What absorbs at 781 cm⁻¹ in an FTIR spectrum?
A band near 781 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
ਤੁਰੰਤ ਜਵਾਬ
A band near 781 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.
ਸੰਭਾਵਿਤ ਫੰਕਸ਼ਨਲ-ਗਰੁੱਪ ਅਸਾਈਨਮੈਂਟਾਂ
| ਫੰਕਸ਼ਨਲ ਗਰੁੱਪ | ਸਹਾਇਕ ਤੱਥ | ਹਵਾਲਾ ਦਿੱਤੇ ਸਰੋਤ | ਉੱਚ ਵਿਸ਼ਵਾਸ |
|---|---|---|---|
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Silicon-oxygen (Si-O) | 2 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Oxalate | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
ਰੈਂਕਿੰਗ ਸੰਚਿਤ ਸਾਹਿਤ ਸਬੂਤਾਂ ਨੂੰ ਦਰਸਾਉਂਦੀ ਹੈ, ਇੱਕ ਸਿੰਗਲ ਅਧਿਕਾਰਤ ਨਿਯਮ ਨਹੀਂ। ਹਮੇਸ਼ਾਂ ਆਪਣੇ ਨਮੂਨੇ ਦੇ ਸੰਦਰਭ ਦੇ ਵਿਰੁੱਧ ਪੁਸ਼ਟੀ ਕਰੋ।
ਸਪੈਕਟ੍ਰਮ ਤਰਕ
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 781 cm⁻¹ is usually not enough for material identification by itself.
ਅਸਲ-ਸੰਸਾਰ ਵਰਤੋਂ
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
ਆਮ ਗਲਤੀਆਂ
- ਘੱਟੋ-ਘੱਟ ਇੱਕ ਜਾਂ ਦੋ ਸਹਾਇਕ ਚੋਟੀਆਂ ਦੀ ਜਾਂਚ ਕੀਤੇ ਬਿਨਾਂ ਇੱਕ ਅਲੱਗ-ਥਲੱਗ ਬੈਂਡ ਨੂੰ ਸਮੱਗਰੀ ਦੇ ਸਬੂਤ ਵਜੋਂ ਮੰਨਣਾ।
- ਓਵਰਲੈਪ ਨੂੰ ਨਜ਼ਰਅੰਦਾਜ਼ ਕਰਦੇ ਹੋਏ: ਕਈ ਕਾਰਜਸ਼ੀਲ ਸਮੂਹ ਇੱਕੋ ਵੇਵਨੰਬਰ ਦੇ ਨੇੜੇ ਯੋਗਦਾਨ ਪਾ ਸਕਦੇ ਹਨ।
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
ਤਸਦੀਕ ਸਲਾਹ
ਜਦੋਂ ਅਸਪਸ਼ਟਤਾ ਬਣੀ ਰਹਿੰਦੀ ਹੈ, ਤਾਂ DSC, GC-MS, ਜਾਂ TGA ਨਾਲ ਪਰਿਕਲਪਨਾ ਦੀ ਪੁਸ਼ਟੀ ਕਰੋ, ਖਾਸ ਕਰਕੇ ਮਿਸ਼ਰਣਾਂ, ਵਿਗੜੇ ਹੋਏ ਨਮੂਨਿਆਂ ਅਤੇ ਭਰੇ ਹੋਏ ਪੌਲੀਮਰਾਂ ਲਈ।
ਇਹਨਾਂ ਅਸਾਈਨਮੈਂਟਾਂ ਪਿੱਛੇ ਸਾਹਿਤ
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Silicon (Si) ਵਿਸ਼ਵਾਸ 1.0
“The cm-1 cm-1 absorption band at 781 and 1050 are assigned to the v 1symmetric vibration and v 3asymmetrical stretching vibration of the Si-O bond.”
Ilmi 等 - 2020 - Multi-analytical characterizations of prehistoric DOI: 10.1016/j.microc.2020.104738 -
ਵਿਸ਼ਵਾਸ 1.0
“cm-1, The spectra produced strong peaks at 521.38 and 516.39 corresponding to the C-I (stretching) functional group of alkyl halides, for the leaf and stem, respectively, as well as cm-1 a strong peak corresponding to the C-Cl (stretching)”
Phytochemical Composition of Combretum molle (R. Br. ex G. Don.) Engl. & Diels Leaf and Stem Extracts DOI: 10.3390/plants12081702 -
Alkyl C-H ਵਿਸ਼ਵਾਸ 1.0
“Both samples treated with TEMPO derivatives show the characteristic signals of their functional groups: in particular, the band at 1709 and 1717 cm-1 can be associated with the cm-1 functional groups: in particular, the band at 1709 and 171”
Cicogna 等 - 2022 - Surface Functionalization of Face Masks with Cold DOI: 10.3390/molecules27238632 -
Oxalate ਵਿਸ਼ਵਾਸ 1.0
“The FTIR spectrum peaks at 780.7, 1336.4, and 1631.0 all correspond to reported peak positions for sodium oxalate [16].”
Evaluation of Formate Salt PCM’s for Latent Heat Thermal Energy Storage DOI: 10.3390/en14030765 -
ਵਿਸ਼ਵਾਸ 1.0
“The vibrational band centred at 781 cm-1 is ascribed to the stretching mode modes due to the formation of nonbridge oxygen.”
Effect of Yb3+ on the Structural and Visible to Near-Infrared Wavelength Photoluminescence Properties in Sm3+-Yb3+-Codoped Barium Fluorotellurite Glasses DOI: 10.3390/ma15093314 -
C c single bond ਵਿਸ਼ਵਾਸ 1.0
“Furthermore, for the spectrum of cm-1 1545, and 1552 cm-1, respectively, can be attributed to the C-C stretching vibration of benzene ring HACSa, HACCa, HACPc, and HACGa, absorption peaks at 781, 767, 772, 735, 739 corresponded 1478cm-1 [3,”
Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity DOI: 10.3390/polym12112460 -
Silicon (Si) ਵਿਸ਼ਵਾਸ 1.0
“The peaks at 113 cm-1 cm-1 876 cm-1 and 781 cm-1 were assigned to Si-O-Si symmetric stretching vibrations [36].”
Adsorption of Hexavalent Chromium Using Banana Pseudostem Biochar and Its Mechanism DOI: 10.3390/su10114250 -
Nucleic acid ਵਿਸ਼ਵਾਸ 1.0
“LLM confirmed rule peak-group candidate”
Zelig 等 - 2010 - Biochemical analysis and quantification of hematop DOI: 10.1117/1.3442728(cid:4)
ਕੀ ਇਸ ਬੈਂਡ ਨਾਲ ਇੱਕ ਸਪੈਕਟ੍ਰਮ ਹੈ?
ਆਪਣਾ FTIR ਸਪੈਕਟ੍ਰਮ ਅੱਪਲੋਡ ਕਰੋ ਅਤੇ ਸਕਿੰਟਾਂ ਵਿੱਚ ਇੱਕ ਪੂਰੀ ਵਿਆਖਿਆ ਰਿਪੋਰਟ ਪ੍ਰਾਪਤ ਕਰੋ — ਪੀਕ ਅਸਾਈਨਮੈਂਟਾਂ, ਲਾਇਬ੍ਰੇਰੀ ਮੈਚ, ਅਤੇ ਇੱਕ ਵਿਸ਼ਵਾਸ-ਦਰਜਾ ਪ੍ਰਾਪਤ ਸਬੂਤ ਲੜੀ।