What absorbs at 774 cm⁻¹ in an FTIR spectrum?
A band near 774 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
Snabbt svar
A band near 774 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.
Möjliga identifieringar av funktionella grupper
| Funktionell grupp | Stödjande fakta | Citerade källor | Högsta förtroende |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 2 | 2 | 1,0 |
| Hydroxyl (O-H) | 1 | 1 | 1,0 |
| C c single bond | 1 | 1 | 1,0 |
| N h | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Alkyl C-H | 1 | 1 | 1,0 |
| Aromatic ring | 1 | 1 | 1,0 |
| Siloxane (Si-O-Si) | 1 | 1 | 0,9 |
Rankingen speglar ackumulerade litteraturbevis, inte en enda auktoritativ regel. Bekräfta alltid mot din provkontext.
Möjliga material
| Material | Stödjande toppar | Överlappande grupper | Citerade källor |
|---|---|---|---|
| PVA | 774, 1660, 2930 | Hydroxyl (O-H) | 1 |
| ZnO | 774, 1400, 3430 | Hydroxyl (O-H) | 1 |
| CuO | 774, 453, 1000 | Hydroxyl (O-H) | 1 |
| glucose | 774, 1740, 1400 | Hydroxyl (O-H) | 1 |
| magnetite | 774, 1740, 1263 | Hydroxyl (O-H), Silicon-oxygen (Si-O) | 1 |
| quartz | 774, 800, 3053 | Silicon-oxygen (Si-O), Hydroxyl (O-H) | 1 |
Material visas endast när samma litteraturpool stöder detta band och minst en ytterligare karakteristisk topp.
Spektrumlogik
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 774 cm⁻¹ is usually not enough for material identification by itself.
Användning i verkligheten
Denna typ av fråga är vanlig inom polymeridentifiering, screening av okänd plast, felsökning av kvalitetskontroll, verifiering av återvunnet material och litteraturstödd toppidentifieringsgranskning.
Vanliga misstag
- Behandla ett isolerat band som bevis på ett material utan att kontrollera minst en eller två stödjande toppar.
- Ignorerar överlapp: flera funktionella grupper kan bidra nära samma vågtal.
- Hoppa över validering när tillsatser, blandningar, oxidation eller föroreningar kan förvränga spektrat.
Verifieringsråd
När oklarhet kvarstår, validera hypotesen med DSC, GC-MS eller TGA, särskilt för blandningar, nedbrutna prover och fyllda polymerer.
Litteratur bakom dessa identifieringar
-
förtroende 1,0
“cm-1 (ii) The peak at 774 can be attributed to 10 Zn (Glass) 3.8 3.6 3.5 symmetric stretching vibrations of P - O - P 10 Zn (comp) 5.1 5.1”
Helmy 等 - 2021 - Preparation and Characterization of some Composite DOI: 10.21608/EJCHEM.2021.80482.3986 -
Aromatic ring förtroende 1,0
“The absorption peaks at 774 are assigned to aromatic C-H vibrations, indicating there are some aromatics with alkyl cm(cid:3)1 cm(cid:3)1 Transmittance substitution [21].”
Gradient separation of ⩾300°C distillate from low-temperature coal tar based on formaldehyde reactions DOI: 10.1016/j.fuel.2015.07.029 -
Water (H2O) förtroende 1,0
“The only exception is that the absorbing band belonging to 774 h in PA11-RH had a 39% increase in curve area, which might be due to the reversible reaction of water with amide”
Comparative Characterization of Hot-Pressed Polyamide 11 and 12: Mechanical, Thermal and Durability Properties DOI: 10.3390/polym13203553 -
förtroende 1,0
“cm-1 1710-1730 corresponds to the stretching vibrations of carbonyl groups (C=O), while the peaks corresponds to the stretching vibrations of carbonyl groups (C=O), while the peaks at 1534 and 774 cm-1 at 1534 and 774 correspond to the bend”
Synthesis of Linseed Oil-Based Waterborne Urethane Oil Wood Coatings DOI: 10.3390/polym10111235 -
Silicon-oxygen (Si-O) förtroende 1,0
“The studied quartz was detected with bands at 460.90 cm-1, 491.73 cm-1, 773.68 cm-1, and 1071.43 cm-1.”
Fawzy - 2021 - Separation of fine beryl from quartz via magnetic DOI: 10.37190/ppmp/132329 -
C c single bond förtroende 1,0
“829 C-C stretching 774 774 OH deformation 771”
Gallegos-Loya 等 - 2012 - An Optical Overview of Poly[mu(2)-L-alanine-mu(3)- DOI: 10.1100/2012/620189 -
förtroende 0,9
“Text: '774 cm-1 (P G1)' for glucose”
Landari 等 - 2018 - Pseudo-Continuous Flow FTIR System for Glucose, Fr DOI: 10.3390/mi9100517 -
Siloxane (Si-O-Si) förtroende 0,9
“explicit assignment in text”
Evaluation of polyvinyl alcohol–borax/agarose (PVA–B/AG) blend hydrogels for removal of deteriorated consolidants from ancient Egyptian wall paintings DOI: 10.1186/s40494-019-0264-z
Har du ett spektrum med detta band?
Ladda upp ditt FTIR-spektrum och få en fullständig tolkningsrapport – toppidentifieringar med litteraturhänvisningar, biblioteksmatchningar och en förtroendebedömd beviskedja – på sekunder.