What absorbs at 445 cm⁻¹ in an FTIR spectrum?

Resposta rápida

A band near 445 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

A classificação reflete a evidência acumulada da literatura, não uma única regra autoritária. Sempre confirme com o contexto da sua amostra.

Materiais possíveis

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 445 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

• Carbonyl (C=O) confiança 1,0

  “443 The FTIR results for the black paint confirmed the presence of the characteristic absorption 444 peaks of an alkyd paint, dominated by the sharp and intense absorptions at 1720 and 1256 445 cm-1, due to the stretching mode of the carbon”

  Catto 等 - 2021 - Bioremoval of graffiti using novel commercial stra DOI: 10.1111/j.1574-6941.2006.00028.x
• Phosphate (PO4) confiança 1,0

  “Therefore, in the obtained Raman spectra the presence of the phosphate group is highlighted by the vibrational bands at around 445 and 432 cm-1 that could be attributed 𝜈 to (PO43-) bending mode.”

  Development of Silver Doped Hydroxyapatite Thin Films for Biomedical Applications DOI: 10.3390/coatings12030341
• confiança 1,0

  “445 asymmetric stretching vibration of the Si-O-T group between 991 and 977 446 Furthermore, when these bands are compared to the same band in the infrared spectra 447 of the precursors, MK and SSA, there is a shift of this band to a lower”

  Istuque 等 - 2019 - Effect of sewage sludge ash on mechanical and micr DOI: 10.1016/j.conbuildmat.2019.01.093
• confiança 1,0

  “The IR spectrum of pure ZnO particles cm-1 (Figure 5a) showed two characteristic peaks: a broad and very weak peak at 3431 (Figure 5a) showed two characteristic peaks: a broad and very weak peak at 3431 cm-1 correcorresponding to the O-H st”

  Deposition of Zinc Oxide Coatings on Wood Surfaces Using the Solution Precursor Plasma Spraying Process DOI: 10.3390/coatings11020183
• Ester confiança 1,0

  “a group of bands at 1238, 1163, 1114 and 1099 obtained from the 445 cm-1 ester groups stretching vibrations (-C-O);”

  Kharbach 等 - 2021 - New insights into the Argan oil categories charact DOI: 10.1016/j.talanta.2020.122073
• Metal oxygen confiança 1,0

  “The two strong bands at 445 and 610 are attributed to the O-Ti-O bending vibration and asymmetric Ti-O stretching vibration, respectively.”

  In Situ High-Pressure Raman Spectroscopic, Single-Crystal X-ray Diffraction, and FTIR Investigations of Rutile and TiO2II DOI: 10.3390/min13050703
• Silicon (Si) confiança 1,0

  “cm-1 cm-1 υ2-type Two peaks at about 445 and 483 associated with internal deformaTwo peaks at about 445 cm-1 and 483 cm-1 associated with υ2-type internal υ4-type tions (O non-Si-O vibrations) and asymmetric bending (ASB) vibrations deforma”

  Madadi 和 Wei - 2022 - Characterization of Calcium Silicate Hydrate Gels DOI: 10.3390/gels8020075
• confiança 1,0

  “These DTG curves also presented peaks 445 related to the formation of hydrated calcium silicates and calcium aluminates.”

  Moraes 等 - 2019 - Production of bamboo leaf ash by auto-combustion f DOI: 10.1016/j.conbuildmat.2019.03.007