Complexes of Platinum and Palladium

Recently compounds containing cyclic polyolefins coordinated to platinum or palladium have received considerable attention as a result of the unique bonding found in these compounds and their possible use as intermediates in a variety of reactions. Several methods have been reported for the synthesis of these compounds, and among these procedures the displacement of ethylene1 from di-Ju-chloro-dichlorobis(ethylene)diplatinum(II) and benzonitrile2 from dichlorobis(benzonitrile)palladium(II) are the most generally applied procedures. Both of these methods involve the preparation of intermediates before the isolation of the product, and in addition these intermediates tend to decompose upon storage. 

The procedures described in the subsequent preparations are rapid and the starting materials are the commercially available 

---

An extensive range of mono- and binuclear halide complexes of platinum and palladium exist. Of the tetrahalometallate(II) ions, some like PtF4 and Pdl4 are elusive, the latter only having been characterized in solution. 

Tertiary phosphine complexes of platinum and palladium M(PR3)2X2 are important [95]. The cis- and trans- somers are readily obtained for platinum,... 

A review11 with 123 references is given on amino acid bonding preferences in complexes of platinum and palladium. The preferences for a particular donor atom for Pd11 depends primarily on relative thermodynamic stabilities of the complexes formed. Sizes of potential chelate rings often play a crucial role in determining donor atom preferences. 

Similar reactions can be utilized to prepare allyl complexes of platinum and palladium. In this case, the product can exist in two isomers as described earlier. Analogous reactions can be used to prepare the tris allyl complexes of several metals. 

Another type of complex for which it is obvious thatQlarge structural changes occur on excitation (probably 0.2-0.3 A) along particular coordinates are the infinite-chain mixed-valence complexes of platinum and palladium (class II, or localized mixed-valence complexes) (11).. These Pti [/PtIV, PdIVPtIV or Pdi [/PdIV... 

Pt(S2CNMe(Hex))2] and [Pd(S2CNMe(Hex))2] have been synthesized and used as precursors to grow the first TOPO-capped PtS and PdS nanoparticles and thin films of PtS and PdS by the metallo-organic chemical vapor deposition (MOCVD) method [204]. Platinum and palladium chalcogenides find applications in catalysis [205-210] and materials science [211,212]. The synthesis of thiocarbamato complexes of platinum and palladium from reaction of an aqueous solution of ammonium dithiocarbamate with the platinum or palladium salt has been reported by Nakamoto et al. [213]. However... 

Some cis complexes of platinum and palladium that show significant antitumor activity. It is thought that the cis complexes work by losing two adjacent ligands and then forming coordinate covalent bonds to adjacent bases on a DNA molecule. 

If we apply the same type of arguments to complexes of platinum and palladium, in which distinct bond-making and bond-breaking maxima apply and square-pyramidal structures are quite common, a reaction profile like Fig. 6 may well be appropriate. The trigonal-bipyramidal structure is certainly not always a transition state, however, particularly when TT-accepting ligands can adopt equatorial sites, so some reactions might well conform to the complicated profile shown in Fig. 

Norbornadiene complexes of platinum and palladium 14 reacted with silver carboxylates to form the carboxymetalation products 15 which, on treatment with triphenylphosphane, underwent intramolecular alkene insertion to form the nortricyclene skeleton 16. Reductive decom-plexation gave the acylated tricyclo[2.2.1.0 ]heptan-ex n-3-ol 17. ... 

After this we embarked upon a comprehensive study of the infrared spectra of amine complexes of platinum and palladium. By we, I don t just mean Joe, the leader, and myself, but Alan Williams, George Gamlen, Bernard Shaw and last, but far from least, Luigi Venanzi who had the gift of being able to synthesise any compound you could think of which might have an interesting infrared spectrum. Incidentally I remember him not just for his chemical skills but as the most... 

Studies on the preparation and reactions of olefin complexes have been the subject of several recent reviews. In particular olefin and acetylene complexes of platinum and palladium have been reviewed by Hartley 0, characterised ole-fin-metal complexes by Quinn and Tsai ) and some acetylene-metal complexes by Greaves, Lock and Maitlis 3>. 

Nitro-complexes of platinum and palladium react with amidosulphuric acid according to reaction (3). 

CCR313R T. G. Appleton, Coord. Chem. Rev., 1997, 166, 313-359. Donor Atom Preferences in Complexes of Platinum and Palladium with Amino Acids and Related Molecules. II... 

---