What absorbs at 1998 cm⁻¹ in an FTIR spectrum?
A band near 1998 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 4 cited sources
Quick answer
A band near 1998 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.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Amide | 2 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Protein | 1 | 0 | 1,0 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
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 1998 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.
Литература, лежащая в основе этих назначений
-
Metal oxygen достоверность 1,0
“The set of vibrational bands cm-1 below 1,000 are characteristic vibrations of W-O Table 1 Raman wave numbers of the products bands (Burcham and Wachs 1998).”
Peter 和 Banu - 2014 - Synthesis and luminescent properties of Tb3+ activ DOI: 10.1007/s10854-014-1941-z -
Ester достоверность 1,0
“cm(cid:3)1 (cid:2)1732 plant leaves the feature arises from methyl- (cid:2)1428, show chemical images under the area at 1371 and et al., esterified pectins, not just lipid in cereal grain (Wetzel cm(cid:3)1, revealing the ultra-spatial dist”
Microprobing the molecular spatial distribution and structural architecture of feed-type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique DOI: 10.1107/S0909049511023727 -
Amide достоверность 1,0
“Cohenford and Rigas, cm(cid:2)1) ((cid:3)1540 and the centroid position of the amide II band 1998;”
Monitoring Cell Cycle Distributions in MCF-7 Cells Using Near-Field Photothermal Microspectroscopy DOI: 10.1529/biophysj.104.053926 -
Alkyl C-H достоверность 1,0
“1315 peak can be Davis MW (1998) A rapid modified method for compositional carbohydrate analysis of lignocellulose by high pH anioninfluenced by the CH wagging band of the cellulose at”
Watanabe 等 - 2012 - Spectroscopic investigation of tissue-specific bio DOI: 10.5511/plantbiotechnology.12.0222a
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