What absorbs at 2991 cm⁻¹ in an FTIR spectrum?
A band near 2991 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
Stutt svar
A band near 2991 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.
Mögulegar úthlutun virkra hópa
Röðun endurspeglar uppsöfnuð ritrýnisgögn, ekki eina valdboðsreglu. Staðfestu alltaf í samhengi við sýnið þitt.
Möguleg efni
| Efni | Stuðningstindar | Skarast hópar | Tilvitnuð heimildir |
|---|---|---|---|
| TiO | 2991, 1730, 1699 | Alkyl C-H | 1 |
| rGO | 2991, 2358, 2930 | Alkyl C-H | 1 |
| PLA | 2991, 1650, 1073 | Alkyl C-H | 1 |
| PEG | 2991, 1650, 1342 | Alkyl C-H | 1 |
| PLLA | 2991, 1182, 921 | Alkyl C-H, Methyl | 1 |
Efni birtast aðeins þegar sama bókmenntasafn styður þessa band og að minnsta kosti einn viðbótar einkennandi hámark.
Rófrök
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 2991 cm⁻¹ is usually not enough for material identification by itself.
Raunveruleg notkun
Þessi tegund fyrirspurna er algeng við auðkenningu fjölliða, skimun óþekktra plasttegunda, bilanaleit í gæðaeftirliti, staðfestingu endurunnins efnis og bókmenntabakkaða endurskoðun á hápunktum.
Algeng mistök
- Meðhöndla eina einangraða öldulengd sem sönnun á efni án þess að athuga að minnsta kosti einn eða tvo stuðningstoppa.
- Hunsa skörun: mörg virkir hópar geta lagt sitt af mörkum nálægt sömu bylgjutölunni.
- Að sleppa staðfestingu þegar aukefni, blöndur, oxun eða mengun geta brenglað litrófið.
Staðfestingarráðgjöf
Þegar tvíræðni er eftir, staðfestu tilgátuna með DSC, GC-MS eða TGA, sérstaklega fyrir blöndur, niðurbrotin sýni og fylltar fjölliður.
Ritlist á bak við þessar úthlutanir
-
Alkyl C-H öryggi 1,0
“The two cm-1 bands at 2991 and 2948 can be attributed to the C-H bond stretching vibrations of the -CH and”
Awad 等 - 2020 - Experimental Investigation of Methyl Methacrylate DOI: 10.3390/ma13245793 -
Alkyl C-H öryggi 1,0
“LLM confirmed rule peak-group candidate”
Structural and Surface Compatibility Study of Modified Electrospun Poly(ε-caprolactone) (PCL) Composites for Skin Tissue Engineering DOI: 10.1208/s12249-016-0500-8 -
Alkyl C-H öryggi 1,0
“The characteristic band at 2991 cm-1 to 2976 cm-1 cm-1 cm-1 (C=C 2976 corresponds to C-H stretching vibrations, 1652 skeletal vibration), 1521”
Complex Permittivity and Electromagnetic Interference Shielding Effectiveness of OPEFB Fiber-Polylactic Acid Filled with Reduced Graphene Oxide DOI: 10.3390/ma13204602 -
Alkyl C-H öryggi 1,0
“The asymmetric and symmetric C-H stretching (St.) cm1 cm1, of the methyl groups were attributed to the transmission bands at 2991 and 2943 respectively.”
Ragab - 2022 - Improved Physical, thermal, and conductivity stren DOI: 10.21203/rs.3.rs-1514992/v1 -
Alkyl C-H öryggi 1,0
“The bands at 2991 and 2868 which were attributed to various C-H stretching vibrations, had opposite signs on the PC2 and PC3 loading curves.”
Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma DOI: 10.3390/diagnostics11112048 -
Methyl öryggi 0,9
“Explicit assignment: CH3 asymmetric stretching”
Differentiation in MALDI-TOF MS and FTIR spectra between two pathovars of Xanthomonas oryzae DOI: 10.1016/j.saa.2014.06.056 -
Methyl öryggi 0,9
“Explicit assignment: 'absorption peak around 2991 ... stretching vibration peak of CH3'”
Li 等 - 2020 - Effect of molecular weight of polyethylene glycol DOI: 10.1039/d0ra08699a -
Alkyl C-H öryggi 0,8
“Text: 'strong peak at 2991.3 cm-1 (Q is assigned as the center branch) ... R(2) transition of our 5ν C-H'”
Perez-Delgado 和 Manzanares - 2010 - Cavity Ring Down and Fourier Transform Infrared Sp DOI: 10.1021/jp105382p
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