What absorbs at 3300 cm⁻¹ in an FTIR spectrum?
A band near 3300 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) | 69 | 67 | 1.0 |
| N h | 19 | 18 | 1.0 |
| Amide | 14 | 11 | 1.0 |
| Water (H2O) | 6 | 5 | 1.0 |
| Alkyl C-H | 3 | 3 | 0.9 |
| Silanol (Si-OH) | 2 | 2 | 0.9 |
| Protein | 2 | 1 | 0.8 |
| Amine primary | 2 | 1 | 0.8 |
| Phenolic | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 0.95 |
| Methacrylate | 1 | 1 | 0.9 |
| Aromatic ring | 1 | 1 | 0.9 |
| Hydrogen bond | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
confidence 1.0
“Broad Zr-OH band centered around 3300 cm-1.”
Asaad 等 - 2023 - New Carbamoyl Surface-Modified ZrO2 Nanohybrids fo DOI: 10.3390/molecules28052219 -
Hydroxyl (O-H) confidence 1.0
“Explicit assignment in text.”
Bao 等 - 2018 - Manufacturing and characterization of long-acting DOI: 10.1016/j.ijpharm.2018.09.004. -
Hydroxyl (O-H) confidence 1.0
“assigned to hydroxyl groups”
Fraser 等 - 2011 - UV-B absorbing pigments in spores biochemical res DOI: 10.3402/polar.v30i0.8312 -
confidence 1.0
“Explicit assignment: '3300cm-1 peak at originates from the stretching vibration defects'”
Li 等 - 2019 - The One-Step Preparation of Green-Emissioned Carbo DOI: 10.1155/2019/8628354 -
Amide confidence 1.0
“Explicit assignment: amide A (3300 cm-1).”
Lungu 等 - 2023 - Physical Chemical Investigation of Gamma-Irradiate DOI: 10.3390/polym15041034 -
confidence 1.0
“explicit assignment in text”
Shishkanova 等 - 2023 - Voltammetric Detection of Vanillylmandelic Acid an DOI: 10.3390/s23073727 -
Amide confidence 1.0
“Explicit assignment in text: 'amide A (~3300 cm-1)'”
Usoltsev 等 - 2019 - Systematic FTIR Spectroscopy Study of the Secondar DOI: 10.3390/biom9080359 -
Water (H2O) confidence 1.0
“Broad absorption band assigned to stretching vibrations of molecular water and hydroxyl groups.”
Vasconcelos 等 - 2012 - Optical characterization of 316L stainless steel c DOI: 10.1016/j.jnoncrysol.2012.07.035
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