Platinum analogues

X = H, F). The platinum analogue behaves similarly, and it also reacts with H2 to form trans-Pt(Pcy3)2H2. 

There is significant metal-metal bonding in the platinum compound, whose geometry involves a square of platinum atoms another important difference is that the coordination geometry is square planar in palladium acetate but octahedral in the platinum analogue. Different oligomers exist in solution, broken down by adduct formation. Palladium(II) acetate may be obtained as brown crystals from the following reaction [65] ... 

With their preference for square planar coordination, palladium(II) and platinum(II) are well suited to binding to porphyrins and related N4 donor macrocycles. Therefore, Pd(octaethylporphyrin) is readily synthesized starting from the labile PhCN complex (like the platinum analogue) [92]... 

Mixed palladium/platinum analogues of these trinuclear clusters have also been reported. The first of these, [PtPd2Cl(PPh2)2(PPh3)3]+, was prepared by the reaction of [PdCl(PPh3)3]+ with [PtCl(PPh3)3]+.538... 

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... 

Calvert, A. H. Thomas, H. Colombo, N. Gore, M. Earl, H. Sena, L. Camboni, G. Liati, P. Sessa, C. European Journal of Cancer 2001, 37 (supp6) Poster Discussion 965. Phase II Clinical Study of BBR3464, a Novel, Bifunctional Platinum Analogue, in Patients with Advanced Ovarian Cancer, 2001. 

For run II, the Pd concentration in both the retentate and the permeate was determined by ICP-AAS analysis. A catalyst retention of 99.5% was determined, which is almost identical to the value determined earlier for an isostructural platinum analogue (R = 99,9%).[35] This low leaching of the catalyst completely accounts for the slow decrease in activity after reaching stable conversion. 

As has been deseribed, the parent monoearbollide-metal earbonyl piano-stool species [2-(CO) -c/oi o-2,l-MCBioHii] are now known for all of the metals M = Mo (12), W (13), Re (14), Fe (11), Ru (6), Os (8), and Ni (18). Evidence also exists for a diearbonyl-platinum analogue of eompound 18, ° and as mentioned earlier, the manganese analogue of 14 has also briefly been reported. A notable absenee from this list, however, is any representative of the Group 9 metals. The earbonyl nitrosyl-cobalt complex 21 is very elosely related to the hitherto unknown dicarbonyl-cobalt dianion [2,2-(CO)2-c/oi o-2,l-CoCBioHii] and this species remains an attractive synthetie target. 

W-(2-Aminoethyl)-l,2-diaminoethane (dien) yields complexes [PdX(dien)]X (X = Cl or I) 204,20s a range of solvated complexes may be obtained by reaction of [Pdl(dien)] with AgC104 in the appropriate solvent. As for the platinum analogue, the aqua complex [Pd(dien)(H20)](C104)2 reacts with tetraphenylborate to yield [PdPh(dien)](BPh4). Reaction of the hydroxo complex with carbon monoxide yields C02 and palladium metal is deposited.206... 

In contrast, the arsine analogues AsBu 2(o-tolyl) and AsBu (o-tolyl)2 yield the complexes fra/tf-[PdCl2L2] and these produced only metallic palladium under conditions which induced cydometallation in the case of their platinum analogues.100 The ligand PBu o-QH t) metallates at the a position, but PBu 2(o-C6H4Pri) produced only metallic palladium.35 Bidentate phosphines are generally reluctant to metallate internally. An exception is... 

Unsurprisingly, dynamic exchange of pyrazolyl groups on the NMR timescale was universally observed, equivalence of all pyrazolyl groups being noted for 192,223, and 224 at ambient temperature, with the process slowed at 40 °C.49,52 In contrast, the platinum analogue 225 exhibits... 

Potassium chlorosmate may also be obtained by heating the finely divided metal with potassium chloride in chlorine,1 by double decomposition of the sodium salt with potassium chloride,2 or by the action of hydrochloric acid on potassium osmyl oxynitrite.3 It is soluble in water, yielding a yellow solution from which alcohol precipitates it as a red crystalline powder. The crystals are deep red oetahedra, iso-morphous with the corresponding palladium, iridium, and platinum analogues. 

Iridium black is soluble in aqua regia, and like its platinum analogue possesses considerable catalytic activity.13 For example, it converts ozone into oxygen, hypochlorites into chlorides, and free oxygen and chlorine water into hydrochloric acid and oxygen. 

Palladium olefin complexes are considerably less stable than the platinum analogues. The dibenzylideneacetone complex Pd2(dba)3 (18-H-IV), however, is air-stable it is a convenient source of Pd° for catalytic applications. 

---