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Organocarboranes from Alkyldiboranes.

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together with silicon-free carbonylcyano complexes of nickel
and iron, which are decomposed by oxygen or moisture and
whose structures have not yet been elucidated. The reaction is
suspected t o follow the overall equation:
M(C0) f NaN[Si(CH3)3]2
+
[M(CN)13Nag
+ 0[Si(CH3)31~
M=(OC)4Fe or (OC)3Ni
This was confirmed indirectly by trapping sodium trimethylsiloxide formed as an intermediate with trimethylchlorosilane
(+ sodium chloride and bistrimethylsilyl ether) and by
isolating tetracarbonyltrimethylsilylisonitriloiron ( 4 ) , which
proved t o be identical with the compound prepared by
Seyferth [3].
(OC)4Fe =C = N-Si(CH3)3
14)
To our knowledge, the reactions of ( I ) with Fe(C0)X and
Ni(CO)4 are the first reactions of metal carbonyls in which
substitution of the carbonyl oxygen occurs without cleavage
of the metal-carbon bond. The isolation of ( 4 ) also implies
that trimethylsilyl cyanide reacts in the form of trimethylsilyl isonitrile in the synthesis [3] of (4) from Fe(C0)5 and
(CH3)3SiCN and that, although the latter compound is
currently generally formulated as the nitrile, it is a t least in
equilibrium with the isonitrile form
(CH&Si-C=N:
+
O
Q
(CH3)3Si--N=C:
Received: March 26th, 1965
[Z 9521777 IE]
German version: Angew. Chem 77, 457 (1965)
[ I ] The Chemistry of SI-N Compounds, Part 49. - Part 48:
U . Wannagat, W. VeigI, and H. Burger, Mh. Chern. 96 (1965),
in the press.
[2] U. Wannagat, H. Kuckertz, C. Kruger, and J. Pump, 2. anorg.
allg. Chem. 333, 54 (1964).
[3] D . Sqvferflz and N. Kahlen, J. Amer. chem. SOC.82, 1080
(1960).
Organocarboranes from Alkyldiboranes
By Dr. R. Kiister and Dr. M. A. Grassbeiger
Max-Planck-Institut fur Kohlenforschung,
Miilheim/Ruhr (Germany)
Chem. internat. Edit. / V d . 4(1955)
2
CzHg
,BH
c ZH5
+ Na
ZH5,
+
B- + Na[BHz(CzH5)zl
Cz d
The formation of the B3C group vin radical intermedia?es 161
and all further steps in the synthesis should take place as in
the dehalogenation. C-Dimethyl-B-pentaethyldicarbaclovoheptaborane(7) (with a molecular weight of 254) then results
from tetraethyldiborane and sodium according t o the
equation :
44(CzH&BH+ 12Na -+ 12 NaBH4t 27 B(C2H&+ C ~ ~ H ~ I B S
The reaction of alkyldiboranes with lithium is significantly
slower than that with sodium. The same carboranes are
obtained, but in lower yields. Carboranates could in no case
be detected. Whereas the metal borohydrides - as described
earlier [ I ] - are obtained in the pure state, evidently n o
"colloidal boron" [I] is formed.
Received. March 29th. 1965
[Z 955/782 IE]
German verslon. Angew. Chem. 77, 457 (1965)
[ I ] R. Koster, German Pat. 1062227 (March 28th, 1956),
Studiengesellschaft Kohle m.b.H. ; Chem. Abstr. 55,7776~
(1961).
[2] R. Koster and G. W . Roterinnnd, Tetrahedron Letters 1965,
777.
[31 R. Koster, W . Larbig, and G. W . Ro/er,nund, Licbigs Ann.
Chem. 682, 21 (1965).
[4] The molecular weights were determined by mass spectrometry (D.Henneberg, Mulheim/Ruhr).
[5] R. Koster and G. W. Rotermund, Tetrahedron Letters 1964.
1667.
161 R. Koster and G. Benedikt, Angew. Chem. 76, 650 (1964);
Angew. Chem. internat. Edit. 3 , 515 (1964).
Azido Complexes of Manganese(I1) and
Palladium(I1) [11
By Priv.-Doz. Dr. W. Beck, Dipl.-Chem. K. Feldl, and
Dr. E. Schuierer
Anorganisch-Chemisches Laboratorium
der Technischen Hochschule Miinchen (Germany)
I n the preparation of alkali borohydrides MBH4 from alkyldiboranes and alkali metals [ l ] , organocarboranes are obtained as by-products.
Sodium (2.3 g ; 0.1 g-atom) is simmered with tetraethyldiborane (28 g; 0.2 mole) with stirring (1-2 hours). The
NaBH4 is filtered off, washed several times with hexane, and
the combined filtrate and washings are fractionally distilled.
After removal of the solvent and triethylborane, about 1.5 g
of a yellow fraction, b. p. 37-49 "C/lO-3 mm, is obtained,
which consists of about 15 "/, organocarboranes and of
organoboranes which are sensitive to oxidation.
The composition of the carboranes here is similar to those
obtained in the hydroboration of acetylene [2,5] and in the
pyrolysis of alkyldiboranes [3]. Mainly C,C-dimethyl-B-ethyl
derivatives of the CzBsH? carboranes [2] with molecular
weights of 254,226 and 198 are present. The retention volumes
in gas chromatography agree with those of the carboranes
prepared by the hydroboration of acetylene. Compounds
with molecular weights [4] of 230 and 202, which are alkyl
derivates of CzBsHll [2], are also found. A carborane with
three B atoms (molecular weight [41 174) with a gas-chromatographic retention volume agreeing with that of 1,5-dimethyl-2,3,4-triethyl-l,5-dicarbaclovopentaborane(5)
151, appears as well.
111 the formation of the carboranes from alkyldiboranes, the
removal of hydrogen from the borohydrides is thought t o be
Airgeiv.
the initial step - in analogy t o the dehalogenation of dialkylhalobornnes [ 6 ] :
1 NO. 3
So far only few homogeneous azido compounds of transition
elements have been isolated [2]. The reaction of silver azide
with [(C~H5)4N]2[MnBr4]in acetone has now led to colorless
tetraethylammonium tetra-azidomanganate(l1) [(CzH5)4Nl2[Mn(N3)4]. This compound is readily soluble in water and
acetone and is not detonated by mechanical shock. I n agreement with its tetrahedral structure, the compound shows paramagnetism corresponding to five unpaired electrons, and an
asymmetric azide valence vibration "3 from the [Mn(N3)4]2(i
anion occurs at 2062 cm-1 in the infrared spectrum (solution
in acetone).
Tetraphenylarsonium triazidopalladate(i1)
[(C&S)~ASI[Pd(Nj)3] can be precipitated from aqueous solutions of
Pd(NO3)2 and NaN3 (in a molar ratio of 1:4) with tetraphenylarsonium chloride; with the divalent cation
[Fe(phen)3]2@, the red, insoluble tetraaz;dopalladate(II)
[Fe(phen)3] [Pd(N3)4] can be precipitated. These compounds
are diamagnetic and d o not explode, although they deflagrate in a flame. On the other hand, the brown insoluble
Pd(N& that is formed as the initial product on adding
sodium azide t o aqueous solutions of palladium nitrate does
detonate upon mere touch [31. [(CsH5)4AS] [Pd(N3)31
crystallizes in brown needles and dissolves readily in acetone
or chloroform t o give orange-red solutions. The salt-like
character of the compound is demonstrated by its conductivity in acetone (129 sZ--1 cmz/mole). Two v j azide bands
439
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