SYNTHESIS, SPECTROSCOPIC, ac CONDUCTIVITY AND THERMAL STUDIES ON Co(III) ACETYLACETONATE-IODINE COMPLEX

2006 ◽  
Vol 13 (04) ◽  
pp. 439-449 ◽  
Author(s):  
H. A. HASHEM ◽  
M. S. REFAT
Keyword(s):  
Ac Conductivity ◽  
Charge Transfer Complex ◽  
Equilibrium Constants ◽  
Thermal Studies ◽  
Spectrophotometric Study ◽  
Graphical Methods ◽  
Mid Infrared ◽  
Iodine Complex ◽  
Donor Acceptor ◽  
Nonisothermal Method

A spectrophotometric study of 1:1 donor–acceptor complex, cobalt (III) acetylacetonate (donor) and iodine (σ-acceptor) has been preformed. The equilibrium constants, (K) and the absorpitivity (ε) for the formation of the iodine complex have been calculated. The predicted structure of the solid triiodide charge-transfer complex reported in this study is further supported by thermal, far and mid infrared spectroscopic measurements. Electron transfer from Co (acac = 2, 4-pentanedionate)3 to iodine leads to the formation of an organic semiconductor with the formula of [Formula: see text]. The kinetic parameters (nonisothermal method) for their decomposition have been evaluated by graphical methods using the equations of Freeman–Carroll (FC), Horowitz–Metzger (HM) and Coats–Redfern (CR). The ac conductivity and dielectric properties of [Formula: see text] have been measured over the frequency 50–106 Hz at temperature 298 K.

Chemical and spectroscopic studies in metal β-diketonates. IX. A novel intermolecular charge-transfer system involving metal acetylacetonate (donor) and iodine (acceptor)

1970 ◽  
Vol 23 (2) ◽  
pp. 269 ◽  
Author(s):  
PR Singh ◽  
R Sahai
Keyword(s):  
Charge Transfer ◽  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Spectroscopic Studies ◽  
Charge Transfer Complexes ◽  
Transfer System ◽  
Metal Acetylacetonates ◽  
Iodine Complex ◽  
Straight Line ◽  
Metal Acetylacetonate

A spectrophotometric study of 1 : 1 charge-transfer complexes derived from five metal acetylacetonates (donor) and iodine (acceptor) has been carried out. Iomzation potential of each metal acetylacetonate and the equilibrium constants for the formation of the chelate-iodine complex have been evaluated. The plot of ionization potential of donors against hvCt values gave a straight line.

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

Spectrophotometric study of the acid-base and optical properties of the 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-(diethylamino)phenol (BrPADAP, ClPADAP) and their complexation equilibria with zinc(II) ions

1982 ◽  
Vol 47 (10) ◽  
pp. 2676-2691 ◽  
Author(s):  
Miroslav Macka ◽  
Vlastimil Kubáň
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Acid Base ◽  
Ethanol Medium ◽  
Triton X ◽  
Mixed Water ◽  
Derivatives Of

The optical and acid-base characteristics of BrPADAP and ClPADAP were studied in mixed water-ethanol and water-DMF media and in 10% ethanol medium in the presence of cationic, anionic and nonionic tensides. The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the ML and ML2 complexes with zinc(II) ions were found by graphical analysis and numerical interpretation of the absorbance curves by the modified SQUAD-G program. Optimal conditions were found for the spectrophotometric determination of Zn(II) in the presence of 0.1% Triton X-100 or 1% Brij 35 in alkaline media with pH = 6.5-10. BrPADAP and ClPADAP are the most sensitive reagents (ε = 1.3-1.6 . 105 mmol-1 cm2 at 557 and 560 nm, respectively) for the determination of zinc with high colour contrast of the reaction (Δλ = 104 nm) and selectivity similar to that for the other N-heterocyclic azodyes (PAN, PAR, etc.).

Ionic dissociation in complexes of iodine with triphenylarsine and triphenylstibine

1991 ◽  
Vol 69 (4) ◽  
pp. 606-610 ◽  
Author(s):  
Ying Ru Zhang ◽  
Ira Solomon ◽  
Seymour Aronson
Keyword(s):  
Complex Formation ◽  
Chemical Nature ◽  
Equilibrium Constants ◽  
Electrochemical Technique ◽  
High Iodine ◽  
Ionic Complex ◽  
Ionization Mechanisms ◽  
Iodine Complex ◽  
Ionic Dissociation ◽  
Iodine Complexes

An electrochemical technique has been employed to study the ionization of the iodine complexes of (C6H5)3As, (C6H5)3Sb, and pyridine. Several different ionization mechanisms are proposed depending on the chemical nature and concentration of the reactants. A new ionic complex, (C6H5)3MI22+ is postulated for the interaction of iodine with (C6H5)3As and (C6H5)3Sb at high iodine concentrations. Equilibrium constants have been calculated from the emf data for the various ionization steps. Key words: triphenylarsine, triphenylstibine, iodine, complex formation, ionization.

Homeotropic alignment through charge-transfer-induced columnar mesophase formation in an unsymmetrically substituted triphenylene derivative

2010 ◽  
Vol 82 (11) ◽  
pp. 1993-2003 ◽  
Author(s):  
Juanjuan Li ◽  
Zhiqun He ◽  
Huan Zhao ◽  
Hemant Gopee ◽  
Xiangfei Kong ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Mesophase Formation ◽  
Homeotropic Orientation ◽  
Donor Acceptor ◽  
Homeotropic Alignment ◽  
Spectroscopy Optical

An unsymmetrically substituted triphenylene, with two adjacent chloroethoxyethyl lateral flexible chains, was synthesized and characterized. Although this compound showed no mesomorphic behavior, it formed a donor–acceptor charge-transfer complex with 2,4,7-trinitrofluorenone (TNF). The resulting 1:1 complex has been investigated using UV–vis and IR spectroscopy, optical microscopy, thermal analysis, and X-ray diffraction. A columnar mesophase with hexagonal symmetry was found. More interestingly, this charge-transfer complex can be easily aligned on a glass surface in a homeotropic orientation, which is stable at room temperature (RT) and over a wide temperature range.

scholarly journals Fermi level pinned molecular donor/acceptor junctions: reduction of induced carrier density by interfacial charge transfer complexes

2020 ◽  
Vol 8 (43) ◽  
pp. 15199-15207
Author(s):  
Paul Beyer ◽  
Eduard Meister ◽  
Timo Florian ◽  
Alexander Generalov ◽  
Wolfgang Brütting ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Fermi Level ◽  
Carrier Density ◽  
Charge Transfer Complex ◽  
Charge Transfer Complexes ◽  
Interfacial Charge Transfer ◽  
Fermi Level Pinning ◽  
Donor Acceptor ◽  
Interfacial Charge

Charge transfer complex (CPX) formation at a donor–acceptor interface reduces the amount of Fermi-level pinning induced interfacial charge transfer.

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