What absorbs at 1654 cm⁻¹ in an FTIR spectrum?
A band near 1654 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) | 7 | 7 | 0.9 |
| Amide | 7 | 6 | 0.95 |
| Protein alpha helix | 3 | 3 | 0.95 |
| C-O single bond | 2 | 2 | 0.9 |
| Protein | 2 | 2 | 0.9 |
| Alkene (C=C) | 1 | 1 | 0.9 |
| Alkyl C-H | 1 | 1 | 0.8 |
| Ammonium | 1 | 1 | 0.8 |
| C c single bond | 1 | 0 | 0.9 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Protein alpha helix confidence 0.95
“Explicit assignment: 'Vibrational components of α-helices in the amide I region can be recognized at 1654 cm-1'”
Nedelkovski 等 - 2013 - Surface-Enhanced Infrared Absorption Spectroscopy DOI: 10.1021/jp4056347 -
Amide confidence 0.9
“Explicit assignment: amide I from proteins.”
Depciuch 等 - 2022 - EFFECT OF HIGH BLOOD CORTISOL CONCENTRATION ON THE DOI: 10.21203/rs.3.rs-228476/v1 -
Carbonyl (C=O) confidence 0.9
“Attributed to C=O stretching.”
Kumar 等 - 2022 - In-situ Production and Collection of Bacterial Cel DOI: 10.1080/15440478.2020.1870638 -
Alkene (C=C) confidence 0.9
“attributed to stretching vibration of C=C”
Li 和 Wang - 2022 - Study on Nitrile Oxide for Low-Temperature Curing DOI: 10.3390/ma15093396 -
Amide confidence 0.9
“Explicit assignment in snippet.”
Miroiu 等 - 2010 - Composite biocompatible hydroxyapatite-silk fibroi DOI: 10.1016/j.mseb.2009.10.004 -
Protein confidence 0.9
“Explicit assignment in text.”
Sharma 等 - 2013 - Microbeam-irradiated tumour tissue possesses a dif DOI: 10.3109/09553002.2012.721052 -
confidence 0.9
“Explicit assignment: 'a-helical 1654 attributable to structures'”
Abbott 等 - 2012 - Interaction between Soluble and Membrane-Embedded DOI: 10.1371/journal.pone.0049070 -
confidence 0.9
“Explicit assignment in text.”
Chatterjee 等 - 2019 - Dual-responsive (pHtemperature) Pluronic F-127 hy DOI: 10.1038/s41598-019-48254-6
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