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.
An Alternative Method of Solving the Rose-Drago Equation for the Determination of Equilibrium Constants of Molecular Complexes
