What absorbs at 3420 cm⁻¹ in an FTIR spectrum?
A band near 3420 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) | 15 | 15 | 0.95 |
| N h | 3 | 3 | 1.0 |
| Water (H2O) | 2 | 2 | 0.9 |
| Silanol (Si-OH) | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
N h confidence 1.0
“The position of 3420cm-1 NH stretching vibration appears from 3500 to C O stretching vibration is particularly clear and is sensitive to 2 and the symmetric NH stretching is observed in the range O stretchits environment in the infrared [73”
Arjunan 等 - 2007 - Fourier transform infrared and Raman spectral assi DOI: 10.1016/j.saa.2006.09.044 -
confidence 1.0
“Explicit assignment in text.”
Sun 等 - 2022 - Synthesis of renewable diesel and jet fuel range a DOI: 10.1039/d2ra01987f -
Hydroxyl (O-H) confidence 0.95
“Explicit assignment in text: 'reduction of the hydroxyl group (3420 cm-1)'”
Zhang 等 - 2019 - Chemical and Rheological Evaluation of Aged Lignin DOI: 10.3390/ma12244176 -
Hydroxyl (O-H) confidence 0.9
“Text: 'stretching vibrations of hydroxyl groups in 3420'”
Ghayempour 和 Montazer - 2018 - A modified microemulsion method for fabrication of DOI: 10.1016/j.ijbiomac.2018.04.037 -
Hydroxyl (O-H) confidence 0.9
“Explicit assignment.”
Suthakaran 等 - 2020 - Hydrothermal synthesis of surfactant assisted Zn d DOI: 10.1016/j.jpcs.2020.109407 -
Hydroxyl (O-H) confidence 0.9
“Assigned to OH groups.”
Wang 等 - 2013 - Hydrothermal synthesis and characterization of alp DOI: 10.1016/j.mssp.2012.12.029 -
N h confidence 0.9
“Characteristic IR absorption band at 3420 cm-1 corresponding to H- monomers.”
Zhang 等 - 2013 - The durability of clear polyurethane coil coatings DOI: 10.1016/j.polymdegradstab.2012.12.003 -
Hydroxyl (O-H) confidence 0.9
“Explicit assignment: '3420 ... correspond to the O-H'”
Alsharaeh 等 - 2014 - Microwave Irradiation Effect on the Dispersion and DOI: 10.3390/ma7075212
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