Polyanthraquinocyclopropanes, Dianthraquinocyclopropanone, and Dianthraquinoethylene. Synthesis and Properties

Article abstract of DOI:10.1021/ja00535a037

Tris(9-anthron-10-ylidene)cyclopropane (7c) was prepared by the Friedel-Crafts reaction of 9-methoxyanthracene with trichloropropenium tetrachloroaluminate, followed by demethylation and oxidation of the resulting bis(9-hydroxy-10-anthryl)cyclopropenylidenanthrone.The corresponding triquinocyclopropanes with one or two anthraquino qroups replaced by 4-oxo-3,5-di-tert-butyl-2,5-cyclohexadien-1-ylidene groups (7a,b) were prepared by stepwise addition of 9-methoxyanthracene and 2,6-di-tert-butylphenol.Reaction of 2 equiv of 9-methoxyanthracene in an analogous fashion resulted in 2,3-bis(9-anthron-10-ylidene)cyclopropanone (8), which loses carbon monoxide photolytically to form dianthraquinoethylene (9).These materials are intensely colored, highly conjugated solids with electronic absorptions in the near infrared.Spectroscopic properties and results of Hueckel MO calculations are reported.