What absorbs at 2993 cm⁻¹ in an FTIR spectrum?
A band near 2993 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 5 cited sources
Quick answer
A band near 2993 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.
可能的官能团归属
| 官能团 | 支持性事实 | 引用来源 | 最高置信度 |
|---|---|---|---|
| Alkyl C-H | 5 | 5 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Methacrylate | 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 |
| Acetate | 1 | 1 | 1.0 |
排名反映了累积的文献证据，而非单一的权威规则。请始终对照您的样品背景进行确认。
Possible materials
| 材料 | 支持峰 | Overlapping groups | 引用来源 |
|---|---|---|---|
| poly(vinyl alcohol) | 2993, 1700, 1382 | Methacrylate, Alkyl C-H, Hydroxyl (O-H) | 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 2993 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.
这些分配背后的文献
-
Alkyl C-H 置信度 1.0
“The peaks at 2993 and 2920 cm-1 apcm-1 C-H vibration of the group.”
Ibrahim 等 - 2022 - Effect of Ammonium Sulfide on Sulfidization Flotat DOI: 10.3390/min12101193 -
Alkyl C-H 置信度 1.0
“3425 C-H stretching (imidazolium ring) 3070 3082 C-H stretching (alkyl) 2993”
Li 等 - 2020 - The Impact of Reactive Ionic Liquids Addition on t DOI: 10.3390/polym12091958 -
Hydroxyl (O-H) 置信度 1.0
“Assignment11,30-36 T T h h2 O-H 3496 3488 stretch vibration of two crystal water molecules with Hydrogen bonding 3269 3260 O-H 3303 3294 stretching of trehalose C-H 2993 2995 Asymmetrical and symmetrical stretching of the ring”
Raimi-Abraham 等 - 2014 - Generation and Characterization of Standardized Fo DOI: 10.1021/cg5004885 -
Alkyl C-H 置信度 1.0
“LLM confirmed rule peak-group candidate”
Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet DOI: 10.1038/s41598-021-88553-5 -
Alkyl C-H 置信度 0.9
“Text: 'stretching fundamental at 2993 cm-1'”
Perez-Delgado 和 Manzanares - 2010 - Cavity Ring Down and Fourier Transform Infrared Sp DOI: 10.1021/jp105382p
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