What absorbs at 3649 cm⁻¹ in an FTIR spectrum?
A band near 3649 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 6 cited sources
Hurtigt svar
A band near 3649 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.
Mulige funktionelle gruppetildelinger
| Funktionel gruppe | Understøttende fakta | Citerede kilder | Højeste tillid |
|---|---|---|---|
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| N h | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Acetyl | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| PE | 3649, 1414, 1700 | Methacrylate, Methoxy (OCH3) | 1 |
Materialer vises kun, når den samme litteraturpulje understøtter dette bånd og mindst en yderligere karakteristisk top.
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 3649 cm⁻¹ is usually not enough for material identification by itself.
Anvendelse i virkeligheden
Denne type forespørgsel er almindelig ved polymeridentifikation, screening af ukendt plast, fejlfinding i kvalitetskontrol, verifikation af genanvendt materiale og litteraturunderstøttet gennemgang af peak-tildeling.
Almindelige fejl
- Behandling af et isoleret bånd som bevis på et materiale uden at kontrollere mindst en eller to understøttende toppe.
- Ignorerer overlap: flere funktionelle grupper kan bidrage nær samme bølgetal.
- Spring validering over, når additiver, blandinger, oxidation eller forurening kan forvrænge spektret.
Verifikationsrådgivning
Når tvetydighed fortsat består, valider hypotesen med DSC, GC-MS eller TGA, især for blandinger, nedbrudte prøver og fyldte polymerer.
Litteratur bag disse tildelinger
-
tillid 1,0
“IR peaks at higher ranges, 3380 cm-1 and 3649 cm-1, corresponding to N-H stretching [58], and O-H stretching [56], respectively.”
Thermal Hazard and Smoke Toxicity Assessment of Building Polymers Incorporating TGA and FTIR—Integrated Cone Calorimeter Arrangement DOI: 10.3390/fire5050139 -
Hydroxyl (O-H) tillid 1,0
“3b) such as hydroxyl, Ti-O cm-1, cm-1, films23, υ υ υ υ ethyl, acetyl and ethoxide in the shows stretching's for at 3649 at 3445 CH2,”
Ghann 等 - 2017 - Fabrication, Optimization and Characterization of DOI: 10.1038/srep41470 -
N h tillid 1,0
“Explicit assignment in text”
Fabrication of Chitosan Nanofibers Containing Some Steroidal Compounds as a Drug Delivery System DOI: 10.3390/polym14102094 -
Hydroxyl (O-H) tillid 1,0
“Therefore, the hypothesis emitted in -1 -1 In contrast, IR bands at 3649 cm and 1741 cm correspond to the previous publication [8] suggesting the presence of nodules of the phenol and ester functions of AO completely dissolved into the AO c”
Physico-chemical analysis of a silane-grafted polyethylene stabilised with an excess of Irganox 1076®. Proposal of a microstructural model DOI: 10.1016/j.polymdegradstab.2020.109453 -
Acetate tillid 1,0
“cm-1 cm-1 777 (C-H bending), 1134 1158 1158 (C-O stretching), 3649 and 3662 R2 (O-H stretching)].”
Relationships in Gas Chromatography—Fourier Transform Infrared Spectroscopy—Comprehensive and Multilinear Analysis DOI: 10.3390/separations7020027 -
tillid 0,8
“attributed to O-Si asymmetric stretch”
Sadeghzadeh 和 Zhiani - 2019 - Photooxidation of triarylphosphines under aerobic DOI: 10.1039/c8ra09721f
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