What absorbs at 1408 cm⁻¹ in an FTIR spectrum?
A band near 1408 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
Jawapan pantas
A band near 1408 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 |
|---|---|---|---|
| Alkyl C-H | 11 | 10 | 1.0 |
| Amide | 9 | 9 | 1.0 |
| Acetate | 8 | 8 | 1.0 |
| Methacrylate | 7 | 7 | 1.0 |
| Carbonyl (C=O) | 6 | 6 | 1.0 |
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| N h | 5 | 5 | 1.0 |
| Carboxyl (COOH) | 5 | 4 | 1.0 |
| Secondary amine | 4 | 4 | 1.0 |
| C-O single bond | 4 | 4 | 1.0 |
| Aromatic ring | 4 | 3 | 1.0 |
| C n single bond | 3 | 3 | 1.0 |
| Amino acid | 3 | 3 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Lipid | 2 | 2 | 1.0 |
| C c single bond | 2 | 2 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Sulfonyl | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Protein beta sheet | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 0.9 |
| Boron nitrogen | 1 | 0 | 1.0 |
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 |
|---|---|---|---|
| PET | 1408, 800, 1205 | Methacrylate, Acetate, Alkyl C-H | 1 |
| TiO2 | 1408, 1700, 1093 | Alkyl C-H, Methacrylate, Acetate | 1 |
| Al2O3 | 1408, 1722, 1383 | Methacrylate, Acetate, Alkyl C-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 1408 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
-
Alkyl C-H keyakinan 1.0
“Among the more intense bands, we observe in the IR SE spectra the characteristic bands corresponding to the vibration modes of the trans C-O stretch (~976 cm-1), the ester C-C, C-O stretch (~1024 cm-1), the ethylene glycol CH2 wagging mode”
Laskarakis 等 - 2004 - A Spectroscopic Ellipsometry study of PET membrane DOI: 10.1002/masy.200450109 -
Amide keyakinan 1.0
“The maximum of 73.1% of antiindicates asymmetric O-H stretching, 1637.7 oxidation activity was indicated by EPsC at 1000 µg/mL but cm-1 represents the Amide I band, and 1408.08 represents”
Lavania 等 - 2023 - Anatomizing extracellular polymer of Calothrix des DOI: 10.14719/pst.2615 -
Carbonyl (C=O) keyakinan 1.0
“The peak at 1408 is due to the cm-1 symmetric stretching of carbonyl group.”
Structural, optical, morphological and thermal properties of TiO2–Al and TiO2–Al2O3 composite powders by ball milling DOI: 10.1016/j.physleta.2017.02.053 -
Acetate keyakinan 1.0
“Compared with P, the spectra of the EP showed the appearance of cm-1, cm-1,1408 cm-1, 1598 which were represented C=O stretching vibration, strong bands at 1743 C=O asymmetric stretching vibration and O-H deformation vibration respectively.”
Ouyang 等 - 2012 - Adsorption of Cu (II) from aqueous single metal so DOI: 10.4028/www.scientific.net/AMR.535-537.1601 -
keyakinan 1.0
“According to the spectra illustrated in Fig.3, besides the CO interference band 2 cm-1, cm-1, near 2350 the bands near 1408 and 871 which correspond to amino acids and 1,2,4-three substituted benzene,”
Xia 等 - 2015 - Removal of Natural Organic Matter by Forward Osmos DOI: 10.1007/s40242-015-4374-1 -
Carbonyl (C=O) keyakinan 1.0
“The FTIR spectrum of the blend membrane showed new peaks at 1669 cm-1 and 1408 cm-1, corresponding to the carbonyl C=O stretching vibration and the O-H bending vibration of the carboxyl group, respec-”
Preparation and Characterization of Polymer Membranes Impregnated with Carbon Nanotubes for Olive Mill Wastewater DOI: 10.3390/polym14030457 -
Amide keyakinan 1.0
“The carbonyl absorption band at 1735 cm-1 27, suggested the presence of an acrylic-based emulsion whereas the presence of the amide stretching at 1408”
Chemically stable Au nanorods as probes for sensitive surface enhanced scattering (SERS) analysis of blue BIC ballpoint pens DOI: 10.1063/1.4997132 -
Amino acid keyakinan 1.0
“COOperenne are slightly higher (65 and 71%, Table 4) compared at 1236 amino acids, as illustrated by the cm-1, to the classification results of approach 1 (46 and 64%, stretching mode at 1408 and carbohydrates, the latter Table 2).”
Discrimination of grass pollen of different species by FTIR spectroscopy of individual pollen grains DOI: 10.1007/s00216-020-02628-2
Ada spektrum dengan jalur ini?
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