What absorbs at 699 cm⁻¹ in an FTIR spectrum?
A band near 699 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 3 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkyl C-H | 3 | 3 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| C c single bond | 1 | 0 | 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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Alkyl C-H confidence 1.0
“The peak at 699 cm-1 performed with high resolution (R = 5000, 10 % corresponds to the C-H out-of-plane deformation valley), in the peak matching mode, with PFK ions for specific to an aromatic ring [15].”
Tosa 等 - 2012 - Simultaneous Determination Of Some Artificial Swee DOI: 10.1063/1.3681976 -
S eq o confidence 1.0
“and 699 The stretching vibration of sulfoxide S=O functional group appeared at”
Research on the Interaction Capability and Microscopic Interfacial Mechanism between Asphalt-Binder and Steel Slag Aggregate-Filler DOI: 10.3390/coatings12121871 -
Aromatic ring confidence 1.0
“The peaks that appear between 910 cm-1 and 699 cm-1 can be analyzed carefully to show ortho-, metaand paradisubstituted rings presented in aromatic compounds and are associated with out-of-plane C-H bending vibrations in this structure.”
Physicochemical and Rheological Properties of a Transparent Asphalt Binder Modified with Nano-TiO2 DOI: 10.3390/nano10112152
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