What absorbs at 795 cm⁻¹ in an FTIR spectrum?
A band near 795 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 795 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 18 | 16 | 1.0 |
| Siloxane (Si-O-Si) | 9 | 9 | 1.0 |
| Silicon (Si) | 7 | 6 | 1.0 |
| Alkyl C-H | 6 | 5 | 1.0 |
| Hydroxyl (O-H) | 4 | 4 | 1.0 |
| Silanol (Si-OH) | 3 | 3 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Silicon carbon | 2 | 1 | 1.0 |
| Silicate | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| Oxalate | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Oxygen heterocycle | 1 | 1 | 0.9 |
| Secondary amine | 1 | 1 | 0.8 |
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 |
|---|---|---|---|
| Polyester | 795, 1700, 1250 | Alkyl C-H | 1 |
| SiC | 795, 791, 805 | Silicon-oxygen (Si-O), Silicon (Si), Siloxane (Si-O-Si) | 1 |
| Polyaniline | 795, 1565, 1570 | Alkyl C-H | 1 |
| copper oxide nanoparticles | 795, 624, 1317 | 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 795 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
-
Silanol (Si-OH) 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 -
Silicon carbon confidence 1.0
“The Raman shifts for appeared as small peaks at 795.6 and 795cm-1 in Fourier Transform Infrared Spectroscopy (FTIR) was also characteristic vibration of SiC at observed.”
In situ formation of β-silicon carbide nanorods from the hybrid of an organic moiety and methyltriethoxysilane DOI: 10.1016/j.matlet.2011.04.040 -
Aromatic ring confidence 1.0
“solution.[36] cm(cid:2)1and sulfuric acid A small peak at 864 the cm(cid:2)1 peak at 795 are attributed to the vibrations of 1,2,4trisubstitution of aromatic ring.”
Polyaniline with Two Types of Functional Groups: Preparation and Characteristics DOI: 10.1002/macp.200400408 -
Aromatic ring confidence 1.0
“The introduction of organic moicm(cid:1)1 (PM) distinguished by aromatic ring vibrations at 795 ety also results in a relative decrease in the silanol bands, with cm(cid:1)1 an associated increase in new bands characteristic of immobiand 95”
Nasreen 等 - 2019 - Hybrid mesoporous silicates A distinct aspect to DOI: 10.1016/j.sjbs.2015.08.014 -
Phosphate (PO4) confidence 1.0
“cm-1 and 794.7 for P=O stretching and stretching POC 2.”
Saefurohman 等 - 2014 - Potentiometric Measurement Of Polymer-Membrane Ele DOI: 10.1063/1.4868773 -
Alkyl C-H confidence 1.0
“The band at 795 was attributed to out of plane - CH.”
Salem 等 - 2019 - Synthesis of compounds having antimicrobial activi DOI: 10.1016/j.bioorg.2019.03.013 -
confidence 1.0
“Explicit assignment: transverse optical phonon of 3C-SiC”
Shim 等 - 1998 - Effects of void formation on electrical and optica DOI: 10.4028/www.scientific.net/MSF.264-268.195 -
Alkyl C-H confidence 1.0
“The -CF 2 CF2 wagging (489 cm-1) and bending (610 cm-1), the skeletal bending (764 cm-1), and the -CH2 cm-1) cm-1), cm-1), wagging (489 and bending (610 the skeletal bending (764 and the -CH rocking 2 rocking (795 cm-1) and twisting (975 cm”
Terraza 等 - 2018 - Preparation of CuONPs@PVDFNon-Woven Polyester Com DOI: 10.3390/polym10080862
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.