What absorbs at 3243 cm⁻¹ in an FTIR spectrum?
A band near 3243 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 |
|---|---|---|---|
| N h | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Synthesis, Structural, Optical, Electrical and Thermal Studies of Poly(vinyl alcohol)/CdO Nanocomposite Films DOI: 10.1007/s10904-017-0662-1 -
confidence 1.0
“The maximum at 3243 cm-1 which corresponds to symmetric valence vibrations of N-H bonds from the sulfonamide NH2 group was shifted for 25 units in relation to its position in the sulfanilamide spectrum (3268 cm-1).”
Modified Sulfanilamide Release from Intelligent Poly(N-isopropylacrylamide) Hydrogels DOI: 10.3390/pharmaceutics15061749 -
Hydroxyl (O-H) confidence 1.0
“Phenols, a group of 3243cm-1 range of is ascribed to stretching vibrations bioactive compounds that define the therapeutic value of of hydroxyl group of water molecules (Muzaffar et al., plants, are known to absorb frequencies in the range”
Qadri 等 - 2022 - Comparative evaluation of apple juice concentrate DOI: 10.15586/qas.v14i2.1037 -
N h confidence 1.0
“220(cid:3)C 223(cid:3)C, Off white solid, Yield: 86%, m.p: to Rf: 0.65 (C6), 148.4 (C14), 134.7 (C12), 130.6 (C15), 130.0 (C16), cm-1): n-hexane [Acetone: (7:3)], FTIR (KBr disk, 122.2 (C17, C19), 121.2 (C10), 111.9 (C9), 109.3 (C8), [M]+,”
Development of an Efficient, One-Pot, Multicomponent Protocol for Synthesis of 8-Hydroxy-4-Phenyl-1,2-Dihydroquinoline Derivatives DOI: 10.1002/jhet.4193 -
N h confidence 0.9
“N-H vibration mode”
Kurmanbayeva 等 - 2020 - Tetrapropylammonium Hydroxide as a Zinc Dendrite G DOI: 10.3389/fenrg.2020.599009
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