[en] Pulse radiolysis of deaerated 1,2-dichloroethane solutions of anisole, methylanisoles, and di(methoxyphenyl)alkanes provide two types of transient species. One is a transient with a λ_max around 470 nm which is commonly observed in all methoxyphenyl compounds as well as in other unsubstituted or corresponding methyl-substituted compounds and identified as dimer cations due to an interaction of π-electrons. The other is a transient with a broad band at 500-700 nm. The λ_max and the intensity of the band are dependent on the structure of the anisole derivatives and the transient was tentatively assigned to a novel type of dimer cation in which n-electrons of the methoxyl group participate in the complex formation. Pulse radiolysis of carbon tetrachloride solutions of above mentioned anisole and its derivatives provided a transient species in visible region which is assigned to a charge-transfer complex with chlorine atoms. The absorption band energy of the complex was dependent on the ionization potential of the anisole derivatives, but the correlation between E _hv vs IP was quite different from that of unsubstituted aromatic compounds. (author)

[en] Radiation-induced cis-trans isomerization of 1,2-bis(4-methoxyphenyl)cyclopropanes(CP) has been investigated in benzonitrile solution. The isomerization from cis-CP to trans-CP proceeded efficiently (G = 80) via a cationic chain mechanism. Three types of transient species were spectroscopically detected by pulse radiolysis and γ-irradiated low-temperature matrix studies. The reaction mechanisms are discussed on the basis of these direct observations. (author)