November,
1956]
Studies
on
the
Studies
on the Synthesis of Metal Complexes. I.*
Synthesis
Ammine-carbonato
Series of Cobalt (III) Complexes
By Motoshichi
Synthesis
of Metal
MORI, Muraji
and
Synthesis-1)
were
contaminated
pitates,
filtrate
was
0•Ž.
a
until
the
baltate
of
(III),
KHCO3
the
mixture
beaker
in
10 cc.
to
this
of
drop
an
for
hour
obtained
was
filtrate
place.
When
the
*
water
filtrate,
Presented
by
with
cooled
10
solution.
solution
clear
mixed
was
separate
to
K3[Co(CO3)3]•E3H2O.-Twenty
was
than
lected
on
then
by
yield
was
g.
and
5 cc.
was
with
of
quickly
about
15 cc.
crystals
30%
began
the
added
KHCO3
allowing
by
about
green
solution
suction,
and
of
was
to
alcohol
to
and
kept
in
was
appear,
the
a dark
added
but
they
9th
Annual
Meeting
of
the
pure
col-
alcohol
and
bottle.
The
soluble
in
but
water,
took
were
yielding
water
suffered
the
hydrous
oxide.
Some
care
had
complex.
ture
If
was
of
too
cobaltic
added,
salts
such
2)
to
be
addition
rapid
it
it
as
Blue
caused
of
was
period
tion
was
order
stop
effect
another
crop
solution
by
crops
were
water
and
ten
of
filtration
of
could
be
the
the
the
the
of
from
the
of
collected
together,
recrystallized
washed
with
pure
inn
and
After
crop
obtained
of
solu-
reaction
product.
first
end
ice-bath
the
addition
Violet
Variety
the
crystals
residual
alcohol.
alcohol.
of
green
ammonium
until
and
Potassium
These
from
Total
yield,
Dicarbonato-
(III),
(CO3)2]•EH2O.-The
blue
in
of
blue,
warm
gradual
diamminecobaltate
bath
At
dipped
the
into
the
progress
the
until
changed
minutes.
1),
and
water-bath
containing
further
in
7 g.
3)
of
a
solution
vessel
from
described
carbonate
on
the
crystallization
by
other
prepared
as
ammonium
about
removal
Chemical
solution,
immediately
to
alcohol
of
Dicarbonato-
mixture
warmed
the
much
Blue-K[Co(NH3)2(CO3)2]
green
of
of
took
this
to
clear
color
precipitation
too
Potassium
CoCl-H2O2
5 g.
about
if
this
mix-
chloride.
(III),
added
isolating
CoCl2-H2O2
co-precipitation
potassium
the
the
brought
Variety
and
in
of
while
diamminecobaltate
which
exercised
the
hydroxide,
was
about
at the
Society of Japan, Kyoto, April 2, 1956.
1) H.A. Laitinen and L.W. Burdett, Anal. Chem., 23,
1268 (1951).
2) M. Mori and M. Shibata, J. Chem. Soc. Japan, 75,
1046 (1954).
3) T.P. McCutcheon and W.J. Schuele, J. Am. Chem.
Sac., 75, 1845 (1953).
was
the
stand
which
crystals
bicarbonate,
by
to
to
a brown
solid
nearly
added
with
in
The
potassium
decomposition
was
washed
the
at
ceased,
stored
g.
place
The
preci-
and
allowed
crystals
hour.
and
13.5
containing
green
a
dissolved
H2O2
The
cooled
and
In
was
stirring,
filtered
again
water
ice-bath.
added
operation.
was
an
of
CoCl2•E6H2O
This
drop
the
in
of
cc.
was
filter,
ether,
off
dark
alcohol
an
glass
a
more
of
half
a
in
solution
deposition
more
mixture
grams
20
the
The
filtered
kept
little
and
bicarbonate.
were
again
Then
filtrate,
was
Tricarbonatoco-
with
therefore,
KHCO3
Potassium
KYUNO
30, 1956)
H2O.-To
Experimental
of an
ADACHI
April
It has been well known that in the presence of alkali bicarbonates
cobaltous salts
such as chloride and sulfate give green coloration by the action of hydrogen peroxide
on the aquous solution, and this reaction has
been used for the iodometric or colorimetric
determination
of cobalt by several workers1 ,2).
