What absorbs at 1049 cm⁻¹ in an FTIR spectrum?
A band near 1049 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 1049 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 | 17 | 17 | 1.0 |
| Methoxy (OCH3) | 12 | 12 | 1.0 |
| Methacrylate | 12 | 12 | 1.0 |
| Acetate | 12 | 12 | 1.0 |
| Silicon-oxygen (Si-O) | 6 | 6 | 1.0 |
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Carbohydrate | 4 | 3 | 1.0 |
| Silicon (Si) | 3 | 3 | 1.0 |
| Siloxane (Si-O-Si) | 3 | 3 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Carbon dioxide | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Ring structure | 1 | 0 | 1.0 |
| Aromatic ring | 1 | 0 | 1.0 |
| Nucleic acid | 1 | 0 | 0.8 |
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 |
|---|---|---|---|
| starch | 1049, 1650, 1540 | Methacrylate, Acetate, C-O single bond | 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 1049 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 results indicate a strong affinity cm-1 metric stretching around 1049 and Si-O-Si bendof ppTEOS film for methanol gas.”
Bougharouat 等 - 2011 - Plasma polymerization of TEOS for QCM-based VOC va DOI: 10.1051/epjap/2011110144 -
Silicon (Si) confidence 1.0
“After silica encapsulation, there was new around 300-600 cm-1), cm-1), Si-OH (779.24 and Si-Obond vibration typical of silica such as Si-O-Si (1049.28 cm-1).”
Deswardani 等 - 2017 - Study of Structural and Magnetic Properties of Sil DOI: 10.1088/1757-899X/202/1/012047 -
Carbohydrate confidence 1.0
“In agreement with the pubin diseased plant when coupled with a change in the cm-1) lished literature, PCA applied to FTIR spectra underlines cellulose peak (1049.1 indicates that both amide I a substantial role of cell wall compounds in rea”
Synchrotron based phase contrast X-ray imaging combined with FTIR spectroscopy reveals structural and biomolecular differences in spikelets play a significant role in resistance to Fusarium in wheat DOI: 10.1186/s12870-014-0357-5 -
N-O bond confidence 1.0
“At the same time, the infrared-inactive 1-NO band cm-1, appears at 1049 which is the spectral feature of (cid:2) 3cm-1, NaNO droplets.”
Lu 等 - 2008 - Molecular events in deliquescence and efflorescenc DOI: 10.1063/1.2973623(cid:5) -
Acetate confidence 1.0
“With the stretching, 1141 to DNA phosphate symmetric stretchcm-1 cm-1 R D-ribose increasing time of the accumulation, the values gradually ing, 1049 to C - O stretching, 913 to”
Gallic acid-coated silver nanoparticles as perspective drug nanocarriers: bioanalytical study DOI: 10.1007/s00216-022-03955-2 -
Amine primary confidence 1.0
“1049 for primary amine, CN stretch;”
Rajakumar 等 - 2015 - Antiplasmodial activity of eco-friendly synthesize DOI: 10.1007/s00436-015-4318-1 -
confidence 1.0
“The weakest band observed at ~1049 tent from 0.002 to 0.004 M, the specific capacitance value assigned to the atmospheric nitrogen trace in the obtained fall from 183 to 135 F/g which may due to the increase of product.”
Physico-chemical properties of pure and zinc incorporated cobalt nickel mixed ferrite (ZnxCo0.005−xNi0.005Fe2O4, where x = 0, 0.002, 0.004 M) nanoparticles DOI: 10.1007/s10854-017-7556-4 -
Carbohydrate confidence 1.0
“cm-1 Bands at 1049 and 995 are associated with crystalline structures of Journal cm-1 starch, whereas at 1018 is an amorphous structure of starch [6,41].”
Ratnaningsih 等 - 2020 - Physicochemical properties, in vitro starch digest DOI: 10.1016/j.ijbiomac.2019.09.092
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