Synthesis and complexation of "back-to-back" capped bis-dioxocyclams.

Pyridine-capped 5,12-dioxocyclams were coupled "back-to-back" directly, with one or two intervening phenyl groups, an ethynyl group, or a diazo group via Suzuki, Sonogashira, or reductive coupling of the 4-nitropyridine monocyclam. These bis-dioxocyclams linked through extended pi-conjugated systems were complexed to copper(II) and cobalt(III), producing bis-metal complexes which were characterized spectroscopically and electrochemically. These studies gave little evidence for electronic communication between metal centers across the pi-conjugated linkers.