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Explosion during the Destruction of Dimethyl Sulfate with Ammonia.

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H2S + 4 FZ+ SF6 + 2 HF). Sulfur oxyfluorides are then present
only in traces. SF6is completely pure after a single washing with
10 % caustic potash. On electrofluorination of N20, products
are formed which explode after condensing in liquid air.
Most of the fluorination products mentioned are known, but
hitherto they could only be prepared by using elementary
Received, February 7th, 1963
[Z 469/300 IE]
Publication withheld until now at the author's request
[I] U.S. Pat. 2519983 (Aug. 22nd, 1950), Minnesota Mining &
Manufacturing Co.; inventor: J. H . Simons; U.S. Pat. 2806817
(Sept. 17th, 1957), General Electric Co.; inventor: J. K. Wove.
[2] J. C . Tatlow, M . Stacey, and A . G . Sharpe: Advances in
Fluorine Chemistry. Butterworth Scientific Publications, London 1960, Vol. 1, p. 129 et seq.; Houben-Weyl: Methoden der
organischen Chemie. Georg Thieme Verlag, Stuttgart 1962, Vol.
V/3, pp. 38-42.
Silicon Tetrakisdiethylphosphide
By Prof. Dr. G. Fritz [I] and Dr. G. Poppenburg
lnstitut fur Anorganische Chemie
der Universitat Munster (Germany)
In continuation of our investigations on derivatives of
H3SiPH2 [2], we have prepared Si[P(CzH&]4 ( I ) , b.p. ca.
16OoC/1 mm, by treating Sic14 with LiP(C2H5)z in a ratio of
1 :4. In addition to ( I ) , considerable quantities of [(C2H&P]z
are formed. Compound ( I ) is decomposed by alkali as
Si[P(CzHs)zl.~ 4 HzO
+ 4 (CzHs)zPH
The reaction proceeds quantitatively o n warming. The
HP(CzH5)z (2) formed is transformed by HgClz solution
into the sparingly soluble compound (C2H5)zPHgCl. This
can be used to estimate (2) quantiratively by subsequent
iodometric titration. Compound ( I ) ignites in air and is
extremely sensitive t o moisture.
Received, February loth, 1963 [Z 456/287 IE]
[l] New adress :Institut fur Anorganische und Analytische Chemie
der Universitat GieDen (Germany).
[2] G. Fritz, Z. anorg. allg. Chem. 280, 332 (1955); G. Fritz and
G. Poppenburg, Angew. Chem. 72,208 (1960); G. Fritz, G. Poppenburg, and M . G. Rocholl, Naturwissenschaften 49, 255 (1962); G.
Fritz and G. Poppenburg, ibid. 49, 449 (1962).
Explosion during the Destruction of Dimethyl
Sulfate with Ammonia
By Dr. H. Lindlar
Chemische Forschungsabteilung,
F. Hoffmann-La Roche & Co. A.G., Base1 (Switzerland)
Excess dimethyl sulfate left over after methylations must be
destroyed because of its poisonous nature. Ammonia is
widely recommended for this purpose in the literature.
Through an experimental error about 1.5 1 of dimethyl sulfate
were brought into contact with 1-2 1 of concentrated aqueous
ammonia. After about 10 seconds, a n extremely violent
reaction occurred which shattered the flask. The fragments
injured a workman, and several windows were broken.
Fortunately, the accident occurred in the open and caused
no extensive damage; no symptoms of poisoning through
inhalation of dimethyl sulfate were observed.
Experiments with smaller quantities showed that pure dimethyl sulfate and concentrated aqueous ammonia react
extremely violently with one another [l].
When destroying dimethyl sulfate with ammonia, the latter
should therefore only be added diluted and in small quanReceived, February 12th, 1963 [ Z 447/277 IEI
[l] Cf. P. Claesson and C. F. Lundvall, Ber. dtsch. chem. Ges. 13,
1700 (1880).
Application of the Becquerel Effect to the
Investigation of Photochemical Reactions
By Dr. H . Mauscr and Dipl.-Chem. U. Sproesser
Institut fur Physikalische Chemie
der Universitit Tubingen (Germany)
We are investigating the Becquerel effect displayed by dissolved organic substances [I]. If two identical electrodes are
introduced into a solution of a suitable organic compound
and one electrode is illuminated, a potential difference, which
becomes stable after a few minutes, is established between
them. The potential difference disappears again after a time
if the light source is switched off.
Over 100 systems were examined; aromatic and aliphatic 0x0
and dioxo compounds, aromatic nitro compounds, aliphatic
halogeno compounds, and nitrous esters, as well as polymerizable unsaturated compounds in polar solvents such as
alcohols, dimethyl sulfoxide, or tetramethylene sulfone. The
photochemical potentials and currents were measured as
functions of time in relation to wave length and intensity [21.
A correlation between ability to fluoresce and Becquerel
activity, as reported in the older literature, could not be
established. Only those systems show this effect which react
photochemically under our experimental conditions and
which undergo reactions where radical mechanisms are
either established or probable. Systems in which cis ->
trans rearrangement or isomerization takes place are, as far
as has been investigated, inactive.
The results of our measurements lead to the conclusion that
r a d i c a l s occur as intermediates and exchange electrons
with the illuminated electrode, which thus accumulates a
charge. All our potential vs. time curves can be reduced to a
few types. Parallels between curves and type of reaction are
indicated. The growth and decay curves can frequently be
interpreted as being formed by superposition of two simple
curves with equal or opposite sign. The conclusion that can
be drawn from this is that different radical intermediates
occur. As expected, the purity of the materials used as well
as the presence of oxygen and other radical acceptors influence the shapes of the curves.
As our work stands at present, the Becquerel effect can be
used to detect photochemical reactions involving radical
mechanisms and to determine the effective spectral ranges
for them, in particular their limits in the long-wave region.
In favorable circumstances, it is possible to identify the
mechanisms by their different spectral regions.
Received, February 25th, 1963 [Z 455/285 IE]
[ I ] E. Becquerel, C. R. hebd. Seances Acad. Sci. 9 , 145 (1839).
Most recent review: A . W. Copeland, 0 . D . Black, and A. B. Garrett, Chem. Reviews 31, 177 (1942).
[2] For experimental details, see U. Sproesser, Diploma thesis,
Universitat Tubingen, 1962.
Intramolecular Coupling of Diazotized
N-(2-Aminophenyl)pyrrole to form
By Dr. H. Gross and Dip].-Chem. J. Gloede
Iiistitut fur organische Chemie der Deutschen Akademie der
Wissenschaften zu Berlin, Berlin-Adlershof (Germany)
On diazotizing N-(2-aminophenyl)pyrrole ( I ) [l] in aqueous
acidic medium, we immediately obtained not the expected
diazonium salt (2) but a yellow, crystalline compound of
m.p. 243-244 "C in over 90 '%,yield. Analysis and molecularweight determination indicate that this compound has the
formula C10H7N3.
The assumption that the hitherto unknown compound
pyrrolo[l,2-c] [1,2,4]benzotriazine ( 3 ) is formed from (2) in
Angew. Chem. internal. Edit. Vol. 2 (1963) 1 No.5
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explosion, ammonia, sulfate, destruction, dimethyl
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