scholarly journals Charge transfer interaction of organic p-acceptors with the anti-hyperuricemic drug allopurinol: Insights from IR, Raman, 1H NMR and 13C NMR spectroscopies

2016 ◽  
Vol 66 (4) ◽  
pp. 533-542 ◽  
Author(s):  
Moamen S. Refat ◽  
Hosam A. Saad ◽  
Abdel Majid A. Adam ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah
Keyword(s):  
Charge Transfer ◽  
Picric Acid ◽  
Chemical Properties ◽  
Stoichiometric Ratio ◽  
Organic P ◽  
H Nmr ◽  
Physicochemical Methods ◽  
Physical And Chemical ◽  
Ct Complexes ◽  
C Nmr

Abstract The topic of charge-transfer (CT) complexation of vital drugs has attracted considerable attention in recent years owing to their significant physical and chemical properties. In this study, CT complexes derived from the reaction of the anti-hyperuricemic drug allopurinol (Allop) with organic p-acceptors [(picric acid (PA), dichlorodicyanobenzoquinone (DDQ) and chloranil (CHL)] were prepared, isolated and characterized by a range of physicochemical methods, such as IR, Raman, 1H NMR and 13C NMR spectroscopy. The stoichiometry of the complexes was verified by elemental analysis. The results show that all complexes that were formed were based on a 1:1 stoichiometric ratio. This study suggests that the complexation of Allop with either the DDQ or CHL acceptor leads to a direct p®p* transition, whereas the molecules of Allop and PA are linked by intermolecular hydrogen- bonding interactions.

Charge Transfer Molecular Complexes of 4-(Dimethylamino)pyridine with Some Conventional and Unconventional Acceptors Involving Fluoroarenes

2006 ◽  
Vol 71 (9) ◽  
pp. 1359-1370 ◽  
Author(s):  
Usama M. Rabie
Keyword(s):  
Charge Transfer ◽  
Nmr Spectra ◽  
Molecular Complexes ◽  
Outer Sphere ◽  
Formation Constants ◽  
Stoichiometric Ratio ◽  
Spectral Bands ◽  
Elemental Analyses ◽  
Ct Complexes ◽  
Solid Complexes

Charge transfer (CT) complexes of 4-(dimethylamino)pyridine (DMAP) with iodine as a typical σ-type acceptor and with typical π-type acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), have been synthesized and characterized. Octafluorotoluene (OFT), octafluoronaphthalene (OFN), perfluorophenanthrene (PFP), and 2,3,5,6-tetrafluoropyridine-4-carbonitrile (TFP) were also used as acceptors for interaction with DMAP. Properties of such CT complexes were investigated by UV/VIS and IR spectra, and elemental analyses of the isolated complexes. The systems DMAP-iodine and DMAP-DDQ are characterized by formation of triiodide ions (I3-) and DDQ•- anion radicals, respectively, which is proposed to occur via initial formation of outer-sphere CT complexes. The systems (DMAP-OFT, DMAP-OFN, DMAP-PFP and DMAP-TFP) are characterized by the appearance of new UV/VIS spectral bands assigned as CT bands; they also furnished the corresponding solid complexes with the stoichiometric ratio 1:1. 1H and 19F NMR spectra were used on confirming the formation of the DMAP-PFP CT complexes. The formation constants (KCT) and molar absorption coefficients (εCT) of the latter complex were obtained.

Charge Transfer Complexes of N-Arylcarbamates with π-Acceptors

1987 ◽  
Vol 42 (3) ◽  
pp. 284-288 ◽  
Author(s):  
Aboul-fetouh E. Mourad
Keyword(s):  
Charge Transfer ◽  
Electron Density ◽  
Nmr Spectra ◽  
Charge Transfer Complexes ◽  
H Nmr ◽  
Ct Complexes

The charge-transfer (CT) complexes of some N-arylcarbamates as donors with a number of π-acceptors have been studied spectrophotometrically. The Lewis basicities of the N-arylcarbamates as well as the types of interactions are discussed. The 1H-NMR spectra of some CT complexes with both 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and 7,7,8,8 tetracyanoquinodimethane (TCNQ) indicate a decrease of the electron density on the donor part of the complex.

Charge Transfer Complexes of Aromatic Nitrocompounds with Disubstituted Naphthalenes. I.Spectroscopic Investigation of the Donor Behaviour of the 2,6- and 23-Dimethylnaphthalene

1984 ◽  
Vol 39 (12) ◽  
pp. 1274-1278 ◽  
Author(s):  
M. H. Abdel-Kader ◽  
R. M. Issa ◽  
M. M. Ayad ◽  
M. S. Abdel-Mottaleb
Keyword(s):  
Charge Transfer ◽  
Spectral Characteristics ◽  
Charge Transfer Complexes ◽  
Element Analysis ◽  
H Nmr ◽  
Aromatic Nitrocompounds ◽  
Donor Acceptor ◽  
The Difference ◽  
Donor Behaviour ◽  
Ct Complexes

The charge transfer complexes of 2,3- (I) and 2,6-Dimethylnaphthalenes (II) as electron donors with tri- and di-nitrobenzenes as electron acceptors are prepared and investigated by element analysis, IR. 1H nmr and electronic absorption spectroscopy. The results showed that I yields CT complexes of 1:1 type only while II is capable of forming 1 : 1 and 1 : 2 (donor: acceptor) compounds. The spectral characteristics of the CT complexes are pointed out and discussed. The difference in the donor behaviour between I and II is explained in the light of PPP-MO calculations.

