Breaking the symmetry in the molecular motor family: synthesis of a dissymmetrized pentaphenyl cyclopentadienyl ligand and its ruthenium tris(indazolyl)borate complex

In order to demonstrate a movement of rotation in a family of rotary molecular motors, 1-bromo-1-(4-tolyl)-2,3,4,5-tetra(4-bromophenyl) cyclopentadiene has been synthesized. The coordination of this C2v cyclopentadiene to a ruthenium trisindazolylborate complex and the quadruple coupling reaction with ethynylferrocene led to the dissymmetrized motor (1).