What absorbs at 2000 cm⁻¹ in an FTIR spectrum?
A band near 2000 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
Snabbt svar
A band near 2000 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 |
|---|---|---|---|
| Silicon hydride | 11 | 7 | 1,0 |
| Alkyl C-H | 8 | 7 | 1,0 |
| Silicon (Si) | 7 | 6 | 1,0 |
| Amide | 6 | 5 | 1,0 |
| Methacrylate | 6 | 5 | 1,0 |
| Acetate | 6 | 5 | 1,0 |
| Methoxy (OCH3) | 5 | 4 | 1,0 |
| Adsorbed carbon monoxide | 5 | 3 | 1,0 |
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| Carbonyl (C=O) | 4 | 4 | 1,0 |
| C-O single bond | 4 | 3 | 1,0 |
| Alkene (C=C) | 3 | 3 | 1,0 |
| Silicon-oxygen (Si-O) | 3 | 3 | 1,0 |
| Hydrogen bond | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Water (H2O) | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| C n single bond | 2 | 2 | 1,0 |
| Silicon silicon | 2 | 2 | 1,0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1,0 |
| Phosphate (PO4) | 2 | 2 | 1,0 |
| C c single bond | 2 | 2 | 1,0 |
| Methyl | 2 | 2 | 1,0 |
| N-O bond | 2 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| Lipid | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Carbon dioxide | 1 | 1 | 1,0 |
| Borate | 1 | 1 | 1,0 |
| Silicate | 1 | 1 | 1,0 |
| C=n | 1 | 1 | 0,5 |
| Protein | 1 | 0 | 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 |
|---|---|---|---|
| honey | 2000, 2005, 1199 | Alkyl C-H, Amide | 1 |
| apatite | 2000, 3053, 1640 | Amide, Alkyl C-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 2000 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
-
C c single bond förtroende 1,0
“and a weak D peak near 1320 FTIR plot of DLC films shows a peak 1550 cm-1 corresponding to C-H stretching mode and peaks below 2000 near 2900 corresponding to C-C modes and C-H bending modes.”
DEPOSITION OF WIDE BAND GAP DLC FILMS USING R.F. PECVD AT VERY LOW POWER DOI: 10.1142/S0217979211100102 -
Carbonyl (C=O) förtroende 1,0
“Strong absorption band at cm(cid:1)1 1742 is a sign of the stretching of the ester carbonyl 2000 C--O group and indication to the acetylation of starch [4].”
Microwave assisted acetylation of mung bean starch and the catalytic activity of potassium carbonate in freesolvent reaction DOI: 10.1002/star.201200081 -
Amide förtroende 1,0
“The peak amounts (Gallardo-Velazquez, Osorio-Revilla, Loa, & 1547cm(cid:3)1 resulted from N-H bending and observed at Rivera-Espinoza, 2009) The band which varied between 1700cm(cid:3)1 C-N stretching vibrations of Amide II (Coates, 2000;”
Cebi 等 - 2020 - An evaluation of FTIR spectroscopy for prediction DOI: 10.1080/00218839.2019.1707009 -
Hydrogen bond förtroende 1,0
“characteristically assigned to another form of bending The lowering of the frequency tends to be a function of the degree and strength of the hydrogen bonding vibration, the out-of-plane bend or wagging vibration of (Coates, 2000).”
Chik 等 - 2011 - Predicting group of metabolites available in parti DOI: 10.5897/AJB11.2736 -
Phosphate (PO4) förtroende 1,0
“The bands at ~2000 are due to overtones of PO 4.”
Clark 等 - 2016 - Quantification of CO2 concentration in apatite DOI: 10.2138/am-2016-5661 -
Alkyl C-H förtroende 1,0
“2011), and changes in the relative importance of lignin methoxyl groups for which the CH stretching 3 vibrations have lower CH stretching frequencies (Coates 2000).”
Esteves 等 - 2013 - CHEMICAL CHANGES OF HEAT TREATED PINE AND EUCALYPT DOI: 10.4067/S0718-221X2013005000020 -
förtroende 1,0
“For example, cm-1 the peak at 2000 is a combination of Si-O-Si stretch-”
Han 和 Aydil - 1997 - Structure and chemical composition of fluorinated DOI: 10.1116/1.580845 -
Silicon (Si) förtroende 1,0
“cm-1-2100 cm-1 3) the peak centered at 2000 due to the Si-H stretching modes;”
Hou 等 - 2011 - Evolution of infrared spectra and optical emission DOI: 10.1088/1674-1056/20/7/077802
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