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.

scholarly journals Electron-transfer complexation of morpholine donor molecule with some π – acceptors: Synthesis and spectroscopic characterizations

2019 ◽  
Vol 21 (4) ◽  
pp. 82-88
Author(s):  
Asma S. Al-Wasidi ◽  
Nawal M. Al-Jafshar ◽  
Amal M. Al-Anazi ◽  
Eid H. Alosaimi ◽  
Moamen S. Refat ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Infrared Spectroscopy ◽  
Charge Transfer ◽  
Extinction Coefficient ◽  
Association Constant ◽  
Spectroscopic Methods ◽  
Donor Molecule ◽  
Intermolecular Charge Transfer ◽  
Elemental Analyses ◽  
Ct Complexes

Abstract Morpholine is an interesting moiety that used widely in several organic syntheses. The intermolecular charge-transfer (CT) complexity associated between morpholine (Morp) donor with (monoiodobromide “IBr”, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone “DDQ”, 2,6-dichloroquinone-4-chloroimide “DCQ” and 2,6-dibromoquinone-4-chloroimide “DBQ”) π–acceptors have been spectrophotometrically investigated in CHCl3 and/or MeOH solvents. The structures of the intermolecular charge-transfer (CT) were elucidated by spectroscopic methods like, infrared spectroscopy. Also, different analyses techniques such as UV-Vis and elemental analyses were performed to characterize the four morpholine [(Morp)(IBr)], [(Morp)(DDQ)], [(Morp)(DCQ)] and [(Morp)(DBQ)] CT-complexes which reveals that the stoichiometry of the reactions is 1:1. The modified Benesi-Hildebrand equation was utilized to determine the physical spectroscopic parameters such as association constant (K) and the molar extinction coefficient (ε).

scholarly journals Synthesis, Spectroscopic Characterization, and In Vitro Antimicrobial Studies of Pyridine-2-Carboxylic Acid N′-(4-Chloro-Benzoyl)-Hydrazide and Its Co(II), Ni(II), and Cu(II) Complexes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jagvir Singh ◽  
Prashant Singh
Keyword(s):  
Metal Complexes ◽  
Acid Hydrazide ◽  
Spectroscopic Characterization ◽  
Fungal Species ◽  
Molar Conductance ◽  
Antimicrobial Studies ◽  
Spectral Bands ◽  
Elemental Analyses ◽  
Solid Complexes

N-substituted pyridine hydrazide (pyridine-2-carbonyl chloride and 4-chloro-benzoic acid hydrazide) undergoes hydrazide formation of the iminic carbon nitrogen double bond through its reaction with cobalt(II), nickel(II), and copper(II) metal salts in ethanol which are reported and characterized based on elemental analyses, IR, solid reflectance, magnetic moment, molar conductance, and thermal analysis (TG). From the elemental analyses data, 1 : 2 metal complexes are formed having the general formulae [MCl2(HL)2] ·yH2O (where M = Co(II), Ni(II), and Cu(II),y= 1–3). The important infrared (IR) spectral bands corresponding to the active groups in the ligand and the solid complexes under investigation were studied. IR spectra show that ligand is coordinated to the metal ions in a neutral bidentate manner with ON donor sites. The solid complexes have been synthesized and studied by thermogravimetric analysis. All the metal chelates are found to be nonelectrolytes. From the magnetic and solid reflectance spectra, the complexes (cobalt(II), nickel(II), and copper(II)) have octahedral and square planner geometry, respectively. The antibacterial and antifungal activity’s data show that the metal complexes have a promising biological activity comparable with the parent ligand against bacterial and fungal species.

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.

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.

Lanthanide Complexes with D-Penicillamine Methyl Ester: Formation Constants, Spectral and Thermal Properties

2006 ◽  
Vol 61 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Shehab A. Sallam ◽  
Marwa A. Mahmoud
Keyword(s):  
Methyl Ester ◽  
Lanthanide Complexes ◽  
Formation Constants ◽  
Ester Formation ◽  
Elemental Analyses ◽  
Dta Analysis ◽  
Neutral Media ◽  
Tg And Dta Analysis ◽  
Atomic Radii ◽  
Solid Complexes

AbstractThe complex-formation of the lanthanide(III) cations with D-penicillamine methyl ester have been investigated in acidic and neutral media. The macroscopic protonation constants of the ligand and the formation constants of [Ln·Pme]2+, [Ln·(Pme)2]+, [Ln·Pme·OH]+ and [Ln·Pme·(OH)2] complexes have been determined from pH-metric data using BEST computer program. Species distribution diagrams of the complexes were obtained and plotted using SPE and SPEPLOT computer programs. Elemental analyses of the solid complexes indicate the formation of 1:1 metal:ligand species. Infrared spectra show that coordination takes place through the NH2, the SH and the C=O groups of the ligand. The complexes decompose in four steps as shown by their TG and DTA analysis with the formation of Ln2(SO4)3 as a final product. Activation energy values (ΔEa) are correlated with the atomic radii of the metal ions. The mechanism of the thermal decomposition is proposed.

