What absorbs at 746 cm⁻¹ in an FTIR spectrum?
A band near 746 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 5 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Fatty acid | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
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Carbonyl (C=O) confidence 1.0
“In addition, 1433.11 cm-1 Moreover, absorption of C=O obtained in 1683.86 4a the presence of the phenethyl group in was also indicated that the carbonyl group belongs to a carboxylic confirmed by the absorption band at 746.45 and acid moiet”
Rasyid 等 - 2022 - Synthesis of N-phenethyl-p-methoxycinnamamide and DOI: 10.22146/ijc.76802 -
Carbonate confidence 1.0
“GC-MS and the carbonate ν4 deformation at 771, 746 cm-1 (see Figures 5c, S17 and S18) [34].”
New Insights into the Medieval Hispano-Muslim Panel Painting: The Alfarje Found in a Balearic Casal (Spain) DOI: 10.3390/molecules28031235 -
Hydroxyl (O-H) confidence 1.0
“The peaks at 746 and 824 cm-1 in the UiO-66 framework, Zr-µ3-OH stretching and OH bending modes, respectively [46].”
Butova 等 - 2023 - In Situ FTIR Spectroscopy for Scanning Accessible DOI: 10.3390/nano13101675 -
Aromatic ring confidence 1.0
“The bands at 1602 and 1507 cm-1 and cm-1 826 and 746 are derived from the stretching and out-of-plane deformation vibrations those at 826 and 746 cm-1 are derived from the stretching and out-of-plane deformation of C ArC and C ArH bonds fro”
A Top-Down Approach and Thermal Characterization of Luminescent Hybrid BPA.DA-MMA@Ln2L3 Materials Based on Lanthanide(III) 1H-Pyrazole-3,5-Dicarboxylates DOI: 10.3390/ma15248826 -
Fatty acid confidence 1.0
“Scarsini (2021) showed how in N-starvation, cells fatty acids with only a baseline correction and cm-1 are principally accumulating neutral lipids through membrane the peak at 1,746 is much more representative of the”
Metabolite Quantification by Fourier Transform Infrared Spectroscopy in Diatoms: Proof of Concept on Phaeodactylum tricornutum DOI: 10.3389/fpls.2021.756421
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