What absorbs at 1145 cm⁻¹ in an FTIR spectrum?
A band near 1145 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
Quick answer
A band near 1145 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.
Possíveis atribuições de grupos funcionais
| Grupo funcional | Fatos de suporte | Fontes citadas | Maior confiança |
|---|---|---|---|
| C-O single bond | 18 | 18 | 1,0 |
| Methoxy (OCH3) | 17 | 17 | 1,0 |
| Methacrylate | 17 | 17 | 1,0 |
| Acetate | 17 | 17 | 1,0 |
| Amide | 4 | 4 | 1,0 |
| Secondary amine | 3 | 3 | 1,0 |
| C n single bond | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Alkyl C-H | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Alkene (C=C) | 2 | 2 | 1,0 |
| S eq o | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Lignin | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| C=n | 1 | 1 | 1,0 |
| Chitosan | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Phospholipid | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.
Possible materials
| Material | Picos de suporte | Overlapping groups | Fontes citadas |
|---|---|---|---|
| PMMA | 1145, 1722, 1383 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
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 1145 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literatura por trás destas atribuições
-
Acetate confiança 1,0
“Zhou, Limin Wu, Polymer 122-129 4 C-O stretching vibrations 1145 (2011).”
Kumar 和 Sidhu - 2013 - Synthesis and Characterization of PMMA-ZrO2 Nanoco DOI: 10.1063/1.4810163 -
Amide confiança 1,0
“stretching (1534 and 1381 C-O and C-N stretching (1145 and 1013 The RA-CPTMS/TiO composite 2 materials showed both characteristic peaks of TiO and the red amaranth extract, indicating the successful 2”
Kurniawan 等 - 2019 - Selective Betalain Impregnation from Red Amaranth DOI: 10.1063/1.5134613 -
Aromatic ring confiança 1,0
“The 1145cm-1 1080cm-1 absorption peak at and corresponded to the benzene ring =C-H bending vibration 916cm-1 in the plane.”
Li 等 - 2011 - The detection of Cypermethrin on the surface of Ap DOI: 10.4028/www.scientific.net/AMR.287-290.2991 -
Acetate confiança 1,0
“In the glycerol cm(cid:1)1 spectra, the peak intensities at about 1145 and 962 are responsible for C-O stretching [27].”
Interactions between polyols and wheat biopolymers in a bread model system fortified with inulin: A Fourier transform infrared study DOI: 10.1016/j.heliyon.2018. -
Phosphate (PO4) confiança 1,0
“Peaks formed at 1145 cm-1 might also be due to the PO2 group vibration of the phospholipids present in the cold pressed walnut oil.”
Walnut Oil Oleogels as Milk Fat Replacing System for Commercially Available Chocolate Butter DOI: 10.3390/gels8100613 -
Acetate confiança 1,0
“Three -C-O-Cpeaks appear at 1145, 1116, and cm-1, ular segments.”
Yang 等 - 2015 - Effect of molecular weight on conformational chang DOI: 10.1007/s10853-014-8714-1 -
Water (H2O) confiança 1,0
“Therefore, the peak position at 1145 of between SO and water molecules are only slightly weaker 42V the band of SO may be related to MgSO gels present as than those between water molecules, the formation of SIPs (and”
Zhao 等 - 2006 - Magnesium sulfate aerosols studied by FTIR spectro DOI: 10.1021/jp055291i -
Amide confiança 1,0
“[46], the peak at 1145 the amide band that accounts for the peak at 1236 cm-1[45].”
Antibacterial Activity of the Green Synthesized Plasmonic Silver Nanoparticles with Crystalline Structure against Gram-Positive and Gram-Negative Bacteria DOI: 10.3390/nano13081327
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