What absorbs at 743 cm⁻¹ in an FTIR spectrum?
A band near 743 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 743 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 | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Amide | 2 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| N n bond | 1 | 1 | 1,0 |
| Methacrylate | 1 | 0 | 1,0 |
| Ketone | 1 | 0 | 1,0 |
| Ester | 1 | 0 | 1,0 |
| Carboxyl (COOH) | 1 | 0 | 1,0 |
| Carbonyl (C=O) | 1 | 0 | 1,0 |
| Acetate | 1 | 0 | 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 |
|---|---|---|---|
| TiO2 | 743, 1700, 1093 | Metal oxygen, Alkyl C-H | 1 |
| TiO | 743, 1730, 1699 | Alkyl C-H, Metal oxygen | 1 |
| zirconia | 743, 1100, 460 | Metal oxygen | 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 743 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
“RIP Fourier Transmission Infra-Red spectroscopy (FTIR) and it is found that the important peaks cm-1 cm-1 were appeared at 490 due to the benzenoid ring stretching vibration, 1562 for C cm-1 quinoid ring vibration and 743 corresponds to the”
Antistatic and Dielectric properties of one-dimensional Al2+:Nd2O3 nanowire doped polyaniline nanocomposites for electronic application DOI: 10.1016/j.sna.2018.07.018 -
N n bond confiança 1,0
“cm(cid:2)1 cm(cid:2)1 The strong absorbance peaks at 743 and 970 can be assigned to the symmetric and asymmetric vibration modes of vibrations.23,29 n n s(P-O-P) and as(P-O-P) stretching This corresponds to the formation of PO tetrahedral c”
High proton conductivity of NaMg1−xLixHx (PO3)3·yH2O with a three-dimensional open framework in the intermediate temperature range DOI: 10.1039/d1ma00592h -
Metal oxygen confiança 1,0
“the same situations that the absorption band between 743 cm(cid:0) VO3(cid:0) 1 Ti-O of the BiVO4/TiO2 sample is contributed to symmetrical stretching vibrations of in monoclinic BiVO4 and the and 470 4 vibration of TiO2 [23].”
Microstructures, thermal and electric properties of bismuth vanadium oxide (BiVO4) as an anode in electrolysis systems coated with a conductive glass indium thin oxide (ITO) DOI: 10.1016/j.csite.2021.101188 -
Hydroxyl (O-H) confiança 1,0
“Operando spectra collected in contact with ⟶h+ cm-1 218O R-FeIII-OH R-FeIV=O H+ exhibited absorption peaks at 743 and 857 (Fig.”
Determination of photoelectrochemical water oxidation intermediates on haematite electrode surfaces using operando infrared spectroscopy DOI: 10.1038/NCHEM.2557 -
Aromatic ring confiança 1,0
“The spectra of poly (o-chloroaniline) and POC-MMT The characteristic point of phenyl C-N stretching mode appeared at nanocomposites with various load percentages 1,297cm-1, 810cm-1 743cm-1 and the spectrum values at and were (0, 1, 3, 5, 7,”
Iqbal 等 - 2022 - Fabrication of Poly(o-Chloroaniline) to MMT Clay a DOI: 10.3389/fmats.2022.874735 -
Metal oxygen confiança 1,0
“Moreover, sharp cm-1, sharp peaks for the Zr-O group in the monoclinic zirconia are observed at 743 peaks for the Zr-O group in the monoclinic zirconia are observed at 743 cm-1, correspondcorresponding to an increase in the concentration of”
Ponnusamy 等 - 2022 - Synthesis, Structural, and Mechanical Behavior of DOI: 10.3390/ma15082924 -
Aromatic ring confiança 1,0
“The small peaks at 1072, 1122 and 1272 were small peak at 1599 cm-1 was attributed to the aromatic ring, and C-H and C-R bending modes were cm´1 due to C-O groups, and the weak peak at 743 was attributed to aromatic =C-H bending.”
Microcapsules Filled with a Palm Oil-Based Alkyd as Healing Agent for Epoxy Matrix DOI: 10.3390/polym8040125 -
confiança 0,8
“Downward shift to 743 cm-1 reveals uncoordinated or free TFSI anion.”
Liew 等 - 2016 - Poly(Acrylic acid)-Based Hybrid Inorganic-Organic DOI: 10.3390/polym8050179
Tem um espectro com esta banda?
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