ASSOCIATION CONSTANTS OF SOME CHARGE-TRANSFER COMPLEXES OF AROMATIC HYDROCARBONS WITH ELECTRON ACCEPTORS

Association constants for various charge-transfer complexes formed between 1,3,5-trinitrobenzene, fluoranil (tetrafluoro-p-benzoquinone), or 1,4-dinitrobenzene and various aromatic hydrocarbons have been determined from n.m.r. chemical-shift measurements. By means of a spectrophotometric method, association constants for a series of tetracyanoethylene-aromatic hydrocarbon complexes have also been determined. The effect on the association constant of increasing the methylation of the benzene, of increasing the length of the side-chain in the mono-n-alkylbenzenes, and of the presence of two or more phenyl groups in the donor is considered.