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Inorganic Syntheses. Volume 33 - Coucouvanis D.

Coucouvanis D. Inorganic Syntheses. Volume 33 - University of Michigan, 2002. - 299 p.
Download (direct link): inorganiksintesis2002.djvu
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C, 22.67; H, 4.35. Found: Mo, 19.71; Co, 4.20; C, 23.05; H, 3.48.
156
Solid-State Materials and Clusters
Properties
The aqua ion -D in HC1 (2 M) or Hpts (2 M) is very air-sensitive and
forms Mo3 and [Co(H20)g]2+ upon exposure to air.
C. MOLYBDENUM-NICKEL CLUSTER AQUA ION, [Mo3NiS4(H2O)10]4+ (Mo3Ni) IN
SOLUTION AND [Mo3NiS4(H2O)10] (CH3C6H4S03)4 7H20 (Mo3Nipts)
I. Decaaquotrimolybdenum-nickel-tetrasulfide, [Mo3NiS4(H20)io]4+
(Mo3Ni), in solution
[Mo3S4(H20)9]4+ +Ni + H20 [Mo3NiS4(H2O)10]4+
Procedure3a
Concentrated HC1 (10 mL) is added to a solution of Mo3 [0.080 M per
trimer in HC1 (2M), 10 mL]. Several pieces of nickel plates (1.25 g, 21.3
mmol), the surface of which has been washed with concentrated HC1, are
introduced to a conical flask containing the aqua ion Mo3, and the
mixture is allowed to stand for 5 days with stirring under a dinitrogen
atmosphere at 50-55C in a water bath. This is the only step that
requires a dinitrogen atmosphere (see Properties). The color of the
solution turns from green to dark brown. The nickel plates are removed by
filtration. After the filtrate is diluted to 20 times, its original
volume with water, is chromatographed through a Dowex 50W-X2 (2.5 x 45
cm). The first band containing [Ni(H20)6]2+ ion is eluted with HC1 (0.5
M), and the second band (deep green) containing the mixed metal aqua
cluster Mo3Ni is collected by elution with HC1 (1 M): yield 75%. The
third band contains small abounds of the starting material, Mo3.
Uncharacterized brown bands remain at the upper part of the column.
II. Decaaquotrimolybdenum-nickel-tetrasulfide-tetrakis-/?-
toluenesulfonate-heptahydrate, |Mo3\iS4fII2())10]
(CH3C6H4S03)4 7H20 (Mo3Nipts)
Procedure
In order to obtain crystals of Mo3Nipts, a solution of Mo3Ni in HC1 (1 M)
is absorbed on a short cation exchanger, Dowex 50W-X2 (diameter 2.2 cm,
length
5 cm). The resin is washed with Hpts (0.1 M) to remove the chloride
ion, and slow elution with Hpts (4 M) gives bluish-green solution. The
eluate from the column is stored in a refrigerator. After days, green
crystals deposited are
23. Sulfur-Bridged Cubane Type Mixed-Metal Clusters
157
collected by filtration and washed with ethyl acetate and air-dried:
yield 0.44 g [50% based on Mo3Ni in HC1 (1 M)].
Anal Calcd. for Mo3NiS8029C28H62 (MW= 1465.82): C, 22.94; H, 4.26. Found:
C, 23.13; H, 4.21.
Properties
The cluster Mo3Ni in dilute HC1 or Hpts is fairly stable toward air
oxidtion and can be handled in the air; the solution of Hpts (2 M) is
air-oxidized by only ~ 15 % per month. However, if the solution is stored
for a prolonged period, storage under a dinitrogen atmosphere is
recommended. The crystals MoNipts dissolve in some organic solvents
(e.g., acetonitrile, acetone, and AyV-dimethyl-folmamide).
Derivatives such as Ca2.5[Mo3NiS4(Hnta)(nta)2Cl]- 14H20 (H3nta =
nitrilotri-acetic acid) can be obtained from Mo3Ni and H3nta.n
D. MOLYBDENUM-COPPER CLUSTER AQUA ION DECAAQUO TRIMOLYBDENUM-COPPER-
TETRASULFIDE, [84(2)10]4+ (), AND BISNONAAQUOTRIMOLYBDENUM-
COPPER-TETRASULFIDE, [(20)938484(20)9]8+ (-D), IN
SOLUTION AND BISNONAAQUOTRIMOLYBDENUM-COPPER-TETRASULFIDE-OCTAKIS-/J-
TOLUENESULFONATE-ICOSAHYDRATE, [(20)938484(20)9]
(CH3C6H4S03)s 20H20 (Mo3Cu-Dpts)
[Mo3S4(H20)9]4+ + + H20 - [Mo3CuS4(H20) 10]4+
2[Mo3CuS4(H2O)10]4+ -" [(H20)9Mo3S4CuCuS4Mo3(H20)9]8++2H20
I. Bisnonaaquotrimolybdenum-copper-tetrasulfide-octakis-/?-
toluenesulfonate-icosahydrate, [(H20)9Mo3S4CuCuS4Mo3(H20)9]
(CH3C6H4S03)s 20H20 (Mo3Cu-Dpts)
Procedure12
Copper plates (0.2 g, 3.1 mmol) are introduced to a conical flask
containing the aqua Mo3 cluster [0.05 M per trimer in HC1 (2 M), 25 mL].
The color of the solution turns from green to green-brown in a few hours.
After two days the resultant brown colution is filtered and
chromatographed through a Dowex (diameter 2.2 cm, length 80 cm).
158
Solid-State Materials and Clusters
[Cu(H20)6]2+*and a very light brown unknown species are eluted with
HCl (0.5 M). The red-brown eluent, containing [Mo3CuS4(H20)io]4+,
(), is obtained by elution with HCl (1 M). A green band of the
unreacted starting material, Mo3, follows the red-brown band. In order to
obtain crystals of -Dpts, the solution is absorbed on a short cation
exchanger, Dow ex 50W-X2 (diameter 2.2 cm, length 5 cm). The resin is
washed with Hpts (0.1 M) to remove chloride ions, and slow elution with
Hpts (4 M) gave a red-brown solution. The eluate from the column is a
refrigerated (ca. - 5C). After several days black-brown crystals
deposit, which are collected by filtration, washed with ethyl acetate,
and air-dried: yield 0.24 g (13% based on Mo3).
Anal Calcd. for Mo6Cu2S16062C56H132 (MW = 3013.41); C, 22.32; H, 4.42.
Found: C, 22.30; H, 3.87.
Properties
Column chromatography, X-ray structural analysis and electronic spectral
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