Ruthenium, Diazide, ZINDO/1 CalculationsThe reaction of [Ru(tpy)(PPh3)(Cl)2] (tpy = 2,2':6',2"-terpyridine) with sodium azide in acetone/water afforded [Ru(tpy)(PPh3)(N3)2]. The new Ru-diazide complex was fully char acterized by elemental analysis, IR, Raman, and multinuclear NMR spectroscopy. The struc tures, energies and vibrational frequencies of the ruthenium diazide isomers, cis-and trans-[Ru(tpy)(PMe3)(N3)2] (Me=CH0, were calculated at the semi-empirical ZINDO/1 level of theory.