What absorbs at 693 cm⁻¹ in an FTIR spectrum?
A band near 693 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 693 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.
可能的官能团归属
| 官能团 | 支持性事实 | 引用来源 | 最高置信度 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 6 | 5 | 1.0 |
| Silicon (Si) | 4 | 4 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
排名反映了累积的文献证据，而非单一的权威规则。请始终对照您的样品背景进行确认。
Possible materials
| 材料 | 支持峰 | Overlapping groups | 引用来源 |
|---|---|---|---|
| kaolinite | 693, 3696, 798 | Silicon-oxygen (Si-O), Silicon (Si), Metal oxygen | 2 |
| bone | 693, 1649, 1660 | Silicon-oxygen (Si-O) | 1 |
| hematite | 693, 1030, 469 | Silicon-oxygen (Si-O), Silicon (Si), Metal oxygen | 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 693 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.
这些分配背后的文献
-
置信度 1.0
“The peak at 693 is associated with Fe-O bands cm-1 of MNPs.”
Covalent diphenylalanine peptide nanotube conjugated to folic acid/magnetic nanoparticles for anti-cancer drug delivery DOI: 10.1016/j.jddst.2017.06.005 -
Silicon (Si) 置信度 1.0
“In the spectra of WFD (Figure 7a), the peaks at 992, 776, and 693 cm-1 were attributed to Si-O stretching vibration bands, whereas the peaks at 598 cm-1 corresponded to F-O bond stretching.”
Kim 等 - 2022 - Removal of Methyl Red from Aqueous Solution Using DOI: 10.3390/ijerph19159030 -
Metal oxygen 置信度 1.0
“Contrary to vibration of the Ti-O-O was identified from the band 693cm-1 film within visible absorption peaks arose in undoped TiO2 [16].”
Gokdemir 等 - 2014 - Structural Modification of Sol-Gel Synthesized V2O DOI: 10.1155/2014/795384 -
置信度 1.0
“790 Si-O stretching, Si-O-Al stretching, (Al, Mg)--O-H, Si-O-(Mg, Al) stretching 693 Si-O stretching, Si-O-Al stretching 538 Si-O bending, Si-O-Al stretching”
The Fourier transform infrared spectroscopy (FTIR) analysis for the clay mineralogy studies in a clastic reservoir DOI: 10.1007/s13202-021-01449-y -
Phosphate (PO4) 置信度 1.0
“which have absorbance maximum at 1,693 cm-1 The region between 1,180 and 1,300 corresponds to the P=O asymmetric band (mostly in nucleic acids”
Synchrotron-based FTIR microspectroscopy of protein aggregation and lipids peroxidation changes in human cataractous lens epithelial cells DOI: 10.1038/s41598-020-72413-9 -
置信度 1.0
“vibrational bands at 3696, 3670, 3653 (surface hydroxyl groups stretching vibration), 3621 (Al2Si2O5(OH)4) disclosed vibrational bands at 3696, 3670, 3653 cm-1 (surface hydroxyl groups cm-1 cm-1 (inner hydroxyl groups stretching vibration),”
Ma 等 - 2019 - Investigation of the Optical, Physical, and Chemic DOI: 10.3390/su11143803 -
Aromatic ring 置信度 1.0
“the pure drug showed the characteristic peaks at 1650.76 due to C=O stretching, at 3364.90 due to O-H stretching, 3252.43 due to N-H stretch, 1435.82 due to C-F stretching, 1316.56 due to C-O stretching, 1217.08 due to C-N stretching, and a”
Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique DOI: 10.3797/scipharm.1301-23 -
Silicon (Si) 置信度 1.0
“5, from which it can be seen that these decorations contained highly comparable spectral features: Si-O stretching vibrations of alucm-1) minosilicate minerals (at about 1000 and quartz bands at 797, 779 and 693 cm-1.20 It can therefore be”
{Physicochemical characterisation of pottery from Vinca culture, Serbia, regarding firing temperature and decoration technique} DOI: 10.2298/JSC160823100P
是否有此波段的光谱？
上传您的FTIR光谱，几秒钟内即可获得完整的解读报告——包含带文献引用的峰分配、库匹配和带有置信度评级的证据链。