What absorbs at 702 cm⁻¹ in an FTIR spectrum?
A band near 702 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
Szybka odpowiedź
A band near 702 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.
Możliwe przypisania grup funkcyjnych
| Grupa funkcyjna | Fakty wspierające | Cytowane źródła | Najwyższa wiarygodność |
|---|---|---|---|
| Alkyl C-H | 3 | 3 | 1,0 |
| Aromatic ring | 2 | 2 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1,0 |
| Silicate | 1 | 1 | 1,0 |
| Metal oxygen | 1 | 1 | 1,0 |
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 0 | 1,0 |
Ranking odzwierciedla zgromadzone dowody literaturowe, a nie pojedynczą autorytatywną zasadę. Zawsze potwierdzaj w kontekście swojej próbki.
Logika widma
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 702 cm⁻¹ is usually not enough for material identification by itself.
Zastosowanie w rzeczywistości
Ten typ zapytania jest powszechny w identyfikacji polimerów, przesiewaniu nieznanych tworzyw sztucznych, rozwiązywaniu problemów z kontrolą jakości, weryfikacji materiałów pochodzących z recyklingu oraz przeglądzie przypisania pików wspartym literaturą.
Częste błędy
- Traktowanie jednego izolowanego pasma jako dowodu materiału bez sprawdzenia co najmniej jednego lub dwóch pików wspierających.
- Ignorowanie nakładania się: wiele grup funkcyjnych może przyczyniać się w pobliżu tej samej liczby falowej.
- Pomijanie walidacji, gdy dodatki, mieszanki, utlenianie lub zanieczyszczenia mogą zniekształcić widmo.
Porada dotycząca weryfikacji
Gdy pozostaje niejednoznaczność, zweryfikuj hipotezę za pomocą DSC, GC-MS lub TGA, szczególnie w przypadku mieszanin, zdegradowanych próbek i wypełnionych polimerów.
Literatura stojąca za tymi przypisaniami
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wiarygodność 1,0
“The band at 996 is assigned to V O stretching of distorted octahedral and distorted cm-1 square pyramids, while the band at 702 is due to coordination of vanadium atoms with the three oxygen”
Vanadium pentoxide nanobelts: One pot synthesis and its lithium storage behavior DOI: 10.1002/crat.201200122 -
Hydroxyl (O-H) wiarygodność 1,0
“cm-1 (Figure S6b), respectively The band at 702 is influenced by three modes of vibration: μ 3cm-1 OH bending + O-C-O bending + C=C-(COO) bending, while the one at 729 corresponds to 13.”
Iodine Uptake by Zr/Hf-Based UiO-66 Materials: The Influence of Metal Substitution on Iodine Evolution DOI: 10.1016/S0167-8140(02)00374-2. -
wiarygodność 1,0
“The band observed at cm-1 702 corresponded to the Ti-O stretching and Ti-O-Ti bridging stretching bonds [30,31];”
Camila Ariza-Tarazona 等 - 2019 - New strategy for microplastic degradation Green p DOI: 10.1016/j.ceramint.2018.10.208 -
Silicate wiarygodność 1,0
“Silicates are represented by the intense peaks at 1989 and 1871 cm-1 [66], and by the specific peaks of quartz at 2236, 2132 and 702 cm-1, and those attributed to muscovite at”
Technological and Functional Approaches Applied to Miniature Vessels with Pigment Traces: Two Middle Bronze Age Case Studies from Eastern Subcarpathians of Romania DOI: 10.3390/app13042093 -
Alkyl C-H wiarygodność 1,0
“cm-1 C-H out-of-plane bending modes at 702 and 761 When a weak peak is present at 3083 and cm-1 a more intense peak at 1599 can be detected, the occurrence of a copolymer of styrene and αmethyl-styrene was suggested.”
Germinario 等 - 2016 - Chemical characterisation of spray paints by a mul DOI: 10.1016/j.microc.2015.04.016 -
Aromatic ring wiarygodność 1,0
“The FTIR spectrum of CIN showed principle -1 -1 The results of the assay indicated that the content in the var- -H absorption peaks at 702.04 cm and 748.33 cm (C bending -1 -1 ious solid systems prepared by different methods was in the -H o”
Multicomponent cyclodextrin system for improvement of solubility and dissolution rate of poorly water soluble drug DOI: 10.1016/j.ajps.2018.02.007 -
wiarygodność 1,0
“The medium strength vibrational band present at 702 The role of FTIR spectroscopy in the clinical analysis of - 1 is assigned to N-H out of plane bending with the cm normal and diabetic blood samples is clearly demonstrated.”
Ramalingam 等 - 2014 - Evaluation of metformin hydrochloride in Wistar ra DOI: 10.4103/0976-9668.136168 -
Alkyl C-H wiarygodność 1,0
“The band at 702 cm is likely due to overlapping peaks of the CH rocking vibration and the out-of-plane vibration of cis-disubstituted 2 olefins, related to the presence of long chain hydrocarbons [108].”
Stefanov 等 - 2013 - Towards combinatorial spectroscopy The case of mi DOI: 10.30744/brjac.2179-3425.2018.5.18.12-27
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