What absorbs at 1370 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1370 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 1370 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

• Carbohydrate confidence 1.0

  “microfibrils.Thepreferred pulpcharacteristicsfor paper productionare Moreover, the characteristic bands for amorphous cellulose at the presence of long fibres with a large diameter that provide me897cm-1, 1273cm-1, 1370cm-1 1430cm-1 and in”

  Exploring the lignolytic potential of a new laccase producing strain Kocuria sp. PBS-1 and its application in bamboo pulp bleaching DOI: 10.1016/j.ibiod.2019.104726
• Alkyl C-H confidence 1.0

  “polysaccharide band, and the CH band at 1370 Th e PCA results show that the clay and light fraction spectra changed during laboratory incubation (Fig.”

  Calderon 等 - 2011 - Chemical Differences in Soil Organic Matter Fracti DOI: 10.2136/sssaj2009.0375
• Amide confidence 1.0

  “A second amide vibration cm-1 cm-1 appeared at 1420 (C-H stretch), and an amide peak appeared at 1370 (C-H cm-1 stretch).”

  Classification and identification of Rhodobryum roseum Limpr. and its adulterants based on fourier-transform infrared spectroscopy (FTIR) and chemometrics DOI: 10.1371/journal.pone.0172359
• Alkyl C-H confidence 1.0

  “zinc ions, confirmed also by the percentage removal of The peaks at 1370 and cm-1 around 1230 can be due to symmetric vibrations of -CH and of C-O single bond 3”

  Study of Polyvinyl Alcohol-SiO2 Nanoparticles Polymeric Membrane in Wastewater Treatment Containing Zinc Ions DOI: 10.3390/polym13111875
• C-O single bond confidence 1.0

  “vera, with the FTIR revealing peaks at 1739.94 cm (C O stretching vibration), 1370 = -1 1H (deformation of the H-C-OH bonds), and 1370 cm (C-O-C asymmetric stretching vibration);”

  Chou 等 - 2023 - Potential of methacrylated acemannan for exerting DOI: 10.1186/s12906-023-04022-8
• Alkyl C-H confidence 1.0

  “Furthermore, the amide characteristic bands were clearly clearly visible at υ = 1655 and 1604 cm-1 in the spectrum, whereas the CH bands throughcm-1 υ visible at = 1655 and 1604 in the spectrum, whereas the CH bands throughout the CS out th”

  Chitosan Capped Copper Oxide Nanocomposite: Efficient, Recyclable, Heterogeneous Base Catalyst for Synthesis of Nitroolefins DOI: 10.3390/catal12090964
• confidence 1.0

  “vibration stretching appears at 1370 and 1010 The function groups related to the cm-1, PANI are located at 3401, 2918, 1105 for N-H, C-H, C-N aromatic, respectively.”

  Conversion of Sewage Water into H2 Gas Fuel Using Hexagonal Nanosheets of the Polyaniline-Assisted Deposition of PbI2 as a Nanocomposite Photocathode with the Theoretical Qualitative Ab-Initio Calculation of the H2O Splitting DOI: 10.3390/polym14112148
• Carbohydrate confidence 1.0

  “cm-1 that the peak around wavelength 1370 appeared This result is in agreement with and analysis FTIR XRD due to modified cellulose, the peak refers to EFB C-H 2327”

  Jahi 等 - 2020 - Empty Fruit Bunch Cellulose based Sorbent for Oil DOI: 10.17576/jsm-2020-4909-29