scholarly journals Synthesis, Characterization and Complexation Behaviour of Chloroquine towards Ti (II) Ion

2019 ◽  
pp. 1-6
Author(s):  
I. E. Otuokere ◽  
L. O. Okpara ◽  
K. C. Amadi ◽  
C. O. Alisa ◽  
A. Okoyeagu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Drug Class ◽  
Bidentate Ligand ◽  
Uv Spectrum ◽  
Imine Group ◽  
Ligand Charge Transfer ◽  
Coordination Behavior ◽  
Metal Charge Transfer

Aims: Chloroquine is a member of the drug class 4-aminoquinoline used for the prevention and treatment of malaria in areas where malaria is known to be sensitive to its effects. Our aim is to synthesize the chloroquine – titanium complex and to study its coordination behavior. Place and Duration of Study: Department of Chemistry, Michael Okpara University of Agriculture, Umudike, 2019. Methodology: Ti(II) complex of chloroquine was synthesized by the reaction of chloroquine phosphate with titanium(IV) oxide. The metal complex was characterized based on UV, IR and 1H NMR Spectroscopy. Results: The UV spectrum of the complex suggested intra ligand charge transfer (ILCT), ligand to metal charge transfer (LMCT), and d-d transition. The IR spectrum of the complex showed the involvement of amine and imine group in coordination to Ti. This showed that chloroquine acted as a bidentate ligand. 1H NMR of the spectrum further showed the involvement of the amine group in coordination. Conclusion: The ability of chloroquine to sequestrate Ti (II) ion has been assured. This drug can be used to chelate Ti ions from solution, environment, and biological system.

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Study of the contact charge transfer behavior between cryptophanes (A and E) and fullerene by absorption, fluorescence and 1H NMR spectroscopy

2009 ◽  
Vol 650 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Caihong Zhang ◽  
Weili Shen ◽  
Ruying Fan ◽  
Guomei Zhang ◽  
Lingzhi Shangguan ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Transfer Behavior

scholarly journals Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Synthesis, Characterization and Photophysical Properties of Thiophene-Containing Chloro Re(I) Complex

2010 ◽  
Vol 146-147 ◽  
pp. 869-872
Author(s):  
Jie Xiu Wang ◽  
Feng Zhao
Keyword(s):  
Charge Transfer ◽  
Electron Density ◽  
1H Nmr ◽  
Photophysical Properties ◽  
Red Shift ◽  
Rhenium Complexes ◽  
Diimine Ligands ◽  
Ligand Charge Transfer

Two tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=1,10-phenanthroline (Phen-Re) and 2-(3-thienyl)-imidazo[4,5-f]-1,10-phenanthroline (TIPh-Re), were successfully synthesized and characterized by 1H NMR and UV–Vis with the aim to analyze the effect of the thiophene(TI) moiety on the photophysical properties of TIPh-Re. It was found that the introduction of an π-electron density moiety into diimine ligands leads to a dramatic red shift of the absorption of the corresponding Re(I) complex. At the same time, the results verify that the triplet metal-to-ligand charge-transfer dπ(Re)→π*(N-N) emission (3MLCT) of Phen-Re and TIPh-Re centered at ca. 566 nm and ca.569 nm, respectively.

Tuning Color of Charged Iridium (III) Complexes with a Spiro N,N'-Bidentate Ligand

2012 ◽  
Vol 229-231 ◽  
pp. 192-196 ◽  
Author(s):  
Kattaliya Mothajit ◽  
Kittiya Wongkhan ◽  
Rukkiat Jitchati
Keyword(s):  
Charge Transfer ◽  
Photophysical Properties ◽  
Bidentate Ligand ◽  
Organic Light Emitting Diodes ◽  
Photoluminescence Spectra ◽  
Absorption Bands ◽  
Light Emitting ◽  
Organic Light ◽  
Ligand Charge Transfer ◽  
Emission Color

Organic light emitting diodes (OLEDs), charged iridium(III) complexes, spiro ligand Abstract. We report the synthesis, characterization and photophysical properties of a cationic cyclometalated Ir(III) complexes of general formula [Ir(ppy)2(spbpy)]+Cl, [Ir(diFppy)2(spbpy)]+Cland [Ir(thiopy)2(spbpy)]+Clwhere ppy, spbpy, diFppy and thiopy are 2-phenylpyridine, 4,5-diaza-9,9′-spirobifluorene, 2-(2′,4′-difluorophenyl)-pyridine and 2-(thiophen-2′-yl)-pyridine, respectively. The complexes exhibit strong absorption bands in the UV region in solution spectra, due to spin-allowed ligand-centred (LC) and weaker absorption bands at longer wavelengths from metal-to-ligand charge transfer (MLCT). The photoluminescence spectra of all the complexes were characterised by a combination of 3MLCT and3π→π*states. The emission color of a cationic cyclometalated Ir(III) complexes in solution have successfully tuned from green to orange (501-582 nm).

scholarly journals Synthesis, characterization and molecular docking studies of Co(II) metal complex of sulfathiazole

