What absorbs at 681 cm⁻¹ in an FTIR spectrum?
A band near 681 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 5 cited sources
Hurtigt svar
A band near 681 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Methyl | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Silicon (Si) | 1 | 1 | 1,0 |
| Metalloid oxygen | 1 | 1 | 0,7 |
Rangering afspejler akkumulerede litteraturbeviser, ikke en enkelt autoritativ regel. Bekræft altid mod din prøvekontekst.
Mulige materialer
| Materiale | Understøttende toppe | Overlappende grupper | Citerede kilder |
|---|---|---|---|
| calcite | 681, 2850, 2864 | Methoxy (OCH3), Hydroxyl (O-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 681 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
-
Silicon (Si) tillid 1,0
“Furthermore, the relatively large new absorption 680.8 3.09 3.07 3.19 3.12 0.06 related to the Si-(CH 3) vibration is essentially unaffected 3”
Chalasani 等 - 2013 - A Spectroscopic Method for Hydroxyl Value Determin DOI: 10.1007/s11746-013-2334-9 -
Metal oxygen tillid 1,0
“stretchingandN-Hbendingvibrationrespectively.FTIRanalcm-1 ysis of MIONPs demonstrated a band at 681 corroborat850To further characterize the phase, orientation and grain size of ing the Fe-O-Fe stretching vibration in the region of cm-1 syn”
Removal of Cr(VI) by magnetic iron oxide nanoparticles synthesized from extracellular polymeric substances of chromium resistant acid-tolerant bacterium Lysinibacillus sphaericus RTA-01 DOI: 10.1007/s40201-019-00415-5 -
Hydroxyl (O-H) tillid 1,0
“1100, 1070, (Si-Ostretching) and 800, 681cm-1 (R-O-H bending, where R is the octahedral ion - peninsula, makes it possible to draw important conclusions.”
Zorba 等 - 2006 - Technique and palette of XIIIth century painting i DOI: 10.1007/s00339-006-3548-6 -
Hydroxyl (O-H) tillid 1,0
“2 bands at 1409 cm-1 (ν3 asymmetric stretching), 1045 cm-1 (ν1 symmetric stretching), 839 cm-1 (ν2 outcm-1 ν bending), the split in the in-plane bending vibration at 690 and 681 and the OH stretching 4 in-plane bending vibration at 690 and”
Investigating the Potential of the Er:YAG Laser for the Removal of Cemented Dust from Limestone and Painted Plaster DOI: 10.3390/coatings10111099 -
Metalloid oxygen tillid 0,7
“Peak at 681 cm-1 associated with Ge bridging oxygen signatures.”
Santos 等 - 2007 - Vibrational spectroscopy study of niobium germanos DOI: 10.1016/j.jnoncrysol.2007.02.018
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