Urea — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Urea 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
Urea 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 Urea
| Vilnu skaitlis (cm⁻¹) | Atbalstošie fakti | Citētie avoti | Augstākā pārliecība |
|---|---|---|---|
| 1619 | 2 | 2 | 1,0 |
| 1450 | 2 | 2 | 1,0 |
| 3300 | 2 | 2 | 1,0 |
| 1635 | 2 | 2 | 1,0 |
| 1639 | 2 | 2 | 1,0 |
| 1640 | 2 | 2 | 1,0 |
| 1645 | 1 | 1 | 1,0 |
| 1707 | 1 | 1 | 1,0 |
| 1682 | 1 | 1 | 1,0 |
| 2063 | 1 | 1 | 1,0 |
| 1647 | 1 | 1 | 1,0 |
| 3335 | 1 | 1 | 1,0 |
| 1582 | 1 | 1 | 1,0 |
| 1107 | 1 | 1 | 1,0 |
| 1663 | 1 | 1 | 1,0 |
| 1587 | 1 | 1 | 1,0 |
| 1057 | 1 | 1 | 1,0 |
| 1658 | 1 | 1 | 1,0 |
| 1686 | 1 | 1 | 1,0 |
| 1065 | 1 | 1 | 1,0 |
| 1650 | 1 | 1 | 1,0 |
| 1634 | 1 | 1 | 1,0 |
| 1685 | 1 | 1 | 1,0 |
| 1703 | 1 | 1 | 1,0 |
| 2850 | 1 | 1 | 1,0 |
| 3100 | 1 | 1 | 1,0 |
| 1670 | 1 | 1 | 1,0 |
| 3410 | 1 | 1 | 1,0 |
| 2918 | 1 | 1 | 1,0 |
| 3351 | 1 | 1 | 1,0 |
Showing the 30 best-supported peaks of 57 total for Urea.
Spectrum logic
A functional-group assignment becomes more reliable 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.
Literatūra aiz šiem piešķīrumiem
-
1623 cm⁻¹ pārliecība 1,0
“Because urea and ChCL intermolecular hydrogen interactions are formed, the stretching vibration of NH2 at 1662 cm-1 and the asymmetric vibration of NH2 at 1606 cm-1 in the FTIR spectra of urea shifted to 1663 and 1623 cm-1, respectively, in”
Can 等 - 2023 - Choline Chloride-Based Deep Eutectic Solvent-Treat DOI: 10.3390/f14030569 -
1635 cm⁻¹ pārliecība 1,0
“The prominent bonded cm-1 band centred at 1635 corresponds to the hydrogen-bonded ordered urea carbonyl [27].”
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 -
1640 cm⁻¹ pārliecība 1,0
“Furthermore, the sharp peak at 1640 cm-1, amine-isocyanate generated by the ing at 1640 is attributed to the urea bond created by the reaction reaction, could not be found in the spectrum of the between the amine group and HDI.”
Cohn 和 Stern - 2000 - Sequential surface derivatization of PET films DOI: 10.1021/ma9900784 -
2060 cm⁻¹ pārliecība 1,0
“3458cm21 17 Local base lines for the urea peak at and the thiocyanate peak 2060cm21 2551cm21 07:56 at were drawn by hand using the points at 3711 and for 1930cm21 the urea peak and 2319 and for the thiocyanate peak, respectively.”
Furlan 等 - 2004 - FTIR analysis of mouse urine urea using IR cards DOI: 10.1081/SL-120038766 -
1639 cm⁻¹ pārliecība 1,0
“Small band at 1639 belongs to carbonyl (-C=O) with C=O-NH arrangements of traces of urea which may be present due to the reaction of excess isocyanate with moisture in air.”
Preparation and characterization of aliphatic polyurethane and modified hydroxyapatite composites for bone tissue engineering DOI: 10.1007/s00289-019-03067-5 -
1690 cm⁻¹ pārliecība 1,0
“1690cm-1 absence of peaks at The PU was cast onto the screen-printed electrode (SPE) representing urea (C=O) in and analyzed using a single voltammetric cycle between this study indicated there is no urea formation as a bypro- -1200 and +15”
Munir 等 - 2022 - Design and Synthesis of Conducting Polymer Bio-Bas DOI: 10.1155/2022/6815187 -
1640 cm⁻¹ pārliecība 1,0
“The H-bonded urea (1640 cm-1) occurring first followed by the free urethane reveals by the free urethane reveals that urea followed the first-order reaction [2].”
Effects of NCO/OH Ratios on Bio-Based Polyurethane Film Properties Made from Acacia mangium Liquefied Wood DOI: 10.3390/polym15051154 -
3197 cm⁻¹ pārliecība 1,0
“The peak at 3197 is attributed to the overtone of the C=O stretching in urea which is also in Fermi resonance with the N-H stretching mode (Perkins, Painter et al.”
Ternary Natural Deep Eutectic Solvent (NADES) Infused Phthaloyl Starch as Cost Efficient Quasi-Solid Gel Polymer Electrolyte DOI: 10.1016/j.carbpol.2017.03.023
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