What absorbs at 638 cm⁻¹ in an FTIR spectrum?
A band near 638 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 638 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 |
|---|---|---|---|
| Metal oxygen | 4 | 3 | 1,0 |
| Chlorine | 1 | 1 | 1,0 |
| Sulfate (SO4) | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Phosphate (PO4) | 1 | 1 | 0,95 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| iron oxide | 638, 1130, 891 | Metal oxygen | 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 638 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
“Micro-Raman analysis of silica powder at an excitation wavelength of 532 nm laser showed cm-1, a spectrum having prominent peaks at 638, 802, and 1300 characteristic of Si particles.”
Dentin Bond Integrity of Filled and Unfilled Resin Adhesive Enhanced with Silica Nanoparticles—An SEM, EDX, Micro-Raman, FTIR and Micro-Tensile Bond Strength Study DOI: 10.3390/polym13071093 -
Alkyl C-H tillid 1,0
“demineralized dentin highlights together with the characteristic bands of apatite ~950 cm-1 cm-1 cm-1 and dentinal collagen 1637 (CC), 1455 (CH 2), specific bands of the monomer cm-1 cm-1 (CC), 1455 cm-1 (CH 2), specific bands of the monome”
Marginal Adaptation Assessment for Two Composite Layering Techniques Using Dye Penetration, AFM, SEM and FTIR: An In-Vitro Comparative Study DOI: 10.3390/app11125657 -
Sulfate (SO4) tillid 1,0
“Such spectral regions host features compatible with those of a sulfate (983, 1087, 1116, and 1182 cm-1), probably barite (BaSO4), to which the two uncertain peaks at 611 and 638 cm-1 also appear to be assigned.”
Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery DOI: 10.3390/app13042124 -
tillid 1,0
“The synthesized IONPs show characteristic absorption cm-1 around 638.4 which is attributed to vibration of Fe-O bonds.”
Kawish 等 - 2020 - Enhancement in Oral Absorption of Ceftriaxone by H DOI: 10.3390/pharmaceutics12060492 -
tillid 1,0
“FTIR Analysis cm-1 cm-1 The FTIR Peaks (KBr): 3323 (amine -NH 2, -NH stretch), 3378 (amine cm-1 cm-1 -NH 2, N-H stretch), 1046 (C-O-C ether linkage stretch), and 638 (C-Cl stretch).”
Copper-Treated Environmentally Friendly Antipathogenic Cotton Fabric with Modified Reactive Blue 4 Dye to Improve Its Antibacterial and Aesthetic Properties DOI: 10.3390/coatings13010133 -
Metal oxygen tillid 1,0
“396 cm-1 (B1g), 516 cm-1 (A1g+B1g), and 638 cm-1 (Eg) inThe minimum energy paths and corresponding activation barcreasingly demonstrated the fabrication of TiO2 on the surface riers for all elementary steps were calculated using the climbof”
Wei 等 - 2023 - Photoelectrocatalytic reduction of CO2 catalyzed b DOI: 10.1016/S1872-2067(23)64395-5 -
tillid 1,0
“the peak at 516 cm-1 was caused by the Si-O-Fe stretching vibrations whilst the peaks at 638 cm-1 and at 838 cm-1 were due to Si-O stretching vibrations and Si-O-Al stretching vibrations, respectively.”
Investigation on the Painting Materials and Profile Structures Used in Ancient Chinese Folk Architectural Paintings by Multiple Analytical Methods DOI: 10.3390/coatings12030320 -
Phosphate (PO4) tillid 0,95
“Explicit assignment in text.”
Preparation of LiFePO4 Powders by Ultrasonic Spray Drying Method and Their Memory Effect DOI: 10.3390/ma14123193
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.