What absorbs at 775 cm⁻¹ in an FTIR spectrum?
A band near 775 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
Snel antwoord
A band near 775 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.
Mogelijke functionele-groeptoewijzingen
| Functionele groep | Ondersteunende feiten | Geciteerde bronnen | Hoogste vertrouwen |
|---|---|---|---|
| Alkyl C-H | 4 | 4 | 1,0 |
| Amide | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Methacrylate | 2 | 2 | 1,0 |
| Acetate | 2 | 2 | 1,0 |
| Silicon (Si) | 2 | 1 | 1,0 |
| Thiocarbonyl | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Secondary amine | 1 | 1 | 1,0 |
| C n single bond | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Ring structure | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| Alkene (C=C) | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Carbonyl (C=O) | 1 | 1 | 1,0 |
Ranglijst weerspiegelt cumulatief literatuurbewijs, niet één gezaghebbende regel. Bevestig altijd aan de hand van uw monsterecontext.
Mogelijke materialen
| Materiaal | Ondersteunende pieken | Overlappende groepen | Geciteerde bronnen |
|---|---|---|---|
| silver nanoparticles | 775, 1636, 1631 | Alkyl C-H, Amide | 1 |
Materialen worden alleen getoond wanneer dezelfde literatuurpool deze band en ten minste één extra karakteristieke piek ondersteunt.
Spectrumlogica
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 775 cm⁻¹ is usually not enough for material identification by itself.
Gebruik in de praktijk
Dit type query komt vaak voor bij polymeeridentificatie, screening van onbekende kunststoffen, probleemoplossing bij QC, verificatie van gerecycled materiaal en literatuurondersteunde beoordeling van piektoewijzing.
Veelgemaakte fouten
- Het behandelen van een enkele geïsoleerde band als bewijs van een materiaal zonder ten minste een of twee ondersteunende pieken te controleren.
- Overlap negeren: meerdere functionele groepen kunnen bijdragen rond hetzelfde golfgetal.
- Validatie overslaan wanneer additieven, mengsels, oxidatie of verontreiniging het spectrum kunnen verstoren.
Advies voor verificatie
Wanneer dubbelzinnigheid blijft bestaan, valideer de hypothese met DSC, GC-MS of TGA, vooral voor mengsels, gedegradeerde monsters en gevulde polymeren.
Literatuur achter deze toewijzingen
-
Acetate vertrouwen 1,0
“TC-DO at 1412 and 779 W-DM had characteristic peaks at 1723 (C=O vibration), 1514, cm-1 corresponding to the characteristic peaks of TC-DM at 1643, 1465, 1413, 1456, 1422 and 775 cm-1.”
Discrimination and similarity evaluation of tissue-cultured and wild Dendrobium species using Fourier Transform Infrared Spectroscopy DOI: 10.1016/j.molstruc.2015.01.027 -
vertrouwen 1,0
“6 FTIR spectra for a b c and of SPEs 16:2251-2260 2258 J Solid State Electrochem (2012) cm-1 8.0×10-8 cm-1 C-Cl functional group of stretching at 775 for aliphatS is obtained at 15% wt.”
Lee 等 - 2012 - Temperature dependence of the conductivity of plas DOI: 10.1007/s10008-011-1633-z -
Phosphate (PO4) vertrouwen 1,0
“In the metaphosphate 775cm-1, (P-O-P) and (P-O-P) bands at about 900 and glass composition, CuO primarily acts as network modias s 43Q2 groups respectively, and the deformation modes of PO fier to depolymerize phosphate chain, until all the”
Shih 等 - 2003 - P-31 MAS-NMR and FTIR analyses on the structure of DOI: 10.1016/S0254-0584(03)00098-1 -
Alkene (C=C) vertrouwen 1,0
“1624 Strong (methyne) 775 Medium Alkenyl C=C stretch Olefinic alkene 1458 Medium C=C-C aromatic ring stretch 775 Medium Alkenyl C=C stretch”
The Antimicrobial Activities of Silver Nanoparticles from Aqueous Extract of Grape Seeds against Pathogenic Bacteria and Fungi DOI: 10.3390/molecules26196081 -
Amide vertrouwen 1,0
“The third (1239 and fourth cm-1) (775 amide band can be clearly seen only for PSi0, because in the PSi samples those bands are overlapped by the stronger aforementioned bands”
Thermal and surface properties of hybrid materials obtained from epoxy-functional urethane and siloxane DOI: 10.1007/s00289-015-1545-7 -
Acetate vertrouwen 1,0
“(C-H 3308 stretching vibration), 2933 stretching of CH2 group), recorded in native nanocomposite components, were assigned corre- - O-H C-H 1602 (COOH stretching), 1429 (uronic acid (COOH)), 1018 825 sponding to stretching vibration at 3292”
Green decoration of graphene oxide Nano sheets with gelatin and gum Arabic for targeted delivery of doxorubicin DOI: 10.1016/j.btre.2022.e00722 -
Amide vertrouwen 1,0
“a major peak has appeared at 775 These peaks were characteristic of C-N stretch (amines), =C-H bend (benzene, alkenes), and C-C (chlorides).”
Potential of Suaeda nudiflora and Suaeda fruticosa to Adapt to High Salinity Conditions DOI: 10.3390/horticulturae9010074 -
Thiocarbonyl vertrouwen 1,0
“The following inference are made from the Cd2+, concentration of free as much of these ions would be in cm-1 found for pure observed FTIR results,The band at 775 42complex and most of the allylthiourea the form of CdCl Allylthiourea is assi”
Perumal 等 - 2023 - Influence of pH on the Growth of Tris-Allylthioure DOI: 10.14447/jnmes.v26i2.a07
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