What absorbs at 401 cm⁻¹ in an FTIR spectrum?

Resposta rápida

A band near 401 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 401 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

• N h confiança 1,0

  “the peak at 401.2 4+ eV corresponds to NH in the APP.”

  Liang 等 - 2020 - Thermal Kinetics of a Lignin-Based Flame Retardant DOI: 10.3390/polym12092123
• confiança 1,0

  “The weak peak at 401.1 eV is indicative of the presence of terminal amino functional group, originating from the incomplete”

  Dual Roles of [NCN]2- on Anatase TiO2: A Fully Occupied Molecular Gap State for Direct Charge Injection into the Conduction Band and an Interfacial Mediator for the Covalent Formation of Heterostructured g-C3N4/a-TiO2 Nanocomposite DOI: 10.1016/j.apcatb.2020.119036
• Ammonium confiança 1,0

  “In this investigation, a novel compound characteristic peak at 401.36 eV corresponding to the -NH3?.”

  Synthesis of a novel compound based on chitosan and ammonium polyphosphate for flame retardancy applications DOI: 10.1007/s10570-019-02671-y
• Metal oxygen confiança 1,0

  “Figure 6b shows that the water contact 2 N-C 15.2° peaks at 400.7 eV were assigned to the bond, suggesting angle of APTMS-TiO 2@SiO was decreased to and that 2 126.2°”

  Wang 等 - 2023 - Surface-Modified TiO2@SiO2 Nanocomposites for Enha DOI: 10.1021/acsomega.3c02679
• confiança 1,0

  “The peaks at 401.0 and 404.6 eV are attributed to the amino group (C-N-H) the graphitic N.”

  Underlying Mechanisms of Reductive Amination on Pd-Catalysts: The Unique Role of Hydroxyl Group in Generating Sterically Hindered Amine DOI: 10.3390/ijms23147621
• N h confiança 1,0

  “In bonds), 400.43 (NH contrast, CoPc-immobilized GO showed the shifting of bands and a considerable intensity enhancement of the peak at 400.69 eV due to the electron-withdrawing effect of GO (Fig-”

  Cobalt Phthalocyanine Immobilized on Graphene Oxide: An Efficient Visible-Active Catalyst for the Photoreduction of Carbon Dioxide DOI: 10.1002/chem.201304189
• Secondary amine confiança 1,0

  “BH (Figure For nylon 6-NH, vibrations of amide I and 401.0 eV attributed to the secondary amine and the new 3”

  Yan 等 - 2022 - Functionalized Nylon 6 Fabric as an Efficient and DOI: 10.1021/acsomega.2c03401