1
342
SKOGAREVA et al.
2
+
diffraction method used in this work is crucial for struc-
ture determination for such compounds.
For MgS O · 6H O anal. calcd., % Mg , 7.49;
2 8 2
2
–
S O , 59.20.
2
8
This work was intended to develop synthesis pro-
cesses and characterize strontium, magnesium, zinc,
and copper peroxodisulfates.
2–
8
2
+
Found, %: Mg , 7.63; S O , 59.17.
2
2
+
The thus prepared samples did not contain Ba and
2
–
SO . All manipulations with hygroscopic compounds
4
EXPERIMENTAL
I and II were performed in a drybox (N
).
2
[
Zn(NH ) ]S O (III). To a solution of ZnCl (2.202 g,
3
4
2
8
2
Synthesis. Commercially available reagents were
used: MgSO · 7H O (chemically pure grade), ZnCl
2
1
6.16 mmol) in water (8 mL), concentrated aqueous
4
2
ammonia (3.5 mL) was added until a faint ammonia
odor was smelled. After filtering and water washing
until the absence of Cl , the Zn(OH) · xH O solid phase
was transferred to a beaker and dissolved in aqueous
ammonia (10 mL). To the solution of (NH ) S O
8
(
pure for analysis), CuSO · 5H O (chemically pure
4 2
grade), and (NH ) S O (chemically pure grade). Stron-
4
2
2
8
–
2
2
tium hydroxide Sr(OH) · 8H O was prepared from
2
2
SrCO (chemically pure grade) by reaction with con-
3
3
4 2
2
centrated HCl (d = 1.18 g/cm ) followed by the reaction
(
3.688 g, 16.16 mmol) in aqueous ammonia (5 mL), an
of the resulting concentrated strontium chloride solu-
tion with carbonate-free ~25% NaOH solution; recrys-
tallization was from hot water. Ba(OH) · 8H O was pre-
2+
ammonic solution of Zn was added. Crystals precipi-
tated in the form of water-color needles were collected
on a filter without washing. They were dried in air for 1
h. Yield: 0.750 g. The results of analysis are below.
2
2
pared as described in [9] by reacting BaCl · 2H O (pure
2
2
for analysis grade) with ~25% NaOH solution. Ammine
2
+
For [Zn(NH ) ]S O anal. calcd., %: Zn , 20.07;
S O , 59.00; N, 17.21; S, 19.69; H, 3.72.
complexes were synthesized in concentrated aqueous
3 4
2
8
2
–
3
ammonia (26.67%, d = 0.902 g/cm ).
2
8
2
–
2
+
SrS O · 4H O (I). To a solution of (NH ) S O
Found, %: Zn , 19.69; S O , 58.83; N, 17.07; S,
2
8
9.60; H, 3.52.
[
2
8
2
4 2
2
8
(
2.659 g, 11.65 mmol) in water (4 mL) carefully stirred
1
with a spatula, solid Sr(OH) · 8H O (4.026 g, 15.15
2
2
Cu(NH ) ]S O (IV). To a solution of CuSO · 5H O
3 4 2 8 4 2
mmol; a 30% excess relative to stoichiometry) was
poured in portions. An uncovered weighing bottle with
the thick suspension was placed in a desiccator over
(
1.505 g, 6.03 mmol) in water (6 mL), concentrated
aqueous ammonia (0.8 mL) was added. A blue copper
hydroxide precipitate was filtered (the filtrate was
almost water-color), washed with water to the absence
CaCl and kept for 2 days until the ammonia odor dis-
2
appeared. After filtering, the liquid phase was pumped
out for 4 h until a bulky crystalline mass of needles
2
–
of SO ions, and dissolved in aqueous ammonia
appeared in solution. This mass was separated on a fil- (20 mL). To the resulting solution, a solution of
ter without washing. The weight of the colorless com- (NH ) S O (1.376 g, 6.03 mmol) in aqueous ammonia
4
4
2
2
8
pound was 1.059 g (yield: 25%). The results of analysis
were as follows:
(
3 mL) was added. The beaker with the clear solution
covered with a watch glass was left to stand in a refrigera-
tor. Next day, azure-blue acicular crystals were collected
on a filter, washed with cold water (5 mL), and dried in air
2
+
For SrS O · 4H O anal. calcd., %: Sr , 24.90;
2
8
2
2
–
S O , 54.61.
2
8
for 0.5 h until the NH odor disappeared yield: 0.515 g.
3
2
8
–
2+
2
+
Found, %: Sr , 24.86; S O , 54.73.
For [Cu(NH
3
)
4
]S
O anal. calcd., %: Cu , 19.62;
2 8
2
2
–
S O , 59.33; N, 17.31; S, 19.80; H, 3.74.
2
8
MgS O · 6H O (II). To a solution of (NH ) S O
8
2
8
2
4 2
2
2
8
–
2
+
(
0.856 g, 3.75 mmol) in water (3 mL) stirred with a
Found, %: Cu , 19.42; S
19.73; H, 3.72.
Strontium in Sr(OH) · 8H O was determined gravi-
2
O , 59.45; N, 17.20; S,
spatula, Ba(OH) · 8H O (1.539 g, 4.88 mmol; 30%
2
2
excess relative to stoichiometry) was poured in por-
tions. To remove ammonia, an uncovered weighing bot-
tle with mixture was placed over CaCl in a desiccator
and transferred to a refrigerator. After 2 days, the sus-
pension was filtered. To the filtrate containing 26.82%
BaS O , MgSO · 7H O (0.618 g, 2.51 mmol; stoichio-
metric amount) in water (2 mL) was poured. Precipi-
tated BaSO was filtered; the filtrate in an uncovered
weighing bottle was placed in a desiccator with anhy- was determined by titrating the excess iron(III) salt,
drone, pumped out (to a residual pressure of 133–266 Pa), added to the analyte solution, by K Cr O solution in
2
2
metrically by ignition in a platinum crucible at 400°ë;
in SrS O · 4H O, strontium was precipitated as SrSO ,
after which the precipitate was dried at 100°ë. Copper
was found iodometrically; zinc was determined gravi-
metrically as ZnO; magnesium was titrated with
2
2
8
2
4
2
8
4
2
2–
Trilon B in the presence of Eriochrome Black. S O
2
8
4
2 2 7
and transferred to a refrigerator. After 6 days (evacua- the presence of diphenylamine [10]. Analyses for nitro-
tion once a day), 0.560 g of a colorless material was gen, sulfur, and hydrogen were performed on an Ele-
obtained. The results of analyses were as follows:
mental Analyzer CHNS-O EA 1108.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 54 No. 9 2009