What absorbs at 1637 cm⁻¹ in an FTIR spectrum?
A band near 1637 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 8 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkene (C=C) | 13 | 11 | 1.0 |
| Carbonyl (C=O) | 6 | 6 | 0.95 |
| Amide | 5 | 4 | 1.0 |
| Protein beta sheet | 4 | 4 | 0.9 |
| Hydroxyl (O-H) | 3 | 3 | 0.9 |
| N h | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 0.85 |
| Water (H2O) | 2 | 1 | 0.9 |
| C-O single bond | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 0.95 |
| C=n | 1 | 1 | 0.9 |
| Protein alpha helix | 1 | 1 | 0.9 |
| C n single bond | 1 | 1 | 0.9 |
| Carboxyl (COOH) | 1 | 1 | 0.8 |
| C c single bond | 1 | 1 | 0.7 |
| Alkyl C-H | 1 | 1 | 0.5 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
C-O single bond confidence 1.0
“Therefore, the very strong band in IR at 1637 and quency of C O stretching dependant on various factors.”
Arjunan 等 - 2007 - Fourier transform infrared and Raman spectral assi DOI: 10.1016/j.saa.2006.09.044 -
N h confidence 1.0
“cm(cid:0) 1 granules, including the amylose content, distribution of branch chains of Prominent peak in the region of 1637 revealed the presence of (-N-H) amylopectin, interactions of amylose-amylose and amylose-lipid could amine group (Ng”
Ashwar 等 - 2021 - Encapsulating probiotics in novel resistant starch DOI: 10.1016/j.lwt.2020.110839 -
Amide confidence 1.0
“Transmittance peak at 1637 cm-1 corresponding to band I of amide.”
Ryu 等 - 2010 - Carbon Nanotube Mat as Mediator-Less Glucose Senso DOI: 10.1166/jnn.2010.1892 -
Alkene (C=C) confidence 1.0
“Text: 'peak at ~1637 C═C stretching'”
Sabatini 等 - 2022 - Mechanical characterization and adhesive propertie DOI: 10.1016/j.jmbbm.2022.105153. -
confidence 1.0
“Assigned to β-strand structure”
Shimizu 等 - 2010 - Pressure Effect on the Conformational Equilibrium DOI: 10.1088/1742-6596/215/1/012153 -
Amide confidence 1.0
“Peak a at 1637 assigned to amide I.”
Ahuja 等 - 2021 - A comparative study on silicon nitride, titanium a DOI: 10.1002/mds3.10139. -
Alkene (C=C) confidence 1.0
“Explicit assignment: '탄소-탄소(C=C) 흡수띠(1637cm-1)'”
XIAO-YONG 等 - 2015 - Self Healing System for Concrete Surface Crack usi DOI: 10.5345/JKIBC.2015.15.6.579 -
Alkene (C=C) confidence 0.95
“Explicitly stated: 'C=C stretching at 1637'”
Rethi 等 - 2022 - Molecularly Targeted Photothermal Ablation of Epid DOI: 10.3390/cancers14205043
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