What absorbs at 3495 cm⁻¹ in an FTIR spectrum?
A band near 3495 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 8 cited sources
Quick answer
A band near 3495 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Possíveis atribuições de grupos funcionais
| Grupo funcional | Fatos de suporte | Fontes citadas | Maior confiança |
|---|---|---|---|
| Hydroxyl (O-H) | 8 | 8 | 1,0 |
| Protein random coil | 1 | 1 | 1,0 |
| Hydrogen bond | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.
Possible materials
| Material | Picos de suporte | Overlapping groups | Fontes citadas |
|---|---|---|---|
| MWCNT | 3495, 2876, 1430 | Hydroxyl (O-H) | 1 |
| Chitosan-Based | 3495, 2924, 1743 | Hydroxyl (O-H) | 1 |
| Cellulose | 3495, 1735, 1650 | Hydroxyl (O-H), Carbohydrate | 1 |
| chitosan | 3495, 1650, 1655 | Hydroxyl (O-H) | 1 |
| CA | 3495, 1045, 1650 | Hydroxyl (O-H) | 1 |
| Bacterial Cellulose | 3495, 1050, 1631 | Hydroxyl (O-H) | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 3495 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literatura por trás destas atribuições
-
Hydroxyl (O-H) confiança 1,0
“x=0.03 x=0.04 x=0.05 x=0.06 O-H stretching 3494.77 3496.70 3494.77 3492.85 3434.98 3454.27 3436.91 Functional group x=0.00 x=0.01 x=0.02 x=0.03 x=0.04 x=0.05 x=0.06 Functional group x=0.00 x=0.01 x=0.02 x=0.03 x=0.04 x=0.05 x=0.06 O-H stret”
Harsono 等 - 2017 - Paramagnetic Zn(1-x)MnxO (0.00≤x≤0.06) Nanopar DOI: 10.4313/TEEM.2017.18.1.46 -
Ring structure confiança 1,0
“3292cm(cid:2)1 1445cm(cid:2)1 In addition, the IR spectral peaks at 1568 and The disappearance of three peaks at 3495, 3450 and due to ring stretching of TP also did not exhibit a series of changes after assigned to O-H stretching for CA mi”
Solid-state thermal behavior and stability studies of theophylline–citric acid cocrystals prepared by neat cogrinding or thermal treatment DOI: 10.1016/j.jssc.2012.04.010 -
N h confiança 1,0
“The value of the of 3473 is accepted as the cm-1 with high pH were treated for a long time at room temperature mean value of (i) free NH band positions at 3495 offreeN-”
Rozenberg 和 Shoham - 2007 - FTIR spectra of solid poly-L-lysine in the stretch DOI: 10.1016/j.bpc.2006.07.008 -
Hydroxyl (O-H) confiança 1,0
“The cm-1 3495 indicating OH stretching due to intradensely packed network of cellulose with thinner molecular hydrogen bonds confirms the absence fibers indicate that BC has more hydrogen-”
Akintunde 等 - 2022 - Bacterial Cellulose Production from agricultural R DOI: 10.1080/21655979.2022.2062970 -
Hydroxyl (O-H) confiança 1,0
“cm-1 typical peak at 3745 assigned to isolated silanols (n(O-H)), whereas curcumin displayed a sharp peak at cm-1 cm-1 3495.1 and a broad peak at 3000-3550 indicating OH group vibrations without and with intermolecular hydrogen bonding, res”
Treatment of breast cancer in vivo by dual photodynamic and photothermal approaches with the aid of curcumin photosensitizer and magnetic nanoparticles DOI: 10.1038/s41598-020-78241-1 -
Hydroxyl (O-H) confiança 1,0
“O-H (stretching of alcohols) band at 3495 The three sericin extracts in this study were found to”
Profiling of Silk Sericin from Cocoons of Three Southern African Wild Silk Moths with a Focus on Their Antimicrobial and Antioxidant Properties DOI: 10.3390/ma13245706 -
Hydroxyl (O-H) confiança 1,0
“A broad band was observed at ~3495 It could be represented to the stretching frequency of Ni(OH) present in the hydrogen bonded hydroxyl groups.”
Ni(OH)2-decorated nitrogen doped MWCNT nanosheets as an efficient electrode for high performance supercapacitors DOI: 10.1038/s41598-019-42281-z -
Hydroxyl (O-H) confiança 1,0
“The broad PEG after hydrolysis (1b C) cm-1 band appearing at 3495.09 corresponds to the associated -OH stretching vibrations of the X-ray diffraction (XRD)”
Shivashankar 和 Mandal - 2013 - Design and Evaluation of Chitosan-Based Novel pH-S DOI: 10.4314/tjpr.v12i2.4
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