Platinum chloride complexes

The first compound to be synthesized containing carbon monoxide as a ligand was another platinum chloride complex, reported in 1867. In 1890, Mond reported the preparation of Ni(CO)4, a compound that became commercially useful for the purification of nickel. Other metal CO (carbonyl) complexes were soon obtained. 

GoTdshleger NF, Es kova VV, Shilov AE et al (1972) Reactions of alkanes in solutions of platinum chloride complexes. Zh Eiz Khim 46 1353-1354... 

N- Methyl- N,2,4,6-tetranitroaniline e 219-0135 (Methylammonia - Platinum Chloride) Complex ... 

Table 7 SSNMR parameters for platinum chlorides complexes from Lucier et al. [41,42]... 

Particular use was made of conductivity measurements of cobalt(iii) and platinum(ii) complexes which allowed a facile determination of the number and type of ions present in solution. For example, the compounds Co(NH3) Cl3 would give a monocation and an monoanion (n=4), a dication and two monoanions (n = 5) and a trication and three monoanions (n=6) respectively. In some cases, it was also possible to distinguish chemically between inner and outer sphere chloride by precipitation of the outer sphere species as AgCl. 

For transition-metal catalyzed hydroxylation of alkane C-H bonds, the reactions of alkanes with platinum(II) complexes were the most successful. In an aqueous solution of hexachloroplatinic acid and Na2PtCl4, alkanes were converted into a mixture of isomeric alkyl chlorides, alcohols, and ketones, and the platinum(IV) is reduced to platinum(II).7 The kinetics of the reaction with methane as the alkane have been described in detail.8... 

When the pH of ribonuclease was raised to 8.0 from 5.5 a second site became partially occupied in which the platinum bound to histidine 119. At the lower pH this group would be protonated and blocked. As stated above for this reason groups such as terminal —NH2, arginines and lysines are not likely to be as effective as thio-ether in displacing chloride from chloride complexes of platinum. (We are grateful to Dr. L. Johnson (Oxford) for supplying us with much of this information). 

Rate constants for reaction of cis-[Pt(NH3)2(H20)Cl]+ with phosphate and with S - and 5/ -nucleotide bases are 4.6xl0-3, 0.48, and 0.16 M-1s-1, respectively, with ring closure rate constants of 0.17 x 10 5 and 2.55x10-5s-1 for subsequent reaction in the latter two cases 220). Kinetic aspects of interactions between DNA and platinum(II) complexes such as [Pt(NH3)3(H20)]2+, ds-[Pt(NH3)2(H20)2]2+, and cis-[Pt(NH3)2(H20)Cl]+, of loss of chloride from Pt-DNA-Cl adducts, and of chelate ring formation of cis-[Pt(NH3)2(H20)(oligonucleotide)]"+ intermediates implicate cis-[Pt(NH3)2(H20)2]2+ rather than cis-[Pt(NH3)2 (H20)C1]+, as usually proposed, as the most important Pt-binder 222). The role of aquation in the overall scheme of platinum(II)/DNA interactions has been reviewed 223), and platinum(II)-nucleotide-DNA interactions have been the subject of molecular modeling investigations 178). 

Na2PtCl6 to ammonium platinum chloride (NH4)2PtCl6. The purified ammonium complex is then ignited to form platinum sponge. 

An attempt was also made to produce 0-iodo acyl iodides by the reaction of iodine, carbon monoxide and olefins in the presence of palladium or platinum chloride. This is, in effect, an attempt to make Dr. Tsuji s reaction catalytic rather than stoichiometric. No carbonyl insertion occurred at 1 atm. of carbon monoxide. However, it was found that iodination of the olefin was catalyzed by platinum olefin complexes and that an additional increase in catalytic activity accompanied the presence of carbon monoxide. There has been much speculation at this conference concerning the possibility of affecting catalytic activity by changing the ligands in the coordination sphere of the catalyst. This would appear to be such a case. 

C4Hi3Cl2N3Pt, Platinum(II), chloro(diethylene-triamine)-, chloride, 34 78 C4H13N3, Diethylenetriamine, platinum(ll) complex, 34 78... 

One of the first important steps in unravelling the problem was taken by Berzelius with regard to ammonia compounds of the platinum salts. Reasoning from the duaiistic theory, he believed these substances to be complexes formed by the union of ammonia with another complex this complex was not decomposed on treatment with aeids, arul it did not affect the saturation capacity of the base. lie used formula of a special type to express the nature of the complex. Thus, the union of platinum chloride and ammonia was represented by... 

In aqueous acetic acid, the disproportionation of the platinum still occurs quite rapidly, and it can be suppressed further by adding mineral acid. Hydrochloric acid is often used, but this has a disadvantage in that the exchange rate is inversely proportional to the chloride ion concentration. Perchloric acid has been found to be more satisfactory (55). The platinum(II) catalyst most used is sodium or potassium tetrachloropla-tinate(II). An aromatic compound added to the reaction mixture also inhibits disproportionation of the platinum(II) complex—benzene, pyrene, and other aromatics have been used. A comparative study of the effect of various aromatics on the H—D exchange in alkanes has been carried out (55). Even under optimum conditions, the disproportionation [Eq. (4)] still takes place, and the catalytic platinum(II) is slowly removed from the reaction mixture. To get useful rates of exchange in alkanes, temperatures of 100° to 120°C have to be used, and the disproportionation rate increases with temperature. 

The color of the (N,N-chelate)(olefin)platinum(0) complexes described in this section varies from light to dark yellow. These complexes are air stable and are fairly soluble in chloroform or methylene chloride. The stability in solution increases as the electron-withdrawing properties of the alkene increase. For example, the fumarate or maleate derivatives decompose very... 

Phenylselenol, diphenylphosphine and diphenylarsine cleave Pt—Me bonds, but N-bromosuccinimide and 2-nitrobenzenesulfenyl chloride oxidize the methyl platinum(II) compounds to methyl platinum(IV) complexes (equations 208 and 209).573 m-Chloroperbenzoic acid cleaves the Pt—benzyl bond in PtCl(CHDPh)(PPh3)2 with retention of configuration at carbon.574... 

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