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
Jawapan pantas
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.
Penetapan kumpulan berfungsi yang mungkin
| Kumpulan berfungsi | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| 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 |
Pemeringkatan mencerminkan bukti literatur terkumpul, bukan satu peraturan berwibawa. Sentiasa sahkan terhadap konteks sampel anda.
Bahan yang mungkin
| Bahan | Puncak sokongan | Kumpulan bertindih | Sumber dipetik |
|---|---|---|---|
| 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 |
Bahan hanya dipaparkan apabila kumpulan literatur yang sama menyokong jalur ini dan sekurang-kurangnya satu puncak ciri tambahan.
Logik spektrum
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.
Penggunaan dunia sebenar
Jenis pertanyaan ini biasa dalam pengenalpastian polimer, saringan plastik tidak diketahui, penyelesaian masalah QC, pengesahan bahan kitar semula, dan semakan tugasan puncak yang disokong oleh literatur.
Kesilapan biasa
- Menganggap satu jalur terpencil sebagai bukti bahan tanpa memeriksa sekurang-kurangnya satu atau dua puncak sokongan.
- Mengabaikan pertindihan: pelbagai kumpulan berfungsi boleh menyumbang berhampiran nombor gelombang yang sama.
- Melangkau pengesahan apabila bahan tambahan, campuran, pengoksidaan, atau pencemaran boleh memesongkan spektrum.
Nasihat pengesahan
Apabila kekaburan masih ada, sahkan hipotesis dengan DSC, GC-MS, atau TGA, terutamanya untuk campuran, sampel terdegradasi, dan polimer terisi.
Literatur di sebalik penetapan ini
-
keyakinan 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 keyakinan 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) keyakinan 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 -
keyakinan 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 keyakinan 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) keyakinan 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 keyakinan 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 keyakinan 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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