Linear Conjugated Systems Bearing Aromatic Terminal Groups. II. The Synthesis and the Electronic Spectra of 9,9′ -Dianthrylpoly-ynes

A series of 9,9′-dianthrylpoly-ynes (II1–II6) were prepared, and their electronic spectra were measured. It was found that the novel linear relation between λmax and the square of the number of the triple bond (n2) which has been found in the spectra of 1,1′-dianthrylpoly-ynes (I1–I6) also held in the 9,9′-series.