What absorbs at 685 cm⁻¹ in an FTIR spectrum?
A band near 685 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
Mabilis na sagot
A band near 685 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.
Mga posibleng pagtatalaga ng functional-group
| Grupong functional | Mga sumusuportang katotohanan | Mga nasiping sanggunian | Pinakamataas na kumpiyansa |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 4 | 4 | 1.0 |
| Metal oxygen | 3 | 3 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Urea | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
Ang pagraranggo ay sumasalamin sa naipon na ebidensya ng literatura, hindi isang solong awtoritatibong tuntunin. Palaging kumpirmahin laban sa konteksto ng iyong sample.
Mga posibleng materyales
| Materyal | Sumusuportang mga peak | Mga overlapping na grupo | Mga nasiping sanggunian |
|---|---|---|---|
| silver nanoparticles | 685, 1636, 1631 | Alkyl C-H | 1 |
Ang mga materyales ay ipinapakita lamang kapag ang parehong literatura pool ay sumusuporta sa banda na ito at hindi bababa sa isang karagdagang katangian na tuktok.
Logic ng spectrum
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 685 cm⁻¹ is usually not enough for material identification by itself.
Paggamit sa totoong mundo
Ang uri ng query na ito ay karaniwan sa pagtukoy ng polymer, screening ng hindi kilalang plastic, pag-troubleshoot ng QC, pag-verify ng recycled na materyal, at pagsusuri ng pagtatalaga ng peak na may suporta ng literatura.
Mga karaniwang pagkakamali
- Pagtrato sa isang nakahiwalay na banda bilang patunay ng isang materyal nang hindi sinusuri ang hindi bababa sa isa o dalawang sumusuportang peak.
- Hindi pinapansin ang overlap: maraming functional group ang maaaring mag-ambag malapit sa parehong wavenumber.
- Pag-laktaw sa pagpapatunay kapag ang mga additives, blends, oxidation, o contamination ay maaaring mag-distort ng spectrum.
Payo sa pagpapatunay
Kapag nananatili ang kalabuan, patunayan ang hypothesis gamit ang DSC, GC-MS, o TGA, lalo na para sa mga blend, degraded na sample, at filled polymers.
Literatura sa likod ng mga pagtatalagang ito
-
kumpiyansa 1.0
“Similarly by GGA cm(cid:2)1 (i) The frequencies due to Si-O in-plane bending vibrations, method, the peak position is 685.2 in [P] and shifts to”
Theoretical and experimental study of structures and properties of cement paste The nanostructural aspects of C–S–H DOI: 10.1016/j.jpcs.2011.05.001 -
kumpiyansa 1.0
“[3] made a MgO 10.46% 15.88% comparison between the FTIR spectra of Mg-rich and Mg-poor K2O 0.71% 0.25% 3585cm-1 palygorskites, and concluded that the vibration was Na2O 0.02% 0.01% 685cm-1 Fe)(cid:2)OH Mg)(cid:2)OH, P2O5 0.04% 0.34% caused”
Cai 等 - 2007 - A Fourier transform infrared spectroscopic study o DOI: 10.1016/j.saa.2006.02.053 -
kumpiyansa 1.0
“(2006), similar bands observed at 685 and are attributed to the Fe-O”
do Nascimento-Dias 等 - 2020 - Detection of organic or inorganic material in Mart DOI: 10.1017/S147355042000021X -
Phosphate (PO4) kumpiyansa 1.0
“The two peaks at 611 and 685 cm-1 cm-1 692 caused by P-O bending in phosphate.”
Ashemary 等 - 2023 - Preparation and characterization of mesoporous Lan DOI: 10.15251/DJNB.2023.182.681 -
Urea kumpiyansa 1.0
“The wavenumber around 1,673-1,685 cm-1 corresponded to free hydrogen-bonded urea carbonyl.”
Che 等 - 2019 - Investigations on Aging Behavior and Mechanism of DOI: 10.3390/ma12213636 -
Phosphate (PO4) kumpiyansa 1.0
“The spectral bands associated with polyphosphates, namely P=O stretching (1165 cm-1) and P-O-P stretching (685 cm-1), were weak and Int.”
Assessment of Biotechnologically Important Filamentous Fungal Biomass by Fourier Transform Raman Spectroscopy DOI: 10.3390/ijms -
Borate kumpiyansa 1.0
“(cm-1) Frequencies Assignment Reference ~685 B-O-B bending vibration [29]”
Facile Synthesis of Calcium Borate Nanoparticles and the Annealing Effect on Their Structure and Size DOI: 10.3390/ijms131114434 -
Aromatic ring kumpiyansa 1.0
“The peak at cm-1 685 may be assigned due to the stretching vibration of aromatic ring that might be attached to the free O-H Gracilaria group.”
Kumar 等 - 2013 - Seaweed-mediated biosynthesis of silver nanopartic DOI: 10.1007/s13204-012-0151-3
May spectrum ka ba na may ganitong band?
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