Redox-active tetraruthenium metallacycles: reversible release of up to eight electrons resulting in strong electrochromism.

Tetraruthenium macrocycles with 1,4-divinylphenylene and diarylaminesubstituted isophthalic acids as the sides display up to eight one-electron redox steps and rich electrochromic behaviour with strong absorptions of the dications in the near infrared and of the tetra-and hexacations at low energies in the visible.