A Comprehensive Treatise on Inorganic and Theoretical Chemistry

286 INORGANIC AND THEORETICAL CHEMISTRY
obtained the same product by heating hydrochloroplatinic acid to 220° to 250°.
L. Wohler and F. Martin said that the powder is black with a greenish tinge unlike
platinum di- or tetra-chloride. R. Klement gave 5-256 for the sp. gr. at 25°/4°,
and 57-4 for the mol. vol. S. Streicher, and Li. Wohler and S. Streicher said the
decomposition temp, is 435°, and that the heat of formation is (2PtCl2, Cl2)
=26-2 CaIs. The trichloride was found by F. Martin, and L. Wohler and F. Martin,
to be reduced by hydrogen in the cold ; it is slightly soluble in cold water, and only
after several days is enough dissolved to impart to the soln. a yellow colour ; it
immediately dissolves in boiling water to form a brownish-red soln. which reacts
acid, and probably contains hydroxytrichloroplatinosic acid, H2PtOCl3, as a
result of hydrolysis. This same acid is formed when an aq. soln. of hydrochloroplatinic
acid is reduced with sulphur dioxide. The aq. soln. of platinum trichloride
yields the original salt if evaporated in vacuo at 60° and then at 100° ; the salt
is almost insoluble in cone, hydrochloric acid at ordinary temp., but the warm
acid forms a yellow soln. containing platinic and platinous chlorides ; it readily
dissolves in an aq. soln. of potassium iodide, forming a dark brown liquid ; and
alcohol reduces it to metal at the same time forming aldehyde. The free acid,
hydrochloroplatinosic acid, H2PtCl5, could not be isolated, but on passing a little
chlorine into hydrochloroplatinous acid, the presence of tervalent platinum can
be recognized by precipitation as a green caesium salt, but decomposition sets in
rapidly. L. TschugaefE and I. TscherniaefE studied the action of liquid ammonia
on platinum trichloride. E. Miiller and R. Bennewitz titrated soln. of tervalent
platinum salts electrometrically with soln. of stannous chloride.
S. M. Jfcrgensen obtained a complex salt, platinosic pyrldineamminotrichlorlde, Pt(NHT3)-
(C6H5N)Cl3, or Pt8(NH8)Jj(C6II5N)2Cl6. There are a few complex salts containing both
platinous and platinic chlorides. Thus, P. C. Ray and co-workers obtained platinosic
bispyridinetrichloride, PtCl3(C6H5N)2 ; and platinosic quaterpyridinotrichloride, PtCl3(C5H5N)4 ;
and they discussed the varying valency of platinum -with respect to the mercaptanic
radicle. J 1 Z. Biilmann and A. Hoff prepared platinic allylacetictrichloride as a double salt
with platinous tetrammine, [(C3H6.CH2.COOH)PtCl3]2[Pt(NH3)4] ; and similarly with
platinic alIylmalonietrichloride, [{C3H6.CH(COOH)a}PtCl3]2[Pt(NH3)4] . and with platinic
vinylacetictrichloride, P. Pfeiffer and H. Hoyer prepared a series: with allyl alcohol,
rCo en2Cl2IrPt(C3H6-OH)Cl3] ; with allyl acetate, [Co Cn2Cl2][Pt(CH3-COOC3H5)Cl3] ; with
crotyl alcohol, K[Pt(C4H7-OH)Cl3]; and in which [Coen2Cl2], LCoOn8(C2O4)], and
[Pt(NHa)4], respectively, take the place of potassium ; with crotyl acetate, [Coen2Cl2J-
[Pt(C6H10O8)Cl3]; and with crotonaldehyde, [Co en2Cl2][Pt(C3H5.COH)Cl3]. A. Cossa,
and S. G. Hedin prepared platinous quaterpyridinechloroplatinate, [Pt(C5H6N)4]PtCl6 ;
A. Cossa, platinic quaterethyiaminechloroplatinite, [Pt(C2H6NH2)4Cl2]PtCl4 ; J. E. Reynolds,
C Prutorius-Seidler, and N. S. KLurnakoff, platinous quaterthlocarbamidechloropiatinite,
[PtJCS(NH2) J4]PtCl6; N. S. Kurnakoff, and H. Debus, platinous quaterxanthogenamidechloroplatinate,
[Pt(NH2.CS.OC2H6)4]PtCl6 ,- L. Tsehugaeff and J. Benewolensky, platinous quatermethylsulphlnechloroplatinate,
[Pt{(CH3)2S}4]PtCl6 ; and A. Cahours and H. Gal, platinous
quaterethylphosphinechloroplatinate, [ Pt(P(C 2HB)a}4]PtCl6. P. C. Ray and co-workers
prepared platinosic p-phenylenediaminotrichloride, PtCl3.4C6H4(NH2)2 ; platinosic piperidinotrichloride,
PtCl3^C5H11N; platinosic triethylenedisulphinotrichloride, PtCl3.(C2H4)3S2,
or Pt{(C2H4)3S2>Cl2]Cl; platinosic benzylsulphinochloride, PtCl3.2( CH a.C6H:6)2S, or
[Pt{(CH2.C6H5)2S}Cl2]Cl ; and platinosic trisethylenedlaminetrlethylenetrisulphlnochlorlde,
2PtCl3.3C2H4(NHa)2.(C2H"4)3S3. There are also platinum quaterpyridinechloride, Pt2Cl7.
4C5H6N ; and platinum quaterdibenzylsulphinochloride, Pt8Cl6.4(CH2.C6H5)2S.
F. Martin, and L*. Wohler and F. Martin prepared csesium chloroplatinosate,
2CsCl-PtCl3, or Cs2PtCl5, as a dark green, crystalline precipitate, by oxidizing
caesium chloroplatinite with chlorine water at 0°. In the case of potassium and
rubidium salts, the chloroplatinates are formed. The salt is also formed by adding
caesium chloride to a well-cooled hydrochloric acid soln. of hydrated platinum
sesquioxide, or by adding csesium chloride to a cold soln. of platinum trichloride.
The salt appears in dark green, cubic crystals. The salt readily decomposes into
a mixture of caesium chloroplatinite and chloroplatinate. In a warm aq. soln.
the green colour quickly changes to yellow—characteristic of caesium chloroplatinate.
Sunlight accelerates the decomposition into the higher and lower
chlorides. The salt also decomposes when heated, or when exposed to moist air.