вход по аккаунту


Dimethylcarbene- and Methylphenylcarbenedicarbonyl(-cyclopentadienyl)manganese.

код для вставкиСкачать
The identity of (2) was ascertained by spraying the chromatograms with a 1 % solution of K M n 0 4 in 2 % aqueous
sodium carbonate. This reagent is relatively unreactive towards
( 4 1 , but rapidly oxidizes (2) at the olefinic double bond141.
This reaction was accompanied by a loss of 3H-radioactivity
in the respective spot to 38 % of the original value. Compound
( 4 ) was occasionally observed in larger amounts than in
Figure 1, but was often also not detected at all. Since ( I )
undergoes reductive Co-C bond cleavage to yield (4)L5l,
we consider it as a by-product of a side-reaction unrelated
to the process of enzymatic catalysis.
Compound (2) was detectable only if the incubations were
performed with exclusion of oxygen and mild methods of
work-up, such as lyophilization at - 78°C (dry ice/acetone),
and with active enzyme preparations['].
Analogous experiments with purified ethanolamine
ammonia lyase produced similar results ;a radioactivity profile
of a chromatography strip is shown in Figure 2.
[5-3Hl-Coenzyme BI2
Dimethylcarbene- and Methylphenylcarbenedicarbonyl(q-cyclopentadieny1)manganese"1
By Ernst Otto Fischer, Roger Lee Clough, Gerhard Bed, and
Fritz Roland Kreissl[*j
The novel manganese compounds ( 1 ) and (2) are the
first transition metal-carbene complexes in which a dialkyl
or an alkylarylcarbene is stabilized as ligand to a metal atom,
in this case manganese. Diarylcarbene complexes of the same
system have already been reported[''.
(I) and (2) are formed on reaction of the cationic carbyne
complexes ( 3 ) and ( 4 ) , respectively, with methyllithium:
BCL- + LiCH,
Received: March 26, 1976 [Z 456 IE]
German version: Angew. Chem. 88, 583 (1976)
CAS Registry numbers:
13870-90-1 ; (21, 20535-04-0; ( 3 ) , 18534-66-2; ( 4 ) . 4754-39-6
( 1 9 7 6 ) No. 9
The 'H-NMR spectrum of ( I ) contains two sharp peaks
at 6=5.07 (C5H5)and 3.02ppm (CH3) in the intensity ratio
5 : 6 (in, [D,]-acetone, relative to CD2HCOCD3 = 2.03 ppm).
(2) shows a multiplet at 7.2ppm (C,H,) and two singlets,
one at 4.75 (C5H5) and one at 3.15ppm (CH3) (intensity
ratio: 5:5:3 recorded in CDC13, rel. to TMS int.).-In the
I3C-NMR spectrum the signal of the carbene carbon of ( I )
and of (2) appears at much lower field than that of (6).
"C-NMR shifts [ppm]. recorded at - 5 5 C in [DJacetone.
CD,COCD, =206.5 ppm.
1 Vol. 15
'C0 C H 3
C . N . Schrauzcr and J . W Siberr, J. A m . Chem. Soc. 92, 1022 (1970).
C. N . Schrauzer and E . A. Sradlbauer, Bioinorg. Chem. 4, 185 (1975).
No other nucleoside fragments were detectable provided that light was
carefully excluded during the enzymatic reactions and work-up procedures.
Personal communication from Dr. J . Verheydm, Syntex S . A.. Stanford.
Calif. (USA).
G. N . Schrauzer, J . A. Seck, R. J . Holland, 7 M . Beckham, E . M . Ruhin,
and J . W Sihert, Bioinorg. Chem. 2, 93 (1972).
The experiments were performed in Pyres centrifuge tubes of 15ml
capacity which were rubber-serum-capped, flushed with pure argon for
20min, and covered with aluminum foil for protection against light.
O n e vial of the commercial enzyme (29mg, 7.0 units) was dissolved
in 7.0ml of 0.01 M potassium phosphate buffer (pH 7.4) containing 2 %
viv of D,L-propanediol. As a rule, 0.9 ml of enzyme stock solution was
injected into the centrifuge tubes and the reaction was initiated by
the addition of 0.1 ml of a solution containing 12.6nmoles of coenzyme
B L ~The
'H-activity of the coenzyme solution added was 11.3nC
(25 000 cpm).
A n q t w . Chriii. I n f . E d . Engl.
