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Compounds Containing a Silicon-Boron Bond.

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Thus it is confirmed that H2S202 is formed primarily in the
course of the Wackenroder reaction:
4)
H-s-n
+ HO-S-OH -,HS-SOH + H ~ O
II
I1
0
Received, August 6th. 1962 [Z 323/157 IE]
0
It can react further to polysulphur oxides, whose composition
approaches the ideal formula (SzO), :
H-S-S-OH
I1
0
+ H-S-S-OH
II
0
of equal parts by volume of conc. hydrochloric acid and
glacial acetic acid. Hitherto TbO2 was available only by the
use of atomic oxygen [ 1,2].
+ H-S-S-S-S-OH
I1
0
4
-+ (SzO),.H20
The formation of the polysulphur oxides cannot be ascribed
to polymerisation of the anhydride of H2Sz02, as monomeric
S20 quickly reacts with water to form H2S + SOz.
Received, August Znd, 1962
[Z 326/163 IE]
[I] H. Stamm, M . Becke-Goehring, and M. Schmidt, Angew.
Chem. 72, 34 (1960).
[2] M. Schmidt and H . Heinrich, Angew. Chem. 70, 572 (1958).
[3] M. Becke-Goehring, Z. anorg. allg. Chem. 257,227 (1948).
[4] P. W. Schenk, Z . anorg. allg. Chem. 265, 177 (1951).
[ 5 ] P. W. Schenk and H. Platz, Z. anorg. allg. Chem. 225, 126
(1933).
Akylated Disulphur(1V) Nitride
By Prof. Dr. Margot Becke-Goehring
and DipLChem. H. P. Latscha
Anorganisch-chemisches Institut
der Universitat Heidelberg (Germany)
[l] N . C. Baenriger, H . A . Eick, H . S. Schuldt, and L. Eyring, J.
Amer. chem. SOC.83, 2219 (1961).
[2] D. M. Gruen, W. C. Koehler, and J. J . Katr, I. Amer. chem.
SOC.73, 1475 (1951).
Triphenylazidosilane and Diphenyldiazidosilane [1I
By Dr. N. Wiberg, cand. chem. F. Raschig,
and cand. chem. R. Sustmann
Institut fur Anorganische Chemie
der Universitat Miinchen (Germany)
To prepare triphenylazidosilane, Ph3SiN3 (I), [l, 21 and diphenyldiazidosilane, PhzSi(N3)~(II), excess NaN3 in pyridine
was allowed to react at room temperature with triphenylchlorosilane and diphenyldichlorosilane, respectively [3]. The
progress of the reaction was measured by titrimetric determination of the salts formed (NaN3, NaCI). After three days
the reaction was almost quantitative. I1 is a water-clear liquid
(b.p. 85 to 9O0C/IO-3 mm. H g , ng = 1.5887) and, like I,
thermally extremely stable [4]. No nitrogen is evolved on
heating for two hours at 300 "C. Sunlight and, more strongly,
dtraviolet irradiation modify 11.
I and I1 react with a 1:1 molar ratio of triphenylphosphine in
ether at 100°C with evolution of nitrogen to give N-silylphosphinimines (111) and (IV).
A new type of sulphur-nitrogen compound with the cation
Ph,Si--N=PPh,
[(CH~)~S-N=S(CH~)Z]+
was obtained by the interaction of
trithiazyl chloride, [NSCI]3, with dimethylsulphoxide:
111, m.p. 215-216°C
[NSCI],
+ 6 (CH3)zSO
-+
3 I(CH1)2S-N'S(CH3)zlCl
I
+ 3 SO2
The yield of compound (I) is about 60 %. It crystallises in
colourless needles, which decompose at about 80°C. It is
soluble in dimethylsulphoxide, and on heating in tetrachloroethane, acetonitrile and nitrobenzene; it is insoluble in
benzene, petroleum ether and carbon tetrachloride.
The solution in dimethylsulphoxide is electrically conductive.
Cryoscopic molecular weight determination in dimethylsulphoxide indicates about 70 % dissociation (1.4 % solution).
Ph,P=N-SiPhz-N=PPh,
IV, m.p. 190-191
O C
In both cases a maximum of only 50 %of the expected amount
of nitrogen is evolved. Consequently a side-reaction must take
place forming further nitrogen-containing compounds (e. g.
triphenylphosphinimonium azide, [Ph3P=NHz]+N?, can be
isolated). At room temperature the reaction of PPh3 with
compound I takes place without nitrogen evolution. Ph6SiNP
(V), isomeric with 111, was found to be one reaction product. (The infrared spectrum of V does not contain the band
dde to the P=N double bond). The structures of 111 and IV
were confirmed by degradation with dry hydrogen chloride
in benzene.
