Synthesis and characterization of chelate and bridging triazenide complexes of palladium and platinum. Stereoselective oxidative addition of chlorineor iodine to [NBu4][Pt(C6F5)(2)(eta(2)-PhNNNPh)]

The triazenide complexes cis-[M(C6F5)(2)(eta (2)-ArNNNAr)] - (M = Pd. Pt: A r = C6H5, C6H4Me-p), anti-[{Pd(C6F5)(L)(mu -PhNNNPh)}(2)] [L = PPh3, t-BuNC , PhCN, tht (tht = SC4H8. tetrahydrothiophene)] and anti-[{ Pd(C6F5)(2)(Br) -(mu -PhNNNPh)}(2)](2-) have been prepared by treatment of the correspondin g precursors [{M(C6F5)(2)(mu -OH)}(2)](2-) (M = Pd, Pt) [{Pd(C5F5)(L)(mu -X )}(2)] (X = OH or Cl) and[{Pd(C6F5)(Br)(mu -Br)}(2)](2-) with either ArN=NN HAr or ArNNNAr-. The stereoselective oxidation of cis-[Pt(C6F5)(2)(PhNNNPh) ](-) with PhICl2 or I-2 leads to the synthesis of the corresponding mononuc lear platinum(IV) complex cis, trans-[Pt(C6F5)(2)(PhNNNPh)(X)(2)](-) (X = C l or I). The crystal structures of cis-[Pd(C6F5)(2)(eta (2)- PhNNNPh)](-), anti-[{ Pd(C6F5)(t-BuNC)(mu -PhNNNPh)}(2)] and cis, trans-[Pt(C6F5)(2)(eta (2)-PhNNNPh)(Cl)(2)](-) have been established by X-ray diffraction. The Pd . . . Pd distance bridged by the rigid triazenido ligands in anti-[{Pd(C6F5 )(t-BuNC)(mu -PhNNNPh)}(2)] is 2.9907(8) Angstrom where a boat conformation of the central 'Pd2N6' eight-membered ring is observed. The [Pt(C6F5)(2)(e ta (2)-PhNNNPh)(Cl)(2)](-) anion shows an octahedral arrangement around the platinum atom, involving two trans-chloro ligands. two cis-C6F5 groups and a chelating triazenide.