What absorbs at 518 cm⁻¹ in an FTIR spectrum?
A band near 518 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 4 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Silicon (Si) | 3 | 3 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Silicon silicon | 1 | 1 | 1.0 |
| Phosphorus | 1 | 0 | 1.0 |
| Phosphate (PO4) | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Silicon (Si) confidence 1.0
“The pronounced peak around cm-1 518 was observed from the Raman spectrum, characteristic of crystalline silicon.”
Nanostructured Silicon Derived from an Agricultural Residue Bagasse Ash via Magnesiothermic Reduction Method DOI: 10.3390/coatings13020221 -
Silicon (Si) confidence 1.0
“tions of SiO4 tetrahedra at 668 and 603 cm-1 (νsSi-O-Si), and 518 and 473 cm-1, due to Sicm-1 cm-1, (ν tions of SiO tetrahedra at 668 and 603 sSi-O-Si), and 518 and 473 due to 4 O-Si and O-Si-O bending vibrations, respectively.”
Phase Composition of Silica Fume—Portland Cement Systems Formed under Hydrothermal Curing Evaluated by FTIR, XRD, and TGA DOI: 10.3390/ma14112786 -
confidence 1.0
“In addition, the absorption and 518 cm-1 and 471 cm-1 for Cn-MT2 are attributed to Mg-O-Si and Mg-O bending vibration,”
Qiu 等 - 2020 - Comprehensive Characterization of the Structure an DOI: 10.3390/min10040378 -
Metal oxygen confidence 0.9
“Peak at 518 related to Fe-O, Al-O, Fe-Al-O”
Heteropolyacid coupled with cyanoguanidine decorated magnetic chitosan as an efficient catalyst for the synthesis of pyranochromene derivatives DOI: 10.1038/s41598-022-21196-2
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