What absorbs at 1999 cm⁻¹ in an FTIR spectrum?
A band near 1999 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 |
|---|---|---|---|
| Aromatic ring | 2 | 1 | 1.0 |
| Amide | 2 | 0 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 0 | 1.0 |
| Hydroxyl (O-H) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Aromatic ring confidence 1.0
“lignin [Pandey and Theagarajan, 1997] 1505-1515 aromatic skeletal vibration (lignin) [Pandey, 1999;”
Experimental assessment of the purity of cellulose produced by variations of the Brendel method: Implications for stable isotope (13C, 18O) dendroclimatology DOI: 10.1029/2012GC004215 -
Water (H2O) confidence 1.0
“The absorption peak at 1649 represents the cm-1 deformation vibration of bound water (Pandey 1999) and the peaks at 1369 and 1369 cm-1 are the bending vibrations of -CH and -OH, respectively.”
Hu 等 - 2021 - Pyrolytic Characteristics and Kinetics of Guanzhon DOI: 10.1016/j.fuel.2014.01.014
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