pi-Conjugated trinuclear iridium and cobalt dithiolenes undergo multiple metal-metal bond formation with Co-2(CO)(8) and Fe(CO)(5), giving rise to Ir3Co6 nonanuclear and Co3Fe3 hexanuclear cluster complexes 5 and 6, respectively. 5 retains a planar framework and intense pi conjugation across the three iridadithiolenes and the phenylene bridge, which results in intense electronic communication among the three Co-2(CO)(5) units in reduced mixed-valent states.