What absorbs at 485 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 485 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 authoritative 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 485 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

  “The FTIR spectra results show (Figure 6) that the absorption peaks at cm-1 485, 519, and 633 are attributed to the Al-O structural vibration and are characteristic peaks of Al 2O 3, consistent with the standard infrared peaks of corundum [1”

  Study on Gemological Characteristics of Blue Sapphires from Baw-Mar Mine, Mogok, Myanmar DOI: 10.3390/cryst11111275
• Metal oxygen confidence 1.0

  “The peak at 485 corresponds to the bending vibration of V-O-V [20].”

  Saravanakumar 等 - 2018 - Role of NaOH concentration on synthesis and charac DOI: 10.1063/1.5047993
• Metal oxygen confidence 1.0

  “Earlier workers have reported the presence of Table 3) which almost matched with the data recorded by cm-1 cm-1 Zn-O 400-500 theDebye-Scherrerprocess.Table4demonstratestherelation the band at 485 [58], 442 [59],”

  Udhayan 等 - 2021 - Evaluation of Bioactive Potential of a Tragia invo DOI: 10.1007/s12668-021-00864-z
• Metal oxygen confidence 1.0

  “Hence, the relative intensity of TiOH(948cm-1),Ti-O-Ti band(485cm-1)”

  Wan 等 - 2006 - Structure and thermal properties of titanium dioxi DOI: 10.1007/s00289-006-0506-6
• Metal oxygen confidence 1.0

  “Zn-O stretching vibrations are shifted to 495 cm-1 from 485 cm-1 with the addition of Cu-O Peak at 485”

  Successive Photocatalytic Degradation of Methylene Blue by ZnO, CuO and ZnO/CuO Synthesized from Coriandrum sativum Plant Extract via Green Synthesis Technique DOI: 10.3390/cryst13020281
• Metal oxygen confidence 1.0

  “2 cm-1 300 (cid:3)C a wide band at 400-500 with maximum at and 500 (cid:3)C almost a plateau in sample mass can be cm-1 about 485 specific to Cu-O vibrations [33] appears.”

  Synthesis of anisotropic Cu2-xS-based nanostructures by thermal oxidation DOI: 10.1007/s10973-019-08622-w
• Acetate confidence 1.0

  “501 νCdO νC-O available, by comparing the position of the bands with charactercoordinates, and the stretching mode, respec485 502 tively.41,73,77 istic bands of similar molecules.”

  Lopes 等 - 2011 - Photochemistry and Vibrational Spectra of Matrix-I DOI: 10.1021/jp110705c
• Acetate confidence 1.0

  “C-O-C likeamines,phenols,alcohols,saponins,carboxylic acids, gave rise to the peak at  485 Antifungal and cytotoxic activities of AgNPs Fourier-transform Si-AgNPs.”

  Rizwana 等 - 2022 - Biosynthesis and characterization of silver nanopa DOI: 10.1515/gps-2022-0048