What absorbs at 908 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 908 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.

Possible functional-group assignments

Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.

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 908 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.

Literature behind these assignments

• confidence 1.0

  “showed special peaks at 908 and 728 related to The FESEM results indicated that Zn/Zn5(OH)8Cl2·H2O consists of a flower-like nanostructure and these flower-shaped structures contain”

  Facile fabrication of Zn/Zn5(OH)8Cl2·H2O flower-like nanostructure on the surface of Zn coated with poly (N-methyl pyrrole) DOI: 10.1016/j.apsusc.2011.07.046
• Alkyl C-H confidence 1.0

  “X X Code (%) (%) (%) lack of the characteristic band at 908 or 912 c(DSC) c1(FTIR) c2(FTIR) b assigned22-24 to the CH rocking mode of crystal 3 T 26”

  Characterization of poly(lactic acid) multifilament yarns. I. The structure and thermal behavior DOI: 10.1002/app.32046
• confidence 1.0

  “A prominent band 908cm-1 at observed in our case corresponds to the bending vibration of V Zn-H ABO║ [15].”

  Singh 等 - 2012 - Detection of Defects in ZnO Nanoparticles by Spect DOI: 10.1063/1.4736887
• Borate confidence 1.0

  “cm(cid:0) (4A2g→ 2T2b) 1 = 10Dq+9B+3C B-O-B ΔE3 The appearance of a band at ~908 may be attributed to (12) units [53].”

  Influence of BaO on spectral studies of Cr2O3 doped titanium-boro-tellurite glasses DOI: 10.1016/j.optmat.2020.110329
• confidence 1.0

  “In the fingerprint region, the HNT showed a series of bands cm-1, cm-1 cm-1 with peaks at wavenumbers 908 798 and 752 that can be assigned to the Al-Al-OH, Al-Mg-OH and Si-O-Al vibrations in the HNT sheet.”

  Selectively Etched Halloysite Nanotubes as Performance Booster of Epoxidized Natural Rubber Composites DOI: 10.3390/polym13203536
• Alkyl C-H confidence 1.0

  “cm-1, the C-H stretching vibration at 2942 cm-1, C-H bending vibrations at 1428 cm-1, and cm-1, cm-1, cm-1, 3322 the C-H stretching vibration at 2942 C-H bending vibrations at 1428 C-O-C stretching vibrations at 1049 cm-1, 988 cm-1, and 908”

  Structural Analysis of Oxidized Sucrose and Its Application as a Crease-Resistant Crosslinking Agent DOI: 10.3390/polym14142842
• confidence 1.0

  “On the other hand, the characteristics 3519cm-1 bands of the Al-OH group transitional vibration band at at 3585 and were observed for calcined kaolinite 908cm-1 Si-O-AlVI 600°C, samples at but the intensity of hydroxide bands was and the be”

  Kassa 等 - 2022 - Characterization and Optimization of Calcination P DOI: 10.1155/2022/5072635
• Silicon (Si) confidence 1.0

  “The IR bands at 2 cm-1 ~1111 and ~1035 were attributed to Si-O stretching out-of-plane and Si-O stretching Wavenumber (cm-1) Assignment cm-1 in-plane, respectively, while the band at ~908 suggested the presence of an Al-OH-Al functional gro”

  Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays DOI: 10.3390/nano12142332