What absorbs at 2991 cm⁻¹ in an FTIR spectrum?
A band near 2991 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
Jibu la haraka
A band near 2991 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.
Ugawaji unaowezekana wa vikundi vya kazi
| Kikundi cha kazi | Ukweli unaounga mkono | Vyanzo vilivyotajwa | Uaminifu wa juu |
|---|---|---|---|
| Alkyl C-H | 6 | 6 | 1.0 |
| Methyl | 3 | 3 | 1.0 |
Cheo kinaonyesha ushahidi wa fasihi uliokusanywa, si sheria moja yenye mamlaka. Thibitisha kila mara dhidi ya mazingira ya sampuli yako.
Nyenzo zinazowezekana
| Nyenzo | Vilele vya usaidizi | Vikundi vinavyoingiliana | Vyanzo vilivyotajwa |
|---|---|---|---|
| TiO | 2991, 1730, 1699 | Alkyl C-H | 1 |
| rGO | 2991, 2358, 2930 | Alkyl C-H | 1 |
| PLA | 2991, 1650, 1073 | Alkyl C-H | 1 |
| PEG | 2991, 1650, 1342 | Alkyl C-H | 1 |
| PLLA | 2991, 1182, 921 | Alkyl C-H, Methyl | 1 |
Nyenzo zinaonyeshwa tu wakati mkusanyiko sawa wa fasihi unaunga mkono bendi hii na angalau kilele kimoja cha ziada cha sifa.
Mantiki ya wigo
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 2991 cm⁻¹ is usually not enough for material identification by itself.
Matumizi ya ulimwengu halisi
Aina hii ya swala ni ya kawaida katika utambuzi wa polima, uchunguzi wa plastiki isiyojulikana, utatuzi wa shida za QC, uthibitishaji wa nyenzo zilizosindikwa, na ukaguzi wa ugawaji wa kilele unaoungwa mkono na fasihi.
Makosa ya kawaida
- Kuchukua bendi moja iliyotengwa kama uthibitisho wa nyenzo bila kuangalia angalau kilele kimoja au viwili vya usaidizi.
- Kupuuza mwingiliano: vikundi vingi vya utendaji vinaweza kuchangia karibu na nambari ya wimbi sawa.
- Kuruka uthibitishaji wakati viongezi, mchanganyiko, uoksidishaji, au uchafuzi unaweza kupotosha wigo.
Ushauri wa uthibitishaji.
Wakati utata unabaki, thibitisha nadharia kwa kutumia DSC, GC-MS, au TGA, hasa kwa mchanganyiko, sampuli zilizoharibika, na polima zilizojazwa.
Fasihi nyuma ya ugawaji huu
-
Alkyl C-H uaminifu 1.0
“The two cm-1 bands at 2991 and 2948 can be attributed to the C-H bond stretching vibrations of the -CH and”
Awad 等 - 2020 - Experimental Investigation of Methyl Methacrylate DOI: 10.3390/ma13245793 -
Alkyl C-H uaminifu 1.0
“LLM confirmed rule peak-group candidate”
Structural and Surface Compatibility Study of Modified Electrospun Poly(ε-caprolactone) (PCL) Composites for Skin Tissue Engineering DOI: 10.1208/s12249-016-0500-8 -
Alkyl C-H uaminifu 1.0
“The characteristic band at 2991 cm-1 to 2976 cm-1 cm-1 cm-1 (C=C 2976 corresponds to C-H stretching vibrations, 1652 skeletal vibration), 1521”
Complex Permittivity and Electromagnetic Interference Shielding Effectiveness of OPEFB Fiber-Polylactic Acid Filled with Reduced Graphene Oxide DOI: 10.3390/ma13204602 -
Alkyl C-H uaminifu 1.0
“The asymmetric and symmetric C-H stretching (St.) cm1 cm1, of the methyl groups were attributed to the transmission bands at 2991 and 2943 respectively.”
Ragab - 2022 - Improved Physical, thermal, and conductivity stren DOI: 10.21203/rs.3.rs-1514992/v1 -
Alkyl C-H uaminifu 1.0
“The bands at 2991 and 2868 which were attributed to various C-H stretching vibrations, had opposite signs on the PC2 and PC3 loading curves.”
Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma DOI: 10.3390/diagnostics11112048 -
Methyl uaminifu 0.9
“Explicit assignment: CH3 asymmetric stretching”
Differentiation in MALDI-TOF MS and FTIR spectra between two pathovars of Xanthomonas oryzae DOI: 10.1016/j.saa.2014.06.056 -
Methyl uaminifu 0.9
“Explicit assignment: 'absorption peak around 2991 ... stretching vibration peak of CH3'”
Li 等 - 2020 - Effect of molecular weight of polyethylene glycol DOI: 10.1039/d0ra08699a -
Alkyl C-H uaminifu 0.8
“Text: 'strong peak at 2991.3 cm-1 (Q is assigned as the center branch) ... R(2) transition of our 5ν C-H'”
Perez-Delgado 和 Manzanares - 2010 - Cavity Ring Down and Fourier Transform Infrared Sp DOI: 10.1021/jp105382p
Una wigo wenye bendi hii?
Pakia wigo wako wa FTIR na upate ripoti kamili ya tafsiri — ugawaji wa vilele na marejeleo ya fasihi, ulinganishaji wa maktaba, na mlolongo wa ushahidi wenye kiwango cha uaminifu — kwa sekunde.