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Bistritylnickel and Tritylnickel Chloride.

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[5] J. Powell, S. D.Robinson, and B. L. Sliaw, Chem. Commun.
1965, 79; R. Mason and D . R. Russell, ibid. 1966, 26.
[*] We thank Dr. E. G. Hoffhann for measurement and dis-
The product (4) is appreciably less stable than ( I ) . Suspensions in benzene decompose in a few hours :
cussion of the IH-NMR spectra.
2 (C&5)3CNiCI
+ ( C ~ H S ) ~ C - C ( C ~+HNiClz
~ ) ~ + Ni
(4)
Received: March 21st, 1966
[Z 185c/23 1El
German version: Angew. Chern. 78, 592 (1966)
Bistritylnickel and Tritylnickel Chloride
By Prof. Dr. G . Wilke and Dr. H. Schottcll
Max-Planck-Institut fur Kohlenforschung.
Mulheim,'Ruhr (Germany)
According to all previous information, pure alkyl- and arylnickel compounds are stable only when stabilized by further
ligands [*I. If, for instance, acetylacetonatonickel is treated
with triethylaluminum in toluene at -78 "C.the diethylnickel
formed as a n intermediate decomposes rapidly with formation
of elemental nickel. The nickel atoms can be trapped, e.g. by
1,5-~yclooctadiene,as bis-(1,5-cyclooctadiene)nickel(0) [31.
We have found that, for instance, bis-(I ,5-cyclooctadiene)nickel(0) (2) reacts with hexaphenylethane at 20 to 7OoC
with loss of cyclooctadiene to yield stable bistritylnickel ( I ) ,
as deep violet crystals. This product can be recrystallized
from benzene (solubility ca. 1 811 at 20 "C). I t is obtained in
more than 90 % yield when acetylacetonatonickel is reduced
with (CzH5)2AlOC2Hj in benzene at about 0 ° C in the
presence of a n excess of hexaphenylethane.
(C&)3C-C(C&5)3
S
Ni(OzC5&), + 2 ( C Z H ~ ) Z A ~ O C+~ H
(3)
Compound ( I ) is also obtained by reaction of NiBr2 with
tritylsodium in ether at -78 'C (yield > 40 %).
Pure bistritylnickel decomposes under argon at about 120 " C .
If it is added to molten triphenylphosphine at 80°C, a deep
red color appears within a few minutes; addition of benzene
precipitates Ni[P(CsH5)3]4 (yield 89 %) :
Ni[C(C6H5)312 + 4 P ( C S H ~ ) ~
+
Ni[P(CsH5)314
0
Preparation of Carbonyl(ch1orodifluorophosphine)nickel Complexes 1'1
By Prof. Dr. 0.Glemser, cand. chem. E. Niecke, and
Dr. A. Miiller
Anorganisch-Chemisches Institut
der Universitat Gottingen (Germany)
The compounds Ni(PFzC1)d ( I ) , Ni(CO)(PFzCI)3 (2),
Ni(C0)2(PFzCI)2 (3), and Ni(CO)3(PFzCl) ( 4 ) can be
prepared by direct reaction of nickel tetracarbonyl and PFzCl
in a Carius tube (molar ratio 1 :4; about 80 hr at 30-90 "C) [*I.
Mixtures of (1) to (4) are always obtained in this reaction,
formation of products with higher phosphine content being
favored by higher temperatures. The products ( I ) to (4) were
separated by fractional distillation in a high vacuum. Except
for ( I ) 121, they were all obtained pure and were characterized
by mass spectra, elemental analyses, and infrared spectra
between 4000 and 300 cm-1.
In the region of v(CO), v(PF)[3], v(PCI)[31, and v(NiC)
vibrations, the infrared spectra of the pure substances (2),
(3), and (4) in the gaseous state showed the number of
vibrations bands expected from group theory [C3, symmetry
assumed for (2), CzVfor (3), and C, for ( 4 ) ] .The compounds
are most easily characterized by their v(C0) vibration frequencies :
Ni(CO)(PF2C1)3: v(A1) at 2079 cm-1
Ni(C0)2(PF2C1)2:v(A1) at 2097 and v(B1) at 2059 cm-1
Ni(CO)3(PF2CI):v(Al) at 21 14 and v(E) at 2058 cm-1 (assignment
skeleton)
+ ( C ~ H ~ ) ~ C - C ( C ~ H S )according
~
to the symmetry of the NiP,(CO) 4-x
Bistritylnickel ( I ) does not change visibly in air at 2OoC
during several days, yet a slow oxidation occurs in solution.
On treatment with pure oxygen, exactly 2 moles of 0 2 are
taken up per mole of ( I ) . Decomposition of the oxidation
product is approximately described by the scheme:
(I)
[l] H. SChOtt, Dissertation, Technische Hochschule Aachen,
1965.
[2] G. Wilke and G. Herrmann, Angew. Chem. 78, 591 (1966),
Angew. Chem. internat. Edit. 5, 581 (1966).
[3] G. Wilke, Angew. Chem. 72, 581 (1960); M . Kroner, Dissertation, Technische Hochschule Aachen, 1961.
Ni[O-- O-C(C6H5)3]2
10 mmoles
The position of the v(C0) frequency corresponds to experience
in that the v(C0) frequencies of substituted carbonyls are
lowered when the ligands are not x-acceptors and are constant or even raised when the ligands are x-acceptors
(PFzCI) [41. In the present case the frequency of the symmetrical stretching vibration increases with increasing number
of PFzCI ligands as a result of the increased proportion of
x-bonding in the CO linkage. Similar observations have been
made for complexes of the type Ni(CO),(PF3)4-,c51.
Received: April 12th, 1966 [Z 198 IE]
German version: Angew. Chem. 78, 593 (1966)
-
~~
[ * ] All the products are colorless liquids at room temperature.
Bistritylnickel reacts only very slowly with non-oxidizing
acids under argon, even in solution ; e.g. in conc. HCI it takes
2 20h before tritylnickel chloride appears in the form of a blue
insoluble product. Pure tritylnickel chloride (4) is obtained
on treatment of 1,5,9-cyclododecatrienenickel(0) with triphenylmethyl chloride in ether at -78 "C:
+ (C6H5)3CCl
(C&&CNiCI + 1,5,9-CycIododecatriene
Ni(l,5,9-Cyclododecatriene)
+
14)
Angew. Chem. internat. Edit.
1 Vol. 5 (1966) 1 No. 6
Determination of their boiling points was difficult because of
their ready decomposition.
[l] Part V of Studies on PF Compounds. - Part I V : A. Miiller,
E. Niecke, and 0. Glemser, 2. anorg. allg. Chem., in press.
[Z] Separation of ( I ) and (2) for preparation of pure ( I ) failed because of the low vapor pressures below the decomposition temperatures.
[31 For infrared spectra of PF2Cl see A . MuNer, 0.Glemser, and
E. Niecke, Z . Naturforsch., in press.
[41 F. A. Cotton, Inorg. Chem. 3 , 702 (1964).
151 M . Bigorgne, Bull. SOC.chim. France 1960, 1986.
-
583
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