Conductometric Studies of Molecular Complexes of Charge Transfer Type Formed between Aza-Aromatics and Haloanils

1993 ◽  
Vol 58 (4) ◽  
pp. 783-790 ◽  
Author(s):  
Harbhajan S. Randhawa ◽  
Rajni Lakhani
Keyword(s):  
Electrical Conductivity ◽  
Charge Transfer ◽  
Ionization Potential ◽  
Equilibrium Constant ◽  
Molecular Complex ◽  
Molecular Interaction ◽  
Lone Pair ◽  
Molecular Complexes ◽  
Nitrogen Ring ◽  
Ct Complexes

Electrical conductivity technique has been employed to investigate the molecular interaction of aza-aromatics viz. pyridine, α-pikoline, β-picoline and γ-picoline with haloanils, namely chloranil, bromanil and fluranil. The stoichiometry of the charge transfer (CT) complexes has been established and molar conductivities of the complexes determined employing the method of Gutmann and Keyzer. A model has been proposed for determining the equilibrium constant (K) of 1 : 1 molecular complexes of CT type by conductometric measurements. The model involves the assumption: 1/σ = [(1 + K c0A)/qdK c0A] (1/c0D) + (1/qd c0A), where σ is the conductivity of the molecular complex, qd is the extent of depolarization of the complex, c0A) and c0D) are the initial concentrations of the acceptors and donors, respectively. The values of K and qd follows the expected trend of the conductometric parameters determined by the method of Gutmann and Keyzer as well as ionization potential of donors, thereby substantiating the validity of the model proposed. The observed and theoretical values of thermodynamic parameters for the aza-aromatic-chloranil systems that the interaction of aza-aromatics with haloanils is occurring through the lone pair of nitrogen ring.

scholarly journals Facile Charge Transfer between Barbituric Acid and Chloranilic Acid over g-C3N4: Synthesis, Characterization and DFT Study

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 636
Author(s):  
Gaber A. M. Mersal ◽  
Mohamed M. Ibrahim ◽  
Mohammed A. Amin ◽  
Amine Mezni ◽  
Nasser Y. Mostafa ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Dft Calculations ◽  
Barbituric Acid ◽  
Molecular Complexes ◽  
Basis Set ◽  
Chloranilic Acid ◽  
Vis Spectroscopy ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Solid Complexes

The molecular complexes between barbituric acid (BU) and chloranilic acid (ChA) over graphitic nitride (g-C3N4) are investigated. The molecular complexes and the nanocomposite were investigated both in solid state and in methanol. The solid complexes and the corresponding nanocomposite were investigated using FTIR, TGA, and UV-Vis spectroscopy. The structures were explored using DFT calculations using wB97XD/ and def2-TZVP basis set. The DFT calculations revealed the formation of hydrogen-bonded complexes, which initiate the proton transfer from ChA to BU. Immobilization of the BUChA complex over the g-C3N4 sheet was stabilized by weak non-covalent interactions, such as π–π interactions. g-C3N4 facilitated the charge transfer process, which is beneficial for different applications.

The electron-donating properties of some phenylfurans. Charge transfer studies

1979 ◽  
Vol 57 (18) ◽  
pp. 2337-2341 ◽  
Author(s):  
Rafie Abu-Eittah ◽  
Maher M. Hamed
Keyword(s):  
Charge Transfer ◽  
Thermodynamic Parameters ◽  
Electron Donor ◽  
Molecular Complexes ◽  
Formation Constants ◽  
Spectroscopic Methods ◽  
Planar Conformation ◽  
Iterative Procedures

The formation of the molecular complexes of some phenylfurans with TCNE has been investigated by spectroscopic methods. The formation constants were determined by graphical and iterative procedures and some thermodynamic parameters were calculated. The formed molecular complexes were π ones. Diphenylfuran proved to be a much stronger electron donor than phenylfuran and the latter stronger than furan. Results at hand suggest that the donors investigated assume an all-planar conformation.

Charge-transfer interaction of bithienyls and some thiophene derivatives with electron acceptors

1976 ◽  
Vol 54 (23) ◽  
pp. 3705-3712 ◽  
Author(s):  
Rafie Abu-Eittah ◽  
Fakhreia Al-Sugeir
Keyword(s):  
Charge Transfer ◽  
Complex Formation ◽  
Molecular Complexes ◽  
Formation Constants ◽  
Electron Acceptors ◽  
Charge Transfer Complexes ◽  
Extinction Coefficients ◽  
Charge Transfer Transitions ◽  
Different Temperatures ◽  
Thiophene Derivatives

The charge transfer complexes of 2,2′-bithienyl, 5,5′-dimethyl-2,2′-bithienyl, and some thiophene derivatives as donors with tetracyanoethylene as an acceptor have been studied spectrophotometrically. In addition, complexes of the first donor with chloranil and iodine have been studied. The formation constants and extinction coefficients of the molecular complexes formed have been determined by graphical as well as iterative methods. From measurements at different temperatures, the thermodynamic functions of the complex formation have been calculated. The ionization potentials of the donors have been obtained from the energies of the charge transfer transitions.

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