- 401- 50 "C
The red, crystalline products are readily soluble in organic
solvents. Their composition and structure follows from elemental analysis and spectroscopic investigations.
In each case the IR spectra (in n-hexane) show two intense
bands in the vco region. Their shift to higher wave numbers
compared to the analogous phenylmethoxycarbene complex
(6)r3l supports the assumption of stronger back-bonding from
metal to carbene carbon.
Fig. 2. Radioactivity profile of a paper chromatogram (Whatman No. I )
of the freeze-dried residue of a reacting solution of ethanolamine deaminase
incubated with 5'-'H-labeled coenzyme B,2 (reaction conditions as outlined
in Refs. [2] and [6]).
The detection of (2) in two coenzyme BI2-dependent
enzymes supports our concept according to which ( I ) is
enzymatically activated by Co-C-bond heterolysis rather than
homolysis and that the highly nucleophilic Co(r)-derivative
of the corrinoid cofactor is the catalytically active species.
1 18.90
rel. to
The mass spectra contain the molecular ion peaks at
m/e=218 [ ( l ) ] and 280 [(2)], respectively, as well as peaks
[*] Prof. Dr. E. 0.Fischer. R. L. Clough, Ph. D., DipLChem. G. Bed,
and Dr. F. R. Kreissl
Anorganisch-chemischer lnstitut der Technischen Universitit
Arcisstrasse 21, 8000 Munchen 2 (Germany)
due to fragments after successive loss of two C O groups,
the carbene residue, and the C5H5 ligand.
All work is carried out in anhydrous and oxygen-free solvents under Nz.
Dicarbonyl( ~-cyclopentadienyl)methylcurby~emun~anese
tetrachloroborate ( 3 ) : BC13 is added to a stirred solution
ofC5HsMn(C0)2C [CH3(0CH3)][31(1.76g, 7.5 mmol) in pentane (100ml) at -40°C. The precipitate which is formed is
filtered off, washed several times with pentane, and dried
in a high vacuum. For further purification the substance is
dissolved in CH2Clz and covered with pentane. After drying,
analytically pure ( 3 ) is obtained in the form of a finely crystalline, yellow-orange thermolabile powder. Yield 2.16 g (80.7 %).
Dicarbonyl( ~~-cyclopentadienyl)dimeth~lcarbenemanganese
(I): To a suspension of ( 3 ) (1.94g, 5.45mmol) in pentane
(50ml) at -40°C is added a suspension of LiCH3 (120mg,
5.45mmol) in the same amount of the same solvent. After
3 hours' stirring at -40°C the red solution is separated from
the solid components of the reaction mixture, concentrated
to 50m1, and chromatographed on a silica gel column at
-25°C with pentane. Of the three zones which are formed
the middle (red) one contains the desired product. After removal of solvent and recrystallization, (1) is obtained as dark
red crystals which melt below room temperature. Yield: 220mg
(1 8.5 %).
Dicurbonyl[ ~-c'~~cloprritodieii!~l)
methylphen~lcurbenet~~ungccnese ( 2 ) : To a suspension of (4)[41 (3.1 g, 7 mmol) [preparation analogous to that of ( 3 ) ] in pentane (20ml) is added
a solution of LiCH3 (10.5mmol) in ether. The mixture is
stirred for 7 h at - 50°C. After removal of solvent the residue
is chromatographed on silica gel at -4O"C, first with pentane
and later with pentane/ether. After two recrystallizations from
pentane, ( 2 ) is obtained as red crystals, m. p. 35-36°C. Yield:
260 mg (14 %).
Received: April 20. 1976 [Z 466 IE]
German version: Angew. Chem. 88, 5x4 (1976)
CAS Registry numbers:
( I ) , 59831-13-9; ( 2 ) . 59831-14-0; 13). 59831-16-2; ( 4 ) . 59831-18-4
(61, 12245-61-3; LiCH,. 917-54-4; C,H,Mn(CO),C[CH,(OCH,)1.
Transition Metal-Carbene Complexes, Part 91.-Part 90: E. 0.F i x h and M! Held, J. Organomet. Chem. 112,C59(19761.
[2] W A . Herrmunti, Chem. Ber. / O X , 486 (1975).
[3] E. 0.Fischer and A . Maashiil, Chem. Ber. 100, 2445 (1967).
[4] E. W Mritieke, Dissertation. Technische Universitit Miinchen 1975.
