What absorbs at 2266 cm⁻¹ in an FTIR spectrum?
A band near 2266 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 320,000+ reference spectra and knowledge graph.
Backed by 7 cited sources
Quick answer
A band near 2266 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 |
|---|---|---|---|
| Isocyanate | 5 | 5 | 1.0 |
| N c o | 2 | 2 | 0.9 |
| Nitrile | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed 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 2266 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
-
Nitrile
- Reported band
- 2266 cm-1
- Assignment
- Nitrile
- Material / context
- sub> films deposited; CNx films
-
Isocyanate
- Reported band
- 2266 cm-1
- Assignment
- Isocyanate
- Material / context
- dicyclohexylmethane-4; 4′-diisocyanate; polyurethane
-
Isocyanate
- Reported band
- 2266 cm-1
- Assignment
- Isocyanate
- Material / context
- methylene diphenyl diisocyanate; degradation kinetics of methylene diphenyl diisocyanate
-
Isocyanate
- Reported band
- 2266 cm-1
- Assignment
- Isocyanate
- Material / context
- Luffa Cylindrica Mats Reinforced Castor Oil-Based Polyurethane Composite as an Alternative; neat COPU resin; luffa/COPU composite
-
N c o
- Reported band
- 2266 cm-1
- Assignment
- N c o
- Material / context
- PDMS molecular weight on transparency; polydimethylsiloxane-urea-elastomer; polysiloxane-urea (PSU)
-
N c o
- Reported band
- 2266 cm-1
- Assignment
- N c o
- Material / context
- polybutadienebased polyurethane liners; nanoclay; mineral fillers
-
Isocyanate
- Reported band
- 2266 cm-1
- Assignment
- Isocyanate
- Material / context
- anti-inflammatory drugs; HDI crosslink
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