What absorbs at 839 cm⁻¹ in an FTIR spectrum?
A band near 839 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
Răspuns rapid
A band near 839 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.
Atribuiri posibile ale grupelor funcționale
| Grup funcțional | Fapte suport | Surse citate | Încredere maximă |
|---|---|---|---|
| Alkyl C-H | 5 | 5 | 1,0 |
| Methoxy (OCH3) | 4 | 4 | 1,0 |
| Methacrylate | 4 | 4 | 1,0 |
| C-O single bond | 4 | 4 | 1,0 |
| Acetate | 4 | 4 | 1,0 |
| C c single bond | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| Metal oxygen | 2 | 2 | 1,0 |
| Ring structure | 2 | 2 | 1,0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| C-S single bond | 1 | 1 | 1,0 |
| Acetyl | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Chlorine | 1 | 1 | 0,9 |
Clasamentul reflectă dovezile acumulate din literatură, nu o singură regulă autoritară. Confirmați întotdeauna în contextul mostrei dvs.
Materiale posibile
| Material | Vârfuri suport | Grupuri suprapuse | Surse citate |
|---|---|---|---|
| PVA | 839, 1660, 2930 | Alkyl C-H, Methacrylate, C-O single bond | 1 |
| PVP | 839, 2983, 1648 | Alkyl C-H, Methacrylate | 1 |
| SiO | 839, 800, 1745 | Methacrylate, Methoxy (OCH3), C-O single bond | 1 |
| CaO | 839, 2909, 1839 | Methacrylate, C-O single bond, Methoxy (OCH3) | 1 |
| SiO2 | 839, 1739, 699 | Alkyl C-H, Methoxy (OCH3) | 1 |
| Al2O3 | 839, 1722, 1383 | Methacrylate, Alkyl C-H | 1 |
Materialele sunt afișate numai atunci când același grup de literatură susține această bandă și cel puțin un vârf caracteristic suplimentar.
Logica spectrului
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 839 cm⁻¹ is usually not enough for material identification by itself.
Utilizare în condiții reale
Acest tip de interogare este comun în identificarea polimerilor, screeningul materialelor plastice necunoscute, depanarea QC, verificarea materialelor reciclate și revizuirea atribuirii vârfurilor bazată pe literatură.
Greșeli comune
- Tratarea unei benzi izolate ca dovadă a unui material fără a verifica cel puțin unul sau două vârfuri de susținere.
- Ignorând suprapunerea: mai multe grupuri funcționale pot contribui în apropierea aceluiași număr de undă.
- Omiterea validării atunci când aditivii, amestecurile, oxidarea sau contaminarea pot distorsiona spectrul.
Sfat de verificare
Când ambiguitatea rămâne, validați ipoteza prin DSC, GC-MS sau TGA, în special pentru amestecuri, probe degradate și polimeri umpluți.
Literatura din spatele acestor atribuiri
-
Metal oxygen încredere 1,0
“cm-1), cm-1), cm-1 (*1,037 (*913 AlAlOH AlMgOH *1,614 The shift of peak at in sample II to higher cm-1), (*839 deformation vibrations of Al-O-Si groups frequency is due to the existence of 2,4-DMP in protonated cm-1), cm-1) (*518 (*449 and”
Janik 等 - 2013 - Effect of different dimethylphenols on the interac DOI: 10.1007/s10973-013-2990-x -
Alkyl C-H încredere 1,0
“Vials were subat 1524.26 cm-1, 1308.30 cm-1, and at 839.48 cm-1 was jected to mechanical shaking at 400 rpm for 24 h observed due to C-H stretching, C-C stretching and”
Batool 等 - 2019 - USE OF GLUTARIC ACID TO IMPROVE THE SOLUBILITY AND DOI: 10.32383/appdr/94246 -
C c single bond încredere 1,0
“The fingerprint region of the IR absorption spectra (Figure 3a,b) reveals typical absorption bands The fingerprint region of the IR absorption spectra (Figure 3a,b) reveals typical absorption bands cm-1 of PVA, occurring at 839, 917 and 108”
Croitoru 等 - 2020 - Physically Crosslinked Poly (Vinyl Alcohol)Kappa- DOI: 10.3390/polym12030560 -
Alkyl C-H încredere 1,0
“LLM confirmed rule peak-group candidate”
Elhosiny Ali 等 - 2022 - Microstructure Study and LinearNonlinear Optical DOI: 10.3390/polym14091741 -
C c single bond încredere 1,0
“(cm-1) (cm-1) assignment observed wavelength for PVA observed wavelength for ZnS-PVA reference OH stretching 3280 3290 [20,21] CH2 asymmetric stretching 2917 2923 [20,21] C=O carbonyl stretching 1690 1718 [20-22] CH2 bending 1425 1430 [20,2”
Structural, optical, opto-thermal and thermal properties of ZnS–PVA nanofluids synthesized through a radiolytic approach DOI: 10.3762/bjnano.6.55 -
încredere 1,0
“Al-O4]5vibration of [AlO 28-29 - 791 778 770 772 Symmetric stretching 839 837 837 835 837 Stretching Si-O-Al vibration 29-30 Raman shift (cm-1)”
Kim 等 - 2013 - Viscous Behavior of Alumina Rich Calcium-Silicate DOI: 10.2355/isijinternational.53.170 -
Acetate încredere 1,0
“β γ, δ ε Ar-O-), 1.80-1.75 (m, 4H, to Ar-O-), 1.48-1.38 (m, 10H, and to Ar-O-) 1,10-Bis[4-(pyreneiminomethylidene)-phenoxy]-decane cm-1): ν, FTIR (KBr, 3037 (=C-H stretch of the aromatic rings), 2922, 2850 (C-H stretch of aliphatic chains),”
Mesomorphic Behavior of Symmetric Azomethine Dimers Containing Different Chromophore Groups DOI: 10.3390/molecules26082183 -
Ring structure încredere 1,0
“735-657cm-1isassignedtoamideorCH 2rockingband[18],839cm-1 cm-1 water,2890 is related tothe asymmetrically stretching vibration cm-1 C\\H C\\C of in a pyranoid ring, and the band at 3332 is attributed to the vibrations occurred due to ring b”
Polyethersulfone membrane embedded with amine functionalized microcrystalline cellulose DOI: 10.1016/j.ijbiomac.2020.09.017
Aveți un spectru cu această bandă?
Încărcați spectrul FTIR și obțineți un raport complet de interpretare — atribuiri de peak-uri cu citări din literatură, potriviri cu biblioteca și un lanț de dovezi cu nivel de încredere — în câteva secunde.