What absorbs at 919 cm⁻¹ in an FTIR spectrum?
A band near 919 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 919 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 |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Metal oxygen | 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 |
|---|---|---|---|
| PVA | 919, 1660, 2930 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| Cellulose | 919, 1735, 1650 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| quartz | 919, 800, 3053 | Hydroxyl (O-H), Alkyl C-H | 1 |
| poly(vinyl alcohol) | 919, 1700, 2993 | Alkyl C-H, Hydroxyl (O-H) | 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 919 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
-
Alkyl C-H confidence 1.0
“The aliphatic bands in the xylite sample BEX at 2,919 cm-1 2,851 show lower intensities in the chars.”
Georgakopoulos 等 - 2003 - Study of low rank Greek coals using FTIR spectrosc DOI: 10.1080/00908310390232442 -
C c single bond confidence 1.0
“1046.54 1024.02 CH rocky 945.02 2 C-C Stretching 918.58”
Abead 等 - 2023 - Study physical characteristics of Polyvinyl Alcoho DOI: 10.15764/pche.2014.02001. -
Metal oxygen confidence 1.0
“The peaks at 943 and 919 cm-1 in 1 cm-1 cm-1 ν 1 919 in and at 939 and 915 in {P 2W 17} could be assigned to terminal as(W O t) vibration.”
Ibrahim 等 - 2020 - Synthesis, Characterization, Electrochemistry, Pho DOI: 10.3390/molecules25184229 -
C c single bond confidence 1.0
“1038 C-C deformation 958 C-C stretching 919 CH2 rocking”
Kannan 等 - 2023 - Exploration of third order nonlinear optical featu DOI: 10.15251/DJNB.2023.181.367 -
Hydroxyl (O-H) confidence 1.0
“stretching), 918.86 (O-H bending in finger print region), 761.61 (Aromatic region in finger print).”
Kumar 等 - 2018 - Identification of Degradant Products of Saroglitaz DOI: 10.5530/ijper.52.4.74 -
confidence 1.0
“The peak at 919 is reduced and overlapped by the shoulder of the Si-O bond peak and is completely removed from samples treated at higher temperatures ◦C”
Multi-Technique Analytical Approach to Quantitative Analysis of Spodumene DOI: 10.3390/min12020175 -
Alkyl C-H confidence 1.0
“Theabsorptionbandat1420.2cm-1, 1086.2cm-1, 919.3cm-1, and828.6cm-1 were attributed to C-H wagging vibrations in the -CH group, C-O, CH stretching, and 2 2 C-C stretching vibrations, respectively [31,32].”
Date-Palm-Derived Cellulose Nanocrystals as Reinforcing Agents for Poly(vinyl alcohol)/Guar-Gum-Based Phase-Separated Composite Films DOI: 10.3390/nano -
Ring structure confidence 1.0
“It is worthy to remind here However, the performed calculations clearly suggest that the cm-1 the sensitivity of the band with peak frequency at 919 to modes underlying those frequencies are due to CNN and ring isotopic substitution (see Fi”
Low-Temperature FTIR Spectroscopic and Theoretical Study on an Energetic Nitroimine: Dinitroammeline (DNAM) DOI: 10.1021/jp711153g
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