What absorbs at 1268 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1268 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 1268 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

• Acetate 신뢰도 1.0

  “The lignin specific FTIR peaks cm-1 noticed at 1268 , depicted the change in lignin's guaicyl ring plus C=O stretch.”

  Majeed 等 - 2017 - Lignin macromolecule's implication in slowing the DOI: 10.1002/star.201600362
• Acetate 신뢰도 1.0

  “Although hardwood lignin also contains guacm-1 (12) for syringyl ring and C-O stretch in lignin and iacyl moities, the absorption band at 1268 may have cm-1(13) cm-1.”

  Pandey 和 Pitman - 2003 - FTIR studies of the changes in wood chemistry foll DOI: 10.1016/S0964-8305(03)00052-0
• Acetate 신뢰도 1.0

  “The cm-1 peak 1507 could be attributed to an aromatic skeletal of lignin from lignocellulosic cm-1 materials and the medium band at 1268 is attributed to C-O stretching of phenol in lignite”

  Optimization of primary sewage sludge and coal lignite by microwave assisted pyrolysis for the production of bio oil DOI: 10.1080/09593330.2020.1797903
• C-O single bond 신뢰도 1.0

  “From the recent degraded sample (A') to the less aged one (B': 19th century), the cm-1 few changes concern the decrease in the intensity band at 1268 related to Car-O of ether group in guaiacyl monomer (methoxyl group branched to aromatic),”

  Impact of Natural Degradation on the Aged Lignocellulose Fibers of Moroccan Cedar Softwood: Structural Elucidation by Infrared Spectroscopy (ATR-FTIR) and X-ray Diffraction (XRD) DOI: 10.3390/fermentation8120698
• Acetate 신뢰도 1.0

  “1300-1320 C-O stretch doublet to lower wavenumbers at 1268 and 1245 cm-1 cm-1.”

  Modelling ATR-FTIR Spectra of Dental Bonding Systems to Investigate Composition and Polymerisation Kinetics DOI: 10.3390/ma14040760
• C c single bond 신뢰도 1.0

  “The three peaks appearing at 1268, 1390, cm-1 and 2925 are characteristic to C-C, C=C, and C-H stretching vibrations, respectively, proving the presence of alkyl and aryl groups [32,35].”

  Fares 等 - 2021 - Influence of Nitrogen-Doped Carbon Dot and Silver DOI: 10.3390/chemosensors9030052
• Phosphate (PO4) 신뢰도 1.0

  “(P-O-C or P-OH stretching), 1268”

  Functionalization of poly(glycidylmethacrylate) with iminodiacetate and imino phosphonate groups for enhanced sorption of neodymium - sorption performance and molecular modeling DOI: 10.1016/j.reactfunctpolym.2022.105389
• Acetate 신뢰도 1.0

  “and at 1268 due to cm-1 -C-O-C stretching.”

  Kuen 等 - 2017 - Increased Loading, Efficacy and Sustained Release DOI: 10.3390/nano7110379