Transfer of 1,1'-dialkyl-4,4'-bipyridinium dication (viologen) across the water-dichloroethane and water-nitrobenzene interfaces

1987 ◽  
Vol 52 (4) ◽  
pp. 830-837 ◽  
Author(s):  
Josef Hanzlík ◽  
Zdeněk Samec
Keyword(s):  
Cyclic Voltammetry ◽  
Charge Transfer ◽  
Ion Association ◽  
Association Constants ◽  
Methyl Ethyl ◽  
Considerable Influence ◽  
Conductivity Measurements ◽  
Gibbs Energies ◽  
Gibbs Energies Of Transfer ◽  
Voltammetric Measurements

Transfer of viologen dications R2V2+ (R = methyl, ethyl, propyl, butyl, pentyl, heptyl or benzyl) across the water-1,2-dichloroethane and water-nitrobenzene interfaces has been studied by cyclic voltammetry. Effects of the changes in the viologen structure and in the composition of solutions of both phases on the voltammetric behaviour have been inspected. Ion association, in particular that occuring in the organic phase, has a considerable influence on the viologen dication transfer and plays the key role in the proposed charge transfer mechanism. From the conductivity measurements the association constants for viologen tetraphenylborates in nitrobenzene have been evaluated. From the voltammetric measurements the Gibbs energies of transfer of viologen dications across the water-nitrobenzene interface have been determined.

Activity Coefficients and Gibbs Energies of Transfer of Tetraalkylammonium Dianilinetetraisothiocyanatochromates(III)

1994 ◽  
Vol 59 (8) ◽  
pp. 1738-1744
Author(s):  
Vladislav Holba
Keyword(s):  
Activity Coefficients ◽  
Transfer Functions ◽  
Butyl Alcohol ◽  
Methyl Ethyl ◽  
Tetraalkylammonium Ions ◽  
Ionic Transfer ◽  
Gibbs Energies ◽  
Gibbs Energies Of Transfer ◽  
Acetonitrile Solutions ◽  
Mixed Systems

The solubilities of tetraalkylammonium dianilinetetraisothiocyanatochromates(III) (alkyl = methyl, ethyl, 1-propyl, and 1-butyl) in water, water - methanol, water - tert-butyl alcohol and water - acetonitrile solutions were measured at 25 °C. The results were used to evaluate the activity coefficients and Gibbs energies of transfer of the saturating salts from water to the mixed systems. The Gibbs energies of transfer of the [Cr(C6H5NH2)2(NCS)4]- ion were obtained by means of known ionic transfer functions for the tetraalkylammonium ions based on the TATB assumption.

Temperature dependence of activity coefficients and Gibbs energies of transfer of LiBr in acetonitrile, dimethyl sulfoxide, and N,N-dimethylacetamide from EMF measurements

1997 ◽  
Vol 75 (11) ◽  
pp. 1500-1507 ◽  
Author(s):  
J. Barthel ◽  
R. Neueder ◽  
A. Schröder
Keyword(s):  
Dimethyl Sulfoxide ◽  
Activity Coefficients ◽  
Redox Reaction ◽  
Electromotive Force ◽  
Association Constants ◽  
Aprotic Solvents ◽  
Temperature Dependent ◽  
Emf Measurements ◽  
Gibbs Energies ◽  
Gibbs Energies Of Transfer

Electromotive force (EMF) measurements based on the redox reaction[Formula: see text]are reported for solutions of LiBr at concentrations 0.005 < cLiBr/(mol dm−3) < 0.1 in acetonitrile (AN), dimethyl sulfoxide (DMSO), and N.N-dimethylacetamide (DMA) in the temperature range 278.15 < T/K < 308.15. Gibbs energies of transfer and activity coefficients are estimated. The association constants of LiBr in AN, DMSO, and DMA from EMF measurements and the enthalpy of transfer AN → DMSO are compared to those from other methods of determination. Keywords: temperature-dependent EMF measurements, aprotic solvents, LiBr, TlBr(s) | TlxHg(l) electrode, activity coefficients, transfer quantities.

Ion Association and Solvation in Dichloromethane of Tetrachloro-and Tetrabromoferrates(III) Compared with Simple Halides

1978 ◽  
Vol 33 (7) ◽  
pp. 745-749 ◽  
Author(s):  
S. Bait ◽  
G. du Chattel ◽  
W. de Kieviet ◽  
A. Tieleman
Keyword(s):  
Hydrogen Bonds ◽  
Ion Association ◽  
Ion Pair ◽  
Association Constants ◽  
Halide Ions ◽  
Conductivity Measurements ◽  
Line Broadening ◽  
Experimental Values

Abstract Conductivity measurements are reported in dichloromethane for tetraethylammonium and tetraphenylarsonium salts of tetrachloro-and tetrabromoferrate(III) and halide ions (chiefly chloride and bromide). Analysis of the data in terms of the recent Fuoss equation has given the ion-pair association constants. The experimental values are close to the ones calculated from the electrostatic Fuoss-Eigen equation. The solvent acts as an acceptor by way of forming hydrogen-bonds to the simple halide ions and to a much less extent to the ferrates. Solvation of chloro-and bromoferrates(III) seems to be comparable, as deduced from the association constants and NMR paramagnetic line broadening. The phenyl groups of the tetraphenylarsonium ion seem to give π-interaction with the solvent.

