What absorbs at 3350 cm⁻¹ in an FTIR spectrum?
A band near 3350 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 29 | 26 | 1.0 |
| N h | 9 | 8 | 1.0 |
| Water (H2O) | 2 | 2 | 0.9 |
| Secondary amine | 2 | 1 | 0.8 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 0.9 |
| C n single bond | 1 | 1 | 0.9 |
| C-O single bond | 1 | 1 | 0.9 |
| Carbohydrate | 1 | 1 | 0.8 |
| Amine primary | 1 | 1 | 0.8 |
| Alkene (C=C) | 1 | 1 | 0.8 |
| Acetate | 1 | 0 | 0.8 |
| Urethane | 1 | 0 | 0.8 |
| Alkyl C-H | 1 | 0 | 0.7 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Silanol (Si-OH) confidence 1.0
“Text: '3350-3390cm-1 ... represent Si-OH bond'”
Osman 和 Sapawe - 2020 - High purity and amorphous silica (SiO2) prepared f DOI: 10.1016/j.matpr.2020.05.299 -
N h confidence 1.0
“explicit assignment”
Pegado 等 - 2018 - First evidence of microplastic ingestion by fishes DOI: 10.1016/j.marpolbul.2018.06.035 -
Hydroxyl (O-H) confidence 1.0
“Explicit assignment: 'can be attributed to O-H stretching'”
Suriyatem 等 - 2020 - Physical Properties of Carboxymethyl Cellulose fro DOI: 10.3390/polym12071505 -
N h confidence 0.95
“Explicit assignment: 'absorptions of N-H' at 3350 cm-1.”
Ngo 等 - 2020 - Improvement of Hydrophilicity for Polyamide Compos DOI: 10.1155/2020/6641225 -
Hydroxyl (O-H) confidence 0.95
“Explicit assignment: 'The peak at 3350 is due to -OH stretching.'”
Rajendran 等 - 2013 - DOI: 10.4152/pea.201303141 -
Hydroxyl (O-H) confidence 0.9
“Explicit assignment: '3350 representing hydroxyl'”
Ashfaq 等 - 2022 - Electro-Oxidation of Metal Oxide-Fabricated Graphi DOI: 10.3390/coatings12050548 -
Water (H2O) confidence 0.9
“Explicitly stated: 'for water liberated'.”
Hsu 和 Lin - 2009 - Rapid examination of the kinetic process of intram DOI: 10.1016/j.tca.2008.12.008 -
Hydroxyl (O-H) confidence 0.9
“Attributed to -OH stretching.”
Kumar 等 - 2022 - In-situ Production and Collection of Bacterial Cel DOI: 10.1080/15440478.2020.1870638
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