What absorbs at 2948 cm⁻¹ in an FTIR spectrum?

Raskt svar

A band near 2948 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 2948 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

• Alkyl C-H konfidens 1.0

  “The two cm-1 bands at 2991 and 2948 can be attributed to the C-H bond stretching vibrations of the -CH and 3 bands at 2991 and 2948 cm-1 can be attributed to the C-H bond stretching vibrations of the -CH3 and -CH 2groups, respectively.”

  Awad 等 - 2020 - Experimental Investigation of Methyl Methacrylate DOI: 10.3390/ma13245793
• Alkyl C-H konfidens 1.0

  “cm-1, At 2948 one can see stretches on the main aliphatic chain of the alkanes and alkyl groups (C-H) with moderately strong absorption intensities, which show no change in the function of the cm-1 number of cryogelification cycles.”

  Coria-Hernandez 等 - 2018 - Thermal, Structural, and Rheological Characterizat DOI: 10.3390/polym10040359
• Alkyl C-H konfidens 1.0

  “2, the broad peak near 3396 was the stretching vibration peak of the cm-1 N-H group participating in the hydrogen-bonding carbamate, while the peak at 2948 was the methylene stretching vibration.”

  Jin 等 - 2021 - Preparation of Microspheres and Microfiber Membran DOI: 10.1002/app.39967
• konfidens 1.0

  “Amide A: peptide, protein N-H stretching 3053 Amide B: peptide, protein N-H stretching 2948”

  Metabolic Profile Characterization of Different Thyroid Nodules Using FTIR Spectroscopy: A Review DOI: 10.3390/metabo12010053
• Alkyl C-H konfidens 1.0

  “C-Hstretching cm-1, cm-1, at 2948 and 2897 C-H deformation of secondary alcohol at 1333 and 1239 C-O stretching cm-1, cm-1”

  Zhuang 等 - 2020 - Observation of Potential Contaminants in Processed DOI: 10.3390/app10124345