Sila-Pharmaka, 9. Mitt. [1] Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, I / Sila-Drugs, 9th Communication [1] Preparation and Properties of Silicon Compounds with Potential Curare-Like Activity, I

1978 ◽  
Vol 33 (4) ◽  
pp. 412-416 ◽  
Author(s):  
Reinhold Tacke ◽  
Roland Niedner
Keyword(s):  
Mass Spectroscopy ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Organosilicon Compounds ◽  
Silicon Compounds ◽  
H Nmr ◽  
Toxicological Data ◽  
Physical And Chemical ◽  
First Time ◽  
And Chemical Properties

Abstract Organosilicon compounds 8, 9 and 10 with potential curare-like action and their precursors 5, 6 and 7 were synthesized for the first time. 5−10 were characterized by their physical and chemical properties, and their structures were confirmed by analyses, 1 H NMR and mass spectroscopy (only for 5−7). The pharmacological and toxicological data of 8, 9 and 10 are reported.

Synthese und Eigenschaften von Alkyloxi-und Aryloxi-substituierten Trithiadiborolanen / Synthesis and Properties of Alkoxi and Aryloxi Substituted Trithiadiborolanes

1981 ◽  
Vol 36 (11) ◽  
pp. 1444-1450 ◽  
Author(s):  
Max Schmidt ◽  
Erich Sametschek
Keyword(s):  
Thermal Stability ◽  
Nmr Spectra ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
H Nmr ◽  
New Compounds ◽  
Physical And Chemical ◽  
Thermal Stability Of ◽  
And Chemical Properties

Abstract The first examples of the hitherto unknown 1,2,4-Trithia-3,5-diborolanes with B-O-C-bonds have been synthesized and characterised. The diiodo substituted ring (2) reacts with 2,6-dimethylphenol, to form 3,5-bis-(2,6-dimethylphenyloxi)-1,2,4-trithia-3,5-di-borolane (3) and HI. 3,5-Diethoxi-1,2,4-trithia-3,5-diborolane, 5, and C2H5I are formed via the cleavage of diethylether by 2. From 2 and diisopropylether, the corresponding 3,5-diisopropyloxi-1,2,4-trithia-3,5-diborolane (6) is formed. The unsymmetrical ethers methyl-t-butylether and methylphenylether undergo reactions with 2 resulting in the formation of 3,5-dimethyloxi-1,2,4-trithia-3,5-diborolane (8) (besides t-C4H9I) and 3,5-diphenyloxi-1,2,4-trithia-3,5-diborolane (10) (besides CH3I). The thermal stability of the new compounds is increasing with increasing size of R in the -OR group and from aliphatic to aromatic R in this group. IR, Raman, 1H NMR and 11B NMR spectra of the compounds are reported as well as some physical and chemical properties.

scholarly journals Synthesis of Picric Acid at Domestic Scales.

2019 ◽  
Author(s):  
Afshan Saleem ◽  
Noureen Rafi ◽  
Sumara Qasim ◽  
Usama Ashraf ◽  
Nasir Hussain Virk
Keyword(s):  
Ir Spectra ◽  
Physical State ◽  
Picric Acid ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Greenish Yellow ◽  
Yellow Color ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
And Chemical Properties

Picric acid and its derivatives are widely used in various applications/industries. The first synthetic dye was prepared in 1771 using picric acid. It was used to dye silk fabric into greenish-yellow color. In this study, Picric acid and their derivatives were synthesized and characterized by their physical and chemical properties. The derivatives of Picric acid which are considered in this research include Picramic acid and Sodium Picramate. The physical properties like melting point, colors, physical state and solubility of Picric acid and its derivatives were determined and confirmed using IR Spectra. IR spectra proved efficient in scanning and mapping.

scholarly journals Sila-Pharmaka, 14. Mitt. Darstellung und Eigenschaften sowie Kristall-und Molekülstruktur von Sila-Difenidol /Sila-Drugs, 14th Communication Preparation and Properties as well as Crystal and Molecular Structure of Sila-Difenidol

