What absorbs at 804 cm⁻¹ in an FTIR spectrum?
A band near 804 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 804 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.
가능한 작용기 할당
| 작용기 | 지원 사실 | 인용 출처 | 최고 신뢰도 |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1.0 |
| Silicon-oxygen (Si-O) | 3 | 3 | 1.0 |
| C-S single bond | 3 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Nitrogen heterocycle | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 0.9 |
순위는 단일 권위 규칙이 아닌 축적된 문헌 증거를 반영합니다. 항상 샘플 상황에 대해 확인하세요.
Possible materials
| 재료 | 지원 피크 | Overlapping groups | 인용 출처 |
|---|---|---|---|
| TiO2 | 804, 1700, 1093 | Alkyl C-H | 1 |
| SiO2 | 804, 1739, 699 | Silicon-oxygen (Si-O), Alkyl C-H, Silicon (Si) | 1 |
| TiO | 804, 1730, 1699 | Alkyl C-H | 1 |
| copolymer | 804, 2921, 1540 | Alkyl C-H | 1 |
| PMMA | 804, 1722, 1383 | 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 804 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.
이 할당의 배경이 되는 문헌
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신뢰도 1.0
“Si-O antisymmetric cm(cid:3)1, stretching band is found at 1108 Si-O symmetric stretching The FTIR spectra of physical mixtures of CoO and SiO having 2 bandat804cm(cid:3)1,andSi-Orockingmotionbandatapproximately theminimumandmaximummolarfra”
Jonynaite 等 - 2010 - Spectroscopic analysis of blue cobalt smalt pigmen DOI: 10.1016/j.vibspec.2009.12.005 -
Alkyl C-H 신뢰도 1.0
“Meanwhile, numerous strong bands 739 804 cm-1, cm-1, cm-1 863 898 and 1455 in DiaRoot suggested the stretching of C-H groups.”
Assiry 等 - 2023 - Microstructural and Elemental Characterization of DOI: 10.3390/app13074517 -
Silicon (Si) 신뢰도 1.0
“The characteristic band at 3464 anti-symmetric and symmetric stretching vibrations of Si-O-Si groups are observed at characteristic bands at 1083 cm-1 and 804 cm-1, respectively [24].”
Functionalized KIT-6/Polysulfone Mixed Matrix Membranes for Enhanced CO2/CH4 Gas Separation DOI: 10.3390/polym12102312 -
신뢰도 1.0
“ACS Omega http://pubs.acs.org/journal/acsodf Article P-O-P effect structure.20,29 synergistic of phosphorus, nitrogen, and silicon, the EP/ In addition, the characteristic absorpcm-1 TDA-5 sample presented a more compact and smooth char tio”
Fang 等 - 2021 - Synthesis of a Novel Flame Retardant Containing Ph DOI: 10.1021/acsomega.1c00076 -
Alkyl C-H 신뢰도 1.0
“However, these peaks disappear cm-1, in the spectrum of the copolymer and a new peak appears at 804 representing the vibration of C-H in vicinity of C-S bond, and thus, confirming the utilization of C=C to form C-S bond meaning a copolymer”
A Degradable Inverse Vulcanized Copolymer as a Coating Material for Urea Produced under Optimized Conditions DOI: 10.3390/polym13224040 -
Silicon (Si) 신뢰도 1.0
“cm-1 at 1086 due to the stretching vibration of Si-O-Si cm-1 and the peak at 804 is ascribed to the Si-C groups.”
Li 等 - 2018 - Thermal insulation of silica aerogelPMMA composit DOI: 10.1515/secm-2017-0248 -
C-S single bond 신뢰도 1.0
“Combination of C-S stretching and S-N - 804 794 791 [39] asymmetric stretching mode of LiTFSI”
Liew 等 - 2016 - Poly(Acrylic acid)-Based Hybrid Inorganic-Organic DOI: 10.3390/polym8050179 -
Alkyl C-H 신뢰도 1.0
“Finally, the bands 804 cm-1 cm-1 at 720 and 667 can be assigned to = C-H planar bending and C-O out of plane respectively.[31] bending, INTERNATIONAL JOURNAL OF FOOD PROPERTIES S2743”
Crude and refined oils from Elaeis guineensis: Facile characterization by FTIR and thermal analysis DOI: 10.1080/10942912.2017.1372470
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