What absorbs at 631 cm⁻¹ in an FTIR spectrum?
A band near 631 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 7 cited sources
Brzi odgovor
A band near 631 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.
Moguće dodjele funkcionalnih skupina
| Funkcionalna skupina | Potporni dokazi | Citirani izvori | Najveća pouzdanost |
|---|---|---|---|
| Hydroxyl (O-H) | 4 | 4 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Phosphorus | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 0,95 |
Rangiranje odražava akumulirane literaturne dokaze, a ne jedno autoritativno pravilo. Uvijek provjerite u kontekstu vašeg uzorka.
Mogući materijali
| Materijal | Potporni vrhovi | Preklapajuće skupine | Citirani izvori |
|---|---|---|---|
| PVA | 631, 1660, 2930 | Hydroxyl (O-H), Amide | 1 |
| starch | 631, 1650, 1540 | Hydroxyl (O-H), Amide | 1 |
| glycerol | 631, 1585, 1630 | Hydroxyl (O-H) | 1 |
| polycaprolactone | 631, 1580, 1751 | Amide | 1 |
| apatite | 631, 3053, 1640 | Phosphate (PO4), Phosphorus, Amide | 1 |
Materijali su prikazani samo kada ista literatura podržava ovu traku i barem jedan dodatni karakteristični vrh.
Logika spektra
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 631 cm⁻¹ is usually not enough for material identification by itself.
Upotreba u stvarnom svijetu
Ova vrsta upita uobičajena je u identifikaciji polimera, probiru nepoznate plastike, rješavanju problema u kontroli kvalitete, provjeri recikliranog materijala i pregledu dodjele vrhova potkrijepljenom literaturom.
Uobičajene pogreške
- Tretiranje jedne izolirane vrpce kao dokaza materijala bez provjere barem jednog ili dva podržavajuća pika.
- Zanemarivanje preklapanja: više funkcionalnih skupina može doprinositi u blizini istog valnog broja.
- Preskakanje validacije kada aditivi, mješavine, oksidacija ili kontaminacija mogu izobličiti spektar.
Savjet za provjeru
Kada nejasnoća ostane, validirajte hipotezu pomoću DSC, GC-MS ili TGA, posebno za mješavine, degradirane uzorke i punjene polimere.
Literatura iza ovih dodjela
-
Hydroxyl (O-H) pouzdanost 1,0
“3 cm-1, cm-1 The sharp narrow band at 630.92 634.47 and wide band at 3525.94 cm-1 are associated with the hydroxyl”
XRD and FTIR study of A&B type carbonated hydroxyapatite extracted from bovine bone DOI: 10.1063/1.5089399 -
Silicon (Si) pouzdanost 1,0
“On the other hand, MMT nanoclays can be identified by stretching of Si-O-Si associated with bands of 631 cm-1 and 1075 cm-1 attributed to the bending of this group.”
Physical-Mechanical Behavior and Water-Barrier Properties of Biopolymers-Clay Nanocomposites DOI: 10.3390/molecules26216734 -
Phosphate (PO4) pouzdanost 1,0
“There are two strong peaks due to the asymmetric ν4 bending mode of (PO4), a smaller peak at 631 cm-1 due to hycm-1 ν3 characteristic of phosphate groups at 1048 and 1087 attributed to asymmetric droxyl groups, a few weaker peaks due to car”
Archaeometric Investigations of the Chalcolithic Pottery from Topolița—Neamț County, Romania DOI: 10.3390/coatings13030488 -
Amide pouzdanost 1,0
“Proteins, including the amide I peak at 1,631 cm-1, exhibit the strongest bands in the spectra depending on the secondary structure of the”
Macotpet 等 - 2020 - Attenuated total reflection Fourier transform infr DOI: 10.4142/jvs.2020.21.e16 -
Hydroxyl (O-H) pouzdanost 1,0
“There is no evidence of any characteristic hydroxyl group vibrations (631 and 3572”
Mirkovic 等 - 2018 - Structural, Morphological and Electrical Propertie DOI: 10.2298/SOS1801095M -
Hydroxyl (O-H) pouzdanost 1,0
“LLM confirmed rule peak-group candidate”
Characterization of PLA/PCL/Nano-Hydroxyapatite (nHA) Biocomposites Prepared via Cold Isostatic Pressing DOI: 10.3390/polym15030559 -
Metal oxygen pouzdanost 0,95
“Explicit assignment: 'peak at 631cm-1 is attributed to the vibration of the Ti-O of anatase.'”
Sun 等 - 2006 - Preparation and gas-sensing property of a nanosize DOI: 10.1016/j.snb.2005.06.006
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