EXCITED PI(ASTERISK) STATES OF DIVINYL CHALCOGENIDES AND CHALCOPHENES

Electron transitions in divinyl chalcogenides (CH2=CHXCH=CH2, where X is S, Se, or Te) have been analyzed using UV absorption spectra of dia lkyl and alkyl vinyl chalcogenides. The following relations for the or bital energies are found: pi --> sigma < pi --> sigma* < pi --> pi* < pi --> pi for Te and pi --> sigma* < pi --> pi* < pi --> pi* < pi -- > sigma for S and Se. For chalcophenes, a correlation between the ene rgy of the excited state (E) of specific symmetry, the ionization pot ential (I) and the electron affinity (EA) is obtained: E = const + (I + EA)/2. The electron affinity of divinyl chalcogenides is estimated. The correlation between the excited pi states of divinyl chalcogenid es and chalcophenes is discussed.