Complex with platinum salts

Thymidine or 2 -deoxyuridine have been converted to corresponding 3 -amino, 5 -amino, and 3, 5 -diamino analogues by a previously reported methodology the resulting amino nucleosides were also complexed with platinum salts, and their biological activity studied. 

In contrast, cyclizations of /V-alkoxy derivatives with iodine are much less selective (Table 30, entry 3), and similar results are observed with systems containing internal double bonds of either ( )- or (Z)-configuration.238 The stereoselectivity of the aminomercuration reaction of /V-methyl derivatives has been reported to be controlled by the choice of mercury(II) salt and solvent (entries 6 and 7).244 Cyclization with platinum salts showed little selectivity (entry 8).239 An iodocyclization of a complex N-alkyl system has been used in a recent synthesis of (+)-croomine.238... 

In extension of this work, a platinum complex with a chiral phosphine ligand and a BINOL template was employed as a metallomonomer [28]. After removal of the template and activation of the complex with silver salts (generation of Lewis acidic platinum centers) the MIP was used as a catalyst for an asymmetric ene reaction. Enantioselectivities of 72% ee were observed (Fig. 15). This compares well to... 

Since platinum(II) and - to a lesser extent - palladium(II) complexes are kinetically stable, most of the complexes described herein are prepared by reacting a preformed platinum(n) or paUadium(II) complex with a salt of a d ° or s cation. In some cases, the Lewis-acidic moiety is also a preformed complex containing labile ligands. There are some examples of more complicated reactions in which coordination to a Lewis acid induces changes in the coordination sphere of Pt to form oligomeric structures that cannot be isolated otherwise (see Sect. 4.2.1). 

There have been only a few examples of reduction of the C=N+ function of catalytic hydrogenation since the reductions with complex hydrides are so easy to do in the laboratory. A possible reduction of an iminium salt 45 to 46 with platinum oxide was reported by McKay et al. (91). A report that platinum oxide reduces 2l tio).jgj yjj.Qqyjp Qjj2idijjjujn perchlorate (25) in quantitative yield to 47 indicates that such reduction should be facile (47). 

The original blue (K.A. Hofmann, 1908) was obtained from the reaction of Pt(MeCN)2Cl2 with silver salts over some hours. Under these conditions, the nitrite is hydrolysed to acetamide. Very recently, the structure of the complex [(H3N)2Pt(MeCONH)2Pt(NH3)2]4(NO3)10 has been determined (Figure 3.37). The average oxidation state of the platinums in the octamer is 2.25. 

The shift in the C=C frequency, vi, for adsorbed ethylene relative to that in the gas phase is 23 cm-1. This is much greater than the 2 cm-1 shift that is observed on liquefaction (42) but is less than that found for complexes of silver salts (44) (about 40 cm-1) or platinum complexes (48) (105 cm-1). Often there is a correlation of the enthalpy of formation of complexes of ethylene to this frequency shift (44, 45). If we use the curve showing this correlation for heat of adsorption of ethylene on various molecular sieves (45), we find that a shift of 23 cm-1 should correspond to a heat of adsorption of 13.8 kcal. This value is in excellent agreement with the value of 14 kcal obtained for isosteric heats at low coverage. Thus, this comparison reinforces the conclusion that ethylene adsorbed on zinc oxide is best characterized as an olefin w-bonded to the surface, i.e., a surface w-complex. 

From the neutral 1 2 complexes introduced before, two kinds of materials were obtained by electrocrystallization fully oxidized salts where both TTF CH= CH—py moieties are oxidized, and mixed valence salts in which the two ligands are partially oxidized. All oxidized complexes were obtained by oxidation at constant current of a neutral 1 2 complex in an electrolyte containing the anions, and using electrocrystallization technique with platinum wires (0 = 1mm) electrodes. 

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... 

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