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High-Pressure Phases of KSi KGe RbSi RbGe CsSi and CsGe with the NaPb-Type Structure.

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Table I. Gas chromatographic enantiomer resolution of 1,2- and 1,3-diols, 2hydroxycarboxylic acids, a-amino alcohols, and N-methyl-a-amino acids
after derivatization with phosgene. Capillary columns, stationary phase: XE60-~-valine-(R)-a-phenylethylamide.
Racemate
Separation
factor a
1,2-propanediol [a]
I ,2-butanediol
I ,2-pentanediol
3-methyl-1,2-butanediol
33-dimethyl- 1,2-butanediol
1,2-hexanediol
1.021
1.017
1.02I
1.013
1.016
1.026
1.013
1.026
1.025
1.03 1
1.025
1.018
1.018
1.031
1.044
1.031
I .020
1.015
1.017
1.022
1.016
1.019
1.020
1.014
1.035
1.040
I .047
1.026
1.025
1.025
1.031
I .020
1.025
1.038
1.031
1.028
1.034
1.049
1.028
1.038
Column
Enantiomer
length [m]/ eluted
Column
first
temp. ["C]
~
4-methyl-l,2-pentanediol
I ,2-octanediol
7-octene- 1,2-diol
phenyl glycol
2-ethyl-1,3-hexanediol
I ,3-butanediol
trans- 1,2-cycloheptanediol
trans- 1,2-cyclooctanediol
trans- I ,2-cyclodecanediol
diisopropyl tartrate [c]
lactic acid
2-hydroxybutyric acid
2-hydroxyvaleric acid
2-hydroxyisovaleric acid
2-hydroxyhexanoic acid
2-hydroxyisohexanoic acid
2-hydroxy-3-methylpentanoic
acid
2-hydroxyoctanoic acid
ephedrine
pseudoephedrine
norephedrine
bupranolol ( l a ) [d]
penbutolol ( l b ) [d]
metoprolol (lc) [dl
N-methylalanine
N-methyl-a-aminobutyric acid
N-methylvaline
N-methylisoleucine
N-methylalloisoleucine
N-methylleucine
N-methylthreonine [el
N-methylallothreonine [el
proline
35/80
35/80
35/80
35/80
35/80
25/100
35/110
25/120
25/120
25/120
25/120
35/140
251'140
25/140
18/175
354145
35/110
35/110
35/110
35/110
35/120
35/120
35/120
35/126
18/165
18/165
181195
18/195
181195
18/195
25/100
25/100
25/100
25/110
25/110
25/110
25/120
25/120
25/140
obtained for the alicyclic truns-1,2-diols (Table 1). For alicyclic truns-1,3-diols, cyclic carbonates do not form for
steric reasons.
Oxazolidine-2-ones from amino alcohols of the ephedrine type are also readily resolvable and configurationally
stable derivatives["]. This also applies to amino alcohols,
which have considerable importance as 0-receptor blockers in the treatment of cardiac-circulation diseases, but
could previously not be resolved["'. Today, 0-blockers are
largely used in the form of racemates; however, because of
the, in part, extremely different action of the enantiomers
the pure enantiomers are sought.
Compared to the derivatives prepared by reaction of isopropyl isocyanate with 2-hydroxy acids or N-methyl-a-amino acids['], those derivatives obtained by reaction with
phosgene offer the advantage of considerably higher volatility. Phosgene is therefore an alternative and/or extension to the isocyanates for the derivatization of chiral,
polyfunctional compounds for resolution by gas chromatography.
Received: March 20, 1984;
revised: May 4, 1984 [Z 765 IE]
German version: Angew Chem. 96 (1984) 516
[a] The diols were kindly supplied by Dr. K. Giinther, Degussa AG, Hanau.
[b] Order of elution was not determined. [c] Separation on XE-60-~-valine
(S)-a-phenylethylamide. [d] BuprdfIOlOl was supplied by Sanol SchwarzMonheim GmbH, penbutolol by Hoechst, Frankfurt, and metoprolol by Hassle, Gothenburg, Sweden. [el As isopropyl ester.
