dodelitev vrhov.
Pogoste napake
- Obravnavanje enega izoliranega pasu kot dokaza o materialu brez preverjanja vsaj enega ali dveh podpornih vrhov.
- Ignoriranje prekrivanja: več funkcionalnih skupin lahko prispeva blizu istega valovnega števila.
- Izpuščanje validacije, ko lahko dodatki, mešanice, oksidacija ali kontaminacija popačijo spekter.
Nasvet za preverjanje
Ko ostaja dvoumnost, potrdite hipotezo z DSC, GC-MS ali TGA, zlasti za mešanice, degradirane vzorce in polnjene polimere.
Literatura za temi dodelitvami
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Aromatic ring zaupanje 1,0
“The peak areas at 1491 and cm-' decreased rapidly, due to the [Nipissing transformation or degradation of the aromatic rings, and the cleavage of the -C-Nof the imide groups, respectively.”
Ha 等 - 2001 - Spectroscopic stuides on the liquid crystal alignm DOI: 10.1080/10587250108028259 -
Aromatic ring zaupanje 1,0
“The FTIR spectrum of the control dye also showed a large band at 1491 cm-1 corresponding to the aromatic stretching vibration of the C=C (Foo et al.”
Biodegradation of Methylene Blue as an Evidence of Synthetic Dyes Mineralization during Textile Effluent Biotreatment by Acinetobacter pittii DOI: 10.1007/s40710-020-00443-6 -
Acetate zaupanje 1,0
“In addition, two bands were observed at 1491 and 1388 that corresponds to C=O stretching and C-C stretching of alkanes respectively.”
Ecotoxicity of Musa paradisiaca leaf extract-coated ZnO nanoparticles to the freshwater microcrustacean Ceriodaphnia cornuta DOI: 10.1016/j.limno.2017.09.004 -
Aromatic ring zaupanje 1,0
“cm-1 [ν(N-H)], to the stretching vibration the band at 1637 cm-1 CO [ν(CO)], stretching vibration the band at 1569 to the quinonoid ring-stretching vibration, the bands at 1505 cm-1 to the benzenoid ring-stretching vibrations, the and 149”
Blaha 等 - 2019 - Role of p-Benzoquinone in the Synthesis of a Condu DOI: 10.1021/acsomega.9b00542 -
Aromatic ring zaupanje 1,0
“FTIR spectra 1600 (typical aromatic skeletal vibration), 1491 (disubstituted benzene ring), 1222 (antisymmetric C-O-C stretching vibration), 934 (O-C vibration 2 in the oxazine ring with a minor contribution from the phenolic ring), 753 (Ar”
Developing Further Versatility in Benzoxazine Synthesis via Hydrolytic Ring-Opening DOI: 10.3390/polym12030694 -
Aromatic ring zaupanje 1,0
“The crystallographic data perspectrum displayed absorption bands at 1491 and refinement 1 taining to crystal structure solution and are given corresponding to the aromatic C=C group while at 1294”
Sadia 等 - 2020 - Schiff-Based Fluorescent-ON Sensor L Synthesis and DOI: 10.1155/2020/2192584 -
Carboxyl (COOH) zaupanje 1,0
“The peaks at 1549 and a cm-1 small peak 1491 are due to the asymmetric and symmetric stretching modes of carboxylic acid, respectively [32].”
Thabede 等 - 2023 - Synthesis of lanthanum metal organic framework usi DOI: 10.15251/DJNB.2023.181.157 -
zaupanje 0,8
“Significant peaks of PAni due to C=C ring stretching.”
Applications of chitosan (CHI)-reduced graphene oxide (rGO)-polyaniline (PAni) conducting composite electrode for energy generation in glucose biofuel cell DOI: 10.1038/s41598-020-67253-6
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