What absorbs at 1801 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1801 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 funktionelle gruppetildelinger

Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.

Possible materials

Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.

Spectrum logic

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 1801 cm⁻¹ is usually not enough for material identification by itself.

Real-world usage

This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.

Common mistakes

• Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
• Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
• Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.

Verification advice

When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.

Litteratur bag disse tildelinger

• Carbon dioxide tillid 1,0

  “For these results, the signals at 870 cm-1 indicating the cm-1 presence of Ca-O bonds, the band at 1386 is the band relative to CaCO (formed 3 presence of Ca-O bonds, the band at 1386 cm-1 is the band relative to CaCO3 (formed cm-1 during t”

  Direct Polypropylene and Polyethylene Liquefaction in CO2 and N2 Atmospheres Using MgO Light and CaO as Catalysts DOI: 10.3390/ma15030844
• Acetate tillid 1,0

  “compares the FTIR spectra of the Eudragit E film at 30 and intensityof a new peak at due to the asymmetric stretching 1801C, Several characteristic IRabsorptionbands and their assignments at the mode of C-O-C also increased beyond strongly”

  DSC-FTIR microspectroscopy used to investigate the heat-induced intramolecular cyclic anhydride formation between Eudragit E and PVA copolymer DOI: 10.1038/pj.2011.15;