What absorbs at 742 cm⁻¹ in an FTIR spectrum?
A band near 742 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
Quick answer
A band near 742 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.
সম্ভাব্য কার্যকরী-গ্রুপ অ্যাসাইনমেন্ট
| কার্যকরী গ্রুপ | সমর্থনকারী তথ্য | উদ্ধৃত সূত্র | সর্বোচ্চ আত্মবিশ্বাস |
|---|---|---|---|
| Alkyl C-H | 7 | 7 | 1.0 |
| Methacrylate | 4 | 4 | 1.0 |
| Acetate | 4 | 4 | 1.0 |
| Ketone | 3 | 3 | 1.0 |
| Ester | 3 | 3 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Amide | 3 | 3 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
র্যাঙ্কিং জমা হওয়া সাহিত্য প্রমাণ প্রতিফলিত করে, একটি একক কর্তৃত্বপূর্ণ নিয়ম নয়। সর্বদা আপনার নমুনা প্রসঙ্গের বিরুদ্ধে নিশ্চিত করুন।
Possible materials
| উপাদান | সমর্থনকারী শিখর | Overlapping groups | উদ্ধৃত সূত্র |
|---|---|---|---|
| PVA | 742, 1660, 2930 | Alkyl C-H, Acetate, Methacrylate | 1 |
| Epoxy | 742, 1660, 1735 | Methacrylate, Acetate, Alkyl C-H | 1 |
| CaO | 742, 2909, 1839 | Methacrylate, Acetate | 1 |
| polyurethane | 742, 2270, 1700 | Alkyl C-H, Methacrylate, Acetate | 1 |
| PLA | 742, 1650, 1073 | Alkyl C-H, Methacrylate, Acetate | 1 |
| epoxy resin | 742, 905, 1100 | Methacrylate, Acetate, Alkyl C-H | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
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 742 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
এই অ্যাসাইনমেন্টগুলোর পেছনে সাহিত্য
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আত্মবিশ্বাস 1.0
“The band at cm-1 742 is probably due to the Ca-O bonds [7].”
Characterization of quicklime as raw material to hydrated lime: Effect of temperature on its characteristics DOI: 10.1063/1.5066668 -
C-S single bond আত্মবিশ্বাস 1.0
“LLM confirmed rule peak-group candidate”
Mesoporous Magnetic Cysteine Functionalized Chitosan Nanocomposite for Selective Uranyl Ions Sorption: Experimental, Structural Characterization, and Mechanistic Studies DOI: 10.3390/polym14132568 -
Carbonyl (C=O) আত্মবিশ্বাস 1.0
“The corresponding light minus dark FTIR difference spectrum ν(C=O) (Figure 4, in the region black line) shows a sigmoidal cm-1 and a positive peak at band with a negative peak at 1,742 cm-1, that are absent in the difference spectrum of the”
Baserga 等 - 2022 - Membrane Protein Activity Induces Specific Molecul DOI: 10.3389/fmolb.2022.915328 -
Acetate আত্মবিশ্বাস 1.0
“The band at 742 cm-1 is assigned to the CH3 rocking cm-1 CH rocking mode, while 596 and 562 are related to [ νasGa-C 2] and [ νsGa-C 2].”
Synthesis of High Surface Area—Group 13—Metal Oxides via Atomic Layer Deposition on Mesoporous Silica DOI: 10.3390/nano12091458 -
Acetate আত্মবিশ্বাস 1.0
“cm-1, cm-1, cm-1, cm-1, C-CH3 stretching at 1042-1046 cm-1, C-COO vibration assigned to 873 cm-1, (possibly due to the to 1095-1098 C-CH stretching at 1042-1046 C-COO vibration assigned to 873 3 cm-1, presence of CaCO3), C=O stretching assi”
Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure DOI: 10.3390/app7060579 -
C c single bond আত্মবিশ্বাস 1.0
“The third one at 1477 cm-1 was associated with CH-cross deformations in CH 2-groups and the fourth band at 742 cm-1 was assigned to H-C-C-H-bound modes in the CH groups.”
Fernández 等 - 2017 - DOI: 10.17230/ingciencia.13.25.6 -
Phosphate (PO4) আত্মবিশ্বাস 1.0
“The bending modes of the P-O bonds in phosphate groups are responsible for the double peak at 563 and 742 cm-1.”
Synthesis and Characterization of New Composite Materials Based on Magnesium Phosphate Cement for Fluoride Retention DOI: 10.3390/ma16020718 -
Acetate আত্মবিশ্বাস 1.0
“cm-1 (imide carbonyl asymmetric stretching), 1715 (imide carbonyl symmetric stretchcm-1 ing and C=O stretching of carboxylic pendant groups), 1370 (C-N stretching), and cm-1 cm-1 742 (C=O bending).”
Novel Polyimide/Copper-Nickel Ferrite Composites with Tunable Magnetic and Dielectric Properties DOI: 10.3390/polym
এই ব্যান্ডের সাথে একটি স্পেকট্রাম আছে?
আপনার FTIR স্পেকট্রাম আপলোড করুন এবং সেকেন্ডের মধ্যে একটি সম্পূর্ণ ব্যাখ্যা রিপোর্ট পান — সাহিত্য সাইটেশন সহ পিক অ্যাসাইনমেন্ট, লাইব্রেরি ম্যাচ এবং একটি আত্মবিশ্বাস-রেটেড এভিডেন্স চেইন।