Charge-Transfer Complexes of Brominated Polycyclic Aromatic Hydrocarbons

1962 ◽  
Vol 15 (2) ◽  
pp. 278 ◽  
Author(s):  
TM Spotswood
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Charge Transfer ◽  
Aromatic Hydrocarbons ◽  
Charge Transfer Complex ◽  
Equilibrium Constants ◽  
Molecular Complexes ◽  
Charge Transfer Complexes ◽  
Extinction Coefficients ◽  
Polycyclic Aromatic ◽  
Molar Extinction Coefficients

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.

CHARGE-TRANSFER COMPLEXES OF BIPHENYLENE

1966 ◽  
Vol 44 (1) ◽  
pp. 9-12 ◽  
Author(s):  
P. H. Emslie ◽  
R. Foster ◽  
R. Pickles
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Equilibrium Constants ◽  
Charge Transfer Complexes ◽  
Kcal Mole ◽  
Dichloromethane Solution ◽  
Entropy Of Formation ◽  
Charge Transfer Transitions ◽  
Different Temperatures ◽  
Enthalpy And Entropy

An attempt has been made to redetermine the enthalpy and entropy of formation of the charge-transfer complex between tetracyanoethylene and biphenylene in dichloromethane solution from measurements of the equilibrium constant at different temperatures. The results obtained under conditions where biphenylene is in excess differ from those previously published in which tetracyanoethylene was in excess. It is argued that the optimum condition for determining equilibrium constants of a 1:1 complex is when the reactants are mixed in solution in this ratio. Determinations under this condition yield ΔH = −2.6 kcal mole−1 and ΔS = −4.1 e.u.The energies of the intermolecular charge-transfer transitions of biphenylene with several different acceptors suggest that the ionization potential of biphenylene is ~7.4 eV.

scholarly journals Synthesis and Properties of NitroHPHAC: The First Example of Substitution Reaction on HPHAC

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2486
Author(s):  
Yoshiki Sasaki ◽  
Masayoshi Takase ◽  
Shigeki Mori ◽  
Hidemitsu Uno
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Charge Transfer ◽  
Functional Groups ◽  
Radical Cation ◽  
Aromatic Hydrocarbons ◽  
Substitution Reaction ◽  
Intramolecular Charge Transfer ◽  
Direct Introduction ◽  
Polycyclic Aromatic

Hexapyrrolohexaazacoronene (HPHAC) is one of the N-containing polycyclic aromatic hydrocarbons in which six pyrroles are fused circularly around a benzene. Despite the recent development of HPHAC analogues, there is no report on direct introduction of functional groups into the HPHAC skeleton. This work reports the first example of nitration reaction of decaethylHPHAC. The structures of nitrodecaethylHPHAC including neutral and two oxidized species (radical cation and dication), intramolecular charge transfer (ICT) character, and global aromaticity of the dication are discussed.

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