Uphill and downhill charge generation from charge transfer to charge separated states in organic solar cells

2021 ◽  
Author(s):  
Shahidul Alam ◽  
Vojtech Nádaždy ◽  
Tomáš Váry ◽  
Christian Friebe ◽  
Rico Meitzner ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Solar Cells ◽  
Charge Transfer ◽  
Energy Level ◽  
Density Of States ◽  
Organic Solar Cells ◽  
Joint Density ◽  
Charge Generation ◽  
Donor Acceptor

Energy level alignments at the organic donor–acceptor interface cannot be predicted from cyclic voltammetry. Onsets for joint density of states and charge generation, reveal cases of energy uphill and – newly observed – downhill charge generation.

scholarly journals Cobalt(II) complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms

2005 ◽  
Vol 70 (8-9) ◽  
pp. 1121-1129 ◽  
Author(s):  
Gordana Vuckovic ◽  
V. Stanic ◽  
Sofija Sovilj ◽  
M. Antonijevic-Nikolic ◽  
J. Mrozynski
Keyword(s):  
Cyclic Voltammetry ◽  
Ir Spectroscopy ◽  
Chair Conformation ◽  
Trans Position ◽  
Cyclic Voltammetric ◽  
Aromatic Carboxylates ◽  
Elemental Analyses ◽  
Electrical Conductivities ◽  
Pendant Arms ◽  
Voltammetric Measurements

Novel binuclear Co(II) complexeswithN-functionalized cyclam N,N?,N",N???-tetrakis( 2-pyridylmethyl)tetraazacyclotetradecane (tpmc) and one of the aromatic monoor dicarboxylato ligands (benzoate, phthalate or isophthalate ions) were prepared. They were analyzed and studied by elemental analyses (C, H, N), electrical conductivities, VIS and IR spectroscopy andmagnetic as well as cyclic voltammetric measurements. In [Co2(C6H5COO)2tpmc]ClO4)2.3H2O, the benzoate ligands are most probably coordinated as chelates in the trans-position to each Co(II) and the macrocycle adopts a chair conformation. In the complexes [Co2(Y)tpmc]ClO4)2.zH2O, (Y = phthalate or i-phthalate dianizon, z = 2; 4) it is proposed that the isomeric dicarboxylates are bonded combined as bridges and chelates. The composition and the assumed geometries of the complexes are compared with the, earlier reported, corresponding Cu(II) complexes. Cyclic voltammetry measurements showed that the compounds are electrochemically stable.

Chemical behavior of charge-transfer complexes. VII. Solvolysis of alkyl arenesulfonate donors in the presence of aromatic acceptors

1978 ◽  
Vol 56 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Allan K. Colter ◽  
Robert E. C. Turkos
Keyword(s):  
Acetic Acid ◽  
Charge Transfer ◽  
Kinetic Data ◽  
Association Constants ◽  
Charge Transfer Complexes ◽  
Chemical Behavior ◽  
Measurable Rate ◽  
Leaving Groups

Rates of solvolysis of several ethyl and 2-propyl arenesulfonates having π donor leaving groups were measured in the absence of accepter and in the presence of the π acceptors 1,3,5-trinitrobenzene (TNB) and 2,4,7-trinitrofluorenone (TNF). With four of the nine combinations investigated, added accepter produced small but measurable rate enhancements. Ester–TNF 1:1 association constants were measured spectrophotometrically at 20, 30, and 40 °C in acetic acid for 2-propyl 4-methoxy-1-naphthalenesulfonate (3b), 4,8-dimethoxy-1-naphthalenesulfonate (4), 3,7-dimethyl-1-naphthalenesulfonate (5), and 1-pyrenesulfonate (6). From the equilibrium and kinetic data, the reactivity of the 1:1 ester–TNF complex relative to that of the uncomplexed ester (kc/ku) in acetolysis at 85.73 °C was estimated to be lessthan 4.2 and 1.4 for 3b and 4, respectively, 4.4 ± 2.0 for 5, and 2.8 ± 0.4 for 6. The value of kc/ku for 6 determined from analysis of the kinetic data alone is 2.7 ± 0.8.

Octahedral cobalt(III) complexes in dipolar aprotic solvents. II. Association between cis- and trans-dichlorobisethylenediamine cobalt(III) cations,[Co en2 Cl2]+, and chloride and bromide ions in the solvents NN-dimethylformamide, dimethyl sulphoxide, and LVN-dimethylacetamide

1966 ◽  
Vol 19 (1) ◽  
pp. 43 ◽  
Author(s):  
WA Millen ◽  
DW Watts
Keyword(s):  
Spectrophotometric Method ◽  
Ion Pairs ◽  
Ion Association ◽  
Ion Pair ◽  
Association Constants ◽  
Dimethyl Sulphoxide ◽  
Aprotic Solvents ◽  
Ion Association Constants ◽  
Cis And Trans ◽  
Dipolar Aprotic Solvents

Ion association constants at 30� have been determined for the cis-[Co en, Cl2]+Cl- ion pair in NN-dimethylformamide (DMF), NN-dimethylacetamide (DMA), and at 20.0�, 25.0�, and 30.0� in dimethyl sulphoxide (DMSO), by a spectrophotometric method. Association constants for the cis-[Co en2 Cl2]+Br- and the trans- [Co en2 Cl2]+Cl- ion pairs have also been determined in DMF at 30�.

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