What absorbs at 2949 cm⁻¹ in an FTIR spectrum?
A band near 2949 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
Mabilis na sagot
A band near 2949 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.
Mga posibleng pagtatalaga ng functional-group
| Grupong functional | Mga sumusuportang katotohanan | Mga nasiping sanggunian | Pinakamataas na kumpiyansa |
|---|---|---|---|
| Alkyl C-H | 12 | 11 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 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 |
Ang pagraranggo ay sumasalamin sa naipon na ebidensya ng literatura, hindi isang solong awtoritatibong tuntunin. Palaging kumpirmahin laban sa konteksto ng iyong sample.
Mga posibleng materyales
| Materyal | Sumusuportang mga peak | Mga overlapping na grupo | Mga nasiping sanggunian |
|---|---|---|---|
| lignin | 2949, 1035, 1510 | Alkyl C-H, Methacrylate, Acetate | 1 |
| polypropylene | 2949, 1030, 1600 | Alkyl C-H, Methacrylate, Acetate | 1 |
| silver nanoparticles | 2949, 1636, 1631 | Alkyl C-H, Methacrylate, Acetate | 1 |
Ang mga materyales ay ipinapakita lamang kapag ang parehong literatura pool ay sumusuporta sa banda na ito at hindi bababa sa isang karagdagang katangian na tuktok.
Logic ng spectrum
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 2949 cm⁻¹ is usually not enough for material identification by itself.
Paggamit sa totoong mundo
Ang uri ng query na ito ay karaniwan sa pagtukoy ng polymer, screening ng hindi kilalang plastic, pag-troubleshoot ng QC, pag-verify ng recycled na materyal, at pagsusuri ng pagtatalaga ng peak na may suporta ng literatura.
Mga karaniwang pagkakamali
- Pagtrato sa isang nakahiwalay na banda bilang patunay ng isang materyal nang hindi sinusuri ang hindi bababa sa isa o dalawang sumusuportang peak.
- Hindi pinapansin ang overlap: maraming functional group ang maaaring mag-ambag malapit sa parehong wavenumber.
- Pag-laktaw sa pagpapatunay kapag ang mga additives, blends, oxidation, o contamination ay maaaring mag-distort ng spectrum.
Payo sa pagpapatunay
Kapag nananatili ang kalabuan, patunayan ang hypothesis gamit ang DSC, GC-MS, o TGA, lalo na para sa mga blend, degraded na sample, at filled polymers.
Literatura sa likod ng mga pagtatalagang ito
-
Alkyl C-H kumpiyansa 1.0
“(+) -CH3 2977 2977 stretching of (-) (-) C-H 2949 2956 2947 2954 2931 2931 antisymmetric (+)”
Maeda - 2001 - IR spectroscopic study on the hydration and the ph DOI: 10.1021/la001346q -
Alkyl C-H kumpiyansa 1.0
“The bands at 2949 and 2992 were also observed and were found to have characteristics of C-H stretching vibration of”
Pathak 等 - 2020 - Attenuation of hepatic and breast cancer cells by DOI: 10.1016/j.bcab.2020.101863 -
Alkyl C-H kumpiyansa 1.0
“LLM confirmed rule peak-group candidate”
Alassod 等 - 2021 - PolypropyleneLigninPOSS Nanocomposites Thermal DOI: 10.3390/ma14143950 -
Alkyl C-H kumpiyansa 1.0
“explicit assignment in text”
Antifungal efficiency and cytocompatibility of polymethyl methacrylate modified with zinc dimethacrylate DOI: 10.3389/fcimb.2023.1138588 -
Alkyl C-H kumpiyansa 1.0
“that the present hydrogen binding functional groups nm.[20] Germany) to measure the absorbance at 570 cm-1, of methyl (C-H) stretch at 2949 methylene (C-H) cm-1, cm-1, cm-1.”
Hamdoon 等 - 2022 - Evaluation of biofilm formation on different clear DOI: 10.4103/jos.jos_7_22 -
Alkyl C-H kumpiyansa 1.0
“For QU-loaded natural saponite and synthetic saponite aliphatic (C-H) band vibration are shown at 2340 cm-1 and 2949 cm-1.”
Kumaresan 等 - 2019 - Synthesis of Saponite Based Nanocomposites to Impr DOI: 10.3390/ph12030105 -
Alkyl C-H kumpiyansa 1.0
“2014;Corazzarietal.,2015).Finally,thebandsofamideI,II and III, which are typical of chitosan, are observed at 1650, 1590and1317cm-1,respectively(Brancaetal.,2016).The CH/PCL FTIR spectra obtained with the mixtures showed cm-1 bands at 2949”
Nunez-Gastelum 等 - 2019 - SCREENING OF THE PHYSICAL AND STRUCTURAL PROPERTIE DOI: 10.24275/uam/izt/dcbi/revmexingquim/2019v18n1/Nunez -
Alkyl C-H kumpiyansa 1.0
“LLM confirmed rule peak-group candidate”
Bacterial Biofilm Formation Using PCL/Curcumin Electrospun Fibers and Its Potential Use for Biotechnological Applications DOI: 10.3390/ma13235556
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