What absorbs at 1585 cm⁻¹ in an FTIR spectrum?
A band near 1585 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 1585 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
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Amide | 16 | 14 | 1.0 |
| Carboxyl (COOH) | 14 | 12 | 1.0 |
| Carbonyl (C=O) | 8 | 8 | 1.0 |
| Aromatic ring | 8 | 7 | 1.0 |
| Methacrylate | 7 | 7 | 1.0 |
| Acetate | 7 | 7 | 1.0 |
| Ketone | 6 | 6 | 1.0 |
| Ester | 6 | 6 | 1.0 |
| Alkene (C=C) | 6 | 4 | 1.0 |
| N h | 5 | 4 | 1.0 |
| Ring structure | 4 | 4 | 1.0 |
| C=n | 4 | 4 | 1.0 |
| Alkyl C-H | 3 | 3 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| Nucleic acid | 2 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Carbon dioxide | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Oxalate | 1 | 0 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PVA | 1585, 1660, 2930 | Carbonyl (C=O), Amide | 1 |
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 1585 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
-
Hydrogen bond confidence 1.0
“A strong absorption cm-1 peak at 1585 is attributed intramolecular H bonds of the alcohols group.”
Chen 等 - 2019 - Baltic amber or Burmese amber FTIR studies on amb DOI: 10.1016/j.saa.2019.117270 -
Carbonyl (C=O) confidence 1.0
“cm-1, with asymmetric mode has a broad peak centered at 1585 Oxygen vacancies, due to thermal treatment, allows for binding cm-1 that suggests higher carbonyl character, a shoulder at 1635 sites into the framework of the AMO structure.”
Durand 等 - 2010 - Reaction of Formic Acid over Amorphous Manganese O DOI: 10.1021/jp104629j -
Alkene (C=C) confidence 1.0
“bending at peak 1629 While for the C=C stretching vibration for alkene was observed at peak 1585 cm-1 cm-1 and 1340 indicated to C=C (aromatic) and asymmetric stretching of N=O (NO 2) Strong peak at 1499 group.”
Synthesis and characterization of Heck-cross coupling 4-(4-nitrostyryl) aniline as potential precursor in Schiff-base synthesis DOI: 10.1063/1.5002293 -
Carboxyl (COOH) confidence 1.0
“in particular, changes provided very similar Q 1 A 1364(+)/1404(-) cm-1 particular, the carboxylate bands at were not observed for the amide I and II bands, of which 1585(+)/1566(-) cm-1 for symmetric and for asymmetric formation was signif”
Kimura 和 Ono - 2001 - Chelator-induced disappearance of carboxylate stre DOI: 10.1021/bi011216w -
Aromatic ring confidence 1.0
“LLM confirmed rule peak-group candidate”
Suneetha 和 Vedhi - 2013 - Synthesis, Characterisation and Voltammetric behav DOI: 10.4028/www.scientific.net/AMR.678.258 -
confidence 1.0
“The vibration at 616 cmat 1585 and 1644 cm-1 can be attributed to the vibrations of Cu-O, confirming the formation of pure Cu-O metal can be attributed to the vibrations of Cu-O, confirming the formation of pure Cu-O metal 1 nanoparticles [”
Spectroscopic and Antibacterial Properties of CuONPs from Orange, Lemon and Tangerine Peel Extracts: Potential for Combating Bacterial Resistance DOI: 10.3390/molecules26030586 -
confidence 1.0
“UV-vis spectroscopy shows cm-1 that the absorption peak of MG decreased, while FTIR shows that the band at 1585 corresponded”
Synthesis of iron-based nanoparticles by green tea extract and their degradation of malachite DOI: 10.1016/j.indcrop.2013.09.024 -
Acetate confidence 1.0
“(2800-3000)cm-1 C=O carbonyl stretch 1732.61 C=O stretching of carbonyl 1585.21 (1550-1780)cm-1 group”
Abead 等 - 2023 - Study physical characteristics of Polyvinyl Alcoho DOI: 10.15764/pche.2014.02001.
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