What absorbs at 1440 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1440 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 1440 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 absorption bands at 668 1502 cm-1 cm-1 and 1440 indicate the metallic stretching vibrations in Fe - O.”

  Effect of Gd and Nb on Dielectric and Magnetic Transition temperature of BaTiO3- Li0.5Fe2.5O4 Composites DOI: 10.1016/j.physb.2019.02.035
• Alkyl C-H confidence 1.0

  “region we observed, respectively, the disappearance of the 2960 (cid:2)-undecene reported in Table 3, shows similar values for (60%) 1440cm-1 and signals, both assigned to the -CH species.”

  Giovannozzi 和 Rocchia - 2008 - Effect of the reaction time, reagent concentration DOI: 10.1016/j.snb.2007.10.043
• Carbonyl (C=O) confidence 1.0

  “cm-1 significant(H The 1740 carbonyl peak bance band remains at 1440 tistically = 2.52,df= 2, p = 0.28).”

  Shedding light on sporopollenin chemistry, with reference to UV reconstructions DOI: 10.1016/j.revpalbo.2016.11.014
• Acetate confidence 1.0

  “At around 1440 cm-1, 2 to the -OH and C-O deformation in the carboxyl, phenoxy, and aryl ester [36].”

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

  “LLM confirmed rule peak-group candidate”

  Formulation and characterization of polyester-lignite composite coated slow-release fertilizers DOI: 10.1007/s11998-022-00670-6
• Hydroxyl (O-H) confidence 1.0

  “The bands at 1440 and are due to a bending vibration of O-H.”

  HPTLC and FTIR Fingerprinting of Olive Leaves Extracts and ATR-FTIR Characterisation of Major Flavonoids and Polyphenolics DOI: 10.3390/molecules26226892
• Acetate confidence 1.0

  “The band showing at 1440 cm-1 corresponds to C-O stretching modes of the CO32and 1618 cm-1 in MRSG sample could be attributed to the ion [41].”

  The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant DOI: 10.3390/su13094840
• Amide confidence 1.0

  “566 and C) cm-1 centred at 1440 was assigned to the vibration of the amide functional group due to C = O 2, -CH bending of the skin lipid constituents.”

  Balazs 等 - 2016 - ATR-FTIR and Raman spectroscopic investigation of DOI: 10.1364/BOE.7.000067