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

Stutt 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.

Mögulegar úthlutun virkra hópa

Röðun endurspeglar uppsöfnuð ritrýnisgögn, ekki eina valdboðsreglu. Staðfestu alltaf í samhengi við sýnið þitt.

Möguleg efni

Efni birtast aðeins þegar sama bókmenntasafn styður þessa band og að minnsta kosti einn viðbótar einkennandi hámark.

Rófrök

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.

Raunveruleg notkun

Þessi tegund fyrirspurna er algeng við auðkenningu fjölliða, skimun óþekktra plasttegunda, bilanaleit í gæðaeftirliti, staðfestingu endurunnins efnis og bókmenntabakkaða endurskoðun á hápunktum.

Algeng mistök

• Meðhöndla eina einangraða öldulengd sem sönnun á efni án þess að athuga að minnsta kosti einn eða tvo stuðningstoppa.
• Hunsa skörun: mörg virkir hópar geta lagt sitt af mörkum nálægt sömu bylgjutölunni.
• Að sleppa staðfestingu þegar aukefni, blöndur, oxun eða mengun geta brenglað litrófið.

Staðfestingarráðgjöf

Þegar tvíræðni er eftir, staðfestu tilgátuna með DSC, GC-MS eða TGA, sérstaklega fyrir blöndur, niðurbrotin sýni og fylltar fjölliður.

Ritlist á bak við þessar úthlutanir

• Alkyl C-H öryggi 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 öryggi 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 öryggi 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
• öryggi 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 öryggi 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