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
Hurtigt svar
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.
Mulige funktionelle gruppetildelinger
| Funktionel gruppe | Understøttende fakta | Citerede kilder | Højeste tillid |
|---|---|---|---|
| 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 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| 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 |
Materialer vises kun, når den samme litteraturpulje understøtter dette bånd og mindst en yderligere karakteristisk top.
Spektrumlogik
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.
Anvendelse i virkeligheden
Denne type forespørgsel er almindelig ved polymeridentifikation, screening af ukendt plast, fejlfinding i kvalitetskontrol, verifikation af genanvendt materiale og litteraturunderstøttet gennemgang af peak-tildeling.
Almindelige fejl
- Behandling af et isoleret bånd som bevis på et materiale uden at kontrollere mindst en eller to understøttende toppe.
- Ignorerer overlap: flere funktionelle grupper kan bidrage nær samme bølgetal.
- Spring validering over, når additiver, blandinger, oxidation eller forurening kan forvrænge spektret.
Verifikationsrådgivning
Når tvetydighed fortsat består, valider hypotesen med DSC, GC-MS eller TGA, især for blandinger, nedbrudte prøver og fyldte polymerer.
Litteratur bag disse tildelinger
-
tillid 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 tillid 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) tillid 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 -
tillid 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 tillid 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) tillid 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 tillid 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 tillid 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
Har du et spektrum med dette bånd?
Upload dit FTIR-spektrum og få en fuld tolkningsrapport — peak-tildelinger med litteraturhenvisninger, biblioteksmatch og en tillidsvurderet beviskæde — på få sekunder.