What absorbs at 1215 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1215 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 1215 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

• Alkyl C-H confidence 1.0

  “suggested the active chemical functional groups concentration of H 2 1437cm-1, 1373cm-1 1215cm-1 eCH CeOeC peak at peak at and peak at were susceptible to of>CH 2 3 oxidation.”

  Effect of oxidation processing on the surface properties and floatability of Meizhiyou long-flame coal DOI: 10.1016/j.fuel.2017.08.053
• C-S single bond confidence 1.0

  “cm-1 Moreover, the absorption around 1214.89 and 1216.14 represents the availability of sulfated functional groups such as C-S-O and S-O [50,54].”

  Characterization of Polyhydroxybutyrate, PHB, Synthesized by Newly Isolated Haloarchaea Halolamina spp. DOI: 10.3390/molecules27217366
• Amide confidence 1.0

  “FTIR peaks and their assignments for as-deposited Sb2S3 0.01M PAni 0.05M PAni Peaks Functional group 591 592 592 Sb2S3 Symmetric bending Sb2S3 Charge delocalization 1024 1020 1046 C-N+ stretching - 1215 - PAni”

  Enhanced electrical response in Sb2S3 thin films by the inclusion of polyaniline during electrodeposition DOI: 10.1016/j.physb.2009.10.016
• N-O bond confidence 1.0

  “All the spectra are shifted along the y-axis for clarity and the region is ~ 4000 to 375 cm-1 samples after the removal process, suggesting that the intense double band at 1215 and 1246 is attributed hydrogel left no residues (within the de”

  Evaluation of polyvinyl alcohol–borax/agarose (PVA–B/AG) blend hydrogels for removal of deteriorated consolidants from ancient Egyptian wall paintings DOI: 10.1186/s40494-019-0264-z
• Nucleic acid confidence 1.0

  “In the dehydrated state for the cm-1 cm-1, same drugs the 1225 had split into two bands 1215 and 1234 which indicates the partial 2cm-1 transformation into the A-DNA conformation [38].”

  The Application of ATR-FTIR Spectroscopy and the Reversible DNA Conformation as a Sensor to Test the Effectiveness of Platinum(II) Anticancer Drugs DOI: 10.3390/s18124297
• confidence 1.0

  “Bands at about 1215, 1085, 807, and are assignable to the asymmetric and symmetric stretching ] (] (a) as(Si-O-Si) and s(Si-O-Si)) of the support framework.”

  Alahmadi 等 - 2013 - Preparation of Organic-Inorganic Hybrid Materials DOI: 10.1155/2013/634863
• Hydroxyl (O-H) confidence 1.0

  “cm-1, cm-1, cm-1, cm-1, cm-1, cm-1 1736 1621 1560 1396 1215 and 1045 related to OH cm-1, 1736 cm-1, 1621 cm-1, 1560 cm-1, 1396 cm-1, 1215 cm-1, and 1045 cm-1 related to OH sp2-hybridized groups, the stretching of carboxylic acid groups, C g”

  Effect of rGO wt.% on the Preparation of rGO/CuO Nanocomposites at Different Test Periods and Temperatures DOI: 10.3390/cryst12101325
• C-O single bond confidence 1.0

  “The cm-1 band at 1650 has been assigned to the carbonyl stretching vibration, a number of cm-1, skeletal ring vibrations at 1598, 1490 and 1413 the asymmetric stretching of ether cm-1, group at 1277 and 1190 the aromatic hydrogen in-plane d”

  Mechano-Chemical Properties of Electron Beam Irradiated Polyetheretherketone DOI: 10.3390/polym14153067