On the other hand, this reaction product
has been regarded as tricarbonatocobalt
(III)
anion, [Co(CO3)3]3-, from measurement
of the
absorption
spectrum2) or chemical analysis
of a derivative
with hexamminecobalt
(III)
cation, [Co(NH3)6][Co(CO3)3]3).
The present study was first directed to the
isolation of the complex salt and the determination of its chemical formula and then turned
to the synthesis
of cobalt (III) complexes
belonging
to an ammine-carbonato
series.
All the objects were attained with success.
I
SHIBATA, Eishin
Tomohiko
(Received
Complexes.
solution
carbonate
the
finally
color
violet.
Violet-K[Co(NH3)2
was
of
the
Then
containing
heated
solution
the
on
the
turned
solution
5g.
waterinto
was
884
Motoshichi
MORI, Muraji
SHIBATA, Eishin
cooled
rapidly
and a large amount
of alcohol was
added
to it, and the whole was allowed
to stand
for some time.
The violet precipitate
was collected
and dissolved
in a little cold water to remove
im-
KYUNO and Tomohiko
in water,
alcohol and acetone
and was
against
day-light.
All the complexes
described
above
in the accompanying
flow sheet (Table
TABLE
A FLOW SHEET
OF SYNTHESIS
very
stable
are
I).
shown
I
OF AMMINE-CARBONATO
purities as residues, and then the complex sought
for was reprecipitated
from the solution by the
addition of alcohol.
After repeating this procedure, the product was washed with alcohol and
ether in turn and finally dried in a vacuum desiccator over sulfuric acid. Thus about one gram
of violet powder was obtained.
The complex was
hygroscopic and very readily soluble in water.
4) Carbonatotetramminecobalt
(III) Chloride,
[Co(NH3)4CO3]Cl.-To
the green solution
were
added 15g. of ammonium carbonate and 30 cc. of
conc. ammonia and the mixture was boiled on the
water-bath
until the color of the solution became
blood-red.
At the end of this heating the liquid
was poured into an evaporating
dish and concentrated to a small volume with the addition of
a small amount of ammonium
carbonate.
On
adding alcohol, the complex was precipitated,
the
yield being about 9 g.
5) Hexamminecobalt
(III) Chloride and Chloropentammine
Cobalt (III) Chloride,
[Co(NH3)6]
Cl3 and [Co(NH3)5Cl]Cl2.-Thirty
grams of ammonium chloride, 40 cc. of conc. ammonia and 2 g.
of active charcoal were introduced into the green
solution and the mixture was boiled until its color
became reddish-brown
(about thirty minutes).
In
this case, a reflux condenser
was used to avoid
the escape of ammonia from the solution.
After
filtering and cooling, conc. hydrochloric
acid was
gradually
added to the filtrate,
until a yellow
precipitate separated out. The purification of the
product was effected by the usual method for this
complex.
Yield, about 4g.
On evaporating
the mother liquor, chioropentamminecobalt (III) chloride was obtained as a byproduct.
6) Hexamminecbalt
(III)
Tricarbonatocobaltate (III),
[Co(NH3)6][Co(CO3)3].-This
compound was quantitatively
precipitated
from the
green solution by the addition of solid hexamminecobalt (III) chloride.
The compound appeared
as light-green powder.
