Reactions of iridium and ruthenium complexes with organic azides

Interaction:of N,R with Ir(mes)(3) (mes = mesityl, C6H2Me3-2,4,6) gave products dependent on the nature of the azide. When R = mes, the tetrazenido amide complex 1 is obtained in which dehydrogenative coupling of the mesityl groups via the o-methyls has occurred; thermolysis of I in toluene resulted in cleavage of the tetrazene ring and formation of amide complex 2. When R = Ph, the aryl tetrazenido amide complex 3 is formed. Photolysis of a mixture of N-3(mes) and [RuCl2(PPh3)(3)] followed by phosphine exchange gave the tetrazene complex [(RuCl2)-Cl-II{N-4(mes)(2)}(PMe3)(2)] 4. Thermal reaction of [RuCl2H2(PPr3i)(2)] with N-3(mes) gave the triazenophosphorane complex [RuCl3(PPr31){N-3(mes)PPr3i}] 5. The ruthenium allyl amide [Ru(PMe3)(3){NHC6H3Pr3(eta(3)-CH2CCH2)}] 6 bearing a new hybrid ligand was obtained by interaction of trans[RuCl2(PMe3)(4)] with Li[NH(C6H3Pr2i-2,6)] in di-n-butyl ether. Plausible reaction mechanisms accounting for the formation:of the new compounds are proposed. Finally, the crystal structures of the complexes 1-6 have been determined. Complexes I and 2 have pseudo-square planar geometries involving the olefin formed by the coupled methyl groups of two mesityls and three (I) or two (2)amide nitrogens and a chlorine atom (2). Compound 3 has a trigonal bipyramidal metal centre with the axial Ir-N amide bonds longer than the equatorial ones; 4 has an octahedral structure with a bidentate tetragonal ligand and trans phosphines whilst 5 is distorted octahedral with a N,N-chelating phosphazide ligand. Complex 6 is also octahedral with the allyl groups occupying cis sites and the three Ru-P bonds in a facial arrangement.