What absorbs at 1675 cm⁻¹ in an FTIR spectrum?
A band near 1675 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 |
|---|---|---|---|
| Carbonyl (C=O) | 4 | 4 | 1.0 |
| Amide | 3 | 2 | 0.9 |
| Protein beta sheet | 1 | 1 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 0.9 |
| Ring structure | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Protein beta sheet confidence 1.0
“assigned to β-sheet”
Frare 等 - 2006 - Identification of the core structure of lysozyme a DOI: 10.1016/j.jmb.2006.06.055 -
Carbonyl (C=O) confidence 1.0
“Important band at 1675 cm-1 attributed to C=O.”
Queiros 等 - 2017 - Composite Superabsorbent Hydrogel of Acrylic Copol DOI: 10.21577/0103-5053.20170046 -
Carbonyl (C=O) confidence 0.95
“Text: 'carbonyl stretching signal (1675 cm-1)'.”
Fabregat-Safont 等 - 2018 - Reporting the novel synthetic cathinone 5-PPDI thr DOI: 10.1007/s11419-013-0215-4 -
Aldehyde (CHO) confidence 0.9
“Assigned to aldehyde vibration.”
Sahmetlioglu 等 - 2006 - Synthesis and characterization of oligosalicylalde DOI: 10.2478/s11696-006-0012-1 -
Carbonyl (C=O) confidence 0.9
“Explicit assignment: C=O stretching at 1675 cm-1.”
Ghumman 等 - 2022 - Degradable Slow-Release Fertilizer Composite Prepa DOI: 10.3390/agronomy12010065 -
Amide confidence 0.9
“Band at 1675 cm-1 is broader amide I band.”
Lovic 等 - 2018 - Electrochemical glucose biosensor with the charact DOI: 10.20964/2018.12.59 -
confidence 0.9
“Assigned to C=O stretching.”
Nayeri 等 - 2019 - Dataset on adsorption of methylene blue from aqueo DOI: 10.1016/j.dib.2019.104036 -
Carbonyl (C=O) confidence 0.9
“HOAc C=O stretch band at 1675 cm-1.”
Renda 等 - 2016 - Thermodynamic and conductivity properties of aceti DOI: 10.1016/j.molcata.2003.09.035
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