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Formation of Electron-donor-acceptor Complexes as a Basis for Specific Adsorption.

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local conversion into unilaterally binding sp hybrid quantum
states bonds can be broken easily while others are strengthened[2,31. The high mobility of the electrons, and thus of the
atoms themselves, should lead to great reactivity of the
atoms and hence to crystallization of the melt.
These relations were verified experimentally for thc systcms
Ge- Sb-Se and Ge--As-%. The electrical conductivity
could be measured up t o high temperatures by a new, very
rapid, electrodeless method 141.
Figure 1 shows the glass-forming region for slow and rapid
cooling in the system Ge-Sb-Se. Glass-forming melts are
Far
semiconducting, with a wide forbidden zone (symbol 0).
Ge
[*I Dr. R. W. Hnisty
Texas Instruments Inc.
Dallas, Texas 75222 (USA)
Prof. Dr. H. Krebs
Institut fur anorganische Chemie der Universitat
7 Stuttgart N,Schellingstrasse 26 (Germany)
I**]
Ct'. R. W . Ifaisty, Dissertation, Universitat Stuttgart, 1968;
R . W. Haisty and H . Krebs, J. non-cryst. Solids, in press.
111 H. Krebs, Angew. Chem. 78, 577 (1966); Angew. Chern. internat. Edit. 5, 544 (1966).
[2] H. Krebs: Grundziige der anorganischen Kristallchemie.
Enke, Stuttgart 1968; translated by H. P . L. Walter: Fundamentals of Inorganic Chemistry. McGraw-Hill, London 1968.
[ 3 ] H . Krebs, V. B. Lnzarev and H. Winkler, Z. anorg. allg.
Chem. 352, 277 (1967).
[4] R. W. Haisty, Rev. sci. Instruments 38, 262 (1967); 39, 778
(1968).
[ 5 ] R. J . Patterson and J . M . Brau, Paper, Electrochem. SOC.
Meeting, Cleveland, Ohio, 1966.
Formation of Electron-donor-acceptor Complexes
as a Basis for Specific Adsorption
By H. Stetter and J. Schroeder [ *I
Fig. I . Glass-forming region in the system Ge-Sb-Se on slow (-)[51
and rapid (- - -) cooling. Typical electrical conductivity curves for the
compositions 1,2,3, and 4 are reproduced in Fig. 2.
We have begun a study of whether the formation of electrondonor-acceptor complexes can be used for specific adsorption
in the chromatography of compounds of high molecular
weight [I]. The most suitable substrates proved t o be cellulose
esters of 3-(pentamethylpheny1)- (1) and 3-(9-phenanthryl)propionic acid (2) [*I, which can be prepared from mercerized
cellulose and the chlorides of the two acids [31. Each glucose
unit could be erterified with 2-3 equivalents of the acid.
outside the glass-forming region the melts have metallic conHowever, relatively high but non-metallic conductivity .).(
ductivity (@) i s found in a transition region; there the melts
seem to be biphasic in microregions, containing metallic
lo7,
-
-
1000800 600
t I"C1
400 300
200
The new cellulose esters permit appreciably better separation
of aromatic nitro compounds and of quinones than is possible
on commercial cellulose powder or silica gel (Figs. 1 and 2).
I
/
do'o,
10-l
I"
0
0
OO
00
0 0 0 0 0
a
Fig. 2. Electrical conductivity of Ge-Sb-Se
compositions 1,2,3, and 4 (cf. Fig. 1).
melts - curves for the
conducting micelles (enriched in Ge and Sb) within a semiconducting matrix (enriched in Se). Crystallization of antimony-containing selenium melts is made easier by a catalytic
influence of the antimony.
IZ 884b IEI
Received: August 21, 1968
German version: Angew. Chem. 80,999 (1968)
948
0 0 0 0 0
b c d e l i a b c d e
2
3
Fig. I .
Thin-layer chromatogram of (a) rn-nitrotoluene. (b) p-nitrotoluene, (c) 2.4-dinitrotoluene, (d) 2,4,6-trinitrotoluene. (e) mixture.
