What absorbs at 2903 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 2903 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.

가능한 작용기 할당

순위는 단일 권위 규칙이 아닌 축적된 문헌 증거를 반영합니다. 항상 샘플 상황에 대해 확인하세요.

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 2903 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.

이 할당의 배경이 되는 문헌

• Alkyl C-H 신뢰도 1.0

  “Figure 1a reveals a broad and intense band in the region of 3321 cm-1 stretching vibrations of cellulose, hemicellulose, and lignin [14, 15] while a peak at 2903 corresponded cm-1 to the -CH stretching vibrations.”

  Nanocellulose-silica polyethersulfone hybrid composite stabilized lipase for esterification DOI: 10.1063/1.5125521
• Alkyl C-H 신뢰도 1.0

  “LLM confirmed rule peak-group candidate”

  Characteristics and Preparation of Designed Alginate-Based Composite Scaffold Membranes with Decellularized Fibrous Micro-Scaffold Structures from Porcine Skin DOI: 10.3390/polym13203464
• Alkyl C-H 신뢰도 1.0

  “phospholipids cm-1 The 2903 and 2861 bands represented the CH symmetric stretch, and”

  Lazaro-Pacheco 等 - 2022 - Deciphering the structural and chemical compositio DOI: 10.1080/05704928.2020.1843471
• 신뢰도 1.0

  “The changes in Si-O-Si bonds The two peaks at 2903 and 2829 corresponding cm-1 cm-1 occurring in between 1100 -1000 were due to the to asymmetrical and symmetrical stretching of CH and 3”

  Loganathan 和 Chandrasekar - 2013 - Analysis of Surface Tracking of Micro and Nano Siz DOI: 10.5370/JEET.2013.8.2.345
• Amine primary 신뢰도 1.0

  “cm-1 the peaks 2903 and 2851 Primary amine, NH bend group is responsible for the peaks 1614 and 1524 The 1232 peak is produced by cm-1.”

  Manjunatha 等 - 2023 - Eco-friendly synthesized silver nanoparticles from DOI: 10.21203/rs.3.rs-2345744/v1
• Alkyl C-H 신뢰도 1.0

  “LLM confirmed rule peak-group candidate”

  Adapalene-loaded poly(#_#x03B5;-caprolactone) microparticles: Physicochemical characterization and in vitro penetration by photoacoustic spectroscopy DOI: 10.1371/journal.
• 신뢰도 1.0

  “1472 sity due to formation of the reduced dimers which contain the same cm-1is The band at 2903 attributed to the N-H stretching of groups.”

  Spectroelectrochemical studies of poly(N-methylaniline) formation, redox behaviour and degradation. A comparison with polyaniline DOI: 10.1016/j.electacta.2013.10.179
• Carbohydrate 신뢰도 0.8

  “Hydrogen bond stretching of CH and CH of cellulose.”

  Enhanced arsenic (iii) adsorption from aqueous solution by magnetic pine cone biomass DOI: 10.1016/j.matchemphys.2018.09.067