Palladous nitrate

Paliadiumoxydul, n. palladous oxide, palladium-(II) oxide, -nitrat, n. palladous nitrate, palladium (II) nitrate, -salz, n. palladous salt, palladium (ID salt. 

The nitrato-derivative of the series is unknown. Treatment of palladous nitrate with ammonia does not yield the corresponding nitrato-derivative, which appears to be unstable. A liquid is, however, obtained by treating the chloro-derivative with silver nitrate, but on evaporation a brown substance separates which detonates on heating. 

C. Marie and R. Marquis, and I. Bellucei and D. Venditori. W. Manchot and A. Waldmiiller obtained with palladium salts the complexes palladous dinitrosyl-chloride, PdCl2.2NO, and palladous dinitrosylsulphate, PdS04.2N0. They are unstable salts giving off nitric oxide in the presence of water. Nitric oxide with palladous nitrate yields Pd(N02)2. Hence, nitric oxide is known to form complexes with the salts of Cu, Mn, Fe, Co, Ni, and Pd. 

W. Manchot and A. Waldmuller found that when nitric oxide acts on a soln. of palladous nitrate the primary nitrosyl complex which is formed produces VOL. vm. 2 L... 

Palladous salts are readily oxidised to palladie compounds, particularly when wanned. For example, a solution of palladous nitrate warmed with concentrated persulphate solution is oxidised to a brown, palladie compound, which decomposes hydrogen peroxide and ammonia vigorously, gaseous products being evolved. With hydrochloric acid it yields free chlorine. 

Hydrated Palladium Sesquioxide, PdjOj.aiHjO, is conveniently prepared9 by electrolytic oxidation of palladous nitrate. This is effected by cooling a concentrated solution to 8° C-, and electrolysing with a current density of 0-5 amperes per sq. cm. It may also be obtained by ozonising a solution of palladous nitrate. 

Palladous Nitrate, Pd(N03)2, may be obtained by dissolving the metal in nitric acid of density 1-35 to 1-4, and cooling the concentrated solution, when the salt crystallises out in brownish yellow, orthorhombic crystals. These are deliquescent, and readily dissolve in water, yielding a solution that is not very stable. When heated, the crystals decompose, yielding palladous oxide.2... 

Detection.—Metallic palladium is the most readily fused of the platinum metals (see Table, p. 5). When heated in air the surface becomes coated with oxides which tint it. The metal is soluble in aqua regia, sparingly soluble in nitric acid, but more readily soluble in the fuming acid, yielding palladous nitrate, from which a brown precipitate of basic salt may be obtained on dilution with water provided the add is not present in too great an excess. A mixture of concentrated hydrochloric acid with chloric add 3 is recommended as a useful... 

Palladium-silica catalysts prepared from tetra-ammine palladous nitrate (to avoid chlorine introduction) showed a marked reduction effect , viz, the specific activity for benzene hydrogenation decreased with increased reduction temperature, i.e., 573 or 723Various explanations were considered, including a metal-support interaction. After reduction at 873 K, X-ray diffraction provided clear evidence of chemical reaction and at lower temperatures silicon insertion into palladium might still occur, which could either disrupt the palladium ensembles required for benzene adsorption or modify the properties of single palladium atoms, if these are the active sites. 

Analytical Characters.—(1.) With AgNOa, a yellow ppt., insoluble in HNOa, and in NHiHO. (2.) With fuming HNOa or with chlorin water, a yellow liquid, which colors starch-paste black or purple, and chloroform violet. (3.) With palladic nitrate, a black ppt., insoluble in cold HNOa and in solutions of alkaline chlorids. but forming a dark brown solution with alkaline iodids. 

Palladous nitrate. See Palladium nitrate (ous) Palm alcohol... 

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