What absorbs at 694 cm⁻¹ in an FTIR spectrum?
A band near 694 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 694 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.
Mögliche Funktionsgruppenzuweisungen
| Funktionelle Gruppe | Unterstützende Fakten | Zitierte Quellen | Höchstes Vertrauen |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 10 | 10 | 1,0 |
| Silicon (Si) | 7 | 7 | 1,0 |
| Alkyl C-H | 5 | 5 | 1,0 |
| Ring structure | 3 | 3 | 1,0 |
| Alkene (C=C) | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Metal hydroxyl | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Silanol (Si-OH) | 1 | 1 | 1,0 |
Das Ranking spiegelt die gesammelte Literatur Evidenz wider, nicht eine einzelne maßgebliche Regel. Bestätigen Sie immer anhand Ihres Probenkontexts.
Possible materials
| Material | Unterstützende Peaks | Overlapping groups | Zitierte Quellen |
|---|---|---|---|
| ZnO | 694, 1400, 3430 | Alkyl C-H | 1 |
| silica | 694, 1100, 1080 | Silicon-oxygen (Si-O), Silicon (Si), Alkyl C-H | 1 |
| ZnO nanoparticles | 694, 1219, 1726 | Alkyl C-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 694 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.
Literatur hinter diesen Zuweisungen
-
Silicon-oxygen (Si-O) Vertrauen 1,0
“gel-silica spectra already observed in the gel compound, the binary material (G 40s 60) present at t=0 min, bands at 1160, 796, 775 and (A) 694cm-1 assigned to quartz phase [23] due to the presence of crystallized silica in the mixture.”
Consolidation mechanism of materials obtained from sodium silicate solution and silica-based aggregates DOI: 10.1016/j.jnoncrysol.2011.04.006 -
Alkene (C=C) Vertrauen 1,0
“The peaks around 840, 954, and 694 cm-1 are due to the bending vibration of =C-H groups.”
Innovative Investigation of Zinc Oxide Nanoparticles Used in Dentistry DOI: 10.3390/cryst12081063 -
Silanol (Si-OH) Vertrauen 1,0
“Actually, [24,25],the deformation of Si-OH bond at Q2/Q3+Q4 870cm-1 694cm-1 an increase in the intensity ratio (Fig.”
Physico-chemistry of silica / Na silicate interactions during consolidation. Part 2: Effect of pH DOI: 10.1016/j.jnoncrysol.2011.11.005 -
Alkyl C-H Vertrauen 1,0
“The peak observed at 694 cm Weight Element name corresponds to the CH out of plane deformations [39].”
Adeniyi 等 - 2022 - Evaluating the nature of captured exhaust soot fro DOI: 10.24200/sci.2021.57008.5017 -
Vertrauen 1,0
“cm-1 cm-1 1,600.6 for the aromatic compounds (C-C stretch), 1,113.5 for aliphatic amines (C-N stretch), and cm-1 693.6 for alkyl halides (C-Cl stretch).”
Role of Salvinia molesta in biodecolorization of methyl orange dye from water DOI: 10.1038/s41598-020-70740-5 -
Silicon (Si) Vertrauen 1,0
“smoothing function of two polynomials and 15 points, and finally normalized based on a reference cm-1 The band at 694 has been attributed to Si-O of SiO symmetrical bending, and its presence confirms the 4 quartz24,25.”
Spectroscopic investigations to reveal synergy between polystyrene waste and paraffin wax in super-hydrophobic sand DOI: 10.1038/s41598-023-36987-4 -
Silicon (Si) Vertrauen 1,0
“cm-1 Moreover, the absorption band at 694 is corresponding to symmetrical bending vibrations of Si-O whereas cm-1 vibration band at 792 can be attributed to symmetrical stretching vibrations of Si-O [37].”
Magnetron sputtering technique for analyzing the influence of RF sputtering power on microstructural surface morphology of aluminum thin films deposited on SiO2/Si substrates DOI: 10.1007/s00339-021-04892-0 -
Ring structure Vertrauen 1,0
“The cm-1, 1164, 1251, 1315, 1493, 1593, and 1651 being assigned to the following vibrational main IR bands of the SPCE-RGO/PDPA platform peak at 694, 750, 779, 881, 916, 970, 1014, modes: inter-ring deformation, ring deformation, W-O c-W (o”
Optical Evidence for the Assembly of Sensors Based on Reduced Graphene Oxide and Polydiphenylamine for the Detection of Epidermal Growth Factor Receptor DOI: 10.3390/coatings11020258
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