What absorbs at 1103 cm⁻¹ in an FTIR spectrum?
A band near 1103 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 1103 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 | 18 | 18 | 1.0 |
| Methacrylate | 17 | 17 | 1.0 |
| Acetate | 17 | 17 | 1.0 |
| Methoxy (OCH3) | 16 | 16 | 1.0 |
| Silicon-oxygen (Si-O) | 6 | 6 | 1.0 |
| Hydroxyl (O-H) | 5 | 5 | 1.0 |
| Silicon (Si) | 4 | 4 | 1.0 |
| Siloxane (Si-O-Si) | 4 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 0.95 |
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 |
|---|---|---|---|
| PMMA | 1103, 1722, 1383 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| Polyethylene | 1103, 1737, 1720 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| polyaniline | 1103, 1565, 1570 | Methacrylate, Acetate | 1 |
| copolymer | 1103, 2921, 1540 | Methacrylate, Acetate | 1 |
| PEG | 1103, 1650, 1342 | 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 1103 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
-
Silicon (Si) confidence 1.0
“The FTIR study on pure cm-1, cm-1 cm-1 SiO confirmed that it exhibits absorption peaks at 1626 1103 and 809 2 cm-1 [83], and its peak at 1103 represents the main asymmetric Si-O-Si stretching mode”
Effects of different inorganic nanoparticles on the structural, dielectric and ion transportation properties of polymers blend based nanocomposite solid polymer electrolytes DOI: 10.1016/j.electacta.2017.07.051 -
Borate confidence 1.0
“∼1103 ∼474 B-O-H δ-bond stretching mode at and located Thus, one may conclude that the deconvoluted cm-1.”
Dalui 等 - 2008 - Boron phosphide films prepared by co-evaporation t DOI: 10.1016/j.tsf.2007.09.047 -
C-O single bond confidence 1.0
“The C-H bending (out of plane) at 925.83 C-H in plane bending (scissoring) at cm-1, cm-1, cm-1 1481.83 C-H stretching (asymmetric) at 2924.09 and stretching ether C-O at 1103.28”
Deswardani 等 - 2017 - Study of Structural and Magnetic Properties of Sil DOI: 10.1088/1757-899X/202/1/012047 -
Alkyl C-H confidence 1.0
“1166 N S bond 1291 C 3214 C H stretching S bond 1103 N FIGURE 3 Scanning electron micrographs (SEM) of copper”
Dey Sadhu 等 - 2020 - Preparation and characterization of polyanilinea DOI: 10.1002/pc.25738 -
Acetate confidence 1.0
“O stretching of ether linkage for lignin (Rosa et al., 2012) 1242 - - - - C 1158 1159 1160 1159 1159 Antisymmetric bridge C O C stretching (glycosidic ring) 1105 1105 1105 1106 C O/C C stretching vibration for ring 1103 1053 1053 1054 C O/C”
Kasyapi 等 - 2013 - Bionanowhiskers from jute Preparation and charact DOI: 10.1016/j.carbpol.2012.10.021 -
Acetate confidence 1.0
“It cm-1 shows that there was a difference at ~1103 between the C-O-C stretching vibration”
Modification of Poplar Wood via Polyethylene Glycol Impregnation Coupled with Compression DOI: 10.3390/f13081204 -
Acetate confidence 1.0
“The presence of the alkene groups (C≡C) can be cm-1 detected at 2344 while 1770, 1554, and 1103 represent C=O stretching, aromatic C=C bending, and C-H stretching,”
Othman 等 - 2017 - Physicochemical properties and methane adsorption DOI: 10.5714/CL.2017.24.082 -
Acetate confidence 1.0
“C-O-C and glycoside (peak 1103 (peak 1467 cm-1) In addition, alpha helix structure (1647 of the amide”
Toan 等 - 2017 - Salicylic acid-induced accumulation of biochemical DOI: 10.1080/17429145.2017.1291859
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