Preparations and spin-spin interactions of 4,4′-(triptycene-1,8-diyl)bis(1-methyl-2,6-diphenylpyridinyl) diradical and its 1,5-diyl isomer

Article abstract of DOI:10.1246/cl.1996.169

4,4′-(Triptycene-1,8-diyl)bis(1-methyl-2,6-diphenylpyridinyl) diradical was prepared by 3%-Na-Hg reduction of the corresponding dication and the ground state was estimated to be triplet or singlet with small S-T energy gap (< 20 J mol^-1). No triplet signal was observed under the similar conditions for the corresponding 1,5-diyl derivative.