What absorbs at 3165 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 3165 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.

Attributions possibles de groupes fonctionnels

Le classement reflète les preuves bibliographiques accumulées, et non une règle faisant autorité. Confirmez toujours dans le contexte de votre échantillon.

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 3165 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.

Bibliographie derrière ces attributions

• Hydroxyl (O-H) confiance 1,0

  “(-OH) profile cm-1 of the matrix rings with CRL appeared as a peak at 3165 ALG/NC/MMT revealed a similar degradation as that of ALG/ NC/MMT(Fig.2a)withnewmasslosses(11.35%)at∼230℃to280℃ -OH (Fig.”

  Hussin 等 - 2020 - Taguchi design-assisted immobilization of Candida DOI: 10.1016/j.enzmictec.2019.109506
• Nitrate confiance 1,0

  “The formation of AgNPs of silver nitrate containing extract showed different characteristic peaks at 3165 cm-1 adenophorum extract was confirmed by observing a visible for -OH stretching vibration, at 1722 for -C-H cm-1 color change from li”

  Green synthesis of silver nanoparticles using Eupatorium adenophorum leaf extract: characterizations, antioxidant, antibacterial and photocatalytic activities DOI: 10.1007/s11696-023-02676-9
• Amide confiance 1,0

  “characteristic absorption peaks of GO but also owns its particular peaks from IPTMS including the -NH cm-1, and C-N stretching vibration of secondary amines at 3165 and 1259 symmetric and asymmetric cm-1 stretching vibrations of -CH and -CH”

  Using 3-Isocyanatopropyltrimethoxysilane to Decorate Graphene Oxide with Nano-Titanium Dioxide for Enhancing the Anti-Corrosion Properties of Epoxy Coating DOI: 10.3390/polym12040837
• Water (H2O) confiance 1,0

  “O-Hpeakcentered stretching bandsat 3165 and3123 attributed to bonding of Otherprominent 4C4-H C5-H) C2-H, respectively.71,81 [BF feature from water are recognized as the bending band at 1637 ] with (or and cm-1andabroadbandat∼2109cm-1assign”

  MacMillan 等 - 2012 - Interaction of Water Vapor with the Surfaces of Im DOI: 10.1021/jp305029n
• N h confiance 1,0

  “It can also be seen that the bands at 3020 and 2820 and at cm-1 3165 in the NH stretching region, are identified as the ammonium ions and coordinated ammonia, respectively.”

  Preparation and Characterization of -Zinc Molybdate Catalyst: Efficient Sorbent for Methylene Blue and Reduction of 3-Nitrophenol DOI: 10.3390/molecules23061462