Silanol (Si-OH) — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Silanol (Si-OH) tends to absorb, compiled from published literature and ranked by supporting evidence. Each assignment is traceable to a source (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
Silanol (Si-OH) is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.
Characteristic FTIR peaks for Silanol (Si-OH)
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 960 | 14 | 13 | 1.0 |
| 3740 | 12 | 10 | 1.0 |
| 3745 | 12 | 9 | 1.0 |
| 950 | 10 | 8 | 1.0 |
| 3500 | 8 | 7 | 1.0 |
| 3400 | 8 | 7 | 1.0 |
| 970 | 7 | 6 | 1.0 |
| 3450 | 6 | 5 | 1.0 |
| 3650 | 5 | 5 | 1.0 |
| 3610 | 5 | 3 | 1.0 |
| 955 | 4 | 4 | 1.0 |
| 3300 | 4 | 4 | 1.0 |
| 3747 | 4 | 3 | 1.0 |
| 800 | 3 | 3 | 1.0 |
| 900 | 3 | 3 | 1.0 |
| 460 | 3 | 3 | 1.0 |
| 3744 | 3 | 3 | 1.0 |
| 956 | 3 | 3 | 1.0 |
| 555 | 3 | 3 | 1.0 |
| 945 | 3 | 3 | 1.0 |
| 3700 | 3 | 3 | 1.0 |
| 943 | 3 | 3 | 1.0 |
| 1635 | 3 | 3 | 1.0 |
| 940 | 3 | 3 | 1.0 |
| 795 | 3 | 3 | 1.0 |
| 1100 | 3 | 2 | 1.0 |
| 3420 | 3 | 2 | 1.0 |
| 3743 | 3 | 1 | 1.0 |
| 3750 | 3 | 1 | 1.0 |
| 3550 | 2 | 2 | 1.0 |
Showing the 30 best-supported peaks of 240 total for Silanol (Si-OH).
Possible materials
Spectrum logic
A functional-group assignment becomes more confident when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.
Real-world usage
These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.
Common mistakes
- Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
- Assuming the strongest band is always the most diagnostic one.
- Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.
Verification advice
Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.
Literature behind these assignments
-
4000 cm⁻¹ confidence 1.0
“The FT-IR data was revealed the existence of peaks at 4000 400 showing the siloxane & silanol groups were present, Fluorescence Spectrophotometer, SEM and EDS.”
Banoth 等 - 2022 - Sustainable Thermochemical Extraction of Amorphous DOI: 10.21203/rs.3.rs-657645/v1 -
1050 cm⁻¹ confidence 1.0
“curve c - T In the insert, IR absorption spectra in the region of Si-OH stretching curve b - T d¼1050(cid:3)C,dopedwithdifferentamountofGd:curve1-1%m.f.Gdandcurve modefortwosamplesdensifiedatT Fraser 2 - 8% m.f.”
Baraldi 等 - 2002 - Vibrational spectroscopy of OH-defects in sol-gel DOI: 10.1080/10420150215814 -
942 cm⁻¹ confidence 1.0
“2 cm-1 were found at around 1078 ascribed to Si-O-Si (asymmetric stretching vibration) and cm-1 around 942 ascribed to silanol (Si-OH) groups (bending vibration).”
Study of Polyvinyl Alcohol-SiO2 Nanoparticles Polymeric Membrane in Wastewater Treatment Containing Zinc Ions DOI: 10.3390/polym13111875 -
1126 cm⁻¹ confidence 1.0
“The subtracted spectrum revealed an increase in the shoulder bands at 1126 and cm(cid:2)1, cm(cid:2)1, 1040 in addition to the silanol band at 900-920 while a decrease in the intensity of methoxy bands could be observed”
Structural studies of alkoxysilyl-functionalised ionic liquid and its application in a hybrid electrochromic device DOI: 10.1016/j.materresbull.2012.08.036 -
900 cm⁻¹ confidence 1.0
“The weak bands at 900 cm-1 and 949 cm-1 are possibly atattributed to the symmetric stretching vibrations Si-OH and Si-O-Si in amorphous silica.”
Biosynthesized Silica Nanosuspension as Thermal Fluid in Parabolic Solar Panels DOI: 10.3390/e23020142 -
3735 cm⁻¹ confidence 1.0
“lated silanol peak at 3735 fresh Si-BEA and Ti-BEA samples All changes discussed above relate to silanol groups and do not displayed equivalent peak areas (less than 5% difference) while the necessarily prove any change in the actual Sn sit”
Effect of water treatment on Sn-BEA zeolite: Origin of 960 cm-1 FTIR peak DOI: 10.1016/j.micromeso.2015.02.012 -
950 cm⁻¹ confidence 1.0
“dense spherical silica powders were separated and settled down shows the presence of silanol (Si-OH) vibrations at 950 after about 600 s.”
De 等 - 2000 - Hydrolysis-condensation reactions of TEOS in the p DOI: 10.1039/B003221M -
795 cm⁻¹ confidence 1.0
“The band at 447.49 is O-Si-O bending [11, 15, 16], at 794.67 cm-1 cm-1 is Si-OH stretching [11], and at 1087.85 is Si-O-Si stretching asymmetric [6, 15].”
Deswardani 等 - 2017 - Study of Structural and Magnetic Properties of Sil DOI: 10.1088/1757-899X/202/1/012047
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