What absorbs at 3684 cm⁻¹ in an FTIR spectrum?
A band near 3684 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
Resposta rápida
A band near 3684 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) | 5 | 4 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Water (H2O) | 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.
Materiais possíveis
| Material | Picos de suporte | Grupos sobrepostos | Fontes citadas |
|---|---|---|---|
| chitosan | 3684, 1650, 1655 | Amide, Hydroxyl (O-H), N h | 1 |
| sodium alginate | 3684, 1636, 1080 | Hydroxyl (O-H), Amide | 1 |
| collagen | 3684, 1408, 1660 | Amide, N h | 1 |
| zeolite | 3684, 1013, 1245 | Hydroxyl (O-H), Metal oxygen, N 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 3684 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
-
confiança 1,0
“O-H M-H-A-S-De-He 1168, 1240 S=O, S-O cm-1 A peak at 3684 was observed on the surface of the M-H sample, which can be attributed to the adsorption of the stretching vibrations of OH groups, suggesting that”
Surface Heparinization of a Magnesium-Based Alloy: A Comparison Study of Aminopropyltriethoxysilane (APTES) and Polyamidoamine (PAMAM) Dendrimers DOI: 10.3390/jfb13040296 -
Hydroxyl (O-H) confiança 1,0
“3b), the sharp and innation for the relative intensity variations of the 3693 and 7240cm-1 ∼7212cm-1 3684cm-1 tense signals observed at and corfeatures between the FTIR and Raman spectra respond to the stretching of inner OH groups in Mg an”
Fritsch 等 - 2021 - Structural, textural, and chemical controls on the DOI: 10.5194/ejm-33-447-2021 -
Hydroxyl (O-H) confiança 1,0
“IR spectrum of tofacitinib presented in Figure 3C showed noticeable bands at cm-1 cm-1 3684 and 3446 due to stretching of the O-H group.”
Development of Tofacitinib Loaded pH-Responsive Chitosan/Mucin Based Hydrogel Microparticles: In-Vitro Characterization and Toxicological Screening DOI: 10.3390/gels9030187 -
Water (H2O) confiança 1,0
“The IR measurements were performed 10(cid:1)3 SAPO-5 with water adsorbed at mbar showed using in situ IR microspectroscopy on single large cm(cid:1)1 IR absorption bands at 3684, 3160 and 2540 with a crystals of MeAPO-5, that allowed us to”
Muller 等 - 2004 - Interactions of water and methanol with MeAPO-5. F DOI: 10.1016/j.micromeso.2003.12.025 -
confiança 1,0
“cm-1 The band located between 3684 and 3113 is attributed to the N-H stretching vibration”
Active Biopolymeric Films Inoculated with Bdellovibrio bacteriovorus, a Predatory Bacterium DOI: 10.3390/coatings11050605 -
Hydroxyl (O-H) confiança 1,0
“(cm-1) Band Functional Group and Commonly Assigned Compound Wavenumber 3684 A O-H stretching (inner-layer Al-O ...”
Assessing the Aflatoxin B1 Adsorption Capacity between Biosorbents Using an In Vitro Multicompartmental Model Simulating the Dynamic Conditions in the Gastrointestinal Tract of Poultry DOI: 10.3390/toxins10110484
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