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Arsenic Oxide Trichloride AsOCl3.

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dent reflections for 8=28" measured on a Siemens AED instrument
with Mo-K, radiation: R =0.057. R,=0.059. Programs by Shrldrick
[5] where used for the calculations.
[5] G M. Sheldrick, Cambridge. unpublished.
= 1.616A. S-.S=2.58
[6] Bond lengths and angles in free S,N4[7](S-N)
and 2.59A; (SNS)=113". (NSN)=105".
[7] B. D Sharma and J . Doitohue, Acla Cryst. 16, 891 (1963).
[I] Thioanhydrides of dithiocarbamic acid [(R,NCS),)S] and xanthic acid
[(ROCS),S] have been reported: D H. Powers. U. S. Patent 1788632
(Jan. 1930): Chem. Abstr. 25, 4890 (1931): A. Gurtncinn, Ber. Dtsch.
Chem. Ges. 56. 2365 (1923); S. N . Dafiiloc,and N . M. Grad, Zh. Obshch.
Khim. 17. 2193 (1947); Chem. Abstr. 43, 1181 (1949): S. V Zhurorln
and M . 1. Galrhefiko, Zh. Prikl. Khim. 20, 1038 (1947): Chem. Abstr.
43, 143 (1949); J . Wor.trtiawt and C. Grittow, 2. Anorg. Allg. Chem.
377. 79 (1970); M . M t ~ r o o k r i 7:
, Yurnr~moto,and 7: Trrkr.shi~tia,Bull. Chem.
SOC.Jpn. 48. 2462 (1975).
Isolation of Crystalline Bis(thioacy1) Sulfides
By Shinzi Kato, Tomonori Katada, and Masateru Mizuta[*]
While carboxylic anhydrides are well known, their sulfur
analogs (3) have remained unknown so far because of their
instability['].
We now report the isolation of the first bis(thioaroy1) sulfides
(3). The compounds listed in Table 1 are obtained on reaction
of aromatic dithiocarboxylic acids ( 1 ) with dicyclohexylcarbodiimide (2) at 0°C. The crystalline thioanhydrides (3a) and
(3 b ) are fairly stable in the solid state at room temperature
in thedark, but the oily compounds (3c) and (3d) decompose
completely within 1 h under similar conditions.
U
13)
Arsenic Oxide Trichloride, AsOC13[**I
By Konrad Seppeltl*]
Like arsenic pentachloride, which remained undiscovered
for some 140 years, existence of the oxide chloride of arsenic,
AsOC1, has so far not been reported. On the other hand
POCl, has been known since 1847 and is presently produced
on an industrial scale.
Two problems were expected to beset the preparation of
AsOC1,: a) decomposition with evolution of chlorine and
reduction to trivalent arsenic, and b) the tendency of the
As=O double bond to polymerization, for AsOF3 is known
only in the polymeric form1']. Attempts to prepare AsOC1,
by careful hydrolysis of A S C I , ~met
~ ~without success because
the HCI formed catalyzed the decomposition of AsCl5. However, AsOC1, can be prepared surprisingly simply by ozonization of AsC1, in inert solvents at low temperatures.
The reaction proceeds quantitatively and results in precipitation of AsOCl,. Its structure is proved by the mass spectrum
Table I . Bis(thioaroy1) sulfides ( 3 ) synthesized.
R
Yield
[ Y,]
M. p.
["CI
80
74 -75
U V (cyclohexane)
/.."AX
~~
( 3 ~ )
CHJ
(3h)
CH,O
85
65-66
(30
H
75
Oil
(3d)
CI
78
Oil
334 nm
(25000)
355 nm
(35900)
307 nm
(14600)
323 nm
(16800)
568 nm
1232, 1242
( 150)
559 nm
(365)
548 nm
(145)
548 nm
1245. 1270
1245 [a]
1245 [a]
(I5 5 )
[a] Neat.
The structures proposed for (3a) to (3d) are in accord
with the results of elemental analysis and UV, IR, and 'HNMRspectroscopicdata.The UV absorption at 310 to 350nm
is due to the x+x* transition, and that at 550 to 570 to
the n+x* transition of the thiocarbonyl groups.
[nz/e=196 (AsOCI:, 420/,), 180 (AsCI:, 50%), 161 (AsOClt,
loo%), and other fragments], the Raman and IR spectrum
(987 cm p, 441 dp, 412 p, 256 dp, 201 p, 160 dp) and by stoichiometric take-up of ozone.
