What absorbs at 2184 cm⁻¹ in an FTIR spectrum?
A band near 2184 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 3 cited sources
Quick answer
A band near 2184 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.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Nitrile | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
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 2184 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.
Literature behind these assignments
-
confidence 1.0
“2124cm(cid:3)1 The bands at 2184 and are observed and ascribed to Au+ Au0, Fig.”
Fabrication and characterization of bimetallic Pt⠍Au nanowires supported on FSM-16 and their catalytic activities toward water⠍gas shift reaction DOI: 10.1016/j.jcis.2010.10.008 -
Nitrile confidence 1.0
“3 Open cm(cid:3)1 the reaction between nitrile group and epoxy group was inexthe single peak around 2184 associated with nitrile group”
Reaction mechanism, cure behavior and properties of a multifunctional epoxy resin, TGDDM, with latent curing agent dicyandiamide DOI: 10.1039/c7ra13233f -
Acetate confidence 1.0
“2358 2358 2 2250 to 2000 C-O (Stretching) CO 2184 2184 1800 to 1684 C=O (Stretching) Acids, Ketones, Aldehydes 1745 1745”
Zhang 等 - 2017 - Comparison Study on Pyrolysis Characteristics and DOI: 10.1016/j.biortech.2009.12.034
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a confidence-rated evidence chain — in seconds.