Received, August 7th, 1962
[Z 328/154 IE]
Received. August 2nd, 1962 [Z 322/159 IEI
111 2nd Communication on silyl azides. 1st Communication: N.
Hydrolytic Fission of the Higher Oxides
of Praseodymium and Terbium
By Prof. Dr. G. Brauer and Dip1.-Chem. B. Pfeiffer
Chemisches Laboratorium
der Universitat Freiburg/Brsg. (Germany)
Higher praseodymium oxides of a composition between
PrOl.05 and Pro133 hydrolize in moist air at room temperature
with valency disproportionation. Thus Pr(OH)3 (lattice constants a = 6.47, c = 3.78 & and Pro2 (a = 5.394 A) are obtained in a heterogeneous mixture and well crystallized. The
reaction is accelerated by boiling with water under reflux.
It can be utilized for a new preparation of Pr02; by extracting Pr6O11 with boiling 90% acetic acid pure PrOz is
obtained.
The hydrolysis of the higher oxides of terbium is much
slower and less simple. A temperature of 200 "C is required.
One obtains the crystalline phases Tb(OH)3 (a = 6.31, c = 3.59
A) Tb01.823 [I] (a = 5.28 A) and Tb02 (a = 5.220 A). Pure
TbO2 with a composition strictly in accord with its formula
can be obtained by extracting Tb407 with a boiling mixture
Angew. Chem. internat. Edif. Voi. I (1962)1 No. I0
Wiberg et al., Angew. Chem. internat. Edit. 2 , 335 (1962).
[2] R. West et al., J. Amer. chem. SOC.84, 1763 (1962).
[3] Phenyltrichlorosilane also reacts in this manner. The azide
obtained is, however, still impure.
[4] The IH-resonancespectrumof the phenyl groups of I indicates
a marked degree of sharing of the d-orbitals of the silicon atom
with the x-electron system of the benzene rings.
Compounds Containing a Silicon-Boron Bond [I]
By Priv.-Doz. Dr. H. Noth and Dip1.-Chem. G. Hollerer
Institut fur Anorganische Chemie
der Universitat Miinchen (Germany)
The synthesis of compounds with stable silicon-boron bonds
is made possible by x-bonds between nitrogen and boron
atoms [2]:
/NRZ
R,SI-B''
\
NRz
I
NRz
R3Si-B
,/
\
X
I1
55 1
Triorganosilyldialkylaminoboranesof Type I are accessible
by one of the following routes:
Tri-irondodecacarbonyl (5 g) in liquid ammonia (100 ml) at
-78 "C and under oxygen-free nitrogen is converted to
NazFe(C0)4 by the addition of metallic sodium (1.37 g). The
ammonia is then evaporated in a stream of nitrogen and the
R3SiLi + CIBIN(CHs)zlz (a)\ -LiCI
+ R ~ S ~ - B [ N ( C H ~ ) Z ] ~ cooling bath (methanol/solid C02) removed. Compound I
(b)=
/CKCI
(5 g) in dry, peroxide-free ether (250 ml) is now added dropRnSiCl+ 2 K + CIB[N(CH3)z12 wise and the mixture reflwed, with stirring, for 24 hours.
The filtered solution is evaporated to dryness in vacuo, the
By route (a) Ph3Si-B[N(CH3)2]C4H9 can also be prepared,
residue taken up in benzene and chromatographed on a
but not however Ph3Si-B(C,,H9)2; this underlines the imcolumn (1.5 cm diameter, 50 cm long) of silica (Merck,
portances of the x-bonds for the stability of the Si-B bond.
0.02-0.05 mm diameter). A green, a red and a yellow-orange
The hydrolysis of Ph3Si-B[N(CH3)2]2 proceeds quantitatively
zone are eluted. The green compound is [Fe(CO)&; the
according to
yellow-orange the ferrole derivative (11), which is further
purified by vacuum sublimation (0.1 Torr) a t 50 "C. Yield:
Ph3Si-B[N(CH1)212 f 3 Hz0 + PhlSiH + B(OH)l + 2 HN(CH3)z.
80 mg (II), m.p. 57 "C.
Methanolic potassium hydroxide reacts with all silylboranes
with the evolution of hydrogen, i.e. with hydrolysis of the
initially formed Si-H bond. Silylboranes reduce silver salts
to silver.
HCI in ether attacks I only at the B-N bond, not at the Si-B
bond. Reaction in the molar proportions of 2 : l leads to
triorganosilyldimethylaminochloroboranesof Type I1 (X=Cl :
,N(CHi)z
+ 2HCI
RlSi-B
k(CH3h
,N(CH&
+ (CH3)zNH'HCl
.,Si-B
'Cl
The physical constants of the compounds which have been
characterised by analysis and infrared spectroscopy are:
Ph,Si-B[N(CH,)z]z
Ph3Si- B [N(CHp)z]CL
The trimethylsilyl compounds are spontaneously inflammable
in air.
