Organometallic complex cations (hn-CnR'n)M(RN:CHCH:NR)Cl+ of 1,4-diazabutadienes (M = Os and n = 6 or M = Rh, Ir and n = 5, R = 2,6-dialkylphenyl). Structures and reduction to neutral compounds (hn-CnR'n)M(RNCH:CHNR). Zeitschrift fuer Anorganische und Allgemeine Chemie, (627)4:620--630, 2001. [PUMA: azabutadiene complex complex;diazabutadiene complex;redn complex;redox complex;rhodium crystal diazabutadiene diisopropylphenyl iridium mol osmium potential prepn redox redox;crystal redox;mol structure structure;iridium]