AsC1,
Experimental:
Freshly prepared 4-methyldithiobenzoic acid ( I a ) (3.36 g,
0.02 mol) and N,N'-dicyclohexylcarbodiimide (2) (2.06g,
0.01 mol) are stirred in n-hexane (80ml) under nitrogen for
I h at 0°C. Removal of the precipitate (N,N'-dicyclohexylthiourea, 2.28 g) by filtration, evaporation of the solvent, and
recrystallization of the resulting residue from petroleum ether
(b. p. <4O"C) gives dark green needle crystals of bis(4-methyl(CC14): F
thiobenzoyl)sulfide (3a) (2.46g, 80 %).-NMR
[ppm]: 2.32 (s, 6H, CH3), 7.05 (ca. d, 4H), 7.82 (ca. d, 4H).
Received: August 27. 1976 [Z 547 I€]
German version: Angew. Chem. 88. 844 (1976)
CAS Registry numbers:
(Iu).2168-80-l;(lh).2168-77-6;(1c).
121-68-6:(ld), 2168-82-3; 1 2 ) . 538-
75-0:(3rf).60410-77-7:(3h).60410-78-8:(3c),21778-02-5: ( 3 d ) . 60410-79-9
[*] Prof. Dr. S. Kato
[+I,
T. Katada. and Prof. Dr. M. Mizuta
Department of Chemistry. Faculty of Engineering. Gifu University
Kagamihara. Gifu 504 (Japan)
[ + ]T o whom correspondence should be addressed.
766
AsC1,
H2OIHCI
+
AsC1, + Cl,
CI:CI,/CH2C12
0,
- 78 "C
AsOC1,
+
0,
Arsenic oxide trichloride is a colorless, crystalline solid,
which is considerably more thermally stable than arsenic pentachloride. As expected AsOC1, has a pyramidal structure,
the oxygen atom being double bonded. This is confirmed
by the Raman spectrum, which closely resembles that of AsC13
with regard to some of the bands. A calcFlation of force
constant^'^] gives a value of f= 7.47 mdyne/A for the arsenicoxygen bond, i. e. AsOC1, is one of the few compounds containing a real arsenic-oxygen double bond. The calculation also
-
[*] Priv.-Doz. Dr. K. Seppelt
Anorganisch-chemisches lnstitut der Universitiit
Im Neuenheimer Feld 270. D-6900 Heidelberg 1
[**] This work was supported by the Fonds der Chemischen Industrie.
The mass spectra were recorded by Dr. R. Grisr.
An{/rw. Chrm Ifrr. €d. €fig/. i Vol. 15 ( 1 9 7 6 ) No. I 2
shows that the strength of the arsenic-chlorine bond increases
[2.04+2.59 mdyne/A] in the transition AsCl3+AsOCI3,
exactly as in the system PCI3+POCl3 [2.34-+2.98 mdyne/A].
The compounds are therefore also related in the details of
their bonding.
AsOCI3 slowly decomposes at -25"C, and much more
rapidly at ca. O'C, with formation of As2O3Cl4.
3 AsOC1,
+ C12 + As20,C14
+ AsC1,
This compound is stable up to 150°C. Its vibrational spectrum reveals disappearance of the As=O double bond, thus
ruling out the structure P2O3CI,[Cl2P(O)-O-(0)PCl2].
It is also not volatile, but decomposes above 200°C with loss
of AsCI3+Cl2 to give "AszOS"-a process which can be
readily monitored in the mass spectrum.
As203CI4 is obviously a polymer. I t can be isolated in
analytically pure form, but is X-ray amorphous. No crystallization takes place even after 50 hours' annealing at 120°C.
In this compounds arsenic is doubtless pentacoordinated, or
hexacoordinated by way of chlorine bridges.
Recrystallization of (3) from ether gives
(COD)2CoLi(THF)2( 3 a )
and on addition of dimethoxyethane (DME), yellow crystals
of
(COD)2CoLi(DME)3( 3 h )
are obtained. The new cobalt complexes ( 3 ) were characterized
by metal analyses and by their reaction with CO, in which
four C O per LiCo were consumed with displacement of COD.
The IR spectrum (THF) shows all four double bonds are
complexed both in (3) and in the isoelectronic compound ( I ) .
The 'H-NMR spectrum ([D,]THF, RT) of (36) displays
two broad signals at ~ = 7 . 5 7(--CH2) and ~ = 7 . 9(CH=CH),
intensity ratio 2 : 1, for the cyclooctadiene.
Received: September 14, 1976 [Z 559 IE]
German version: Angew. Chem. 88, 806 (1976)
CAS Registry numbers:
AsOCIJ. 60646-36-8: ASCIS,7784-34-1 : 0 s . 10028- 15-6: A s ~ O ~ C I60646-37-9
J.
