Temperature dependence of association constant, extinction coefficient and total absorption intensity of an organic charge-transfer complex

1967 ◽  
Vol 23 (7) ◽  
pp. 2037-2042 ◽  
Author(s):  
R. Foster ◽  
I.B.C. Matheson
2005 ◽  
Vol 108 (2) ◽  
pp. 317-321 ◽  
Author(s):  
G. Grampp ◽  
P.B. Sczaniecki ◽  
S. Żurek ◽  
W. Bednarski

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 ◽  
...  

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).


1964 ◽  
Vol 42 (5) ◽  
pp. 1084-1087 ◽  
Author(s):  
H. KOKADO ◽  
K. Hasegawaj ◽  
W. G. Schneider

Single crystals of the perylene–fluoranil charge-transfer complex were found to be photoconductive throughout the near ultraviolet, visible, and near infrared spectral regions. The temperature dependence of the semiconduction and photoconduction are characterized by apparent activation energies of 0.73 ev and 0.12 ev, respectively. Conductivity parallel to the c-crystallographic axis (along which the complex units are stacked in columns) was found to be about threefold greater than that in the perpendicular direction. Attempts to measure carrier mobilities proved unsuccessful. The results suggest extrinsic carrier generation accompanied by pronounced carrier trapping processes.


1991 ◽  
Vol 42 (1-2) ◽  
pp. 1471-1474 ◽  
Author(s):  
L.A Galchenkov ◽  
S.N Ivanov ◽  
F.Ya Nad' ◽  
V.P Chernov ◽  
T.S Berzina ◽  
...  

1989 ◽  
Vol 44 (9) ◽  
pp. 825-832 ◽  
Author(s):  
H.-P. Werner ◽  
W. Grauf ◽  
J. U. von Schütz ◽  
H. C. Wolf ◽  
H. W. Helberg ◽  
...  

Abstract Conductivity (dc and ac), ESR-properties and proton relaxation rates of the charge transfer complex Tetrathiafulvalene N,N′-dicyanonaphthoquinonediimine in the temperature range be­ tween 300 K and 3.8 K are reported. This salt belongs to the unusual group of organic conductors, in which segregated donor and acceptor stacks are associated in a pairwise manner. The physical properties, which are compared with TTF-TCNQ, give evidence of non-stoichiometric charge transfer (ρ ≠ 1). A metal like state can be identified for T> 70 K, as is seen from the weak temper­ ature dependence of the conductivity (σrt ≈ 30 Scm-1) and the susceptibility (Xrt ≈ 7.5 ⋅ 10-4 emu/ mole) and from the Korringa like temperature dependence of the proton relaxation rates. The drop of the susceptibility at Tc ≈ 70 K and the activated temperature dependence of the conductivity for T < 70 K are explained by a metal-to-semiconductor transition.


Pulse radiolysis of solutions of iodine in cyclo hexane resulted in the formation of a transient absorption with wavelength maximum at 3300 Å. This transient spectrum was assigned to the C 6 H 12 ... I' charge-transfer complex. The spectrum and extinction coefficients of the complex over the wavelength range 2500 to 6500 Å were obtained, the coefficient at 3300 Å being 2025 1. mole -1 cm -1 . Hydrogen iodide in cyclo hexane gave rise to the same transient absorption. Pulse radiolysis of cyclo hexane and cyclo hexyl iodide alone gave rise to different transient spectra attributed to the cyclo hexyl radical, absorbing in the ultraviolet, extinction coefficient 3401. mole -1 cm -1 at 2550 Å and the C 6 H 11 .. .I* charge-transfer complex, absorption maximum 3900 A, extinction coefficient ~ 10 3 to 10 4 1. mole -1 cm -1 , respectively. During the course of the investigations rate constants were obtained for the following reactions: C 6 H 11 + I 2 C 6 H 11 I + I', k II = 7 x 10 9 1. mole -1 s -1 , 2C 6 H 12 ...I' -> 2C 6 H 12 + I 2 , k II = 1.06 x 10 10 1. mole -1 s -1 , or 21' -> I 2 , a C 6 H 10 + C 6 H 12 2C 6 H 11 k 11a + k 11b =2.5 x 10 9 1. mole -1 s -1 bC 12 H 22 Dilute solutions of iodine (10 -4 M) in cyclo hexane yielded experimental evidence for neutral radical intermediates only. There were, however, indications that ionic radical intermediates occur in more concentrated solutions ( > 10 -3 M). :


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