What absorbs at 1694 cm⁻¹ in an FTIR spectrum?
A band near 1694 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
Risposta rapida
A band near 1694 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.
Possibili assegnazioni di gruppi funzionali
| Gruppo funzionale | Fatti di supporto | Fonti citate | Affidabilità massima |
|---|---|---|---|
| Amide | 5 | 3 | 1,0 |
| Carbonyl (C=O) | 3 | 3 | 1,0 |
| Carboxyl (COOH) | 3 | 3 | 1,0 |
| Hydroxyl (O-H) | 2 | 2 | 1,0 |
| Carbonate | 1 | 1 | 1,0 |
| Protein beta turn | 1 | 1 | 1,0 |
| Protein alpha helix | 1 | 1 | 1,0 |
| Protein | 1 | 1 | 1,0 |
| Carbohydrate | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| Ketone | 1 | 1 | 1,0 |
| Ester | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| N-O bond | 1 | 0 | 1,0 |
| Urethane | 1 | 0 | 1,0 |
La classifica riflette le prove bibliografiche accumulate, non una singola regola autorevole. Conferma sempre nel contesto del tuo campione.
Materiali possibili
| Materiale | Picchi di supporto | Gruppi sovrapposti | Fonti citate |
|---|---|---|---|
| chitosan | 1694, 1650, 1655 | Amide, Hydroxyl (O-H) | 1 |
| protein | 1694, 1650, 1640 | Amide, Carbonyl (C=O), Carboxyl (COOH) | 1 |
| magnetite | 1694, 1740, 1263 | Hydroxyl (O-H), Carboxyl (COOH) | 1 |
I materiali vengono mostrati solo quando lo stesso pool di letteratura supporta questa banda e almeno un picco caratteristico aggiuntivo.
Logica dello spettro
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 1694 cm⁻¹ is usually not enough for material identification by itself.
Utilizzo nel mondo reale
Questo tipo di richiesta è comune nell＇identificazione dei polimeri, nello screening di plastiche sconosciute, nella risoluzione dei problemi di controllo qualità, nella verifica dei materiali riciclati e nella revisione dell＇assegnazione dei picchi supportata dalla letteratura.
Errori comuni
- Trattare una banda isolata come prova di un materiale senza verificare almeno uno o due picchi di supporto.
- Ignorando la sovrapposizione: più gruppi funzionali possono contribuire vicino allo stesso numero d＇onda.
- Saltare la convalida quando additivi, miscele, ossidazione o contaminazione possono distorcere lo spettro.
Consiglio di verifica
Quando permangono ambiguità, convalida l＇ipotesi con DSC, GC-MS o TGA, specialmente per miscele, campioni degradati e polimeri caricati.
Letteratura dietro queste assegnazioni
-
Hydroxyl (O-H) affidabilità 1,0
“Peak of TLE was broad and strong occurred at 3261 as -OH group vibration, 1694 as max cm-1 cm-1 C=O group, 1359 as -NH group, and 1056 as C-O group.”
A facile method for green synthesis of Nd2O3 nanoparticles using aqueous extract of Terminalia catappa leaf DOI: 10.1063/1.5064090 -
Alkyl C-H affidabilità 1,0
“The absorption peak located at 232 cm-1 cm-1 1694 corresponds to C =O stretching of alkanes.”
Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles DOI: 10.1016/j.micpath.2015.11.021 -
Acetate affidabilità 1,0
“In the absorption spectrum of the C=O stretching (1694 which indicates the oxidation”
Potential effects of nano-cellulose and nano-silica/polyvinyl alcohol nanocomposites in the strengthening of dyed paper manuscripts with madder: an experimental study DOI: 10.1038/s41598-022-23907-1 -
Protein affidabilità 1,0
“was also found, of lower intensity 1628 cm-1 II band around 1545 cm-1 (Figure 1 and Figure cal of protein aggregates, and by the upshift of and broader compared to the prefixation stage, 2 A,B,C), the absorption of proteins dominates the 16”
Ami 等 - 2014 - Role of water in chromosome spreading and swelling DOI: 10.4081/ejh.2014.2330 -
Carboxyl (COOH) affidabilità 1,0
“of the methyl and methylene group at 2880 and 2935 cm-1 The sharp band at 1694 assigns to stretching vibration The saturated adsorbent with oil was filtered in a vacuum (C = O) of carboxylic acid.”
Eco-friendly adsorbents based on abietic acid, boswellic acid, and chitosan/magnetite for removing waste oil from the surface of the water DOI: 10.1007/s11356-022-20169-2 -
Protein alpha helix affidabilità 1,0
“(β-sheets), (α-helix/ Teknoloji peaks at 1694 tion proteins during Similar results were also 1680 (turn/loop), 1647 cm-1 (α-helix)”
Guler 等 - 2019 - Characterization of CD133(+)CD44(+) human prostat DOI: 10.1039/c9an00093c -
Hydroxyl (O-H) affidabilità 1,0
“1 the vibrational peaks of MnO found at 1694 1533 1385 987 2 cm1 cm1 corresponds to -OH bending vibrations complexed with Mn atoms and those around 684 and”
Helen 等 - 2023 - Amelioration of ionic conductivity (303 K) with th DOI: 10.21203/rs.3.rs-1557220/v1 -
Amide affidabilità 1,0
“Particularly, a down-shift from 1666 shifts to For Xano bound spectra we also amide-I 1656cm-1 7cm-1 1694cm-1 Asn4046.52 to observed a of amide-I band upon binding of ACh points to an up shift in signal to and”
Vibrational spectroscopy analysis of ligand efficacy in human M2 muscarinic acetylcholine receptor (M2R) DOI: 10.1038/s42003-021-02836-1
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