What absorbs at 1532 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1532 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 1532 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

• N-O bond confidence 1.0

  “There were polysaccharides in FA, cm-1, absorption band at around 1532 cm-1 due to -NO group stretching observed in FA was since the peaks were around 1085~1030 which were assigned to the C-O stretching 2”

  Co-Thermal Oxidation of Lignite and Rice Straw for Synthetization of Composite Humic Substances: Parametric Optimization via Response Surface Methodology DOI: 10.3390/ijerph192416875
• Urethane confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Mudri 等 - 2020 - Comparative Study of Aromatic and Cycloaliphatic I DOI: 10.3390/polym12071494
• Alkene (C=C) confidence 1.0

  “PG showed N-H Figure 2a-d depicts the SEM images of the hydrogels withcm-1, cm-1, stretch at 3292 C=C stretch at 1532 and C-Cl out the drugs.”

  Owonubi 等 - 2018 - Characterization and in vitro release kinetics of DOI: 10.1007/s40090-018-0139-2
• confidence 1.0

  “asymmetric stretching 2931 2929 2932 2929 2916 CH2 2873 2874 2876 2878 2874 CH3 symmetric stretching symmetric stretching 2854 2852 CH2 C=O 1640 1640 1635 1634 1652 stretching (Amide I) C=O 1592 stretching +C-N N-H 1532* 1539 1532 1549 1562”

  Organic biopolymers of venus clams: Collagen-related matrix in the bivalve shells with crossed-lamellar ultrastructure DOI: 10.1016/j.bbrep.2021.100939
• Amide confidence 1.0

  “LLM confirmed rule peak-group candidate”

  A comparative study on silicon nitride, titanium and polyether ether ketone on mouse pre-osteoblast cells DOI: 10.1002/mds3.10139.
• confidence 1.0

  “60 85 stretch N-H stretch 1532 80 40 1378”

  Alexander 等 - 2016 - Carboxylation and Decarboxylation of Aluminum Oxid DOI: 10.1155/2016/7950876
• Aromatic ring confidence 1.0

  “0.5V Oxidized 1720 1702 Carboxylic acid (C=0) stretching state 1600 1599 Imine (C=N) stretching 1560-30 Quinoid ring (C=C) stretching 1532 1480-40 1435 Quinoid (>C-N=) stretching 1378 1336 Intermediate order (C- • N)”

  Benyoucef 等 - 2005 - Synthesis and in situ MRS characterization of cond DOI: 10.1016/j.eurpolymj.2004.10.047
• Amide confidence 1.0

  “In case of PU adhesive, a sharp peak at 1532 cm-1 can be identified as amide II vibration of N-H and C=N and a shoulder at 1310 presents the amide III peak [28].”

  The Use of Laminates of Commercially Available Fabrics for Anti-Stab Body-Armor DOI: 10.3390/polym13071077