What absorbs at 1189 cm⁻¹ in an FTIR spectrum?
A band near 1189 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 5 cited sources
Quick answer
A band near 1189 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 | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| Chitosan | 1189, 1650, 1655 | Amide, 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 1189 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
-
Carboxyl (COOH) confidence 1.0
“are those at 1460 and 2 3 1276cm-1 COOH stretch/bend combination is observed at and 1189cm-1.”
Font 等 - 2007 - Fourier transform infrared spectroscopy as a suita DOI: 10.1016/j.aca.2007.07.021 -
Amide confidence 1.0
“Amide II 1272.94±0.16 0.443±0.121 *** *** II/COO(cid:3) Amide stretching 1188.83±0.08 1195.40±0.05 0.466±0.025 0.324±0.011 ***”
Differentiation in MALDI-TOF MS and FTIR spectra between two pathovars of Xanthomonas oryzae DOI: 10.1016/j.saa.2014.06.056 -
confidence 1.0
“These control experiments also in the Fe-containing systems (Figure 6c and e), as an additional cm-1, signifying the existence of at uptake of the support the fact that the dissimilar initial NO nitrite band exists at 1189 x least one more”
Kayhan 等 - 2010 - Fe Promoted NOx Storage Materials Structural Prop DOI: 10.1021/jp907982q -
Ring structure confidence 1.0
“to one in-plane ring deformation, predicted at 1189 vibration modes, are essentially invariant upon deuteration, the Our on cm-1”
Low-Temperature FTIR Spectroscopic and Theoretical Study on an Energetic Nitroimine: Dinitroammeline (DNAM) DOI: 10.1021/jp711153g -
C-O single bond confidence 1.0
“at 1189 cm-1, due to 1,4-glycosidic bonds;”
Chitosan Graft Copolymers with N-Vinylimidazole as Promising Matrices for Immobilization of Bromelain, Ficin, and Papain DOI: 10.3390/polym14112279
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