1 = M N silica gel, 2 = cellulose estel of ( I ) , 3 = cellulose ester of ( 2 ) .
Eluant: etherllight petroleumlacetone 50:40: 10. Color of the complexes:
yellow-red.
Moreover the position of the substances o n the plate can b e
easily determined by the color of the donor-acceptor complexes formed. We consider this principle of specific adsorption 10 be capable of extension.
Angew. Chem. internat. mit. Vol. 7 (19681 / N O .12
1,5,9-Cyclododecatriene Complexes of Nickel(0) [*:Dl
By K. J m a s , P. Heimbach, and G. WiZke[*l
00000
2
a b c d e
3
Fig. 2. Thin-layer chromatogram of (a) chloranil, (b) tetrachlorohydroquinone, ( c ) l,Z-naphthoquinone, (d) 1,4-naphthoqumone, ( e ) mixture.
Adsorbant and eluant as for Fig. 1. Color of thecomplexes: yellow-red.
Cellulose ester of' ( I ) :
Mercerized cellulose[41 (10.6 g) is made into a slurry with
pyridine (22 ml) and djoxane (78 ml). T h e acid chloride (56 g)
of ( I ) in dioxane (200 ml) is added and the whole is heated at
95 "C for 24 h, and the ester is then precipitated by pouring
the mixture into methanol (500 ml). The ester is isolated,
boiled with acetone, triturated with a little methanol for 3 h
in a ball mill, filtered off, and dried (yield 39.6 g; insoluble in
alcohols, sparingly soluble in chlorinated hydrocarbons; sap.
Val: found 75.0% of acyl; calc. for diester 71.7% and for
triester 79.3 %).
C$litlose ester of (2) :
Cellulose (11.3 g) in pyridine (23 ml) and dioxane (150 ml) is
heated with the acid chloride (68 g) of (2) in dioxane (220 ml)
as above for 48 h. The viscous solution is poured into methanol(1 I)+ acetone(500ml). Theprecipitatedester is filtered off,
ground twice with methanol/acetone, and triturated with a
little acetone in a ball mill for 2 h. It is insoluble in most
organic solvents (yield 50 g; sap. Val: found 75.3 % of acyl;
calc. 74.4% for diester).
For thin-layer chromatography 5 g of the cellulose ester of
( I ) is homogenized on a shaker with 0.3 g of gypsum, 8 ml of
methanol, and 5 ml of water. For the ester of (21,4 g are
similarly treated with 0.2g of gypsum, 2 0 m l of methanol,
and 5 ml of water. These materials are placed on plates,
dried in the air, and heated at 90-100 O C shortly before use.
Received: September 12, 1968
IZ 891 IE]
German version: Angew. Chem. 80, 1035 (1968)
H. Stetter and Dr. J. Schroeder
Institut fur Organische Chemie der Technischen Hochschule
51 Aachen, Prof. Pirlet-Str. 1 (Germany)
111 G. Smets, V. Balogh, and Y. CastiNe, J. Polymer Sci. Part C 4 ,
I467 (1966); H. Sugiyama and If. Kamogawa, ibid. Part C 4,2281
(1966); M . Kryszewsky, ibid. Part C 4, 4595 (1966); H . Hoegl,
J. physic. Chem. 69, 755 (1965); K . Yagi and M . Hanai, J. chem.
SOC.Japan, ind. Chem. Sect. (KGgy6 Kagaku Zdsshi) 69, 881
(1966); D. A. Seanor, Fortschr. Hochpolymeren-Forsch. 4, 31 7
(1965); W. Kfoeppfer and H. Rabenhorst, Angew. Chem. 79, 278
(1967); Angew. Chem. internat. Edit. 6, 268 (1967); G. Manecke
and G. KossmehZ, Chemie-1ng.-Techn. 39, 1052,1079 (I 967).
[21 J . Schroeder, Dissertation, Technische Hochschule, Aachen,
1967.
131 R. R . Aitken, G . M . Badger, and J . W. Cook, J. chem. SOC.
(London) 1950, 331; G. M . Badger, W. Carruthers, J . W . Cook,
and R. Schoental, ibid. 1949, 171.
