What absorbs at 1216 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1216 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 1216 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

• C-O single bond confidence 1.0

  “To establish a thermal degradation assessment methodology in rapid 1452 Moreover, the growth of a shoulder is detected in the high cm-1 high-temperature processing of PEEK and CF-PEEK, samples that went frequency side of the ether peak at 1”

  Detecting, characterising and assessing PEEK’s and CF-PEEK’s thermal degradation in rapid high-temperature processing DOI: 10.1016/j.polymdegradstab.2022.110096
• Amide confidence 1.0

  “The FTIR spectra of AC in Acknowledgement ACINA shift in N-H stretching frequency from cm-1 3363 to 3280 and C-N stretching from 1216 The research was funded by DRPM of Ministry of cm-1.”

  Wicaksono 等 - 2017 - Enhancement of solubility and dissolution rate of DOI: 10.4314/tjpr.v16i7.6
• Acetate confidence 1.0

  “After the nitric acid treatment, the peak was observed cm-1 at 1700 due to the C=O stretches of carboxyl or carbonyl groups [33], and the C-O cm-1 stretching at 1216 [34] proved that oxidation generates more oxygenated functional groups on”

  Modified Activated Carbon for Copper Ion Removal from Aqueous Solution DOI: 10.3390/pr10010150
• Silicon (Si) confidence 1.0

  “The band at 1216 (S-28) can be assigned to the Si-O stretching vibrations in Q3 site, characteristic for presence of 1.1 nm tobermorite, while the bands at”

  Colovic 等 - 2013 - Creating of Highly Active Calcium-Silicate Phases DOI: 10.2298/SOS1303341C
• Hydroxyl (O-H) confidence 1.0

  “cm-1), cm-1), cm-1), stretching (1615 C-H bending (1438 O-H bending (1216 C-O-C cm-1), O-H bending (1216 cm-1), C-O-C stretching (1066 cm-1), -CH-O-CHstretching (1003 cm-1), cm-1)”

  Substantial Proton Ion Conduction in Methylcellulose/Pectin/Ammonium Chloride Based Solid Nanocomposite Polymer Electrolytes: Effect of ZnO Nanofiller DOI: 10.3390/membranes12070706
• Acetate confidence 1.0

  “A significant decrease in the O-H stretching band at 3347 with a cm-1 cm-1 corresponding increase in the C=O stretching absorbance at 1740 and C-O stretching at 1216 indicates esterification of wood.”

  Giridhar 等 - 2017 - DIMENSIONAL STABILIZATION OF WOOD BY CHEMICAL MODI DOI: 10.4067/S0718-221X2017005000002
• Aromatic ring confidence 1.0

  “cm-1 In Figure 4, the diffraction peaks of the corn stalks The bands at 1216 and 878 were assigned to the stretch20.7°, 26.5°, 27.7°, 49.9° at and indicated the crystal area ing of the aromatic ring and the out-of-plane bending of -CH exist”

  Guo 等 - 2015 - Synthesis and application of functionalized ionic DOI: 10.1515/epoly-2014-0195
• Acetate confidence 1.0

  “The slight vibrations at 1183 and 957 cm-1 correspond to epoxy groups (C-O), and 2 cm-1 The influential bands at 1216 and 1088 were determined through a siloxane group the 1102 cm-1 is in agreement with C-O of COOH groups [53].”

  Sustainable Remedy Waste to Generate SiO2 Functionalized on Graphene Oxide for Removal of U(VI) Ions DOI: 10.3390/su14052699