What absorbs at 3693 cm⁻¹ in an FTIR spectrum?
A band near 3693 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) | 3 | 2 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
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confidence 1.0
“cm-1 Peaks occurring around 3693 and 3699 are probably related to the presence of brucite Mg(OH)2, as similar features have been observed in previous studies [65-67].”
Del Vecchio 等 - 2019 - High-Temperature Evolution of Point Defect Equilib DOI: 10.3390/min9100574 -
Metal oxygen confidence 1.0
“The origin of weak bands at 3693 and 3645 Figure 3A shows an MIRIR spectrum of a particulate TiO 2 cm-1 is not clear at present.”
Nakamura 等 - 2003 - In situ FTIR studies of primary intermediates of p DOI: 10.1021/ja029503q -
Hydroxyl (O-H) confidence 1.0
“Fritsch et al.: OH stretching vibrations in serpentines 3693cm-1 spectral change is attributed to the relative intensity of the assignment of the feature to an inner OH group 3693cm-1, shoulder at which increases gradually from Ctl1 is thus”
Fritsch 等 - 2021 - Structural, textural, and chemical controls on the DOI: 10.5194/ejm-33-447-2021
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