What absorbs at 3490 cm⁻¹ in an FTIR spectrum?
A band near 3490 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
Resposta rápida
A band near 3490 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 |
| Hydrogen bond | 2 | 2 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
| Chitosan | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| N h | 1 | 1 | 0,9 |
A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.
Materiais possíveis
| Material | Picos de suporte | Grupos sobrepostos | Fontes citadas |
|---|---|---|---|
| chitosan | 3490, 1650, 1655 | Methacrylate, Hydroxyl (O-H), Methoxy (OCH3) | 1 |
| gelatin | 3490, 1652, 3300 | Methacrylate, Hydroxyl (O-H) | 1 |
| Fe3O4 | 3490, 2358, 1673 | Hydroxyl (O-H), Methacrylate | 1 |
| polyester | 3490, 1700, 1250 | Methacrylate, Methoxy (OCH3) | 1 |
| TiO2 | 3490, 1700, 1093 | Hydroxyl (O-H), Methacrylate, Methoxy (OCH3) | 1 |
| bio-based | 3490, 1720, 1740 | Methacrylate, Hydroxyl (O-H) | 1 |
Os materiais são mostrados apenas quando o mesmo conjunto de literatura suporta esta banda e pelo menos um pico característico adicional.
Lógica do espectro
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 3490 cm⁻¹ is usually not enough for material identification by itself.
Uso no mundo real
Este tipo de consulta é comum em identificação de polímeros, triagem de plásticos desconhecidos, solução de problemas de CQ, verificação de materiais reciclados e revisão de atribuição de picos apoiada pela literatura.
Erros comuns
- Tratar uma banda isolada como prova de um material sem verificar pelo menos um ou dois picos de suporte.
- Ignorando sobreposição: vários grupos funcionais podem contribuir próximo ao mesmo número de onda.
- Ignorar a validação quando aditivos, misturas, oxidação ou contaminação podem distorcer o espectro.
Conselho de verificação
Quando a ambiguidade persistir, valide a hipótese com DSC, GC-MS ou TGA, especialmente para misturas, amostras degradadas e polímeros carregados.
Literatura por trás destas atribuições
-
Hydroxyl (O-H) confiança 1,0
“prevalence of gypsum, of the calcium sulfate dihydrate crystalline variety, was confirmed by the IR absorption bands ascribed to the stretching vibration of OH groups at 3490 and 3395 cm-1, bands at 1680 and 1621 cm-1 associated with deform”
New Insights into the Medieval Hispano-Muslim Panel Painting: The Alfarje Found in a Balearic Casal (Spain) DOI: 10.3390/molecules28031235 -
Hydrogen bond confiança 1,0
“The author analyzed the FTIR ter/intramolecular hydrogen bonds and confirmed the cellulose I transition (3290 cm-1 and bands of inter/intramolecular hydrogen bonds and confirmed the cellulose I transition 3333 cm-1) to cellulose II (3440 cm”
Impact of NaOH Concentration on Deweaving of Cotton Fabric in Aqueous Solutions DOI: 10.3390/su13042015 -
Chitosan confiança 1,0
“1 Infrared Spectroscopy cm-1 Investigation of IR spectral data of chitosan films showed a broad band around 3490 due to presence of -OH and -NH groups.”
Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base DOI: 10.3797/scipharm.0912-20 -
Hydroxyl (O-H) confiança 1,0
“The broader absorption centered at 3490 is due to OH groups experiencing stronger”
Mino 等 - 2016 - A surface science approach to TiO2 P25 photocataly DOI: 10.1016/j.apcatb.2016.05.029 -
Hydroxyl (O-H) confiança 1,0
“The cm-1, both uncured and cured UPR samples showed a band at about 3490 originating from cm-1, origspectra of both uncured and cured UPR samples showed a band at about 3490 OH stretching vibration.”
The Effect of Glycol Derivatives on the Properties of Bio-Based Unsaturated Polyesters DOI: 10.3390/polym14152970 -
Hydroxyl (O-H) confiança 1,0
“analyzed in the mid-IR due to broad O-H stretching vibra3490cm(cid:3)1 tions at approximately (Tamm and Tatulian, 1997), which may be an indication of fluid inclusions, water of hydration, or water held in a crystal structure (Anderson et a”
Preston 和 Genge - 2010 - The Rhynie Chert, Scotland, and the Search for Lif DOI: 10.1089/ast.2008.0321 -
Hydroxyl (O-H) confiança 1,0
“Indeed, the stretching vibrations of the cm-1, C-H C-N and are appeared at 2877 and 1382 Furthermore, the absorption bands centered at 3490 and cm-1 1639 are attributed to the acidic OH and carbonyl groups, respectively, which all confirm t”
Ultrasound-Promoted preparation and application of novel bifunctional core/shell Fe3O4@SiO2@PTS-APG as a robust catalyst in the expeditious synthesis of Hantzsch esters DOI: 10.1038/s41598-023-33990-7 -
Hydroxyl (O-H) confiança 1,0
“It is obvious that the peak at 1738/cm is caused by stretching vibration of the functional group of Discussions C-O and the peak at 3490/cm is attributed to the stretching Fourier-transform infrared spectroscopy analysis vibration of functi”
Shirazaki 等 - 2017 - Electrospun Gelatinpoly(Glycerol Sebacate) Membra DOI: 10.4103/abr.abr_197_16
Tem um espectro com esta banda?
Carregue seu espectro FTIR e obtenha um relatório de interpretação completo — atribuições de picos com citações da literatura, correspondências de biblioteca e uma cadeia de evidências com nível de confiança — em segundos.