What absorbs at 3351 cm⁻¹ in an FTIR spectrum?
A band near 3351 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 6 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 5 | 4 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Urea | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Alkyl C-H confidence 1.0
“In a comparison, the band peaked at 2906 cm-1 can be attributed to presence of OH groups that could be confirmed by the appearance of broad band with a maximum at 3351cm-1 cm-1 C-H stretching in dextran [32,33], since such band was not obse”
Development of Polymer Blend Electrolyte Membranes Based on Chitosan: Dextran with High Ion Transport Properties for EDLC Application DOI: 10.3390/ijms20133369 -
Hydroxyl (O-H) confidence 1.0
“dispersions using sucrose), and etoricoxib and characteristic 3350.7cm-1 (in case of O-H stretching of vibration peaks, 3349.7cm-1 (in case of solid solid dispersions using lactose), 3.3.3.”
Das 等 - 2011 - Solubility and dissolution enhancement of etoricox DOI: 10.5402/2011/819765 -
Hydroxyl (O-H) confidence 1.0
“Compared cm-1 with isoprene, the broad characteristic peak at 3351 was related to the existence of hydroxyl groups in PI-OH (Figure 4b).”
Synthesis and Characterization of Linear Polyisoprene Supramolecular Elastomers Based on Quadruple Hydrogen Bonding DOI: 10.3390/polym12010110 -
N-O bond confidence 1.0
“cm(cid:4)1 The band centered between 3351 and 3332 correspond to the No additional information is available for this paper.”
The long term effect of Olive Mill Wastewater (OMW) on organic matter humification in a semi-arid soil DOI: 10.1016/j.heliyon.2020.e03181 -
Hydroxyl (O-H) confidence 1.0
“and HCA (g), is that the broad band O-H stretching vibration band is shifted at 3351”
Organic Bio-Based Aerogel from Food Waste: Preparation and Hydrophobization DOI: 10.3390/gels8110691 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Evaluation of Physico-Mechanical Properties on Oil Extracted Ground Coffee Waste Reinforced Polyethylene Composite DOI: 10.3390/polym14214678
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