For tartaric acid, the resolution on the XE-60-~-valine-(S)a-phenylethylamide phase[@is better than on the diastereomeric phase. Particularly large separation factors a are
[I] a) I. Benecke, W. A. Konig, Angew. Chem. 94 (1982) 709; Angew. Chem.
Int. Ed. Engl. 21 (1982) 709; Angew. Chem. Suppl. 1982, 1605; b) W. A.
Konig, I. Benecke, N. Lucht, E. Schmidt, J. Schulze, S. Sievers, J . Chromatogr. 279 (1983) 555.
[2] 0. Gyllenhaal, J. Vessman, .I. Chromatogr. Biomed. Appl. 273 (1983)
129.
[3] a) J. Nemirowsky, J . Prakt. Chem. 28 (1883) 439; b) P. Brown, C. Djerassi, Tetrahedron 24 (1968) 294Y.
[4] W. H. Davies, J. Chem. Soc. 1951, 1357.
[5] H. Leuchs, Ber. Dtsch. Chem. Ge.v. 39 (1906) 857.
[6] a) W. A. Konig, S. Sievers, 1. I3enecke in R. E. Kaiser: Proc. 4. In[. Symp.
Capillary Chromatogr., Huthig-Verlag, Heidelberg 1981, p. 703; b) W. A.
Konig, I. Benecke, S. Sievers, .I. Chromatogr. 217( 1981) 72; c) W. A. Konig, I. Benecke, H. Bretting, Angew. Chem. 93 (1981) 688; Angew. Chem.
Int. Ed. Engl. 20 (1981) 693.
[7] a) K. Mori, M. Sasaki, S. Tamada, T. Suguro, S. Masuda, Tetrahedron 35
(1979) 1601; b) M. Asami, T Mukaiyama, Chem. Lett. 1983, 93.
181 a) J. Barry, H. B. Kagan, Synrhecis 1981. 453; b) G . Helmchen, R. Wierzchowski, Angew. Chem. 96 (1984) 59; Angew. Chem. Int. Ed. Engl. 23
(1984) 60.
[9] a) H. Frank, G. J. Nicholson, E. Bayer, Angew. Chem. 90 (1978) 396; Angew. Chem. Int. Ed. Engl. 17 (1978) 363; b) E. Bayer, 2. Naturforsch.
B 38 (1983) 1281.
[lo] W. A. Konig, K. Ernst, J. Vessman, J . Chromatogr. 294 (1984) 423.
Ill] W. A. Konig, K. Ernst, J. Chmmatogr. 280 (1983) 135.
High-pressure Phases of KSi, KGe, RbSi, RbGe,
CsSi, and CsGe with the NaPb-Type Structure**
By Jiirgen EverP, Gilbert Oehlinger, Gerhurd Sextl, and
Armin Weiss
The compounds SrGe,['], BaSi2 and BaGe,''], which
crystallize in the BaSi,-type structure"] at normal pressure
(NP), are characterized by two unusual properties: (i) their
Si or Ge sublattice is reminiscent of the P4 tetrahedron of
white phosphorus, (ii) they are semiconductor^^^^. The
semimetal sublattice of these phases contains isolated Si,or Ge,-tetrahedra of three-bonded atoms which can be formulated ionically as
.I
3Si:'
60
50
LO
30
f Irninl
20
10
[*I Dr. habil. J. Evers, G. Oehlinger, Dipl.-lng. G. Sextl,
Fig. I. Enantiomer resolution of the cyclic carbonates of 1,2- and 1,3-diols.
35m fused-silica capillary, coated with XE-60-L-valine-(R)-a-phenylethylamide; column temperature 90°C, temperature program 1 "C/min up to llO"C,
then 2.5"C/min up to 170°C. Carrier gas HI, 0.9 bar.
528
0 Verlag Chemie GmbH. 0-6940 Weinheim, 1984
and >Ge:'
Prof. Dr. Armin Weiss
Institut fur Anorganische Chemie der Universitat
Meiserstrasse 1, D-8000 Munchen 2 (FRG)
[**I This work was supported by the Deutsche Forschungsgemeinschaft.
