Platin-containing compounds

When an oxygen-containing compound is pyrolyzed at 950°C in the presence of platinized carbon in a nitrogen or helium atmosphere, the organic molecule is broken up and all oxygen is converted to carbon monoxide according to the following reactions ... 

Tetrammino-platinous salts are known containing pyridine in place of ammonia. Thus, diammino-dipyridino-platinous salts have been prepared. These salts are interesting, as they exist in isomeric forms, and through them the configuration of the isomeric diacido-diammino-platinous compounds have been determined. It is well known that diacido-diammino-platinum exists in stereo-isomeric forms. These isomers react with two molecules of pyridine in such a manner that pyridine replaces acidic radicles in the complex with formation of diammino-dipyTidino-platinous salts. Depending upon which isomer is treated with pyridine, two different diammino-dipyridino-platinous salts are produced. Cis- or unsymmetrical dichloro-diammino-platinum is... 

A series of compomids has been prepared containing a hydroxo-group in place of an acidic group in the pentaminino-platinic compounds. These have general formula [Pt(NH3)sOH]R3. 

Ammino-derivatives of Platinum Salts—Derivatives of Platinous Salts— Derivatives of Platinio Saits—Derivatives containing Hydroxylamine and Hydrazine in place of Ammonia—Symmetrical and Asymmetrical Compounds—Diplato-animino-salts—Diplati-ammino-salts. 

The high affinity of many platinum compounds for sulfur and the availability of many sulfur-containing biomolecules have raised the question whether Pt-sulfur biomolecule interactions could serve as a drug reservoir for platination at DNA, necessary for the antitumor activity of cis-Pt. Two reaction paths are possible, i.e., spontaneous release of plantinum from the sulfur, or nucleophilic displacement of platinum from sulfur by guanine (N7), for example. At the moment, there is no real evidence for the existence of such reactivation mechanisms. In fact, it has been reported that Pt-protein interactions in the plasma (albumin) are not reversible under normal conditions (161, 165). Further, a mixture of cis-Pt-methionine products does not show antitumor properties (166), indicating no induced platination of DNA. More research is required to investigate the existence of a reactivation mechanism. However, it is predicted that if such a reactivation phenomenon is operational, the most likely candidate is the labile Pt-methionine bond, as has been shown by its rapid reaction with Naddtc, STS, and thiourea (vide supra) (131). 

Salts of these elements, on treatment with soda, yield no precipitate, for they are dissolved by the alkali the compounds formed are indefinite, but it may be supposed that they contain aurate, MAuOg.Aq, or platinate, titanate, zirconate, or thorate, MPtOg.Aq, c. Iron and calcium titanates occur native FeTiOg is termed ilmenite, and CaTiOg perowskite. The first is isomorphous with and crystallises along with native ferric oxide the ore is known as titanic iron ore. It is the commonest compound of titanium. 

The alkali chlor-ruthenates are isomorphous with the chlor-platinates, and therefore, by the application of llitscherlich s Law, they must be assumed to contain, like the platinum derivatives, one atom of ruthenium, their generic formula being M,RuC16. Similarly, ruthenium dioxide is isomorphous with cassiterite, SnO,. and with rutile, TiCL. from which it may be concluded that its formula is RuO.,. Analyses of these compounds indicate that the atomic weight of ruthenium is 101-7. 

The acid may also be obtained electrolytically5 by passing an electric current through concentrated hydrochloric acid containing precipitated platinum in a fine state of subdivision, using platinum foil as electrodes. The anodic chlorine attacks the finely divided metal, yielding the tetrachloride, which dissolves in the liquid to form the acid. The finely divided metal is conveniently prepared for this purpose by precipitation with metallic zinc from a solution of a platinum salt. On concentrating the solution to obtain the pure chlor-platinic acid it is advisable to introduce a small quantity of chlorine to ensure the absence of platinous compounds. 

Nitrosyl Brom-platinate, (NO)2PtBr6, is formed in an analogous manner to the preceding compound, namely, by dissolving platinum in a solution containing nitric and hydrobromic acids. 

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