What absorbs at 1678 cm⁻¹ in an FTIR spectrum?
A band near 1678 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 2 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Ring structure confidence 1.0
“The peak cm-1 at 1678 and the A-ring bands are coupled with all other vibrations.”
Chenchiliyan 等 - 2023 - Ground-state heterogeneity and vibrational energy DOI: 10.1063/5.0135268 -
Carbonyl (C=O) confidence 1.0
“A t-test was used to compare (1678a)21 PVP-VA 64 carbonyl stretching (amide) 1672 significance difference the of the between two sets of data.”
Worku 等 - 2014 - Drug-olymer Miscibility across a Spray Dryer A Ca DOI: 10.1021/mp4003943
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