What absorbs at 768 cm⁻¹ in an FTIR spectrum?
A band near 768 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 768 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 |
|---|---|---|---|
| Water (H2O) | 2 | 2 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Silicon silicon | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Alkyl C-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.
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 768 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
-
Phosphate (PO4) confiança 1,0
“cm-1 (ii) The peak at 768 is assigned to symmetric stretching vibrations of the P-O-P rings and possible sharing At high dose of irradiation, most of the IR spectral bands of (AlO show distinct decrease in their intensities and a prominent”
Photoluminescence, optical and structural properties of Pr3+-doped fluorophosphate glasses and their induced defects by gamma irradiation DOI: 10.1007/s10854-018-9120-2 -
Aromatic ring confiança 1,0
“The band at 768 was 3.18% regression attributed to the ortho-disubstituted phenyl group.”
Attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) for quantification of piroxicam in tablet dosage from as a green analytical method DOI: 10.1002/vjch.202000049 -
confiança 1,0
“Explicit assignment in text”
Novel Copper(II) Complexes with N4,S-Diallylisothiosemicarbazones as Potential Antibacterial/Anticancer Drugs DOI: 10.3390/inorganics11050195 -
Hydroxyl (O-H) confiança 1,0
“The around 1600 cm-1 H-O-H bending were assigned to Si-Si and The former could be attributed to the bands at ν= 768 and 728 Al-Si stretching vibrations, respectively.”
Nojiri 等 - 2013 - Structural change of alkali feldspar by ball milli DOI: 10.2465/jmps.121122 -
Water (H2O) confiança 1,0
“cm-1 cm-1, both DFO-B applications, the increased maxima at 1637 and 3342 assigned to as the intensive agarose peaks at 1370cm-1, 1037 cm-1, 928 cm-1, 887 cm-1 and 768 cm-1 were hydroxyls, are probably due to the water absorbed during the a”
Desferrioxamine B: Investigating the Efficacy of Hydrogels and Ethanol Gels for Removing Akaganeite and Maghemite from Dry Wooden Substrates DOI: 10.3390/f14020247 -
confiança 1,0
“cm-1 cm-1 parameter in this study, we attempted to estimate those 768 (C-Cl stretch = alkyl halides) and 646 (- C:C-H: phytochemicals quantitatively in MEAIL.”
Identification of food preservative, stress relief compounds by GC–MS and HR-LC/Q-TOF/MS; evaluation of antioxidant activity of Acalypha indica leaves methanolic extract (in vitro) and polyphenolic fraction (in vivo) DOI: 10.1007/s13197-017-2590-z) -
Metal oxygen confiança 1,0
“In Figure 7, the strong peak at 768 cm-1 is due to the W-O bond in the tetrahedral.”
Electro-Oxidation of Metal Oxide-Fabricated Graphitic Carbon Nitride for Hydrogen Production via Water Splitting DOI: 10.3390/coatings12050548 -
Alkyl C-H confiança 0,9
“Text: '768 cm-1 for C-H bending'.”
Bromo-substituted blocked hexamethylene diisocyanate adduct: synthesis, characterization and applica DOI: 10.1080/10601325.2020.1845569
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.