What absorbs at 3631 cm⁻¹ in an FTIR spectrum?
A band near 3631 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 2 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 3 | 2 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Hydroxyl (O-H) confidence 1.0
“The water O-H stretches at 18O 3631cm-1 assign water stretching vibrations, we normally use 3628 and probably correspond to the previously Fukuda et al.: Water vibration of Clpump in water 171 2685cm-1, bonding strength of such water molecu”
Fukuda 等 - 2013 - Detection of a protein-bound water vibration of ha DOI: 10.2142/biophysics.9.167 -
Hydroxyl (O-H) confidence 1.0
“For Mt 10A, the absorption cm-1 band at 3631 375 represents the -OH stretching of Si-OH and Al-OH (Shabanian et al., cm-1 376 2016).”
Influence of montmorillonite/carbon nanotube hybrid nanofillers on the properties of poly(lactic acid) DOI: 10.1016/j.clay.2020.105925
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