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
Jawapan pantas
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.
Penetapan kumpulan berfungsi yang mungkin
| Kumpulan berfungsi | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| 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 |
Pemeringkatan mencerminkan bukti literatur terkumpul, bukan satu peraturan berwibawa. Sentiasa sahkan terhadap konteks sampel anda.
Bahan yang mungkin
| Bahan | Puncak sokongan | Kumpulan bertindih | Sumber dipetik |
|---|---|---|---|
| calcite | 681, 2850, 2864 | Methoxy (OCH3), Hydroxyl (O-H) | 1 |
Bahan hanya dipaparkan apabila kumpulan literatur yang sama menyokong jalur ini dan sekurang-kurangnya satu puncak ciri tambahan.
Logik spektrum
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.
Penggunaan dunia sebenar
Jenis pertanyaan ini biasa dalam pengenalpastian polimer, saringan plastik tidak diketahui, penyelesaian masalah QC, pengesahan bahan kitar semula, dan semakan tugasan puncak yang disokong oleh literatur.
Kesilapan biasa
- Menganggap satu jalur terpencil sebagai bukti bahan tanpa memeriksa sekurang-kurangnya satu atau dua puncak sokongan.
- Mengabaikan pertindihan: pelbagai kumpulan berfungsi boleh menyumbang berhampiran nombor gelombang yang sama.
- Melangkau pengesahan apabila bahan tambahan, campuran, pengoksidaan, atau pencemaran boleh memesongkan spektrum.
Nasihat pengesahan
Apabila kekaburan masih ada, sahkan hipotesis dengan DSC, GC-MS, atau TGA, terutamanya untuk campuran, sampel terdegradasi, dan polimer terisi.
Literatur di sebalik penetapan ini
-
Silicon (Si) keyakinan 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 keyakinan 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) keyakinan 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) keyakinan 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 keyakinan 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
Ada spektrum dengan jalur ini?
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