What absorbs at 3618 cm⁻¹ in an FTIR spectrum?
A band near 3618 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 7 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Metal hydroxyl | 1 | 1 | 0.8 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Alkyl C-H confidence 1.0
“cm-1 C-H in the Peaks at 3618 and 3709 are Kaolinite[12,26].”
Zhao 等 - 2015 - Evaluation of Oil Yield of Oil Shale by Infrared S DOI: 10.1007/s40242-015-4364-3 -
confidence 1.0
“[36] 2011 Al-Fe-OH the symmetric stretching bands at 3324 and 3618 cm-1 correspond to and 3445-3440 Zeoliticwater”
Benjamin Ortega-Lazcano 等 - 2021 - Study of Pigments from the Colonial Convent of Act DOI: 10.3390/min11080852 -
confidence 1.0
“This latter amphibole indeed represents a reference point 3618 cm-1, whose relative intensities are correlated with the Mg/Fe2+ ratio at M(1,3).”
Della Ventura 等 - 2018 - Infra Red Spectroscopy of the Regulated Asbestos A DOI: 10.3390/min8090413 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Morphology and Selected Properties of Modified Potato Thermoplastic Starch DOI: 10.3390/polym15071762 -
Alkyl C-H confidence 1.0
“and 3618 The peak related to the asymmetric stretching vibration of methylene at cm-1 2920 [40] was clearly visible in all techniques, while the peak related to the symmetric cm-1 stretching vibration of aliphatic methylene at 2850 [26] was”
Application of FTIR-PAS in Rapid Assessment of Rice Quality under Climate Change Conditions DOI: 10.3390/foods10010159 -
Hydroxyl (O-H) confidence 0.95
“Text: 'peak at ν = 3618 is due to OH stretching frequencies'”
Microsoft Word - Finished - Mineral Identification of Rocks From Pohon Batu Hot Springs in West Seram Using FTIR Spectroscopy DOI: 10.1088/1742-6596/1572/1/012045 -
Hydroxyl (O-H) confidence 0.8
“Assigned to stretching vibration of hydroxyl groups.”
Multi-Method Analysis of Painting Materials in Murals of the North Mosque (Linqing, China) DOI: 10.3390/coatings13071298
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