Isomerization platinum chloride

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... 

The reaction between cyclopropane and deuterium has been investigated over pumice-supported palladium, rhodium, and platinum catalysts between 0 and 200°, and the resulting deuteropropanes have been analysed mass-spectrometrically. The exchange reaction between propane and deuterium over these catalysts has been similarly studied. In every case there is extensive multiple exchange, and the distribution of deuterium atoms in the propanes is more characteristic of the metal than of the reacting hydrocarbon. Experiments with the isomeric propyl chlorides confirm that exchange proceeds through the equilibria... 

As is the case of tetrasubstituted phthalocyanines, a mixture of four structural isomers is obtained if the 5,6-substituents of isoindolinediimine are different. For example, 5-ethoxy-6-octyl-oxyisoindolinediimine, when treated with platinum(II) chloride in refluxing 2-(dimethylamino)-ethanol under nitrogen for 12 hours, yields a mixture of the corresponding isomeric piatinum(II) phthalocyanines in a yield of 28 %.117... 

Denmark pursued intramolecular alkyne hydrosilylation in the context of generating stereodefined vinylsilanes for cross-coupling chemistry (Scheme 21). Cyclic siloxanes from platinum-catalyzed hydrosilylation were used in a coupling reaction, affording good yields with a variety of aryl iodides.84 The three steps are mutually compatible and can be carried out as a one-pot hydro-arylation of propargylic alcohols. The isomeric trans-exo-dig addition was also achieved. Despite the fact that many catalysts for terminal alkyne hydrosilylation react poorly with internal alkynes, the group found that ruthenium(n) chloride arene complexes—which provide complete selectivity for trans-... 

In an electrolytic cell (Fig. 5) consisting of platinum electrodes (2 cm x 5 cm in area) and cathode and anode compartments separated by an asbestos divider, each compartment is charged with 17 g (0.4 mol) of lithium chloride and 450 ml of anhydrous methylamine. Isopropylbenzene (12 g, 0.1 mol) is placed in the cathode compartment and a total of 50,000 coulombs (2.0 A, 90 V) is passed through the solution in 7 hours. After evaporation of the solvent the mixture is hydrolyzed by the slow addition of water and extracted with ether the ether extracts are dried and evaporated to give 9.0 g (75%) of product boiling at 149-153° and consisting of 89% of a mixture of isomeric isopropylcyclohexenes and 11% of recovered isopropylbenzene. 

The process involves first separating mixed butane compounds by distillation to isobutane and n-butane. The n-butane is then mixed with hydrogen, heated and passed through a reactor containing a platinum catalyst or an HC1 activated aluminum chloride catalyst. The n-butane is isomerized to isobutane and separated. 

Gis-dichloro-diammino-platinum, [Pt(NH3)2Cl2], was first prepared by Peyronne.2 It is easily formed by adding ammonia to a cold solution of platinous chloride in hydrochloric acid, when a greenish-yellow voluminous precipitate separates. This is boiled with water and filtered hot, when, on cooling the filtrate, the substance crystallises in yellow microscopic needles. It is sparingly soluble in water, and is more pure yellow than the isomeric trans-compound. Both cis- and fraws-dichloro-diammino-platinum are obtained on heating tetrammino-platinous chloride with hydrochloric acid. 

Isomerization catalysts were developed along two paths—by Friedel-Crafts halide systems or by dual site heterogeneous catalysts, originating with the commercial introduction of platinum-aluminas for catalytic reforming in the 1940,s. The Friedel-Crafts systems (aluminum chloride-hydrocarbon complexes) were used exclusively during the early stages of... 

In this context, additional isobutane availabilities could be derived from n-butane isomerization, an operation which offers two variants, one of them induding the recyding of unconverted n-butane after separation. As a rule, isomerization takes place in the gas phase, around 150 to 200"C, under hydrogen pressure (13 to 15.10 Pa absolute), in the presence of a fixed catalyst bed of the reforming type, based on platinum (0.35 per cent weight) deposited on alumina promoted by traces of organic chlorides. Ooce-through... 

The approved platinum complexes, with antineoplastic activity, differ in their photochemical stability. Among these, cisplatin, in particular, undergoes a photolysis reaction. Early studies proposed that this degradation was due to the photoaquation of the chloride ligands, and its subsequent photon-induced isomerization to trans-platin (32,33). Later studies found that the main photolysis-induced degradation product, was trichloroammineplatinate II (TCAP) (34,35). This decomposition product is limited to 1% in cisplatin for injection by the USP. 

In 1926, Chernyaev introduced the concept of the trans effect in platinum chemistry. In reactions of square-planar Pt(II) compounds, ligands trans to chloride are more easily replaced than those trans to ligands such as ammonia chloride is said to have a stronger trans effect than ammonia. When coupled with the fact that chloride itself is more easily replaced than ammonia, this trans effect allows the formation of isomeric... 

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