Intercalation Compounds of Zirconium Phosphate
By Dietmar Behrendt, Klaus Beneke, and Gerhard Lagaly[*]
The ability of layer compounds to form intercalation compounds requires a particular kind of structure and bonding
between the layers. Apart from graphite only few inorganic
layer compounds capable of intercalating neutral molecules
between the layers were hitherto known : kaolinite[']; binary
sulfides like TiS2 and TaS2[']; and crystalline silicic acidsL31.
We have now found that crystalline MIv phosphates
M(HX04)Z.nHz0, with M=Zr, Si, Sn, Ce and X=P, As
take up certain neutral molecules to form a large number
of intercalation compounds. Zirconium phosphate
[*] D. Behrendt, K. Beneke. and Prof. Dr. G. Lagaly
Institut fur Anorganische Chemie der Universitat
Olshausenstrasse 40/60, 2300 Kiel (Germany)
Zr(HP04)2.nH20(n=O, 1, 2) may be cited as an example.
The layer structure of the monohydrate was established by
and confirmed with the aid of cation exchange
experiments with n-alkylarnmonium ions by Michel and
All three hydrates can be used for formation of intercalation
compounds. For this purpose the zirconium phosphates are
allowed to react for several days at 6C-80"C with the corresponding liquids, and in the case of solid guest componds
with an excess of a concentrated aqueous solution.
Zr(HPO4j2.2H20 (y-ZrP according to ref. I4I) reacts with
a larger number of guest molecules than the monohydrate
(a-ZrP) because the zirconium phosphate layers are widely
separated from each other by bimolecular water layers. y-ZrP
also reacts wjth long-chain compfunds (e.g. hexanol :basal
spacing :24.9A ; butyronitrile :21.3A). The intercalation compounds of Zr(HP04)2(p-ZrP) are identical with those of y-ZrP
provided they are not prepared with exclusion of water because
P-ZrP immediately transforms into y-ZrP in the presence of
The basal spacings of the intercalation compounds of a-ZrP
and y-ZrP are different (Table 1). In a-ZrP they repeatedly
suggest that the H 2 0 molecules are replaced by approximately
Table I . Basal spacings dL of the intercalation compounds of Zr(HP04),. H 2 0
(a-ZrP) and Zr(HPO4),.2 H 2 0 (y-ZrP).
Intercalated molecule
Dirnethyl sulfoxide
N,N-Dimet hylformamide
Urea [a]
N,N-Dimethylurea [a]
N,N'-Dimethylurea [a]
Hydrarine hydrate
Basal spacing dL [A]
_ _ ~ . . _ _ _ _ _ _ _ _ _
14. I
[a] Concentrated aqueous solution
spherical guest molecules (Table 2). The increase in basal
spacing AdL is then equal to the diameter of the intercalated
molecule D minus 2.8A (diameter of a water molecule). Of
course, this cannot hold if the intercalated molecule is unable
to adopt a spherical shape, as in the case of piperidine. Urea
compounds warrant interest; only the unsymmetrical methyl
derivative ( 5 ) appears to assume a spherical shape.
The intercalation compounds of cc-ZrP are characterized
by their remarkable stability. The guest molecules are retained
so firmly between the layers that their removal is difficult
even in uucuo above 100°C. The monohydrate itself displays
similar stability.
Many guest molecules in y-ZrP replace only one H 2 0 molecule; the increase in basal spacing is then equal to or slightly
greater than D minus 2.8 A. In some cases (urea, N,N-dimethylurea, glycol, glycerol) both H,O molecules are replaced by
an intercalated molecule (AdL significantly smaller than D
minus 2.8 A).
The reaction of cc-ZrP and y-ZrP with alkylamines[61 to
form compounds*with large basal spacings (e.g. cc-ZrP
hexylamine: 23.3 A; + dodecylamine: 36.4 A)is also an intercalation reaction. However, the alkylamines are bound with
formation of alkylammonium ions and unlike the other intercalated compounds cannot be washed out.
Zirconium phosphate has a number of superior properties
compared with other intercalating compounds: apart from
their ability to intercalate neutral molecules between the layers,
their protons have been known for some time to be susceptible
to cation exchange reactions in the normal pH range, in
Anyew. Chrm. l n t . Ed. Engl.
/ Val. 1 5 ( 1 9 7 6 ) No. 9
Без категории
Размер файла
240 Кб
dimethylcarbene, methylphenylcarbenedicarbonyl, cyclopentadienyl, manganese
Пожаловаться на содержимое документа