1979 ◽  
Vol 34 (9) ◽  
pp. 1279-1285 ◽  
Author(s):  
R. Tacke ◽  
M. Strecker ◽  
W. S. Sheldrick ◽  
E. Heeg ◽  
B. Berndt ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Mass Spectroscopy ◽  
Crystal And Molecular Structure ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
H Nmr ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Sila-difenidol (6b), a sila-analogue of the drug difenidol (6a), was synthesized according to Scheme 1. 6b and its new precursors 3 and 5 were characterized by their physical and chemical properties, and their structures confirmed by elementary analyses, 1H NMR and mass spectroscopy. 6 b crystallizes orthorhombic P212121 with a = 11.523(1), b = 14.366(4), c = 11.450(1) Å, Z = 4, Dber = 1.14 gcm-3. The structure was refined to R = 0.050 for 1897 reflexions. A strong nearly linear intramolecular O-H···N hydrogen bond of 2.685 Å is observed. The anticholinergic, histaminolytic and musculotropic spasmolytic activities of 6 a and 6 b are reported.

N,N'-diphenylacetamidinium carboxylates

1990 ◽  
Vol 55 (2) ◽  
pp. 469-478 ◽  
Author(s):  
Jiří Krechl ◽  
Svatava Smrčková ◽  
Miroslav Ludwig ◽  
Josef Kuthan
Keyword(s):  
Lactate Dehydrogenase ◽  
Active Site ◽  
Nmr Spectra ◽  
Chemical Properties ◽  
H Nmr ◽  
Physico Chemical ◽  
C Nmr

Various N,N'-diphenylacetamidinium carboxylates were prepared and the nature of amidinium-carboxylate interactions was examined by 1H and 13C NMR spectra. Correlation between pKa of the respective acids and 1H NMR shifts in CHCl3 is described. The compounds due to their solubility and other physico-chemical properties represent valuable models of lactate dehydrogenase active site.

Diethyl 2-Benzimidazol-1-ylsuccinate–Picric Acid (1/1) – An Inclusion Molecular Complex

1997 ◽  
Vol 53 (6) ◽  
pp. 961-967 ◽  
Author(s):  
P. Zaderenko ◽  
M. S. Gil ◽  
P. López ◽  
P. Ballesteros ◽  
I. Fonseca ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Molecular Complex ◽  
Picric Acid ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
H Nmr ◽  
Intramolecular Hydrogen ◽  
C Nmr

The crystal structure of the diethyl 2-benzimidazol-1-ylsuccinate–picric acid (1/1) molecular complex has been determined by X-ray diffraction analysis. Diethyl 2-benzimidazol-l-ylsuccinate molecules form channels along the a axis, in which the picric acid molecules are located. The benzimidazole moiety and the phenol group are held together by hydrogen bonding between the hydrogen of the phenol and the N3 atom of benzimidazole. Additionally, this hydrogen forms an intramolecular hydrogen bond with one O atom of the ortho-nitro group, thus producing a bifurcated hydrogen bond. 1H NMR spectra in DMSO-d 6 solution and CP/MAS solid 13 C NMR studies of this 2-benzimidazol-1-ylsuccinate–picric acid (1/1) molecular complex, as well as those of dimethyl, diethyl, di-n-butyl and 1-n-butyl-4-ethyl 2-imidazol-1-ylsuccinates, diethyl 2-pyrazol-1-ylsuccinate, ethyl imidazol-1-ylacetate, ethyl pyrazol-1-ylacetate and ethyl pyrazol-l-ylsuccinate, suggest that the picric acid linkage depends on the nature of the azole. Actual proton transfer is deduced for the imidazole derivatives, but only weak hydrogen bonding could be inferred for pyrazole derivatives.

Molecular Complexes of Cyclophanes, Part XVI On the Donor Properties of Polynuclear Paracyclophanes and their Sulfur Analogues

1987 ◽  
Vol 42 (9) ◽  
pp. 1142-1146 ◽  
Author(s):  
Aboul-fetouh E. Mourad ◽  
Joachim Hucker ◽  
Henning Hopf
Keyword(s):  
Charge Transfer ◽  
Infrared Spectra ◽  
Molecular Complexes ◽  
Electron Donors ◽  
Effect Of Temperature ◽  
H Nmr ◽  
High Basicity ◽  
The Stability ◽  
Ct Complexes

Visible, 1H NMR and infrared spectra of the charge-transfer (CT) complexes of polynuclear- [2.2]paracyclophanes and their sulfur analogues as electron donors with 2,3-dichloro-5.6-dicyanobenzoquinone (DDQ ), tetracyanoethylene (TCNE) and 9-dicyanom ethylene-2,4,7-trinitrofluorene (DTF) as π-acceptors have been measured. The data indicate an unexpected high basicity of the polynuclear hydrocarbons relative to their sulfur analogues. The types of CT interactions as well as different factors governing the stability of the CT complexes studied are discussed. The effect of temperature on the CT complexes studied are discussed. The effect of temperature on the CT complexes with TCNE is reported.

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