What absorbs at 3140 cm⁻¹ in an FTIR spectrum?
A band near 3140 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 5 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkyl C-H | 2 | 2 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| N h | 1 | 1 | 0.7 |
| Water (H2O) | 1 | 0 | 1.0 |
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
“In the FTIR spectrum of [DEIm][Br] (Figure 1b), cm-1 C-H the peak at 3140 was due to the bond of imidazole ring,63”
Ionic Liquid Functionalized Metal–Organic Framework ([DEIm][PF6]@MOF-5): Synthesis, Characterization, and Catalytic Application in the Reduction of 4-Nitrophenol DOI: 10.1021/acsomega.2c05808 -
Aromatic ring confidence 1.0
“Louis, MO, USA) were added to the inactivated peaks observed at 3140 are attributed to aromatic C-H cell medium at 45 °C for 1 h and incubated at 37 °C in an stretching vibration bands.”
Erol 等 - 2023 - ZnO-containing nanocomposites produced from Mentha DOI: 10.1007/s10965-023-03461-8 -
Hydrogen bond confidence 1.0
“Bands at 3140 and 3093 could be attributed to the valence vibration of intramolecular hydrogen bond in the EA molecule cm-1 [44].”
Ilic-Stojanovic 等 - 2018 - Thermosensitive hydrogels for modified release of DOI: 10.1080/00914037.2017.1354202 -
Silicon-oxygen (Si-O) confidence 1.0
“7 the FTIR absorption between 3236 and 3250 is due to hydroxyl ions of the clay minerals, cm-1 and the peak at 3140 can be attributed to hydrated ferric oxide.”
Sanchez-Polo 等 - 2019 - An Archaeometric Characterization of Ecuadorian Po DOI: 10.1038/s41598-018-38293-w -
N h confidence 0.7
“Same sentence as above.”
Innovative non-thermal plasma disinfection process inside sealed bags: Assessment of bactericidal and sporicidal effectiveness in regard to current sterilization norms DOI: 10.1371/journal.
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