It was extremely insoluble
ADACHI [Vol. 29, No . 8
CO(III)
COMPLEXES
Analysis.-Determination
was
carried
2),
3)
by
their
of
out
and
6).
for
the
The
complexes
were
properties
pitation
Water
reaction
and
of crystallization
absorption
the
of
the
loss
means
weight
of
fact
a
Shimazu
nothing
removed
but
was
hydrated
When
the
were
in
ammonia
ions
attached
of
of
(perhaps,
from
by
and
crystallization
the
has
re-dissolving
been
the
was
temperature
de-
and
to
part
all
the
car-
cobalt
and
carbonate
The
with
300•Ž,
of
central
sample,
Co2O3).
heated
up
the
the
follows
preci-
water.
potassium
as
1),
100-130•Ž
Balance
by
to
from
consisted
represented
at
molecules
expelled
cobalt
was
sample
of
as
product
of
dehydrated
elevation
the
bonate
water
in
identified
such
spectrum.
determined
Thermano
confirmed
sample
gradual
of
of
formulas
obtained
other
characteristic
chemical
complexes
the
and
atom
remainder
an
reaction
oxide
may
be
:
The
quantity
of ammonia
and
carbondioxide
expelled
was estimated
from the observed
loss of
weight.
The potassium
carbonate
was alkalimetrically
estimated
after the residue
was extracted
with hot water
and the cobalt content
was iodometrically
determined
after
the oxide in the residue was dissolved
with hot sulfuric
acid.
To confirm
the validity
of the above
methods,
direct
analysis
of ammonia
and carbondioxide
was
also carried
out.
Absorption
Spectra.-The
absorption
spectra
of the above complexes
in aqueous
solution
were
measured
with
a Beckman
Model
DU Spectrophotometer
using
a cell 1.0 cm.
Results
The
shown
results
in Fig.
and
of thermal
1 and all
in thickness.
Discussion
the
decomposition
numerical
are
values
November,
1956]
Studies
on the
Synthesis
of Metal
TABLE
ANALYTICAL
TABLE
ABSORPTION
are
given
justify
mulae
in
Table
II.
K[Co(NH3)2(CO3)2]•EH2O
to
our
of
these
Thus,
the
similar
absorption
to
that
of
2
and
Table
curve
of
AND log ƒÃ
the
the
abIII).
K3[Co(CO3)3]
K3[Co(C2O4)3],
and
to
and
III
to
of
in
violet -K[Co[NH3)2(CO3)2]
NH4[Co(NH3)2(C2O4)2]
II
forviolet-
evidence
exists
(Fig.
885
RESULTS
MAXIMA
seem
chemical
blueand
I
[Co(NH3)6][CoCO3)3]
formulae
data
data
such
Additional
sorptiometric
of
and
compounds.
validity
is
These
the
assignment
of
as
K3[Co(CO3)3]•E3H2O,
Complexes.
those
that
of
K[Coedta].
Fig. 2. Absorption spectra of :
A. K3[Co(CO3)3]
B. Blue-K[Co(NH3)2(CO3)2]
C. Violet-K[Co(NH3)2(CO3)2].
Fig.
1.
plexes
Thermal
at
decomposition
of
com-
100-300•Ž.
A.
K3[Co(CO3)3]•E3H2O
B.
Blue-K[Co(NH3)2(CO3)2]•EH2O
C.
Violet-K[Co(NH3)2(CO3)2]•EH2O
D.
[Co(NH3)6]
[Co(CO3)3]
K3[Co(CO3)3]•3H2O.-The
exact formula for
this complex had not been determined before.
According to reference1), job assigned to it
the formula K3CoO3, Durrant
considered it
to be (KCO2-O)2-Co-O-Co-(O-O2CK)2 and Duval
called it cobalt (III) tricarbonatocobaltiate,
Fig. 3. Frequency
positions of the ammine-carbonato
Co(III) complexes.
1. [Co(CO3)3]32. [Co(NH3)2(CO3)2]3. [Co(NH3)4CO3]+ 4. [Co(NH3)6]3+
Co[Co(CO3)3]. None of these formulas, however, correctly represents
the constitution
of
the pure substances obtained by the present
workers.
886
Motoshichi
From
the
of
the
absorption
is
reasonable
results
of
state
the
fact
resolve
In
fact,
the
into
were
(III)
original
In
solution
optical
was
not
of
and
it
precifrom
complex.
took
the
the
since
place
dur-
important
a
ion
can
will
group
span
only
intramolecular
be
the
of
reaction
be
an
earlier
through
while
blue
form.
