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Disilylmercury and Digermylmercury.

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water (70h at 60°C). The (CF3)zN group was diagnosed by
I9F-NMR (single peak 58.3 ppm upfield from internal CCI,F)
and by characteristic infrared absorption at 990 cm-' and
mass spectral fragment at m/e = 114 (C2F4N+).The C E N
stretching frequency occurs at 2260 cm- '; further IR bands
appear at 1360 vs, 1270 vs, 1230 vs, 1180 s, 1155 s, 990
s, and 728 s cm- '. The mass spectrum shows the molecular
ion at m/e=177.9971, and other fragments at 159, 133, 90
(CFzNCN+), 69, and 50. Two isomers of (I),
CF,=NCF,N=CF,
and CF,N=C=NCF,,
have been previously reported [ '1.
Cyanogen chloride reacts with chlorine to give ClNECC12[21,
but the reaction appears to be easily reversed.
ClCN
+
Clz
* ClN=CC12
Consequently, reaction of ClN=CCl, with K F in tetramethylene sulfone gives some ( I ) , but the major products are
CF,NCI, and CF,N=NCF,, as previously reported for the
reaction of ClCN with AgF and chlorine under conditions
more conducive to a radical mechanism[31.
-
2 ClN=CC12
+
3 MF
2 ClN=CC12
+
6 M F -CFsN=NCFX
CF3NC12
+
ClCN
+
+
3 MC1
6 MC1
We have found that use of KF favors formation of CF~NCIZ,
while AgF favors CF,N=NCF,,
suggesting the following
scheme which does not involve radicals:
ClN=CC12
+
3 F@
0
- 2 Cl@"
F3C-N<l
CIz
x
CFsNC12
&+ 1
+[M%1N:CC12]
-MCI
FsC-N-N=CClz
I
c1
F@
-CIQ
CF3N=NCF3
for 60 h. Vacuum fractionation yields ( I ), which at ca.
torr is passed by a trap at -96°C and stopped at - 112°C.
Yield 0.35 mmol (23 %).
Fluorination of N-Chlorodichloromethyleneamine
K F (19 mmol), tetramethylene sulfone (1.8 g), and CIN=CCl,
(5.8 mmol) are sealed together in a Pyrex ampoule under the
conditions described above, and heated to 60°C for 70h.
Unreacted ClN=CCI, (0.13 mmol) and ClCN (1.95 mmol) are
separated by vacuum fractionation, to yield a mixture of
CF,NCl, (1.98 mmol) and CF,N=NCF, (0.42 mmol) which
may be further separated by gas chromatography.
Received: July 29, 1974 [Z 108 IE]
German version: Angew. Chem. 87,208 (1975)
CAS Registry numbers:
( l ) , 54657-79-3; CF,NCl,, 13880-73-4; CF,N=NCF,, 372-63-4;
cyanogen chloride, 506-77-4, N-chlorodichloromethyleneamine,25240-91-9,
potassium fluoride 7789-23-3; tetramethylene sulfone, 126-33-0
[l] P. H. Ogden and R . A. Mirsch, J. Amer. Chem. Soe. 89, 5007 (1967).
[2] H. Hagemann, D. A r k , and I. Ugi, Angew. Chem. 81, 572 (1969); Angew.
Chem. internat. Edit. 8, 606 (1969).
[3] W J . Chambers, C. W Tullock, and D. D. Coffman, J. Amer. Chem.
SOC.84, 2337 (1962).
[4] J. Geeuers, W P. Trompen, and J. Th. Hackmann, Rec. Trav. Chim.
Pays-Bas 91,331 (1972).
Disilylmercury and Digermylmercury
By Stephen Cradock, E. A. V Ebsworth, Narayan S. Hosmane,
and Kenneth M. Mackay"]
We have recently prepared trimethylsilylsilane by the reaction
between silyl bromide and bis(trimethylsily1)mercury.This
reaction is very slow in solution. If, however, an excess of
solid mercurial is treated with silyl bromide, trimethylsilyl
bromide is rapidly formed in almost quantitative yield. Trimethylsilylsilane is evolved over a period of days:
H3SiBr + (Me2Si)zHg + Me3SiBr + [Me3SiHgSiH3] * Me3SiSiH3
Reaction of ClN=CCl, with SbF, gives mainly non-volatile
products, but inclusion of CCI,, CC13H, or CC1,F in the
mixture leads to CF,N=CCI, (3). In contrast to the formation
of ( 1 ) in the basic reactions, the source of the extra carbon
atom in (3) is clearly the added chloromethane. An acid-catalyzed reaction of CIN=CCl, with CCl, has been independently reported[41.
