What absorbs at 1043 cm⁻¹ in an FTIR spectrum?
A band near 1043 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 1043 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 |
|---|---|---|---|
| C-O single bond | 14 | 14 | 1.0 |
| Methoxy (OCH3) | 12 | 12 | 1.0 |
| Methacrylate | 12 | 12 | 1.0 |
| Acetate | 12 | 12 | 1.0 |
| Alkyl C-H | 6 | 6 | 1.0 |
| Silicon-oxygen (Si-O) | 5 | 5 | 1.0 |
| Silicon (Si) | 4 | 4 | 1.0 |
| Secondary amine | 4 | 4 | 1.0 |
| C n single bond | 4 | 4 | 1.0 |
| Amide | 4 | 4 | 1.0 |
| Alkene (C=C) | 3 | 3 | 1.0 |
| N h | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 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 |
|---|---|---|---|
| TiO2 | 1043, 1700, 1093 | Methacrylate, Acetate, C-O single bond | 1 |
| PE | 1043, 1414, 1700 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| PP | 1043, 1700, 1776 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| gold nanoparticles | 1043, 1638, 3252 | Methacrylate, Acetate | 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 1043 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
-
Amide confidence 1.0
“The peak appearing at 1043 is owing to C-N stretching vibration.”
Crystal Growth, Spectral, Optical, Laser damage, Photoconductivity and Dielectric Properties of Semiorganic L-cystine hydrochloride Single Crystal DOI: 10.1016/j.saa.2015.06.113 -
Alkene (C=C) confidence 1.0
“The transmittance bands at 1043.15 and 944.89 are due to C=C and C-F stretching respectively.”
Haq 等 - 2018 - Fabrication of pure and moxifloxacin functionalize DOI: 10.1016/j.jphotobiol.2018.07.011 -
Amide confidence 1.0
“The peaks 1043, 1643, 2088, 2366-2368 and 3251A cm-1 1o 3410 correspond to the presence of C-N bond of aliphatic amines, N-H bend of amine, M 1o, 2o C≡C stretch of alkynes, C-N bond of nitrogen compounds and N-H stretch of amines and D”
Oladipo 等 - 2017 - Enterococcus species for the one-pot biofabricatio DOI: 10.1016/j.jphotobiol.2017.06.003 -
confidence 1.0
“groups are noted following reaction of bacteria and biomolecules with 2O and a 3 n However, the data also reveal that the presence of low-level amounts (i.e., 0.45-0.79%) of u s cm-1 biomolecular phosphorous groups result in strong IR bands”
Parikh 等 - 2014 - ATR-FTIR spectroscopic evidence for biomolecular p DOI: 10.1016/j.colsurfb.2014.04.022. -
Acetate confidence 1.0
“-OH in plane bending 1043 -C-O stretching 1044 -C-O stretching (cid:3)-glucosidic”
Slightly carbomethylated cotton supported TiO2 nanoparticles as self-cleaning fabrics DOI: 10.1016/j.molcata.2014.11.012 -
Alkyl C-H confidence 1.0
“the 2C-series, which had a single band around 1043 tions for methyl and methylene and the C-H and The ring-related vibrations are observed.”
Identification and characterization of 2,5dimethoxy3,4dimethylphenethylamine (2CG) A new designer drug DOI: 10.1002/dta.1396 -
Acetate confidence 1.0
“Shurvell (2001) [53] reported that the peaks at 1085 cm-1 and 1043 cm-1 are important for ethanol and methanol quantification, corresponding to the C-O stretch absorption bands.”
Characterization of a Spirit Beverage Produced with Strawberry Tree (Arbutus unedo L.) Fruit and Aged with Oak Wood at Laboratorial Scale DOI: 10.3390/app11115065 -
Acetate confidence 1.0
“vibration showed a band at 408 In contrast to IR spectra, C-O bond ester vibrations in PLA were weak, cm-1 and the Raman bands with maxima at 1043 and 1128 were associated with C-CH vibrations.”
Optical photothermal infrared spectroscopy with simultaneously acquired Raman spectroscopy for two-dimensional microplastic identification DOI: 10.1038/s41598-022-23318-2
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