What absorbs at 3120 cm⁻¹ in an FTIR spectrum?
A band near 3120 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 7 cited sources
Snabbt svar
A band near 3120 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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| Hydroxyl (O-H) | 3 | 2 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Möjliga material
| Material | Stödjande toppar | Överlappande grupper | Citerade källor |
|---|---|---|---|
| polyurethane | 3120, 2270, 1700 | Alkyl C-H, Methacrylate, N h | 1 |
| polysaccharide | 3120, 1637, 1320 | Methacrylate, Hydroxyl (O-H), Alkyl C-H | 1 |
| PANI | 3120, 2930, 1300 | Alkyl C-H, N h | 1 |
Material visas endast när samma litteraturpool stöder detta band och minst en ytterligare karakteristisk topp.
Spektrumlogik
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 3120 cm⁻¹ is usually not enough for material identification by itself.
Användning i verkligheten
Denna typ av fråga är vanlig inom polymeridentifiering, screening av okänd plast, felsökning av kvalitetskontroll, verifiering av återvunnet material och litteraturstödd toppidentifieringsgranskning.
Vanliga misstag
- Behandla ett isolerat band som bevis på ett material utan att kontrollera minst en eller två stödjande toppar.
- Ignorerar överlapp: flera funktionella grupper kan bidra nära samma vågtal.
- Hoppa över validering när tillsatser, blandningar, oxidation eller föroreningar kan förvränga spektrat.
Verifieringsråd
När oklarhet kvarstår, validera hypotesen med DSC, GC-MS eller TGA, särskilt för blandningar, nedbrutna prover och fyllda polymerer.
Litteratur bakom dessa identifieringar
-
Secondary amine förtroende 1,0
“The N-H) of the thioamide and amide can be observed at asymmetric stretching vibration of the secondary amine (ν 3177cm-1 3120cm-1 and respectively.”
Adan 等 - 2014 - Synthesis, Characterization and Antibacterial Stud DOI: 10.1063/1.4895199 -
Hydroxyl (O-H) förtroende 1,0
“The vibrational bands at between between 3680 cm-1 and 3120 cm-1 are due to O-H and N-H stretching and can be attributed to cm-1 cm-1 between 3680 cm-1 and 3120 cm-1 are due to O-H and N-H stretching and can be attributed to 3680 and 3120 a”
Self-Healable Supramolecular Vanadium Pentoxide Reinforced Polydimethylsiloxane-Graft- Polyurethane Composites DOI: 10.3390/polym11010041 -
Hydroxyl (O-H) förtroende 1,0
“cm(cid:3)1 3000-3550 467 In the range, a strong and wide -OH absorption band can be seen, which corresponds to stretchingvibrations.Thepeaksat3120and2980cm(cid:3)1thatcan be observed in Fig.”
Synthesis and characterization of a novel ruthenium(ii) trisbipyridine complex magnetic nanocomposite for the selective oxidation of phenols DOI: 10.1039/c9ra05079e -
Acetate förtroende 1,0
“The asymmetric and symmetric stretching CH3 C=O stretching of CH group and band vibrations were found at 3120 and 1670-1665 3”
Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR) and Artificial Neural Networks Applied to Investigate Quantitative Changes of Selected Soluble Biomarkers, Correlated with H. pylori Infection in Children and Presumable Consequent Delayed Growth DOI: 10.3390/jcm9123852 -
Alkyl C-H förtroende 1,0
“LLM confirmed rule peak-group candidate”
Mucilage from Yellow Pitahaya (Selenicereus megalanthus)Fruit Peel: Extraction, Proximal Analysis, and Molecular Characterization DOI: 10.3390/molecules28020786 -
förtroende 1,0
“The 3409cm-1 3120cm-1 1614cm-1 the peaks at peak at and are attributed to Nrepresents the N-H bend vibration.”
Zhu 等 - 2013 - Electrochemical Properties of PANI as Single Elect DOI: 10.1155/2013/940153 -
förtroende 0,8
“Observed band assigned to C-H.”
Density Functional Theory and Molecular Docking Investigations of the Chemical and Antibacterial Activities for 1-(4-Hydroxyphenyl)-3-phenylprop-2-en-1-one DOI: 10.3390/molecules26123631
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