Perylene salts of unsymmetrical nickel and gold dithiolene complexes with 3 2 stoichiometry: conformational polymorphism and strong antiferromagnetic interactions
Résumé
The square-planar AuIII complex of the unsymmetrical tfadt dithiolate ligand (tfadt: 2-(trifluoromethyl)acrylonitrile-1,2-dithiolate) is found to exhibit conformational polymorphism in its n-Bu4N+ salt, as both cis and trans isomers were found to crystallize separately in the same crystallization batch. Electrocrystallization of perylene in the presence of the diamagnetic [n-Bu4N][Au(tfadt)2] or the paramagnetic (S= 1/2)[n-Bu4N][Ni(tfadt)2] nickel analog affords isostructural salts with an unusual 3 2 stoichiometry, that is [Per]3[M(tfadt)2]2(M = Au, Ni), with an alternation of dicationic [Per]32+ perylene triads and dianionic [M(tfadt)2]22– dithiolene complex dyads within one-dimensional chains. These salts are characterized by strong antiferromagnetic interactions within perylene triads and [Ni(tfadt)2]22– dyads and an essentially diamagnetic behaviour.