2020 ◽  
Vol 34 (1) ◽  
pp. 83-92
Author(s):  
Otuokere Ifeanyi Edozie ◽  
Ohwimu Joseph Godday ◽  
Amadi Kingsley Chijioke ◽  
Igwe Okenwa Uchenna ◽  
Nwadire Felix Chigozie
Keyword(s):  
Molecular Docking ◽  
Charge Transfer ◽  
Metal Complex ◽  
1H Nmr ◽  
Metal Ion ◽  
Cobalt Complex ◽  
Tridentate Ligand ◽  
Ligand Complex ◽  
E Coli ◽  
Ligand Charge Transfer

Sulfathiazole (SFTZ) is a sulfonamide used for the treatment of bacterial infection. The cobalt complex of sulfathiazole was synthesized by reaction of sulfathiazole with CoCl2.6H2O. The metal complex was characterized based on AAS, UV, IR, 1H NMR spectroscopy and X-ray powder diffraction. The electronic spectrum of the ligand showed intra ligand charge transfer (ILCT) which were assigned to the chromophores present in the ligand, while that of the complex suggested intra ligand charge transfer (ILCT) and ligand to metal charge transfer (LMCT). The IR spectra of the complexes showed the involvement of amine, sulfonyl and cyano group in coordination to the metal ion. This showed that sulfathiazole acted as a tridentate ligand. 1H NMR spectrum of [Co(SFTZ)] complex further showed the involvement of the amine and sulfonyl group in coordination to the metal ions. The structure of [Co(SFTZ)] complex was assigned as trigonal. The crystal structure of [Co(SFTZ)] complex belongs to cubic system, space group P1, with cell parameters of a = 4.007 Å, b = 5.0078 Å, c = 5.9844 Å, 𝑉 = 30.61 Å3, α = 90o, β  90o, γ = 90o. Molecular docking suggested that the ligand/complex binded effectively with the E. Coli and S. aureus because their global binding energies were negative. The binding interactions of ligand/complex with E. Coli and S. Aureus were predicted. Molecular docking predicted the feasibility of the biochemical reactions before experimental investigation.   Bull. Chem. Soc. Ethiop. 2020, 34(1), 83-92. DOI: https://dx.doi.org/10.4314/bcse.v34i1.8

Asymetrical Dimer - allyl-palladiu Complexes II. Data from Infrared Spectra and Chemical Behaviour

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Maria Maganu ◽  
Filip Chiraleu ◽  
Constantin Draghici ◽  
Gheorghe Mihai
Keyword(s):  
Carbon Monoxide ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Infrared Spectra ◽  
Analytical Methods ◽  
1H Nmr Spectroscopy ◽  
Chemical Behaviour ◽  
The Asymmetry ◽  
Pd Complexes

The previous data obtained by 1H-NMR spectroscopy established the existence of an asymmetry of the bond between Pd and p-allylic groups, even in the p-allyl-Pd complexes dimers which are considered usually symmetric dimers. The asymmetry of the bond depends by the substitutes of the allylic group. Other analytical methods were investigated for additional proof of the obtained results. Thus, this paper discusses how this asymmetry would be reflected in the infrared spectra and in the reaction of the complexes with carbon monoxide.

Diastereoselective Reduction of Selected α-substituted β-keto Esters and the Assignment of the Relative Configuration by 1H-NMR Spectroscopy

2020 ◽  
Vol 07 ◽  
Author(s):  
Christian Trapp ◽  
Corinna Schuster ◽  
Chris Drewniok ◽  
Dieter Greif ◽  
Martin Hofrichter
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Selective Reduction ◽  
Reducing Agents ◽  
Relative Configuration ◽  
Curtius Rearrangement ◽  
Keto Esters ◽  
Hydroxy Esters ◽  
Diastereoselective Reduction

Background:: Chiral β-hydroxy esters and α-substituted β-hydroxy esters represent versatile building blocks for pheromones, β-lactam antibiotics and 1,2- or 1,3-aminoalcohols. Objective:: Synthesis of versatile α-substituted β-keto esters and their diastereoselective reduction to the corresponding syn- or anti-α-substituted β-hydroxy esters. Assignment of the relative configuration by NMR-spectroscopy after a CURTIUS rearrangement of α-substituted β-keto esters to 4-substituted 5-methyloxazolidin-2-ones. Method:: Diastereoselective reduction was achieved by using different LEWIS acids (zinc, titanium and cerium) in combination with complex borohydrides as reducing agents. Assignment of the relative configuration was verified by 1H-NMR spectroscopy after CURTIUS-rearrangement of α-substituted β-hydroxy esters to 4-substituted 5-methyloxazolidin-2-ones. Results:: For the syn-selective reduction, titanium tetrachloride (TiCl4) in combination with a pyridine-borane complex (py BH3) led to diastereoselectivities up to 99% dr. High anti-selective reduction was achieved by using cerium trichloride (CeCl3) and steric hindered reducing agents such as lithium triethylborohydride (LiEt3BH). After CURTIUS-rearrangement of each α-substituted β-hydroxy ester to the corresponding 4-substituted 5-methyloxazolidin-2-one, the relative configuration was confirmed by 1H NMR-spectroscopy. Conclusion:: We have expanded the procedure of LEWIS acid-mediated diastereoselective reduction to bulky α-substituents such as the isopropyl group and the electron withdrawing phenyl ring.

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

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