(1)
The solid ( 1 ) is soluble in benzene. The NMR spectrum
of the solution showed new peaks at r x 5 (associated with
SiH) and r = 10 (associated with SiCH). Each peak had associated 199Hgsatellites,and both sets of satellites were collapsed
by irradiation at the same 199Hg frequency, showing that
the two resonances were due to the same molecular species.
Table 1. NMR data of trimethylsilyl(silyl)mercury and disilylmercury, and of trimethylsilyl(germyI)mercury and digermylmercury. Chemical shifts in ppm, coupling constants in H z
r(SiH 3JGeH
r(Me,Si)
6('99Hg) [a1
6("Si) [b] Me$
H3Si
'J(HZ9Si)
*J(H 29Si)
2J(H'99Hg)
3J(H'99Hg)
4.98
9.90
+327.1
63.7
- 22.1
178.0
6.0
66.0
54.0
+
5.46
-
+ 196.0
-
10.3
185.0
-
84.0
~
4.54
9.86
+ 159.0
+ 41.1
-
5.16
- 147.45
~
~
6.8
92.0
62.0
~
147.0
~
[a] In ppm relative to Me2Hg (positive to high frequency); in (Me3Si)2Hg the value is +481.0ppm.
[b] In ppm relative to Me& (positive to high frequency); in (Me3Si)lHg the value is +64.0ppm.
N,N-Bis (trijluoromethyl)cyanamide (I)
KF (20mmol) is dried in a Pyrex tube at 120°C in vacuum,
then dry tetramethylene sulfone (2g) is added, and the mixture degassed. ClCN (4.5mmol) is condensed in from the
vacuum system, and the tube is sealed and heated to 60°C
Anyex,, Chpm. inrernar. Edit. J V d .
14 ( 1 9 7 5 ) J No. 3
[*] Prof. Dr. E. A. V. Ehsworth, Dr. S. Cradock, and N. S. Hosmane
Department of Chemistry, Edinburgh University
West Mains Road, Edinburgh EH9 3JJ (Scotland)
Dr. K. M. Mackay
University of Waikato
Hamilton (New Zealand)
167
When equimolar proportions of reactants were taken initially,
the species could be obtained virtually free of SiH3Br or
(Me3Si)2Hg;the relative intensities of the SiH and the SiCH
peaks were roughly 1 :3, and the 29Si and '99Hg INDOR
spectra confirmed the identification of the compound as
Me3SiHgSiH3. Treatment of solid (Me3Si)2Hg with excess
of SiH3Br gives Si2Hbrbut if SiH3Br is added to a solution
of Me3SiHgSiH3 and the solution kept at 50°C for some
days, the yellow color fades; trimethylsilyl bromide is formed
and the 'H-NMR spectrum shows a new resonance at r z 5
with 29Si and '99Hg satellites. The '99Hg INDOR spectrum
shows the seven-line pattern expected for (H3Si)2Hg. Both
(CH3)3SiHgSiH3 and (H3Si),Hg are stable for a matter of
days at room temperature in solution, but the compounds
are exceedingly reactive as solids towards traces of air and
moisture. The NMR parameters for both compounds are
given in Table 1.
Treatment of bis(trimethylsily1)mercury with germyl bromide
leads similarly to the formation of (CH3)3SiHgGeH3 and
(H3Ge),Hg; these two compounds were identified by their
199Hg INDOR spectra (Table 1). The germyl compounds
are much less sensitive than are their silyl analogs to traces
ofair and moisture, but are somewhat less stable over extended
periods in solution.
(rA1
=4.43, 'sB1=6.02, r,,=4.61,
r,,=6.18, r,,=5.53, and
r,,=5.99; J,,,, =J,,,,= JA3B3=9.0Hz) for the methylene
groups at - 106°C were identified by homonuclear INDOR
spectroscopyi4'. They coalesced to a sharp singlet (r = 5.51)
at -36°C. This observation indicates that the ground state
conformation has C l symmetry and examination of models
suggests that the molecule (6) adopts the helical conformation
(Scheme 1).
