N c o — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where N c o tends to absorb, compiled from published literature and ranked by supporting evidence. Each assignment is traceable to a source (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
N c o is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.
Characteristic FTIR peaks for N c o
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 2270 | 19 | 18 | 1.0 |
| 2260 | 4 | 4 | 1.0 |
| 2262 | 3 | 3 | 1.0 |
| 2272 | 2 | 2 | 1.0 |
| 2266 | 2 | 2 | 0.95 |
| 2360 | 1 | 1 | 1.0 |
| 1032 | 1 | 1 | 1.0 |
| 3287 | 1 | 1 | 1.0 |
| 473 | 1 | 1 | 1.0 |
| 2251 | 1 | 1 | 1.0 |
| 1159 | 1 | 1 | 1.0 |
| 2253 | 1 | 1 | 1.0 |
| 2273 | 1 | 1 | 1.0 |
| 2276 | 1 | 1 | 1.0 |
| 1634 | 1 | 1 | 1.0 |
| 2300 | 1 | 1 | 1.0 |
| 1180 | 1 | 1 | 1.0 |
| 2252 | 1 | 1 | 1.0 |
| 3436 | 1 | 1 | 1.0 |
| 1016 | 1 | 1 | 1.0 |
| 1106 | 1 | 1 | 1.0 |
| 1700 | 1 | 1 | 1.0 |
| 3330 | 1 | 1 | 1.0 |
| 1735 | 1 | 1 | 1.0 |
| 1628 | 1 | 1 | 1.0 |
| 3473 | 1 | 1 | 1.0 |
| 1285 | 1 | 1 | 1.0 |
| 1313 | 1 | 1 | 1.0 |
| 964 | 1 | 1 | 1.0 |
| 1730 | 1 | 1 | 1.0 |
Showing the 30 best-supported peaks of 39 total for N c o.
Spectrum logic
A functional-group assignment becomes more confident when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.
Real-world usage
These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.
Common mistakes
- Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
- Assuming the strongest band is always the most diagnostic one.
- Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.
Verification advice
Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.
Literature behind these assignments
-
2270 cm⁻¹ confidence 1.0
“troscopy is from the disappearance of the NCO peak at 2270 still observed even after 7 days of RT curing followed by 545 h 50◦C composition, time for complete cure, hard segment content curing at at 25% RH.”
Hydrogen bonding and thermomechanical properties of model polydimethylsiloxane based poly(urethane-urea) copolymers: Effect of hard segment content DOI: 10.1016/j.porgcoat.2015.06.015 -
2262 cm⁻¹ confidence 1.0
“LLM confirmed rule peak-group candidate”
Preparation of one-shot and two-shot method of semi-rigid polyurethane film based on functionalized liquid natural rubber DOI: 10.1063/1.5047200 -
3317 cm⁻¹ confidence 1.0
“peak at 3317 and disappearance of the NCO peak at 2295 The semirigid PU with low rubber polyol chain favored solubility in non-polar solvent (toluene and chloroform) and low polar solvent (THF).”
The behavior of semi-rigid polyurethane film based on functionalized rubber by one-shot and two-shot method preparation DOI: 10.1007/s10853-018-2578-8 -
2280 cm⁻¹ confidence 1.0
“LLM confirmed rule peak-group candidate”
Norshahli 等 - 2018 - Mechanical Properties of Palm Oil Polyol based Pol DOI: 10.1088/1742-6596/1082/1/012041 -
1730 cm⁻¹ confidence 1.0
“The formation of urea linkages at 1640 which occur increasing NCO/OH ratio, and its occurrences after 1730 cm-1 revealed that a high earlier as revealed by the 2D-COS study, suggests the significant side reactions between NCO/OH ratio induc”
Effects of NCO/OH Ratios on Bio-Based Polyurethane Film Properties Made from Acacia mangium Liquefied Wood DOI: 10.3390/polym15051154 -
964 cm⁻¹ confidence 1.0
“v3P-O and1-weekintraoralexposure.Thepeaksidentifiedwere:-OH (3500and1640cm(cid:2)1),-NH(3300-3100cm(cid:2)1),-CH 3/-CH 2-(2890, vibrations of amorphous Ca-P, and the peaks at 964 and 6101460cm(cid:2)1), (2052cm(cid:2)1), (1741cm(cid:2)1), 5”
Rahiotis 等 - 2008 - Characterization of oral films formed in the prese DOI: 10.1016/j.jdent.2008.01.005 -
1313 cm⁻¹ confidence 1.0
“amide III band (1313 which contains information C-N C-O N-H Based on this work, however, spectral analysis of the regarding the and stretching and the and cm-1”
Shi 等 - 2018 - Biochemical alterations of Candida albicans during DOI: 10.1039/c8an01452c -
1285 cm⁻¹ confidence 1.0
“The peaks at 1285 and 1078 are due to Ar-O = prepared with NCO/OH 2 are shown in Figure 3A and B, and R-O stretching, respectively, showing the presence of 1700 1720”
Shoaib 和 Bahadur - 2016 - Synthesis of thermally and mechanically improved p DOI: 10.1515/epoly-2016-0134
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