Platinum complexes bridged

Figure 3.98 A dimeric platinum(III) complex with no bridging ligands.

The great majority of platinum(I) complexes are binuclear with monofunctional or bifunctional bridging groups. However, there is also a series of unsupported dimers with the general structure shown in (12). These are generally stabilized by phosphine, carbonyl, and isocyanide ligands.17 Dimeric hydride complexes can have terminal or bridging hydrides and these are discussed above in Section 6.5.2.1.4. 

A versatile synthesis of monoamine platinum(II) complexes of the type ptCl3(amine)], where the nature of the amine ligand can be varied readily, involves treatment of the iodo-bridged dimer [PtI(/r-I)L]2 (L = NH3, methylamine, ethylamine, isopropylamine, cyclobutylamine, and... 

Platinum(III) complexes are remarkably rare and most examples date from less than 30 years ago. The great majority are dimeric species with only a few authenticated stable monomers reported. Most of the dimers are bridged by bidentate ligands and are almost exclusively doubly or quadruply bridged, the latter giving rise to the classic lantern structure. 

The sulfate bridged dimer K2[Pt2(S04)4(H20)2] was among the first platinum(III) compounds prepared and the analogous hydrogenphosphate bridged complexes [Pt2(HP04)4(L)2]2+ are... 

Lippert and co-workers have reported a similar series of A-,O-bridged platinum(III) dimers in which the bridging ligands are the pyrimidines, 1-methyluracil, 1-methylthymine, or 1-ethylthy-mine. Chemical oxidation of dimeric platinum(II) complexes gave [Pt2XY(L)2(NH3)4]2+, X,Y = N03", N02, H20, Cl", or Br", L=l-MeU, 1-MeT, 1-EtT. 27 t30 They too found that the HT dimers are more stable than the HH.430... 

The localized-valence halogen-bridged platinum(II)/platinum(IV) complexes (175) are of interest because of their highly anisotropic electrical and optical properties. The complexes are characterized by broad and intense intervalence bands in their electronic spectra.542 Partial oxidation of [PtCl(dien)]Cl with iodine yields the mixed valence species [PtI(dien)][PtI3(dien)]I2,543 but when 4Me-dien is used, the mixed valence compound is only obtained if it is trapped quickly, before isomerization of the meridional platinum(IV) complex to a facial form.544 Although these species nominally have localized valences, the extent of delocalization increases as the bridging halide... 

Halide bridged nickel(II)/platinum(IV) and palladium(II)/platinum(IV) complexes with onedimensional linear-chain structures have been studied extensively.556-559 These are analogous to the linear-chain platinum(II)/platinum(IV) systems described in Section 6.5.13 and have similar broad and intense intervalence bands.556-559 However, they have weaker metal-metal interactions resulting in more localized valences than the all platinum analogues.556-559... 

C. Oxidation of Organic Substances Catalyzed by Amidate-Bridged Platinum(III) Complexes... 

II. Syntheses and Structures of Platinum-Blues and Related Amidate-Bridge Platinum"1 Complexes... 

A special type of reaction is observed with the platinum(IV) complex [PtI(Me)3] which cleaves the Af,N,Af, A -tetraphenyltetraaminoethylene under reduction to form the dimeric cyclometallated mono(NHC) complex of platinum(II) iodide [Eq. (31)]. Cyclometallation with the same ligand is also observed for ruthe-nium. Additional cyclometallations with various substituents of NHCs have been reported for ruthenium(II), rhodium(III), iridium(I), palladium(II), " and platinum(II). In the case of iridium, alkyl groups can be activated twice. In rare cases like for nickel(II) /x-bridging NHCs have been obtained. ... 

Oligomers, condensation, in formation of hy-droxo-bridged complexes, 32 91 Oligonucleotides, platinum binding, 37 185-187... 

Figure 7.35. Dinuclear palladium(II) and platinum(ll) complexes with phenylene- and ethylene-bridged bis(oxazolone) ligands.

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