What absorbs at 3140 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 3140 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.

Possibili assegnazioni di gruppi funzionali

La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.

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 3140 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.

Letteratura dietro queste assegnazioni

• Alkyl C-H affidabilità 1,0

  “In the FTIR spectrum of [DEIm][Br] (Figure 1b), cm-1 C-H the peak at 3140 was due to the bond of imidazole ring,63”

  Ionic Liquid Functionalized Metal–Organic Framework ([DEIm][PF6]@MOF-5): Synthesis, Characterization, and Catalytic Application in the Reduction of 4-Nitrophenol DOI: 10.1021/acsomega.2c05808
• Aromatic ring affidabilità 1,0

  “Louis, MO, USA) were added to the inactivated peaks observed at 3140 are attributed to aromatic C-H cell medium at 45 °C for 1 h and incubated at 37 °C in an stretching vibration bands.”

  Erol 等 - 2023 - ZnO-containing nanocomposites produced from Mentha DOI: 10.1007/s10965-023-03461-8
• Hydrogen bond affidabilità 1,0

  “Bands at 3140 and 3093 could be attributed to the valence vibration of intramolecular hydrogen bond in the EA molecule cm-1 [44].”

  Ilic-Stojanovic 等 - 2018 - Thermosensitive hydrogels for modified release of DOI: 10.1080/00914037.2017.1354202
• Silicon-oxygen (Si-O) affidabilità 1,0

  “7 the FTIR absorption between 3236 and 3250 is due to hydroxyl ions of the clay minerals, cm-1 and the peak at 3140 can be attributed to hydrated ferric oxide.”

  Sanchez-Polo 等 - 2019 - An Archaeometric Characterization of Ecuadorian Po DOI: 10.1038/s41598-018-38293-w
• N h affidabilità 0,7

  “Same sentence as above.”

  Innovative non-thermal plasma disinfection process inside sealed bags: Assessment of bactericidal and sporicidal effectiveness in regard to current sterilization norms DOI: 10.1371/journal.