What absorbs at 3655 cm⁻¹ in an FTIR spectrum?
A band near 3655 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 3 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 2 | 1 | 0.8 |
| Metal oxygen | 1 | 1 | 1.0 |
| Bronsted acid site | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Water (H2O) confidence 1.0
“NO+ The weak band at 2159 indicates the formation of the nitrosonium ion cm-1 below).[15-16] exchanging Brønsted sites (see The very weak signal at 1380 (labelled with # in right hand panel) is related to the formation of a very small amoun”
Negri 等 - 2018 - Investigating the Low Temperature Formation of Cu- DOI: 10.1002/chem.201802769 -
Metal oxygen confidence 1.0
“The at a wave number of 802 cm-1, which are bonds formed in the framework of TiO2 2 cm-1 TiO spectrum showed intense peaks at 3655 and 3860 due to the stretching of the”
Physical Properties of Fast-Growing Wood-Polymer Nano Composite Synthesized through TiO2 Nanoparticle Impregnation DOI: 10.3390/polym14204463 -
Hydroxyl (O-H) confidence 0.8
“Attributed to hydroxyl stretching.”
Experimental study on the influence of water immersion on spontaneous combustion of anthracite with high concentrations of sulfur-bearing minerals DOI: 10.1007/s10973-019-09073-z
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