Studies
plexes
may
the
shed
Absorption
first
and
Fig.
3.
the
values
line
of
except
other
among
the
this
the
such
absorption
frequency
as
in
Table
linearity
that
EDTA-Co
III.
the
(III)
series
of
in
seen
on
a
that
single
complex.
can
the
maximum
is
lie
violet
of
added
a
plotted
it
band
a
com-
values
of
are
of
frequencies
be
the
frequency
diagram,
one
trans-
both
problem.
bands
first
for
hand,
should
has
the
formed
as
of
complexes
From
reaction
one
regarded
on
second
ammine-carbonato
the
resolution
light
on
compound
of
Spectra.-The
the
salt
blue
is
no
occurs
violet
complex
of
that
ammonium
stage
cis-form,
carbonate
and
the
at
must
as
configuration
of
con-
Provided
such
tricarbonatocobaltate,
formed
the
cis-positions
change
during
determine
stereoisomers.
bifunctional
and
Tomohiko
ADACHI
[Vol.
29, No.
8
Synthesis.-Our
methods in which green
tris-cobaltate
is used as starting
material,
have the advantage
of simplicity.
For example, carbonatotetramminecobalt
(III) salt,.
which is useful for the synthesis of various
complexes, is prepared by the successive substitution
of carbonate
ions with ammonia
groups without atmospheric
oxidation,
and
hexamminecobalt (III) salt is also prepared
by further
substitution
in the presence of
active charcoal.
It has also been observed
that the cobalt (III) complexes belonging to,
an ethylenediamine-carbonato
series is synthesized in the same way, and this will be
reported later.
Summary
complex
studies
to
these
KYUxo
precipitants,
fractionated
Further
the
But,
complex
of
of
that
dicated
using
Violet-K[Co(NH3)2(CO3)2]•EH2O.-
is
figuration
It
by
green
removing
rotation
Blue-
the
antipodes.
out
out.
Now,
for
the
cases,
the
measured.
carried
draw
necessary
obtained
the
process
the
both
of
of
the
is
carried
fractionally
decomposition
to
d-tris-(ethylenediamine)-
ion.
were
easily
order
it
complex
the
considering
(III)
In
and
pitates
in
by
however,
attempts
it
The
complex
appreciated
conclusion,
cobalt
complex,
tris-structure.
day-light.
1-strychnine
ing
it
Eishin,
because
this
trioxalatocobaltate
in
to
and
of
this
be
that
final
give
will
SHIBATA,
analysis
isolating
decomposes
a
of
Muraji
spectrum
to
difficulty
pure
MORI,
On
not
second
band.
violet
at
complex
exist
A green compound is isolated from the
concentrated
solution obtained by the action
of hydrogen peroxide on cobalt (II) ions in
the presence of potassium bicarbonate, and
the formula K3[Co(CO3)3]•3H2O is assigned to
it on the basis of the analysis of the solid
and of the absorption spectrum of the solution..
A series of ammine-carbonatocobalt
(III) complexes, K3[Co(CO3)3]•3H2O, blue (perhaps, cis)and violet(perhaps,
trans)-K[Co(NH3)2(CO3)2]•
H2O, [Co(NH3)4CO3]Cl and [Co(NH3)6Cl3, are
synthesized
from the abovementioned
green
solution by means of successive substitution
of carbonate
ions by ammonia
groups..
Hexamminecobalt
(III) tricarbonatocobaltate,.
[Co(NH3)6] [Co(CO3)3], is also obtained by adding a hexamminecobalt
(III) salt to the green
solution of tricarbonato-complex.
Three complexes,
K3[Co(CO3)3]•3H2O and blue- and
violet -K[Co(NH3)2(CO3)2]•H2O, are probably to
be regarded as new complexes and may be
identified by their absorption spectra.
complex
the
same
as
in-
Department
Science,
of Chemistry,
Faculty
Kanazawa
University
Kanazawa
of