[ I ] W Dr/iiiicke and J . Weidlriri. Z. Anorg. Allg. Chem. 342. 225 (1966).
[2] K . Seppelt. Angew. Chem. X8. 410 (1976): Angew. Chem. Int. Ed. Engl.
15. 377 ( I 976).
[3] Calculation according to the method ofJ. Becher and R . Motre.+,Spectrochim. Acta, Part A, 23, 2449 (1967).
Bis(q-l,5cyclooctadiene)cobaltlithium
By Klaus Jonas, Richard Mynott, Carl Kriiger, Janine C . Sekutowski, and Yi-Hung Tsay[*l
Nickel(o)-olefin complexes which d o not contain
pronounced acceptors as ligands form defined dilithium-nickel-olefin complexes with lithiom[']. We now wish to report
a further example of this class of compounds.
Reaction ofmetallocene complexes (C5H&M with an alkali
metal leads to release of the two C5H5 rings and formation
of alkali metal-CsHS and elemental transition metal[21. In
the case of cobaltocene and nickelocene we have now found
that the deposition of transition metal is suppressed on addition of cyclooctadiene (COD). The new cobalt complex (3)
and the known nickel complexes (1)[31 and (2)"' can then
be isolated in high yield [ e . g . (3): 85 %]['I.
(CsH5)zCo
LI. COD
C ~ H ~ C O C O+D L I C ~ H ,
THF. 0°C
THF. 0°C
1
2 LI. COD
(COD)ZCoLi(THE'), 1 3 )
2 LI.2 COD
(C,H5)2Ni
THF. 0°C
(C0D)zNi
+
+
L1C5H5
2 LiC5H,
(1)
THF.0-C
1
2 LI
(COD)2K~Li2(THF)4
(2)
[*I
Dr. K. Jonas ['I, Dr. R. Mynott [**I, Dr. C. Kruger [***I, Dr. J. C.
Sekutowski [***I [****I,and Dr. Y.-H. Tsay [***I
Max-Planck-Institut fur Kohlenforschung
Lembkestrasse 5. D-4330 Mulheim (Germany)
['I
T o whom correspondence should be addressed.
[**] '-'C-NMR spectra.
[***I X-Ray structure analysis.
[****] J . C S. thanks the Deutsche Forschungsgemeinschaft for a study
grant.
A i i g w . Climni. I i i r
Ed. Engl.
1 Vol. 15 ( 1 9 7 6 ) No.
12
Fig. 1. Crystal structure of (COD)ICoLi(THF), (30)
Figure 1 shows the result of an X-ray structure analysis
of ( 3 a ) [a=14.094(1), b= 18.799(3), c = 17.500(3)&
/?=97.74(1)", space group C2/c, 3219 reflections, 1485 unobserved, R =0.064]. The bond angles at the cobalt atoms diverge
'pairwise so markedly from an ideal tetrahedron (such as occurs
in the isoelectronic complex Ni(COD)2141)that the molecule
is better described as a trigonal bipyramid. Its equatorial
positions are occupied by Li and by one double bond each
of the two olefinic ligands [ C l - C S : 1.413(7)A; C 1 1 4 1 8 :
1.419(7)A]. Owing to bridging with the axial positions of
the Co [C4-C5: 1.391(8)A; C 1 4 4 1 5 : 1.401(8)A] the COD
ligands assume a highly distorted boat conformation. Short
L i - C distances ( L i - C I ; L i - C l 1) indicate strong ion-pair
interaction['] between the Li atom in a tetrahedral environment and C atoms of the double bonds in equatorial positions.
The L i - C o distance [2.654(8)A] is significantly longer than
the sum of the respective covalent radii.
The 13C-NMR spectrum[61of ( 3 a ) at room temperature
shows only two signals for the C O D at 69.1 and 34.7ppm
([D,]THF) or at 69.5 and 33.7 ppm ([D,]toluene). On cooling a
solution in [DJTHF the C O D signals become much broader
only below -60°C. In [D,]toluene, on the other hand, broadening begins at O'C, and at -77°C eight signals of approximately equal intensity are observed. Four of the signals lie
at 79.6, 74.3, 71.5, and 50.7 ppm (all d, average chemical shift
69.0ppm), and the other four at 38.3, 38.0, 30.2, and 29.0ppm
(all t, average chemical shift 33.9 pprn). These temperature
effects are reversible. The 13C-NMR spectrum of ( 3 a ) in
[D8]toluene at -77°C is compatible with the structure of
the crystalline complex: owing to the equatorial position of
the Li atom on the cobalt, four distinct pairs of olefinic and
aliphatic C atoms are expected. On raising the temperature
in [D8]toluene, the Li atom is found to undergo a shift in
767
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