Platinum chlorides

In biological materials, various nonspecific precipitants have been used in the gravimetric deterrnination of choline, including potassium triiodide, platinum chloride, gold chloride, and phosphotungstic acid (28). Choline may also be determined spectrophotometricaHy and by microbiological, enzymatic, and physiological assay methods. 

Reagent 1 Spray solution I l eat 1 ml of a platinum chloride solution (5 Vo) with... 

A platinum disk electrode was electrolytically platinized in a platinum chloride solution to increase the surface area and enhance the adsorption power. The platinized platinum electrode was then immersed in a solution containing 10 mg ml l ADH. 0.75 mM and 6.2 mM NAD. After sufficient adsorption of these molecules on the electrode surface, the electrode was transferred into a solution containing 0.1 M pyrrole and 1 M KC1. Electrochemical polymerization of pyrrole was conducted at +0.7 V vs. Ag/AgCl. The electrolysis was stopped at a total charge of 1 C cm 2. An enzyme-entrapped polypyrrole membrane was deposited on the electrode surface. 

Another interesting example involves the dihydrosilylation of alkynes [20], which is carried out at room temperature in two steps, the first one with platinum chloride (0.01%) and the second one with palladium-MOP catalysts (0.3%). The reaction can be done with solely the palladium catalyst, but in that case the yield for the first step is low. The work-up leads to the formation of a chiral diol in high optical yield when the MOP derivative shown is used (Figure 18.12). 

The earliest catalytic application of C-H bond activation and functionalisation is that of methane using platinum chlorides as the catalyst and oxidising reagent. The exchange of hydrogen atoms in arenes with D20 was... 

Compounds Ammonium chloroplatinate sodium chloroplatinate platinic chloride platinum chloride sodium tetrachloroplatinate potassium tetrachloroplatinate ammonium tetrachloroplatinate sodium hexachloroplati-nate potassium hexachloroplatinate ammonium hexachloroplatinate... 

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

Lee and co-workers reported an interesting example of a conjugated polymer obtained by polymerizing 5-phenyl-2-(propynylamino)-4(57/)-oxazolone in the presence of palladium or platinum chlorides. The authors predict this unique material may have applications for polymer electrolytes, semiconductors, and nonlinear optical (NLO) materials. 

But [said he] it was still necessary to learn the base of the salt. Its solution could not be precipitated either by tartaric acid in excess or by platinum chloride. Consequently it could not be potassium. I mixed another portion of a solution of the same salt with a few drops of pure potash, but without its becoming cloudy. Therefore it contained no more magnesia hence it must be a salt with soda for a base. I calculated the quantity of soda which would be necessary to form it but it always resulted in an excess of about 5 parts in 100 of the mineral analyzed. Therefore, since it seemed probable to me that the different substances might not have been well washed, Or that the analysis might not have been made with sufficient precision in other respects, I repeated it twice more with all the care possible, but always with results very little different. I obtained. Silica. 78 45, 79.85, Alumina 17 20, 17.30 Sulfate 19.50, 17.75. At last, having studied this sulfate more closely, I soon found that it contained a definite fixed alkali, whose nature had not previously been known (21). 

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. 

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... 

Azopiperidine (called N.N-Azopiperidin Dipiperidinodiimid or l.l 4.4-Bis-pentamethyIen cetrazene-(2) in Ger) (called "Dipiperyl-terazone by Knorr, and Angeli Angelico), C,Hl0.N-N N-N C H10 mw 196.29, N 28.55%, crysts (from dil ale), mp 45 (distills without decompn) readily sol in ale, eth, benz or ligroin insol in w. Its prepn is described in Beil and in Refs 2,3 4. The platinum chloride salt, (QoHaoN HjPtCIe, an amorph powd, decomposes with deton at 70° (Ref 2)... 

The Shilov method, discussed in Section 10.4.1, has been accomplished as a catalytic process.327 Aqueous platinum chlorides can be used as catalysts for the homogeneous catalytic chlorination of methane. The reaction is carried out at 100-125°C with chlorine to yield methyl chloride that is partially hydrolyzed to... 

Solubility in Absolute Alcohol. — 1 gm. of platinum chloride should dissolve completely in 10 cc. of absolute alcohol, yielding a clear solution. Platinic chloride should also afford a clear, pure yellow solution with water any red or dark-brown tinge would indicate the presence of platinous chloride or iridium. 

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