Vibrational and Nuclear Magnetic Resonance Properties of 2,2′-Biquinolines: Experimental and Computational Spectroscopy Study

2021 ◽  
Vol 21 (4) ◽  
pp. 2404-2412
Author(s):  
Elisabeta I. Szerb ◽  
Réka-Anita Domokos ◽  
Carmen Creţu ◽  
Massimo La Deda ◽  
Vasile Chiş
Keyword(s):  
Nmr Spectra ◽  
Close Relation ◽  
Tetraethylene Glycol ◽  
Dft Methods ◽  
Trans Conformation ◽  
Parent Molecule ◽  
Resonance Properties ◽  
Computational Data ◽  
Nmr Techniques ◽  
Computational Spectroscopy

Experimental (IR, Raman and NMR) techniques and quantum chemical (DFT) methods have been applied to investigate the vibrational and NMR properties of a new ligand based on 2,2′-biquinoline (bq) functionalized with polar hydrophilic tetraethylene glycol monomethylether (TEG) chains (bq_TEG). Vibrational and NMR spectra of the ligand have been explained based on DFT computational data obtained at B3LYP/6-311+G(d,p) level of theory. For the spectroscopic analysis we started from the parent molecule 2,2′-biquinoline and explained the changes in the spectra of bq_TEG in close relation to the corresponding spectra of bq. Our data point to a trans conformation of bq_TEG in solid state, as wells as in liquid phase. The excellent agreement between the experimental and computed data allowed for a reliable assignment of the vibrational and NMR spectra, both for bq and bq_TEG.

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

1995 ◽  
Vol 60 (4) ◽  
pp. 619-635 ◽  
Author(s):  
Václav Křeček ◽  
Stanislav Hilgard ◽  
Miloš Buděšínský ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Coupling Constants ◽  
Side Chain ◽  
Oxidation Reactions ◽  
H Nmr ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Intramolecular Association ◽  
C Nmr

A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1H NMR, 13C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1H and 13C NMR spectra are discussed.

scholarly journals NMR Spectroscopy as a Tool for Studying Asphaltene Composition

2019 ◽  
Vol 92 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Jelena Parlov Vuković ◽  
Predrag Novak ◽  
Tomislav Jednačak
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Analytical Techniques ◽  
Complex Mixtures ◽  
Aggregation Process ◽  
Molecular Architecture ◽  
Valuable Data ◽  
Molecular Weights ◽  
Nmr Techniques ◽  
Oil Components

Asphaltenes are the most polar oil components with molecular weights between 500 and 1000 Da, which primarily consist of carbons and hydrogens, some heteroatoms, such as nitrogen, sulphur, oxygen and traces of nickel, vanadium and iron. Owing to their extreme complexity, it is almost impossible to completely identify all the compounds present in asphaltene samples. Various analytical techniques and approaches were used to characterize asphaltenes but their structure and composition are still a matter of thorough investigations. NMR spectroscopy can reveal useful information on asphaltene molecular architecture and aggregation process. In that respect, one- and two-dimensional NMR techniques have widely been employed. Although NMR spectra of these complex mixtures are difficult to interpret, they still can provide valuable data, especially in combination with statistical methods. Some distinctive examples of using NMR spectroscopy to study asphaltenes are given in this review.

scholarly journals Five sesquiterpenes from the root Aucklandia lappa Decne.

2019 ◽  
pp. 5-11
Author(s):  
Chjuo Fuguan ◽  
Seesregdorj S ◽  
Gerelt-Od Ya
Keyword(s):  
Phenolic Compounds ◽  
Nmr Spectra ◽  
Previous Literature ◽  
Two Dimensional ◽  
Nmr Data ◽  
Nmr Techniques ◽  
The One ◽  
Dehydrocostus Lactone ◽  
First Time

