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Carbene-Analogous Germylene Complexes.

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6=4.58 ($5) [CSH~], 4.60 (M,2), and 5.00ppm (M,2)
[C,H,].-The
I3C-NMR spectrum (CD'CI, solution at
- 30°C; rel. CD,Cl, = 54.2ppm) shows six signals at 6 = 275.1
(Ccarbyne),193.4 (CO), 89.5, 72.7, 71.6, and 71.0ppm
(CloH9Fe)[31.
The mass spectrum of ( 2 ) contains the molecular ion at
m/e=572 (referred to Is4W, 56Fe, and 79Br;ion source T04,
50eV).
The reversibility of the oxidation of ( 2 ) was proven by
cyclic voltammetry in 0.5 M KPF6/DME (1,2-dimethoxyethane; -20°C). The difference between the anodic and cathodic
peak potential confirms that a reversible one-electron transfer
is involved, as in the case of ferrocene (FcH). Since the electrochemical oxidation of X(CO),W=C-CrCPh
(X = C1, Br,
I) only takes place irreversibly and does not begin below
the range + 1.5 to + 1.8V us. SCEL4]we attribute the reversible
oxidation of (2) to formation of the carbyne-substituted ferrocenium ion (2)'. There is no indication of a secondary reaction
of (2)+-the quotient of the cathodic and anodic peak currents iPc/iPais almost unity, irrespective of the rate of polarization v. Owing to the withdrawal of electrons from the Fc
system by the complex carbynetungsten group, El 2 ( 2 ) / ( 2 ) +
is shifted about f280mV us. E,,,FcH/FcH+ ; the ratio
iP,(FcH)/iP, (2) yields a diffusion coefficient for (2) which is
smaller than that for ferrocene by a factor of about 2.
aat
10-
at - 78 "C : cryptocrystalline product; decomposes above
70°C; yield 0.80g (70%).
Received. June 24, 1976 [Z 518 IE]
German version. Angew. Chem. 88, 719 (1976)
CAS Registry numbers:
( 1 ), 34691-66-2; ( 2 ) , 60364-07-0; AI2Br,, 18898-34-5; "C, 14762-74-4
[l] Transition Metal-Carbyne Complexes, Part 22.-Part 21 : E . 0.Fischer,
E . W Meineke, and f. R. Kreissl, Chem. Ber., in press.
121 J . A . Connor and J . P. Lloyd, J. Chem. Sac. Dalton 1972, 1470.
[3] Measurements by Dr. F. R. Kreissl. TU Munchen.
[4] If. J. Kalder and 7: Wiirminghauwn, private communication,
[5] G . L. K . Hoh, W E . McEwen, and J . Kleinberg, J. Am. Chem. Soc. 83,
3949 (1961); J. Tirouflet, E . Loairoti, R. Dubard, and J. Kometidu, Bull.
Soc. Chim. Fr. 1963, 857.
Carbene-Analogous Germylene Complexes[**]
By Peter Jutzi and Wolfgang Steiner"]
Using an oxygen-germanium-ylide complex as starting
material we have been able to prepare the first true germylene
complexes. Thus, reaction of pentacarbonyl[dichloro(tetrahydrofuran)germylene]chromium(o) [compound (Z)][']
with
trimethyl(mesity1thio)silane (2u) or trimethyl(methy1thio)silane (26) leads, via loss of trimethylchlorosilane and tetrahydrofuran, to [bis(mesitylthio)germylene]pentacarbonylchromium(o) [compound (3 u ) ] and [bis(methylthio)germylene]pentacarbonylchromium(0) [compound ( 3 b)], respectively.
.-
(CO)5Cr-GeC12 + 2 RSSi(CH,),
Y
t
5-
0-
SR
+
(CO),Cr-G/
-5
-
THF
+
-
2 (CH3),SiCI
SR
(3)
CH3
0
200
400
600
800
(a): R
f
0
.
H
.
E [mV vs. SCE]+
;
(b):R
= CH3
'33
Fig. I . Cyclovoltammogram of a) ferrocene, and b) ( 2 ) at Pt. c = 2 x 1 W 3
mo1.l-l; V = iaamv.s-'.
A linear relationship between I ~ ~ , ~ X F C / X Fand
C + the Hamof the substituents X has been
mett constants om and
demonstrated on many occasions for substituted ferrocenes
(XFc)I5]. From the correlation curves determined by Hoh,
McEwen, and Kleinberc~[~',values of om=+0.45 and
u p =f0.59 were calculated for X = G Z W ( C O ) ~ BThese
~.
values approximate those for X = C = N (om= 0.56;
o,,=+0.66) and thus confirm, in accord with other data,
the "electron attracting" influence of the carbyne group.
