What absorbs at 1700 cm⁻¹ in an FTIR spectrum?
A band near 1700 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) | 67 | 60 | 1.0 |
| Amide | 24 | 21 | 0.95 |
| Carboxyl (COOH) | 10 | 9 | 1.0 |
| Ester | 3 | 3 | 0.9 |
| Hydroxyl (O-H) | 3 | 3 | 0.9 |
| C-O single bond | 3 | 3 | 0.9 |
| Urethane | 2 | 2 | 0.9 |
| Water (H2O) | 2 | 2 | 0.8 |
| Alkene (C=C) | 2 | 2 | 0.8 |
| C=n | 2 | 2 | 0.7 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 0.9 |
| Methacrylate | 1 | 1 | 0.9 |
| Oxalate | 1 | 1 | 0.9 |
| S eq o | 1 | 1 | 0.8 |
| Carbohydrate | 1 | 1 | 0.8 |
| Protein beta sheet | 1 | 1 | 0.8 |
| N h | 1 | 1 | 0.7 |
| C n single bond | 1 | 1 | 0.7 |
| Imide | 1 | 1 | 0.7 |
| C c single bond | 1 | 0 | 0.8 |
| Alkyl C-H | 1 | 0 | 0.8 |
| Nitrate | 1 | 0 | 0.7 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Carbonyl (C=O) confidence 1.0
“Explicit assignment: 'new main peak at 1700 which corresponds to C=O functional groups'”
Abu-Jdayil 等 - 2022 - Utilization of Polyurethane Foam Dust in Developme DOI: 10.3390/buildings12020126 -
Carbonyl (C=O) confidence 1.0
“Explicit assignment: 'carbonyl peak at 1700'”
Chen 等 - 2022 - Effect of Re-Recycling on Rheology and Microstruct DOI: 10.3390/ma15196641 -
confidence 1.0
“PE-g-MAH MAH C=O group at 1700 cm-1”
Harris 等 - 2021 - Partial Polymer Blend for Fused Filament Fabricati DOI: 10.3390/polym13193353 -
confidence 1.0
“explicit assignment”
Khudaida 等 - 2022 - Microparticle Production of Active Pharmaceutical DOI: 10.3390/cryst12070922 -
Carbonyl (C=O) confidence 1.0
“Explicit assignment: 'band C=O (~1700 cm-1)'.”
Nardeli 等 - 2019 - Preparation of Polyurethane Monolithic Resins and DOI: 10.3390/polym11111890 -
Carbonyl (C=O) confidence 1.0
“Band around 1700 cm-1 corresponds to C=O functional groups.”
Perez-Rosa 等 - 2022 - Influence of Nanoparticles on the Degradation Proc DOI: 10.3390/en15041520 -
Carbonyl (C=O) confidence 1.0
“Explicit assignment in text.”
Sun 等 - 2022 - Effect Investigation of Ultraviolet Ageing on the DOI: 10.1155/2022/7190428 -
Carbonyl (C=O) confidence 1.0
“Text: 'carbonyl absorbance peak at ~1700 (C=O_1700) showed the existence of carboxyl, alde'”
Wang 等 - 2021 - Surface Chemical Heterogeneity of Low Rank Coal Ch DOI: 10.3390/min11030239
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a confidence-rated evidence chain — in seconds.
Interpret my spectrum