STRUCTURES AND PHOTOCHEMISTRY OF INCLUSION-COMPOUNDS OF -9,10-ETHENOANTHRACENE-11,12-BIS(DIPHENYLPHOSPHINE OXIDE)

Inclusion complexes of -9,10-ethenoanthracene-11,12-bis(diphenylphosph ine oxide) (1) as host are synthesized using a variety of guest solven t molecules and the photochemistry of the host molecule is studied in solution and in the crystalline complexes. The crystal structures of f our complexes are determined and correlated with their photochemical r eactivity. In each case only one dibenzosemibullvalene photoproduct is obtained in the photolysis. Since three of the complexes studied crys tallize in the chiral space group P2(1)2(1)2(1), irradiation of single crystals produces a chiral photoproduct in >90% enantiomeric excess. Determination of the absolute configurations of reactants and products allows elucidation of the key structural features that control the en antiospecific solid-state photorearrangements.