The evaluation of equilibrium constants and extinction coefficients for weak charge-transfer complexes. Part II

Author(s):  
S. Carter
1962 ◽  
Vol 15 (2) ◽  
pp. 278 ◽  
Author(s):  
TM Spotswood

Charge-transfer complex formation between the donors 1-bromonaphthalene. 9-bromophenanthrene, 9-bromoanthracene, 3-bromopyrene, and 7-bromobenz[a]-anthracene and the acceptors iodine, tetrachlorophthalic anhydride, 1,3,5-trinitrobenzene, and 2,4,7-trinitrofluorenone has been investigated. The positions of the charge-transfer absorption maxima, apparent molar extinction coefficients, and equilibrium constants have been determined in carbon tetrachloride solution and the results compared with those for the corresponding unsubstituted polycyclic aromatic hydrocarbons. The positions of the absorption maxima of the charge-transfer bands of the brominated hydrocarbons were anomalous but the apparent molar extinction coefficients and equilibrium constants were similar to those obtained for the parent hydrocarbons. The strength of charge-transfer bonding in molecular complexes of brominated polycyclic aromatic hydrocarbons is shown to be of the same order as that in molecular complexes of the unsubstituted hydrocarbons.


1984 ◽  
Vol 109 (6) ◽  
pp. 615-619 ◽  
Author(s):  
M.H. Kuok ◽  
E.C. Looi ◽  
S.H. Tang ◽  
C.T. Lin ◽  
C.A. Caetano

1966 ◽  
Vol 44 (8) ◽  
pp. 945-952 ◽  
Author(s):  
D. F. R. Gilson ◽  
C. A. McDowell

"Wide line" nuclear magnetic resonance studies of several charge transfer complexes are reported. Line width transitions and comparisons of theoretical and experimental second moments indicate that molecular rotation occurs in several of these complexes. Estimates of the barriers to reorientation in the complexes show these to be lower than those observed for the corresponding pure compounds.


1970 ◽  
Vol 23 (2) ◽  
pp. 269 ◽  
Author(s):  
PR Singh ◽  
R Sahai

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.


Far infrared spectra of charge-transfer complexes between iodine and substituted pyridines, dissolved in cyclohexane, have been measured in the region 20 to 200 cm -1 . Bands have been assigned to the modified iodine molecule stretching vibration near 180 cm -1 , and to the stretching of the intermolecular bond in the range 65 to 95 cm -1 . The shifts of the vibration frequencies, and force constants calculated using a simple valency force field, have been discussed in relation to the mass, electronic and steric effects of substituent groups. Equilibrium constants for the formation of the complex have been determined. From the intensities of the absorption bands, further evidence has been found for a vibronic interaction, leading to a delocalization of the transition moment in the vibrations of the complexes, and to an enhancement of the intensity of absorption.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hulya Demirhan ◽  
Mustafa Arslan ◽  
Mustafa Zengin ◽  
Mustafa Kucukislamoglu

Charge transfer complexes (CTC) of mirtazapine with tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), and tetracyanoquinodimethane (TCNQ) have been studied spectrophotometrically in dichloromethane at room temperature. The stoichiometries of the complexes were found to be 1 : 1 ratio by the Job Method between mirtazapine and the acceptors. The equilibrium constants and thermodynamic parameters of the complexes were determined by the Benesi-Hildebrand and Van't Hoff equations. Mirtazapine in pure and dosage form was applied in this study. The results indicate that the formation constants for the complexes depend on the nature of electron acceptors and donor. And also the spectral studies of the complexes were determined by FT-IR and NMR spectroscopy.


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