What absorbs at 3485 cm⁻¹ in an FTIR spectrum?
A band near 3485 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 6 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| N h | 2 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
C-O single bond confidence 1.0
“x = For pure PVA, four characteristic absorption bands are observed: the one at 3485 cm-1 which is assigned to vibration along the C-OH-chains bonds in PVA;”
Fernández 等 - 2017 - DOI: 10.17230/ingciencia.13.25.6 -
confidence 1.0
“Furthermore, the cm-1 cm-1 in the typical area was attributed to the N-H stretching vibration at 3485 cm-1 [36].”
Purification and Characterization of a Novel Calcium-Binding Heptapeptide from the Hydrolysate of Tilapia Bone with Its Osteogenic Activity DOI: 10.3390/foods11030468 -
Alkene (C=C) confidence 1.0
“The characteristic cm-1 which can assign to the stretching vibrations of conjugate double bonds in aromatic ring absorption peak of hydroxyl appeared at 3485 and the peak of carbonyl splits into two peaks cm-1 cm-1 framework.”
Effect of Phenolic Resin Oligomer Motion Ability on Energy Dissipation of Poly (Butyl Methacrylate)/Phenolic Resins Composites DOI: 10.3390/polym12020490 -
Hydroxyl (O-H) confidence 1.0
“The sharp pair bands at 3485 cm-1 Thr11814, 36, (+)/3428 (-) in MRh originate from the O-H stretch of and similar bands at 3485 in MG and cm-1 (+)/3432 (-) 3486 in MR are expected because of the O-H stretches of the corresponding Ser residu”
Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy DOI: 10.1038/s41598-017-05177-4 -
Amide confidence 1.0
“In the spectrum of PMA (B) in Figure 2, sponded to C=O stretching (amide I), N-H bending (amide II), and C-N stretching (amcm-1 the characteristic absorption bands appeared at 3485, 2930, and 2890 due to -OH”
Sathya Seeli 等 - 2023 - Zinc Oxide-Incorporated Chitosan-Poly(methacrylic DOI: 10.3390/jfb14040228 -
Alkene (C=C) confidence 0.9
“Explicit assignment: 'C=C from DiEP1 and DiEP2 is observable at 3485'”
New Eco-Friendly Synthesized Thermosets from Isoeugenol-Based Epoxy Resins DOI: 10.3390/polym12010229
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