Platinum interaction

The rhenium interacts strongly with the oxygen atoms of the support and also with platinum platinum interacts less strongly with the support than rhenium. One is tempted to generalize that when one of the metals in a supported bimetallic cluster is noble and the other oxophihc, the oxophUic metal interacts more strongly with the support than the noble metal if the bimetalhc frame of the precursor is maintained nearly intact, then this metal-support interaction helps keep the noble metal highly dispersed. 

The [111] plane the most closely packed (six-coordinated) surface of the fee structure and is very stable. The five-coordinated B5 structures may have [110] or [311] configuration (137). The four-coordinated [100] plane rearranges reversibly to a six-coordinated structure (138). Carbon-platinum interactions cause faceting of the [100] plane, giving rise to the formation of [211] or [311] structures (139). 

Phosphate platinum interactions have been reported by e.g. Bose134, Appleton135 and Marzilli147. ... 

As far as we are aware, the number of luminescent extended systems with gold-platinum interactions is reduced to only one report. This is a puzzling situation since the situation of platinum in the periodic table suggests considerable relativistic effects for this atom and extended chains of squared-planar Pt(II) cation-anion complexes built by metal-metal interactions are not strange. In fact, salts such as [Pt(CNR)4][Pt(CN)4] ,67 which are luminescent and display vapochromic behavior, and the modified form of the Magnus salt [Pt(NH3)4][Pt(CN)4] ,68 which shows semiconducting properties, are examples of this type of supramolecular systems. Therefore, the stable combination of gold and platinum in cation/anion-acid/base systems should be anticipated. 

Several electrode types can be achieved by choosing the proper electrolyte solutions. When platinum interacts with a ferri-ferrocianide solution, a low polarization occurs as a result, e.g., of the follow reaction... 

Hartinger, C.G., Ang, W.H., Casini, A., Messori, L., Keppler, B.K., Dyson, P.J. Mass spectrometric analysis of ubiquitin-platinum interactions of leading anticancer drugs MALDl versus ESI. J. Anal. At. Spectrom. 22, 960-967 (2007)... 

Silver electrodissolution produces a sharp peak from the silver-silver domains at 0.65 V along with three distinct voltammetric peaks corresponding to the upd processes one at 0.89 V, and two near each other at 1.04 and 1.15 V. The latter peaks are associated with the splitting of the 1.1 V peak due to the first stages of silver-platinum alloy formation. The positive shift peak corresponds to the oxidation of silver from the inner platinum lattice (from the alloy), and the peak at 1.04 V is probably due to the silver oxidation process from the outer silver-platinum interaction. The peak... 

The image charge model has not been used, because additional assumptions would have to be made for the l -platinum interactions. The total PMFs of the iodine atom and the iodide ion are shown in Fig. 34. 

Bonzel and Ku investigated the interaction of CO and H2S over Pt(lOO). As shown in Figure 27, sulfur preferentially poisons the sites of high-energy binding states of CO, as indicated by the shift in the CO desorption peaks toward lower temperatures. Sulfur-platinum interaction was also studied by IR spectroscopy of coadsorbed CO. 

There are cases when heavy metals are used in chemotherapy, for example cytostatic chemotherapy with as-platinum (Rosenberg 1969 [cited by Lippert 1999], Garban etal. 1989, Haiduc and Silvestru 1989, Johnsson et al. 1995). Numerous research studies into the interaction of DNA with metal ions also dealt with ds-platinum (Lippert 1999, Garban 2000). Cis-platinum interacts with nucleosides preferentially through the Ny site of guanine, but may also form bidentate chelates as a result of interaction both with Ny and sites. Modifications induced to ds-platinum by the interaction with guanine have been studied using quantum chemistry (Lippert 1999, Chojnacki et al. 2001). 

CSRs between Sn(C2Hs)4 and hydrogen adsorbed on supported platinum (see reaction (1) below) has been first described in 1984. Under properly chosen experimental condition the reaction between Sn(C2Hs)4 and surface OH groups of the support has been completely suppressed. Consequently, reaction (1) provided direct tin-platinum interaction that was maintained upon decomposition of the primary surface complex (PSC) in a hydrogen atmosphere (see reaction (2) below). The net result is the formation of alloy type bimetallic surface entities... 

Apesteguia, C.R., Brema, C.E., Garetto, T.F., Borgna, A., Parera, J.M. (1984). Sulfurization of Pt/AbOs-Cl Catalysts VI. Sulfur-Platinum Interaction Studied by Infrared Spectroscopy. Journal of Catalysis, Vol.89, No.l, (September 1984), p>p. 52-59, ISSN... 

In the case of the Pt(lOO) surface the interaction potential is derived from semiempirical quantum chemical calculations of the interactions of a water molecule with a 5-atom platinum cluster [35]. The lattice of metal atoms is flexible and the atoms can perform oscillatory motions described by a single force constant taken from lattice dynamics studies of the pure platinum metal. The water-platinum interaction potential does not only depend on the distance between two particles but also on the projection of this distance onto the surface plane, thus leading to the desired property of water adsorption with the oxygen atoms on top of a surface atom. For more details see the original references [1,2]. This model has later been simplifled and adapted to the Pt(lll) surface by Berkowitz and coworkers [3,4] who used a simple corrugation function instead of atom-atom pair potentials. 

All three of which are strongly affected by the characteristics of the support. The use of a relatively inert support such as carbon reduces strong tin-support interactions, thus facilitating the tin-platinum interaction and leading to an easy formation of Pt-Sn alloy phases. On the other hand, reduction of tin species is easier on a carbon support than on typical oxidic supports. 

In accordance with this mechanism, the catalyst containing the reduced platinum interacts with a monomer molecule to form a 5-membered intermediate, which in turn interacts with the next monomer molecule to give a 9-membered cyclic Pt-containing intermediate. The latter forms the stable dimer (as in the case of Pt-phosphine catalysis) via reductive elimination. When phosphine ligands are absent, the approach of the monomer to the Pt-center becomes apparently much easier therefore, it can efficiently interact with the Pt-cyclic intermediate to produce the final polymer. 

Macquet JP, Theophanides T (1976) DNA-Platinum interactions. Characterization of solid DNA-K2[PtCl4] complexes. Inorg Chim Acta 18 189-194... 

---