16c I
11 f6a)
11
Received: August 1, 1974 [Z 110 IE]
German version: Angew. Chem. 87, 207 (1975)
The Conformational Behavior of 6H,12H,18H-5,11,17Trithiatribeozo[a,e,i]cyclododecene
By W David Ollis, J. Fraser Stoddarr, and Michael NdgrbdipJ
The trisalicylides ( I)-(3)[lJ, the hydrocarbon (4)l2], and
its hexamethyl derivative (5)121are conformationally mobile
in solution. Studied'. 21 on these compounds suggest that the
barrier heights for conformational changes in the twelve-membered rings depend on the nature of the substituent atoms
or groups at the ortho positions of the aromatic rings. Since
the hydrocarbon (4) is a rather inconvenient molecule to
study by NMR line shape methods due to the complexity
of the 'H-NMR spectrum of its CH2--CH2 groups, we have
prepared the trithia analog (6), m. p. 197-1 98 "C, by reaction
with sodium hydroxide in
of 2-(~hloromethyl)thiophenol~~~
methanol, in order to investigate a molecule where the ortho
substituents are hydrogen atoms.
(61)
(6el
(6di
Scheme 1. HelixGHelix' inversions required l o exchange the six methylene
protons with six dinerent sites. If (6a), ( 6 ~ ) and
.
( 6 e ) correspond lo Helix
then (6h), (6r/), and (6f) correspond to Helix'.
The rate constants for HelixgHelix* inversion at different
temperatures were determined by comparing the observed
'H-NMR spectra with theoretical spectra generated by line
shape equations suitable for a six-site exchange process
between Hc, HD, HE, HF, HG, and He. Inspection reveals
that there are four ways in which three AB systems can be
assigned to the pairs of sites represented by 1, 2, and 3.
The density matrix approachi5' was used to examine the
exchange process (7). Attempts to perform line shape analyses indicated that only the program constructed on the
basis of the depicted exchange process provides good matches
between computed and experimental spectra over the entire
temperature range.
YA2
A1
\
F==B3
\A3
(7)
B2
Thus, like the hydrocarbon (5)'21, the trithia compound (6)
exists in the helical conformation in solution. However, the
[I]
W D. Ollis and 1. 0. Surherland, Chem. Comm. 1966,402: A. P. Downing,
W D. Ollis, and 1. 0. Surherland, Chem. Comm. 1967, 171; A. P. Downing,
The 'H-NMR spectrum of this heterocyclic compound (6)
in CS2 showed temperature dependence. Three AB systems
[*I
Prof. Dr. W. D. Ollis and Dr. J. F. Stoddarl
Department or Chemistry, The University
Shefield S3 7HF (England)
Dr. M. N6ggradi
Institute of Organic Chemistry
Technical University
Budapest XI. Gellerl ler 4 (Hungary)
168
W D. Ollis, I. 0.Surhurlonrl, J . Mason, and S. F. Mason, Chem. Comm.
1968. 329; A. P. Downing, W D. Ollis, and I . 0.Sutherland, J. Chem. SOC.
B 1970, 24.
[2] D. J . Brickwood, W D. Ollis, and J . F . Storldart, J . C. S. Chem. Comm.
1973,638.
[3] C. W Stat!., F. W Villaesrusa, and 7: E. Wollner, J. Org. Chem. 30.
4074 (1965).
141 We thank Mr. A . G. Ferrige,
Wellcome Research Laboratories, Beckenham, Kent, for obtaining this result.
[S] J. I . Kaplan, J. Chem. Phys. 28, 278 (1958); 29,462 (1958): S . Alexander,
ibid. 37, 967 (1962); 38, 1787 (1963); 40, 2741 (1964); C. S. Johnson, ibid.
41, 3277 (1964): Adv. Magn. Resonance 1, 33 (1965): J . Magn. Resonance
I , 98 ( I 969).
Anguw. Chum. inrrrnot. Edit.
Vol. 14 (1975)
1 No. 3
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