What absorbs at 783 cm⁻¹ in an FTIR spectrum?
A band near 783 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 783 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 |
|---|---|---|---|
| Metal oxygen | 2 | 2 | 1,0 |
| Secondary amine | 2 | 2 | 1,0 |
| Alkyl C-H | 2 | 1 | 1,0 |
| Metal oxo | 1 | 1 | 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 |
| Nucleic acid | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Metalloid oxygen | 1 | 1 | 0,8 |
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 |
|---|---|---|---|
| MWCNT | 783, 2876, 1430 | Alkyl C-H | 1 |
| TiO2 | 783, 1700, 1093 | Metal oxygen, Alkyl C-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 783 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
-
Amide confiança 1,0
“the FTIR spectra of as prepared PPy showed the important characteristic cm-1, peaks at 783 which corresponds C-N vibration.”
Highly Biological Active Antibiofilm, Anticancer and Osteoblast Adhesion Efficacy from MWCNT/PPy/Pd nanocomposite DOI: 10.1016/j.apsusc.2017.10.142 -
confiança 1,0
“Furthermore, and 783 cm-1, which have been assigned to Ti-O-Ti vibrations [34,35].”
Enhancing Free Cyanide Photocatalytic Oxidation by rGO/TiO2 P25 Composites DOI: 10.3390/ma15155284 -
N h confiança 1,0
“The FTIR of LX (pure drug) shown intense bands at 3060 cm-1, 1647 cm-1, 1590 cm-1, cm-1, cm-1 1590 1323 and 783 corresponding to the functional groups NH, C=O, cm-1, 1323 cm-1, and 783 cm-1 corresponding to the functional groups NH, C=O, CO”
Almotairi 等 - 2022 - Design and Optimization of Lornoxicam Dispersible DOI: 10.3390/ph15121463 -
Alkene (C=C) confiança 1,0
“Peak at 783.4 indicates treatment with US and O3 C-- To estimate cumulative biogas production, many studies have the presence of alkene compounds and C bending.”
Enhancement of biogas production from individually or co-digested green algae Cheatomorpha linum using ultrasound and ozonation treated biochar DOI: 10.1016/j.ultsonch.2022.106197 -
Hydroxyl (O-H) confiança 1,0
“cm-1 cm-1 cm-1 3296 (OH vibration), 2947 (asymmetrical CH stretching vibration), 2875 shifted slightly to 1110, 993 and 783 cm-1, respectively.”
Morphology and Selected Properties of Modified Potato Thermoplastic Starch DOI: 10.3390/polym15071762 -
Nucleic acid confiança 1,0
“In particular, a decrease in Raman bands related to nucleic acids (1484, 783 cm-1) in the log phase compared to lag phase was observed [25].”
Kochan 等 - 2020 - Vibrational Spectroscopy as a Sensitive Probe for DOI: 10.3390/s20123452 -
confiança 1,0
“The bands at ~3550, (C=O 3406 (OH stretching vibration), and additionally 1113 and 668 cm-1 (S-O stretching and bending, respectively) indicated the presence of gypsum, whereas the bands at 1640, 1325 stretching cm-1 respectively) indicated”
Investigating the Potential of the Er:YAG Laser for the Removal of Cemented Dust from Limestone and Painted Plaster DOI: 10.3390/coatings10111099 -
confiança 1,0
“30 cm(cid:0) 1, Al(cid:0) OH stretching and bending of tetrahedral 1120 31 Al(cid:0) aluminum is observed, respectively, while O stretching of 32 octahedral aluminum is assigned to the bands at 783 and”
Synthesis and Characterization of Ru‐Loaded Anodized Aluminum Oxide for Hydrogenation Catalysis DOI: 10.1002/open.201900091
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