What absorbs at 740 cm⁻¹ in an FTIR spectrum?
A band near 740 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
Jawapan pantas
A band near 740 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.
Penetapan kumpulan berfungsi yang mungkin
| Kumpulan berfungsi | Fakta sokongan | Sumber dipetik | Keyakinan tertinggi |
|---|---|---|---|
| Alkyl C-H | 7 | 7 | 1.0 |
| Aromatic ring | 5 | 5 | 1.0 |
| Ring structure | 3 | 3 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Fatty acid | 2 | 2 | 1.0 |
| Ester | 2 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Guanidine core | 1 | 1 | 1.0 |
| Metal oxo | 1 | 1 | 0.9 |
| Metal oxygen | 1 | 1 | 0.9 |
Pemeringkatan mencerminkan bukti literatur terkumpul, bukan satu peraturan berwibawa. Sentiasa sahkan terhadap konteks sampel anda.
Logik spektrum
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 740 cm⁻¹ is usually not enough for material identification by itself.
Penggunaan dunia sebenar
Jenis pertanyaan ini biasa dalam pengenalpastian polimer, saringan plastik tidak diketahui, penyelesaian masalah QC, pengesahan bahan kitar semula, dan semakan tugasan puncak yang disokong oleh literatur.
Kesilapan biasa
- Menganggap satu jalur terpencil sebagai bukti bahan tanpa memeriksa sekurang-kurangnya satu atau dua puncak sokongan.
- Mengabaikan pertindihan: pelbagai kumpulan berfungsi boleh menyumbang berhampiran nombor gelombang yang sama.
- Melangkau pengesahan apabila bahan tambahan, campuran, pengoksidaan, atau pencemaran boleh memesongkan spektrum.
Nasihat pengesahan
Apabila kekaburan masih ada, sahkan hipotesis dengan DSC, GC-MS, atau TGA, terutamanya untuk campuran, sampel terdegradasi, dan polimer terisi.
Literatur di sebalik penetapan ini
-
Guanidine core keyakinan 1.0
“The guanidine peak is lower compared to 740 between modifi ed and untreated materials in relation to others.”
Uner 等 - 2016 - Wood Waste Turned Into Value Added Products Therm DOI: 10.5552/drind.2016.1534 -
Fatty acid keyakinan 1.0
“3 cm-1 2,800 and of the C = O absorption around 1,740 cm-1 was found to slightly increase, while the complex Fatty acid quantification by gas chromatography cm-1 absorption between 1,250 and 1,000 GC is the most used technique to evaluate l”
Ami 等 - 2014 - Fourier transform infrared spectroscopy as a metho DOI: 10.1186/1754-6834-7-12 -
Fatty acid keyakinan 1.0
“Infact, theester 1,740cm-1 in our experiments are most The response of the fatty acid ester bands in the same experiment band maxima at around (Figure 3B) likely representativeof asituationin which thesolventenvironment is coherent with thi”
Baserga 等 - 2022 - Membrane Protein Activity Induces Specific Molecul DOI: 10.3389/fmolb.2022.915328 -
Hydroxyl (O-H) keyakinan 1.0
“1442 and 1352 to the regions under 830 According to Liang, Marchessault Liang and Marchessault cm-1 [31, 32], these regions correspond to the O-H bending [31] suggested that the regions near 740 and 800 cm-1) in-plane vibration (1442 and th”
Rapid estimation of sugar release from winter wheat straw during bioethanol production using FTIR-photoacoustic spectroscopy DOI: 10.1186/s13068-015-0267-2 -
Ring structure keyakinan 1.0
“cm(cid:2)1 ThespectrumofO.Xappliiessentialoil(Figure3E)depictsfingerprint -CH 943 [14,15], 804 (TOH out of plane vibration) [14, 15] cm(cid:2)1 Carvat1254,1175,1116,995,937,864and813cm(cid:2)1[14,15] peaksof and 740 (TOH phenolic ring vibra”
Detection of carvacrol in essential oils by electrochemical polymerization DOI: 10.1016/j.heliyon.2020.e03714 -
Alkyl C-H keyakinan 1.0
“1E, 1F) record the appearcm-1 cm-1), and 1,660 aroC=O stretching (around 1,740 cm-1, cm-1, 780 and ance of some absorption peaks at 1,318 cm-1), and C-H matic ring skeleton vibration (around 1,545”
Ch'ng 等 - 2016 - Vasorelaxation Study and Tri-Step Infrared Spectro DOI: 10.3831/KPI.2016.19.016 -
Ring structure keyakinan 1.0
“At 670 °C, the degradation of the PI-2 occurs and in the FTIR spectrum, it can be observed only at the following absorption bands: 3430 cm-1 (-OH), 1584 cm-1 (C=C), 1445 cm-1 (P-Ar), 1384 cm-1 (C-H), 1117 cm-1 (P=O), 987 cm-1 (P-O-Ar) and 7”
Optical and Flame-Retardant Properties of a Series of Polyimides Containing Side Chained Bulky Phosphaphenanthrene Units DOI: 10.3390/ijms232113174 -
Aromatic ring keyakinan 1.0
“(1996) claimed that stronger 3 740cm-1) ] and SNS at around the peak of benzene ring interaction between ether groups and cations causes a larger s cm-1).”
Kim 等 - 2020 - Lithium Salt Dissociation in Diblock Copolymer Ele DOI: 10.3389/fenrg.2020.569442
Ada spektrum dengan jalur ini?
Muat naik spektrum FTIR anda dan dapatkan laporan tafsiran penuh — penetapan puncak dengan petikan literatur, padanan perpustakaan, dan rantaian bukti berkadar keyakinan — dalam beberapa saat.