PREPARATIVE SYNTHESIS OF PALLADIUM(II) ACETATE
1535
previously [2]. Reagent grade organic solvents were
used as received.
Modification of Procedure [16. clause 2.2.3a]—the
Reaction Performed in the Presence
of Alkali Metal Acetates
Palladium nitrate (1.000 g) and sodium acetate
Investigation Methods
NaOAc · 3H O (1.750 g) were dissolved in a mixture of
2
The solutions were concentrated in vacuum on a
LABOROTA 4000ꢀefficient (Heidolph instruments)
rotary evaporator. The elemental analysis of solid
compounds (CHN) was carried out on Carlo Erba
4
0 mL of water and 50 mL of acetic acid, the solution
was stirred for 3 h at room temperature, and the crysꢀ
tals of precipitated. After 24 h, the precipitate was filꢀ
I
tered off, washed with distilled water, and dried in vacꢀ
uum. The yield of crude palladium acetate was 0.688 g.
The resulting yellowꢀbrown crystals were extracted
with benzene, the filtrate was concentrated in vacuum,
and the residue was dried in vacuum over alkali. The
yield was 0.675 g (80%).
(
Italy) and EA3000 (EuroVector, EC) laboratory
CHN(S) analyzers. IR spectra were measured on a
Nexus FT IR spectrometer (Nicolet, USA) using an
ATR attachment. The photometric determination of
the nitrite ion was carried out on a Cary 50 Scan specꢀ
1
trophotometer (Varian). H NMR spectra were
Found (%): N, 0.00; C, 21.42; H, 2.64; Pd, 47.43.
recorded on a Bruker AVANCEꢀ300 spectrometer.
–
1
IR, cm
94.
:
ν
as(COO) 1596,
ν
s(COO) 1414, (СОО),
δ
6
1
Attempted Preparation of Palladium Acetate
by Described Procedure [16. clause 2.2.3b]
H NM (390 MHz, dry CDCl , ppm): 215 (s).
3
The reaction with potassium acetate at the stoichiꢀ
Palladium(II) nitrate (2.500 g) was dissolved in ometric reactant ratio proceeds in a similar way; the
mL of anhydrous acetic acid in a flatꢀbottomed flask yield of reaches 90%. An increase in the MOAc :
O) (NO molar ratio above 2 : 1 sharply
9
I
2
and stirred for 3 h at room temperature. The stirring Pd(H
)
3 2
2
gradually became impossible due to the formation of a decreases the yield of
bulky precipitate. The suspension was diluted with
I.
acetic acid, and the product was isolated by centrifuꢀ
gation, washed with water and acetone, and dried in
vacuum above sodium hydroxide. Instead of crystalꢀ
Reaction of Palladium Nitrate with Alkali Metal
Acetates in Water
line palladium acetate
I
, this gave the polymeric aceꢀ
A mixture of palladium nitrate (0.880 g) and
tate [Pd(OAc)2]n, yield 1.800 g (85% of theoretical). sodium acetate (0.900 g) (in 1 : 2 molar ratio) was
The obtained compound was a beigeꢀcolored amorꢀ stirred in a twoꢀphase system consisting of 15 mL of
phous powder insoluble in organic solutions.
distilled water and 45 mL of chloroform at 20
°С for
4
h. Then the reaction mixture was filtered. After
For C H O Pd anal. calcd. (%): N, 0.00; C, 21.38;
4
6
4
breaking of the emulsion, the chloroform layer was
separated and concentrated on a rotary evaporator.
The residue was dissolved in benzene; evaporation of
benzene gave 0.240 g of crystalline palladium acetate
H, 2.67; Pd, 47.40.
Found (%): N, 0.00; C, 22.50; H, 2.33; Pd, 47.35.
–1
IR, cm :
(COO) 710.
ν
as(COO), 1494;
ν
s(COO), 1404;
δ
(
yield 32%). The elemental composition and the IR
spectrum of the product correspond to pure
I
.
Synthesis of Palladium Acetate by Described
Procedure [16. 2.2.3a]
Generally Accepted Synthesis [2]. Reaction of Palladium
Metal with a Mixture of Acetic and Nitric Acids
Palladium nitrate (1.000 g) was dissolved in a mixꢀ
ture of 40 mL of water and 50 mL of acetic acid in a
glass beaker with magnetic stirring. After 10 min at
room temperature, palladium acetate started precipiꢀ
tating from the solution. After 3 h, yellowꢀcolored
crude palladium acetate was filtered off. The comꢀ
pound was washed with glacial acetic acid and ether
and dried in vacuum over alkali. The yield was 0.645 g
Palladium black (9.900 g) in 500 mL of acetic and
mL of nitric acid was refluxed for 5 h until nitrogen
oxide evolution ceased, the hot reaction mixture was
filtered and then cooled to room temperature. After
h, the separated redꢀbrown crystals were filtered off,
washed with acetic acid and ether, and dried in vacꢀ
uum. The yield was 12.486 g (fraction 1):
Found (%) N, 0.26; C, 21.44; H, 2.38 (up to 12%
of II).
On concentrating the filtrate, the following fracꢀ
tions of the product were obtained: fraction 2, 2.523 g
of a yellowꢀbrown powder.
Found (%): N, 0.4; C, 22.15; H, 2.53 (up to 21% of II).
Fraction 3, 0.486 g of a yellowꢀbrown powder.
Found (%): N, 0.70; C, 21.89; H, 1.87 (up to 31%
of II).
6
2
(
a mixture of
The mixture was extracted with benzene and the
resulting solution was filtered (polymeric palladium
acetate [Pd(OAc)2]n III) remained on the filter). The
filtrate was evaporated to dryness at 40 in a vacuum
I and III).
(
°С
using a rotary evaporator. The yield of pure acetate
was 0.515 g (61%).
I
Found (%): N, 0.00; C, 20.30; H, 2.64.
IR, cm–1
(СОО) 694.
:
ν
as(COO) 1595,
ν
s(COO) 1415,
δ
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 56 No. 10 2011