A Comprehensive Treatise on Inorganic and Theoretical Chemistry

PLATINUM
hydrochloric acid, and treating the soln. at a low temp, with alcohol. The colourless
needle-like crystals are soluble in water, and insoluble in alcohol, or in cone, hydrochloric
acid. Alkali hydroxides form a gelatinous precipitate of the dihydroxylaminediamminochloride
; alkali carbonates, oxalates, and phosphates give
white, crystalline precipitates ; and potassium chloroplatinite, or hydrochloroplatinous
acid, forms platinous trans-dihydroxylaininediainiiiinochloroplatiiiite,
[Pt(NHa)2(NH2OH)2JPtCl4, in dark green, acicular crystals. L. Tschugaeff and
I. I. TscherniaefE could not confirm H. Alexander's observations on the action
of ammonia on a-Pt(NH2OH)Cl2 ; and F. W. Pinkard and co-workers found that
with a small proportion of aq. ammonia of sp. gr. 0-880, in the cold, the tetrammine,
[Pt(NH2OH)2(NH3)2J(OH)2, is formed, but with dil. ammonia, a yellowish-brown
precipitate of variable composition, is obtained, and which probably contains some
[Pt(NH2OH)2(NHg)2J(OH)2. I. I. TscherniaefE and A. S. Samsonova studied the
subject.
F. Hoffmann, and L*. Tschugaeff and T. I. Tscherniaeff also obtained platinous
c^dihydroxylaminediamminochloride, [Pt(NH3)2(NH2OH)2JCl2, by triturating
platinous cis-dichlorodiammine with ten times its weight of water, adding the
theoretical proportion of hydroxylamine hydrochloride, warming the mixture on
a water-bath, then adding the theoretical amount of potassium carbonate dissolved
in five times its weight of water, warming until solution is complete, and
cooling. White, crystalline masses are formed. The salt is sparingly soluble in
water, soluble in warm acids, and in acetic acid ; it can be recovered unchanged
by the evaporation of its soln. in hydrochloric or sulphuric acid. The aq. soln. is
always turbid, and if the turbid soln. is clarified by animal charcoal, it slowly
becomes turbid again at ordinary temp., and rapidly when heated. When treated
with potassium chloroplatinite, violet crystals of platinous cis-dihydroxylaminediamminochloroplatinite,
[Pt(NHg)2(NH2OH)2JPtCl4, are formed, sparingly soluble
in water and acids. L. Tschugaeff and I. I. TscherniaefE also prepared platinous
dihydroxylaminodiamminochloropalladite, [ Pt(NH3) 2(NH2OH)2JPdCl4 ; platinous
trihydroxylaminoamminochloride, [Pt(NH3)(NH2OH)3JCl2; platinous trihydroxylaminoamminochloroplatinite,
[Pt(NH3)(NH2OH)3JPtCl4 ; platinous trihydroxylaminoamminochloropalladite,
[Pt(NH3)(NH2OH)3JPdCl4; platinous
hydroxylaminotriamminochloride, [Pt(NH3)3(NH2OH)JCl2 ; and platinous hydroxylaminotriamminochloroplatinite,
[Pt(NH3)3(NH2OH JPtCl4.
H. Alexander prepared platinous /raws-dichlorodihyfcoxylamine,
JPt(NH2OH)2JCl2, by treating with warm hydrochloric acid the precipitate obtained
by adding an excess of hydroxylamine to a soln. of platinous chloride ; by evaporating
on a water-bath the pale yellow soln. of platinous tetrahydroxylaminechloroplatiiiite,
and cooling the liquor ; and by digesting platinous tetrahydroxylaminechloride
with an excess of hot hydrochloric acid and cooling—H. Wolfram employed
a similar process. R. TJhlenhut obtained the salt by evaporating the filtrate,
obtained in the preparation of platinous tetrahydroxylamine chloride, to about
half its vol. and then cooling. The orange-yellow, or golden yellow, acicular
crystals are less soluble in water than the tetrahydroxylaminechloride. They are
soluble in alcohol, and in ether. The salt can be recrystallized from a soln. in dil.
hydrochloric acid. Aq. ammonia forms the dihydroxylaminediamminochloride ;
and hydroxylamine, the tetrahydroxylaminechloride. Neither alkali hydroxides
nor silver oxide produces the free base. When the soln. mixed with silver nitrate
is allowed to stand for a long time in the cold, a feeble turbidity appears.
H. Wolfram prepared platinous e/s-dichlorodihydroxylamine, [Pt(NH2OH)2Cl21,
by mixing 2 c.c. of an 83 per cent. soln. of hydroxylamine with 2 Cc. of water, and
adding the soln. to 11 grms. of potassium chloroplatinite dissolved in 50 c.c. of
water ; and F. Hoffmann, by mixing a mol. of potassium chloroplatinite in 100 c.c.
of water with 2 mols. of hydroxylamine hydrochloride, and a mol. of potassium
carbonate. The dark brown precipitate crystallizes after standing in contact with
the mother-liquor for some hours.
269