What absorbs at 921 cm⁻¹ in an FTIR spectrum?

Raskt svar

A band near 921 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.

Mulige funksjonelle gruppe-tilordninger

Rangeringen gjenspeiler akkumulert litteraturbevis, ikke en enkelt autoritativ regel. Bekreft alltid mot prøvekonteksten din.

Mulige materialer

Materialer vises kun når samme litteraturbase støtter dette båndet og minst en annen karakteristisk topp.

Spektrum-logikk

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 921 cm⁻¹ is usually not enough for material identification by itself.

Virkelig bruk

Denne typen forespørsel er vanlig i polymeridentifikasjon, screening av ukjent plast, feilsøking i kvalitetskontroll, verifisering av resirkulert materiale og litteraturstøttet gjennomgang av topptilordning.

Vanlige feil

• Behandle ett isolert bånd som bevis på et materiale uten å sjekke minst en eller to støttende topper.
• Ignorerer overlapping: flere funksjonelle grupper kan bidra nær samme bølgetall.
• Hopp over validering når tilsetningsstoffer, blandinger, oksidasjon eller forurensning kan forvrenge spekteret.

Verifiseringsråd

Når tvetydighet gjenstår, valider hypotesen med DSC, GC-MS eller TGA, spesielt for blandinger, nedbrutte prøver og fylte polymerer.

Litteratur bak disse tilordningene

• Silicon (Si) konfidens 1.0

  “Asymmetric stretching of Si-Ois indicated by a peak at 921 [24], symmetric bending of Si-O bond in the SiO4 1 3 cm(cid:0) cm(cid:0) 1 1 units is shown by the peak at 640 [25], asymmetric bending of Si-O-Si bond is shown by the peak at 491 [”

  Reddish-orange emission from sol-gel derived Sm3+-doped Sr2La8(SiO4)6O2 phosphors DOI: 10.1016/j.ijleo.2020.165935
• Alkyl C-H konfidens 1.0

  “Small peaks at 921 and 1045 associated with adventitious hydrocarbons.”

  Wong 等 - 2015 - Synthesis and Characterization of Atomically Flat DOI: 10.1021/jacs.5b03339
• Alkyl C-H konfidens 1.0

  “The peak at 3,014 is due cm-1 3,213 are due to the -C=Cand =CH modes of adsorbed to CH stretching of alkenes (Mistry, 2009), the doublet at 2,9642,921cm-1 groups,whilethe2,877cm-1 acetylene, whose formation is accompanied by the complete is”

  Carbon Domains on MoS2/TiO2 System via Catalytic Acetylene Oligomerization: Synthesis, Structure, and Surface Properties DOI: 10.3389/fchem.2017.00091
• Alkyl C-H konfidens 1.0

  “In detail, the peak at 921 corresponds to the typical bending of C-H of”

  Durazzo 等 - 2018 - Qualitative Analysis of Traditional Italian Dishes DOI: 10.3390/su10114112
• konfidens 1.0

  “Text: 'band at 921 cm-1 is ascribed to the PLLA crystal phases'”

  Nguyen Thai Cuong 等 - 2020 - On the Nanoscale Mapping of the Mechanical and Pie DOI: 10.3390/app10020652
• Alkyl C-H konfidens 1.0

  “cm-1 cm-1 (C=O stretching), ≈1645 (C=O stretching), ≈1329 (C-H bending), ≈1022 and cm-1 cm-1 ≈1100 (C-H carbohydrate skeleton stretching) and 921 (Wang et al., 2016).”

  Development of functional pectin edible films with fillers obtained from red cabbage and beetroot DOI: 10.1111/ijfs.14886
• C c single bond konfidens 1.0

  “The characteristic IR band of cm-1 921 was assigned to the coupling of the C-C backbone stretching with the CH rocking 3 α(cid:48)-forms αmode, which is ascribed to the and [32,33,55].”

  Temperature-Dependent Polymorphism and Phase Transformation of Friction Transferred PLLA Thin Films DOI: 10.3390/polym14235300
• konfidens 0.9

  “Text: 'bands at 946 and 921 correspond to stretching'.”

  Silver-controlled evolution of morphological, structural, and optical properties of three-dimensional hierarchical WO3 structures synthesized from hydrothermal method DOI: 10.1016/j.jallcom.2017.11.095