What absorbs at 1263 cm⁻¹ in an FTIR spectrum?
A band near 1263 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 1263 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 |
|---|---|---|---|
| Methacrylate | 10 | 10 | 1,0 |
| Acetate | 10 | 10 | 1,0 |
| Methoxy (OCH3) | 8 | 8 | 1,0 |
| C-O single bond | 8 | 8 | 1,0 |
| Alkyl C-H | 6 | 4 | 1,0 |
| Carboxyl (COOH) | 3 | 3 | 1,0 |
| Alkene (C=C) | 3 | 3 | 1,0 |
| Ketone | 2 | 2 | 1,0 |
| Ester | 2 | 2 | 1,0 |
| Carbonyl (C=O) | 2 | 2 | 1,0 |
| Amide | 2 | 2 | 1,0 |
| Methyl | 2 | 0 | 1,0 |
| Thiocarbonyl | 1 | 1 | 1,0 |
| Lignin | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Silicon carbon | 1 | 1 | 1,0 |
| C c single bond | 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 |
|---|---|---|---|
| PET | 1263, 1408, 800 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| polypropylene | 1263, 1030, 1600 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| nanocomposite | 1263, 2921, 3300 | Methacrylate, Acetate, C-O single bond | 1 |
| magnetite | 1263, 1740, 1088 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| Kraft lignin | 1263, 1744, 1710 | Methacrylate, Acetate, Methoxy (OCH3) | 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 1263 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
-
Alkyl C-H confiança 1,0
“The spectrum shows also two bands at 1263cm(cid:2)1, C-H C-O 1369 and owing to bending of cellulose and the stretching vibration 1040cm(cid:2)1”
Alkali and epoxy-silane surface modified pine cone flour reinforced polypropylene/poly (lactic acid) DOI: 10.1080/01694243.2021.1952677 -
C c single bond confiança 1,0
“The starch spectrum exhibited three characteristic scattering peaks at 1263, and941cm-1, 1053, whichareduetothestretchingofC-O,C-C,andC-OHbondsbelonging cm-1 to starch [37].”
Preparation and Characterization of Super-Absorbing Gel Formulated from -Carrageenan–Potato Peel Starch Blended Polymers DOI: 10.3390/polym13244308 -
Silicon carbon confiança 1,0
“LLM confirmed rule peak-group candidate”
A forensic international market survey of condom lubricants and personal hygiene products using ATR-FTIR coupled to chemometrics DOI: 10.1016/j.scijus.2021.01.005 -
Alkene (C=C) confiança 1,0
“The characteristic bands at 1508 cm-1 and 1263 cm-1 were determined to be C=C, C-O stretching or bending vibrations of the groups in lignin.”
Cresnar 等 - 2021 - Insight into the Surface Properties of Wood Fiber- DOI: 10.3390/polym13101535 -
Acetate confiança 1,0
“C=O stretching 1724 O-H Overlapping (def.) of C=C ring stretching 1585, 1442 C-O stretching due to phenol 1263 C-H C=C-H (def.) of (o.o.p.) from aromatic rings 800 Weak absorption indicating C-S stretching 730, 710, 678 reported melanins ar”
Purification and characterisation of a sulphur rich melanin from edible mushroom Termitomyces albuminosus Heim DOI: 10.1080/21501203.2018.1494060 -
Acetate confiança 1,0
“Additional lignin-related peaks are those at 1603 cm-1 for aromatic skeletal and C=O stretch vibrations, 1506 cm-1 for the C=C stretch of aromatic skeletal vibration and 1263 cm-1 for the G-ring plus C=O stretch [23].”
Jambrekovic 等 - 2022 - Viscoelastic and Thermal Properties of Styrene Mod DOI: 10.3390/polym14040786 -
Acetate confiança 1,0
“The peaks at 1263 cm-1 is the characteristic peak of CO-O-C, and the characteristic peak of C-O-C is at 1091 cm-1.”
Surface Modification of Carbon Microspheres with Guanidine Phosphate and Its Application as a Flame Retardant in PET DOI: 10.3390/polym12081689 -
Acetate confiança 1,0
“Nanoscale Research Letters Page 6 of 10 (2016) 11:152 cm-1 C-O are attributed to the stretching of 1263”
Kolodynska 等 - 2016 - Development of New Effective Sorbents Based on Nan DOI: 10.1186/s11671-016-1371-3
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.