The four sesquiterpenes calameone (1), dehydrocostus lactone (2), aristolone (3), alantolactone (4) and one triterpenoid α-amyrine (5), simple phenolic compounds such as 4-hydroxybenzaldehyde, (6), piceol (7), apocynin (8), dihydroconiferyl (9) and coniferyl (10) have been identified by using the proton and carbon NMR spectra which were isolated from a dichloromethane extract of the roots of Aucklandia lappa Decne. Their structures were established by the one‐and two‐dimensional NMR techniques including DEPT, COSY and HMBC spectroscopy. This work examined proton and carbon NMR data of calameone (1) and aristolone (3) for the first time, which had not yet been fully studied in previous literature. Рүда ургамлын (Aucklandia lappa Decne.) терпент нэгдлийн судалгаа Хураангуй: Рүда ургамлын үндэсний дихлорметаны ханднаас хроматографийн аргуудаар эвдесман хэлбэрийн сесквитерпен каламеон (1), аристолон (3), алантолактон (4), гвяан хэлбэрийн сесквитерпен дегидрокостасын лактон (2), тритерпеноид α-амурин (5) болон энгийн фенолт нэгдэл 4-гидроксибензальдегид (6), пицелол (7), апоцинин (8), дегидрокониферол (9), кониферол (10) зэрэг бодисыг химийн цэвэр байдалтай ялгав. Эдгээр бодисын бүтэц байгуулалтыг нэг болон хоёр хэмжээст ЦСР-ын DEPT, COSY, HMBC спектроскопийн аргаар таньж тодорхойлов. Урьд өмнө каламеон (1), аристолон (3) бодисуудын устөрөгч ба нүүрстөрөгчийн атомуудын химийн шилжилтийн утгуудад оноолт бүрэн хийгдээгүй байсан ба энэ хоёр бодисын оноолтыг гүйцээж хийв. Түлхүүр үг: Терпеноид, сесквитерпент лактон, дегидрокостасын лактон, ЦСР.

5,10,15-Triarylcorrole atropisomerism

2020 ◽  
Vol 24 (01n03) ◽  
pp. 153-160
Author(s):  
Martina Bischetti ◽  
Giuseppe Pomarico ◽  
Sara Nardis ◽  
Federica Mandoj ◽  
Daniel O. Cicero ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Aryl Ring ◽  
H Nmr ◽  
Ring Rotation ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Thermodynamic Factors

A series of 5,10,15-triarylcorroles has been prepared, with the meso-aryl rings functionalized with different substituents to investigate their influence on the aryl ring rotation with respect to the corrole plane. The study has been carried out by different NMR techniques, allowing the complete assignment of the 1H NMR spectra and giving insights on the kinetic and thermodynamic factors driving the atropisomerism in triarylcorrole derivatives.

ChemInform Abstract: Total Assignment of the 1H and 13C NMR Spectra of Benzo(f)(1) benzothieno(2,3-c)quinoline (I) by Inverse-Detected Two-Dimensional NMR Techniques.

ChemInform ◽  
2010 ◽  
Vol 23 (20) ◽  
pp. no-no
Author(s):  
J. P. SHOCKCOR ◽  
R. C. CROUCH ◽  
G. E. MARTIN ◽  
A. CHERIF ◽  
J.-K. LUO ◽  
...  
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Two Dimensional ◽  
1H And 13C Nmr ◽  
Nmr Techniques

Total assignment of the1H and13C NMR spectra of benzo[f][1]benzothieno[2,3-c]quinoline by inverse-detected two-dimensional NMR techniques

1991 ◽  
Vol 28 (8) ◽  
pp. 2035-2039 ◽  
Author(s):  
John P. Shockcor ◽  
Ronald C. Crouch ◽  
Gary E. Martin ◽  
Abdallah Cherif ◽  
Jiann-Kuan Luo ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Two Dimensional ◽  
Nmr Techniques

Structures, Theoretical Vibrational Frequency and 1H-NMR Spectral Analysis of Pyrazine-Dibenzylsulfoxide Platinum(II) Complexes

2011 ◽  
Vol 391-392 ◽  
pp. 1375-1382
Author(s):  
Zheng Ping Wu ◽  
Ian S. Butler
Keyword(s):  
Vibrational Frequency ◽  
Density Functional ◽  
Nmr Spectra ◽  
Mixed Ligand ◽  
High Symmetry ◽  
Dft Methods ◽  
Functional Theory ◽  
H Nmr ◽  
Calculation Results ◽  
Cis And Trans

Mixed-ligand Pt(II) complexes containing pyrazine (C4N2H4, pz) and dibenzyl sulfoxide [C6H5CH2)2SO, DBzSO] ligands have been studied using density functional theory (DFT) methods with a particular emphasis on the theoretical1H-NMR spectra of the methylene protons. The DFT optimization calculations on Pt(DBzSO)Cl2(pz) and {Pt(DBzSO)Cl2}2(pz) predicted the structure parameters, vibrational frequency and1H-NMR spectra. Different structures of DBzSO will affect the bond lengths and angles in the complexes, except for the pz ligands. The [shift(Pt(II)complex)-shift(sulfoxide)] values of trans-Pt(DBzSO)(pz)Cl2were smaller than those for cis-Pt(DBzSO)(pz)Cl2and the calculation results appear to be reasonable. The1H-NMR spectra of the methylene protons of cis- and trans-{Pt(DBzSO)Cl2}2(pz) indicate that these two structures have high symmetry.

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