FTIR PEAK-TOLKNING

What absorbs at 738 cm⁻¹ in an FTIR spectrum?

A band near 738 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.

Backed by 7 cited sources

Quick answer

A band near 738 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

Funktionel gruppe Understøttende fakta Citerede kilder Højeste tillid
Carboxyl (COOH) 1 1 1,0
Alkene (C=C) 1 1 1,0
Metal oxygen 1 1 1,0
Imide 1 1 1,0
Ring structure 1 1 1,0

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

Possible materials

Materiale Understøttende toppe Overlapping groups Citerede kilder
polyimide 738, 1720, 1778 Carboxyl (COOH), Imide 1

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 738 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

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