+
Experimental:
All operations are carried out in anhydrous, oxygen-free
solvents in an inert atmosphere (Nz).
AI2Br6 (0.79 g, 1.5 mmol) is added spatula-wise at - 78 "C
to a solution of (I) (1.132 g, 2 mmol) in CHzCIz (70ml). The
solution, which changes color from red-black to deep-blue,
is then warmed until gentle evolution of gas occurs. Meanwhile
the solution turns raspberry-red in color. It is now stirred
for 40min at -15°C. Adducts of the carbyne complex with
AI,Br, are destroyed by addition of about 10ml methanol. The
product is purified by column chromatography on silica gel
at -30°C. Dark-red, unreacted (1) is first eluted (with
CHzClz/pentane, 1 : 1). The second, raspberry-red zone is
eluted with pure CH2C12,the eluate evaporated to dryness,
and the resulting residue washed three times with pentane
684
The complexes ( 3 a ) and ( 3 b ) are stable toward atmospheric oxygen but somewhat sensitive toward hydrolysis. They
precipitate as orange yellow cubic crystals [(3 a ) , decomp.
pt. 141"CI and yellow-green needles [(3b) decomp. pt.
112"C], respectively, and are very soluble in chlorinated hydrocarbons, carbon disulfide, and benzene, but only moderately
soluble in hydrocarbons. The structures have been confirmed
by spectroscopic and analytical data and, in the case of (3a),
by an X-ray structure analysis[']. Mass spectra and molecular
weight determinations (cryoscopicallyin benzene) confirm the
monomeric structure of the compounds. In the IR spectra
(in CH2Cl2)three absorptions which correspond to local C4"
symmetry are observed in the region of the vC0 vibrations
[(3a): 2060 (s,Al), 1990 (m,A,), 1955 (s,E) cm-'; ( 3 b): 2050
(s,A,), 1990 (m,Al), 1945 (s,E) cm-'1. The position of the
long-wave A! vibration is indicative of the Ge(SR)' ligands
being good n-acceptors. The synthesis of pentacarbonyl(dichlorogermylene)chromium(o) [compound (411 by cleavage of
(3a) + 213 BCI,
-
c1
( C O J ~ C I - - G ~C(l
+
2 1 3 B(SR),
(4)
p]
Doz. Dr. P Jutzi and Dipl.-Chem. W. Steiner
Institut fur Anorganische Chemie der Universitlt
Am Hubland, D-87M) Wurzburg (Germany)
I**] This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie.
Angew. Chem. Int. Ed. Engl. f Vol. I S ( 1 9 7 6 ) No. I 1
T H F from ( I ) is not possible[']. We have succeeded in preparing this complex, however, by reaction of ( 3 a ) with boron
trichloride.
Compound ( 4 ) precipitates as bright red, needle-like crystals, (decomp. pt. 105"C), has solubility properties comparable
to those of (3 a ) and ( 3 b), but, unlike the latter two compounds, is extremely sensitive toward air and moisture. Its
structure was also confirmed by spectroscopic and analytical
data. Molecular weight determinations and the mass spectrum
are consistent with the monomeric structure of the complex.
IR spectrum: v C 0 (in CH2CI2):2075 (s,Al), 1985 (m,Al),
1960 (s,E) cm-'; vGe--Cl (in Nujol): 360 (w), 320 (w) cm-'.
The germylene complexes ( 3 a ) , ( 3 b ) , and ( 4 ) can be readily
converted into the corresponding ylide complexes by addition
of bases (ether, tertiary amines, or tertiary phosphanes).
Experimental
Preparation of (3a) and (3b): 20 mmol of (2) or ( 3 )
[4.48 g ( 2 ) ; 2.40g ( 3 ) ] is added dropwise to a solution of
(1) (IOmmol, 2.04g) in benzene (30ml) and the mixture is
stirred for 30min at 50°C. After removal of volatile components the remaining oil is extracted with petroleum ether
(boiling range 50-70°C). On concentration of the extract
( 3 a ) and ( 3 b ) , respectively, crystallize out. Recrystallization
from petroleum ether affords the analytically pure complexes.
Yields: 4.50g (79 %) ( 3 a ) ; 0.7g (19 %) (3b).