[41 Cellulose N M 300 for thin-layer chromatography from
Firma Macherey und Nagel, Diiren (Germany), was mercerized
as described by H . Staudinger and W. Ddhle [J. prakt. Chem.
161, 219 (1943)l.
[*j Prof. Dr.
Angew. Chem. internat. Edit. / VoI. 7 (1968) 1 No. I 2
Cyclotrimerization of butadiene on 'naked' nickel leads t o
three isomeric cyclododecatrienes 1 1 1 (crs,cis,lrans-CDT,
cis,trans,trans-CDT, and all-trans-CDT). all-cis-CDT is not
formed catalytically but can be prepared from all-/ran.yCDTf*l. Of the nickel complexes, so far only the deep rcd
all-truns-CDT-NI(0) ( I ) has been prepared [31; its X-ray
structure analysis [41 shows the nickel atom t o occupy the
center of t h e ring and to interact with all three double bonds.
We have now studied the problem whethcr the other isomers
can form defined complexes with nickel(0).
On treatment of bis(2,4-pentanedionato)nickel(11), Ni(acac)Z,
with triethylalumiiiuin (3:2; in ether) in the presence of
cis,cis,frans-CDT or rruns,trLins,cis-CDT, red solutions are
obtained from which Al(acac)j can be separated at -78 "C.
If the filtrate therefrom is concentrated and cooled t o -20 O C .
pale red needles are precipitated whose composition corresponds approximately to C12H18Ni. The very soluble products decompose extremely easily so that attempts at further
purification have so far failed.
However, all-cis-l,5,9-cyclododecatrienenickel(O)(2) can be
very easily obtained in pure form by mixing the all-transcomplex ( I ) with all-cis-CDT in the molecular ratio 1:l in
ethereal solution at -78 "C and warming the whole slowly to
room temperature. The color of the solution soon changes
from deep red to yellow and on renewed cooling to -78 O C
almost colorless needles of composition Cl2H18Nj (mol. wt.
210, cryoscopic) in benzene are precipitated in 75 "/, yield.
ttt-CDT.Ni(0)
+
ccc-CDT
--f
ccc-CDT.Ni(0)
+
ttt-CDT
This complex ( 2 ) reacts with CO, yielding Ni(C0)4 and free
all-cis-CDT. Its LH-NMR spectrum (in deuteriobenzene)
shows two signals at T = 5.24 (=CH-) and 7.68 (-CHz-)
with the intensity ratio 6: 12, i e . , all three cis-double bonds
are bound to the nickel atom, as in (Z). It can be seen from
the model that cis-CDT in (2) thus very probably occurs in
the crown form.
In the complex of this isomer there is maximum overlap of
the metal orbitals with those of the double bonds, since both
the bonding and the antibonding orbitals of all three cisdouble bonds lie in one plane, whereas in the less stable
complex ( I ) the three trans-double bonds are turned propellor-wise out of this planel4J.
There is clearly no relation between the stability of the individual complexes with nickel(0) and the isomer distribution of
the cyclododecatrienes formed from butadiene on 'naked'
nickel, since the isomer, all-cis-CDT, giving the most stable
complex with Ni(O), is not formed catalytically.
The fourth coordination position of the nickel atom in (2)
can be occupied by another ligand, as in ( I ) ; but only tris(o-biphenylyl) phosphita gives a stable 1:1 adduct with (2),
whereas phosphines also form stable 1:1 complexes with ( I ) .
Received: September 19, 1968
[Z 890 IEJ
German version: Angew. Chem. 80, 1033 (1968)
[*] Prof. Dr. G. Wilke, Priv.-Doz. Dr. P. Heimbach,
and Dr. K. Jonas
Max-Planck-Institut f u r Kohlenforschung
433 Miilheim-Ruhr, Kaiser-Wilhelm-Platz I (Germany)
[**I Part of the dissertation by K . Jonas, Universitiit Bochum
(Germany), 1968.
949
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adsorption, basic, formation, specific, acceptor, donor, electro, complexes
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