Received, August 15th, 1962 [Z 331/160 IE]
[l] XIXth Communication on "Contributions to the Chemistry
of Boron".
[Z] A similar system exists in B-tris(triphenylsily1)-N-trimethylborazole; D. Seyferzh and H. P. Kogkr, J. inorg. nucl. Chem. 15,
99 (1960).
[3] Oil bath temperature. HV = high vacuum.
By Doz. Dr. Ernst Bayer, Dr. H. A. Brune,
and DipLChem. K. L. Hock
111 F. G. A. Stone, H. D. Kaesz, and R. B. King, J. Amer. chem.
SOC.82, 4749 (1960).
[21 M. L. H. Green, L. Pratt, and G. Wilkinson, J. chem. SOC.
(London) 1960, 989.
Derivatives of ferrole, i.e. of the 5-membered heterocycle
with iron as the hetero-atom, can be synthesised from sodium
iron carbonyl and 1,4-dichlorobutadiene derivatives. In .this
way dichlormuconic acid dimethyl ester (I) yields an orangeyellow tricarbonyl compound (11) of ferrole dicarboxylic
acid dimethyl ester.
NaZFe(C0)4
1
c1
.1
HC-
(1)
Dimethyldiazidosilane
By Dr. W. Sundermeyer
Anorganisch-wissenschaftlichesLaboratorium
der Farbenfabriken Bayer AG., Leverkusen (Germany)
The previously reported method for the preparation of
pseudo-halogen Fompounds of silicon from alkali pseudohalogenides and chlorosilanes in fused salts as solvents [l]
could also be used for the preparation of azides. Trimethylchlorosilane reacts with sodium azide, dissolved for example
in an anhydrous ZnC12-KCI melt, at 230-250°C to give a
good yield of trimethylazidosilane (I) [2] (b.p. 96 "C corr.).
(CH3)zSiCIz
Institut fur Organische Chemie
der Technischen Hochschule Karlsruhe (Germany)
yCH-"Y
'C-COOCH,
[Z 332/161 IEI
Similarly, an approximately 60 % yield of dimethyldiazidosilane (11) [3,4] was obtained.
Synthesis of Ferrole Derivatives
I
Received, August 15th, 1962
150--160/HV [3]
150--160/HV [3]
155-165/HV [3]
65/9 mm Hg
42/9 mm Hg
(CH3hSi- B"(CHdz1z
(CH3)3Si--B [N(CH3)21CI
HlCOOC-C
With its unsubstituted 8-C-atoms (11) is suitable for electron
distribution investigation, and is especially suited to answer
the problem of whether or not there is present in ferrole a
cyclic conjugation similar to that of the quasi-aromatic
heterocycles pyrrole and thiophen. In its NMR-spectrum
(Varian A 60) the proton bands of the p-CH-groups show a
chemical shift of 6 = 6.54 ppm. This value is in the region of
those found for analogous furan-, thiophen- and pyrrole
derivatives. In addition the iron complex prepared from
thiophen by Stone et al. [l] and claimed as a x-complex of
ferrole is found to have a value for 6 of 6.48 ppm [2].
H3COOC-8
CH
!-COOCH,
\F/
+ 2 NaN3
--f
(CH&Si(N&
I1
+ 2 NaCl
Whereas with phenylazidosilanes - analagous to the phenylsilylaminesand phenylsilanols - stability due to contributions
from mesomerism and the strong double bond character of
the Si-N bond would be expected, the existence of I1 is
surprising. The compound boils, without decomposition, at
144.3 OC (corr.) and is, like I and like triorganoazidosilanes
containing phenyl groups [5,6], remarkably stable thermally.
I1 is not sensitive to percussion, but in contrast to I burns
with deflagration.when ignited on an open spoon. Atmospheric moisture quickly hydrolyses the compound to dimethylpolysiloxanesand hydrazoic acid. Its infrared spectrum
resembles that of dimethyldichlorosilane and in addition
shows characteristic bands at 3436 (w), 2619 (w), 2146 (vs),
1322 (vs), 1157 (w), 1073 (w), and 1020 (w) cm-1 [*I.
I1 is also obtained in almost quantitative yield by the reaction
of I with dimethyldichlorsilane.
C'PC
(11)
552
2 (CH,),SiN,
AlCl
+ (CHs)zSiC12 -A
Angew. Chem. internat. Edit.
11
+ 2 (CH&SiCl
Vd. I (I962) I No. I 0
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