Preparation of ( 4 ) : A solution of ( 3 4 (10mmo1, 5.67g)
in 100mI petroleum ether (boiling range 50 to 70°C) is added
to a solution of BCI3 (6.8mmo1, 0.80g) in 50ml petroleum
ether at - 30°C. An orange-yellow precipitate of ( 4 ) immediately separates out and is filtered after 30 minutes' stirring
at 0°C. Recrystallization from petroleum ether affords analytically pure ( 4 ) . Yield 1.25g (37 %).
was considered the best candidate for initial model experiments
on account of the two catechol partial structures already
present.
We were able to prepare the crown-ether type bridged
analog of benzo[l5]crown-5['], papaverine derivative (2)
(m.p. 104"C),in 25% yield by reaction of the doubly demethylated papaverine ( I b ) with 1,11-dichloro-3,6,9-trioxaundecane without employing the dilution principle[31.
RO
RO%
OR'
OR'
(1)
(a): R = R' = CH,
( b ) : R = CH,, R ' = H
(c): R = R ' = H
12). n
=
1
Reaction of the hydrobromide of (1c) r2,41 with 1,l l-dichloro-3,6,9-trioxaundecaneafforded a doubly crowned product of the composition ( 3 ) or ( 4 ) (m.p. 109--110°C; sinters
at 100°C) in 20 % yieldI31. From a comparison of the NMR
spectra of (2) and ( 3 ) it was assumed that (3) was present,
yet nanogram thin-layer chromatography of the analytically
pure substance (silica gel F254, methanol/water = 1 : 1 )
revealed the presence of further components, presumably ( 4 a),
( 4 b ) or corresponding oligomers.
The composition of (2) and (3) was confirmed by elemental
analysis and by high resolution mass spectrometry.
Received: July 28, 1976 [Z 526 IE]
German version: Angew. Chem. 88, 720 (1976)
CAS Registry numbers:
( I ) , 60260-16-4; ( Z a ) , 60253-72-7; (26), 3908-55-2; ( 3 a ) , 60260-11-9; (36),
60260-12-0; ( 4 ) , 60260-13-1 ; BC13, 10294-35-5
[I] P. Juczi and M! Striner, Chem. Ber. 109, 3473 (1976)
[2] G. Hurtner, unpublished work.
Papaverine Crown
Ethers[**]
By Fritz Vogtle and Klaus Frenschy]
The endohydrophilic/exolipophilic structure of the crown
ethers permits lipophilization of alkali metal ions. As synthetic
analogs of the well-known ionophores, neutral ligands of the
crown ether type have contributed greatly to our understanding of selective ion transport processes in biological membranes.
The present communication concerns the novel concept
of altering the hydrophilicflipophilic properties of physiologically active molecules by intramolecular incorporation of
crown ether rings and especially of enabling or facilitating
selective complex formation with alkali or alkaline-earth metal
ions. Thereby it ought to be possible to modify the physiological action, e. g. as regards rate and site of attack. The isoquinoline alkaloid papaverine ( I a ) , that constitutes about 0.5 to
1.O % of opium and is used as an antispasmodic, e. g. for
relieving spasms of the gastro-intestinal and the bile duct,
[*] Prof. Dr. F. VogtleI'[
and K. Frensch
lnstitut fur Organische Chemie und Biochemie der Universitat
Max-Planck-Strasse 1, D-5300 Bonn (Germany)
['I Author to whom correspondence should be addressed.
[**I This work was supported by the Fonds der Chemischen Industrie.
Angex'. Chem. I n r .
Ed. Engl. J Vol. IS ( 1 9 7 6 ) N o . I 1
The 'H-NMR spectra of (2) and ( 3 ) show besides the
characteristic signals for the papaverine m~iety[~'-including
the benzyl -CH2singlet at 6 =4.52 ppm - the characteristic
-OCH2-- absorption pattern for the crown ether bridges
centered around 6 = 3.75 and 3.95 ppm (in CDCI3 and CD30D,
resp.).
While solid potassium permanganate cannot be dissolved
in chloroform with papaverine, this is readily possible with
the bridged papaverines (2) and ( 3 ) . As expected the violet
color of the solution is much more intense with the doubly
crowned ether ( 3 ) than with ( 2 ) . ( 2 ) , of which we obtained
gram amounts, reacts with Ca(SCN)2.4H20even in the cold
in ethyl acetate with formation of mm-long crystalline needles
of the 1 : 1 complex, which contains one molecule of water
of crystallization and melts at 173"C[61.Its IR spectrum
shows a strong and sharp characteristic band at 2055 cm-',
its 'H-NMR spectrum slight shifts of the O C H 2 - C H 2 0 protons [in (CD3)2SO].
685
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