0570-0833/84/0707-0528 $ 02.50/0
Angew. Chem. Int. Ed. Engl. 23 (1984) No. 7
with fully occupied octets; they contain the same number
of valence electrons as phosphorus. Fully occupied valence shells confer non-metallic properties on the solid
species.
At high pressures and temperatures (e.g. 4GPa, 1000°C)
the isolated tetrahedra in S T G ~ , [ ~
BaSi,"]
],
and BaGe2[61can
be transformed into layer or three-dimensional network arrays of three-bonded atoms, with concomitant loss of semiconducting properties. This transformation is most impressive in the case of BaGe,; its "high pressure/high temperature (HPHT) phase", which can be kept in the metastable
state at normal pressure, is superconducting (critical temperature: 4.9 K)"].
The structures of the compounds formed from the alkali
metals K, Rb and Cs and the Group IV elements Si, Ge,
Sn, and Pb also consist of isolated tetrahedra at normal
pressure. The silicides and germanides of K, Rb and Cs
crystallize in the cubic KGe-type structure[*], the corresponding stannides and plum bide^[^] in the tetragonal
NaPb-type structure"'! In this paper we report on transformations of the silicides and germanides at high pressures and high temperatures.
The cubic NP-phases were synthesized from the elements under argon. The alkali metals (10% excess) were
fused together with semiconductor silicon (or germanium)
in a corundum crucible. Due to the considerably high vapor pressure of the alkali metals at the synthesis temperature (65O-75O0C), the corundum crucible was heated in a
copper-sealed iron container. Both the alkali metals and
their silicides and germanides are extremely sensitive to air
and moisture; therefore all operations with open crucibles
had to be carried out in a glove box under very pure argon.
The HPHT experiments were performed in boron nitride
crucibles in a Belt type apparatus at 4GPa and 600700°C.
We were able to quench six high-pressure (HP) phases
of the alkali metal silicides and germanides to ambient
conditions. When heated to about 400°C at NP, these
phases were transformed into the thermodynamically stable phases with the cubic KGe-type structure in exothermic reactions. Chemical analyses of the new phases of KSi
gave no indication of a change in the 1 : 1 composition.
The pycnometrically determined densities and those calculated from X-ray data were in good agreement. All six HPphases are isotypic. Their X-ray powder diagrams (DebyeScherrer method, CuKa, 114.6 mm) can be indexed tetragonally. Intensities of the reflections were calculated with
Table 1. Lattice parameters of the tetragonal NaPb-type phases AB (A=K,
Rb, Cs; B = Si, Ge, Sn, Pb).
Compound
Phase
[a1
a Axis
[pml
c Axis
[pml
Axial ratio
c/a
KSi
KGe
KSn
KPb
RbSi
RbGe
RbSn
RbPb
CsSi
CsGe
CsSn
CsPb
HP
HP
N P [91
N P [91
HP
HP
N P 191
NP P I
HP
HP
N P [91
N P [91
1057
1069
1 I42
1 I50
1083
I I04
1171
II84
1710
1737
1857
1876
1758
1787
1909
1942
1.62
1.62
1.63
1.63
1.62
1.62
1.63
1.63
1123
1138
1219
I226
1834
1850
1987
1999
1.63
1.63
1.63
1.63
[a] HP= high-pressure phase, NP=normal-pressure phase: the standard deviations of the lattice parameters in the HP-phases are a: + 3 pm, c: +_5
Pm.
Anqew. Chem. Int. Ed. Engl. 23 (1984) No. 7
the "Lazy Pulverix'""' program (position parameters: single-crystal data of KSd9])and found to be in good agreement with the NaPb-type structure.
In Table 1 the a and c axes of the six new phases of the
silicides and germanides of potassium, rubidium and cesium are compared with those of the known NP-pha~es'~]
of the corresponding stannides and plumbides. The c/a ratio of all twelve phases has a constant value of 1.62-1.63,
convincingly indicating a geometrical relationship as for
the NaPb-type structure. This value corresponds to :
(0.96~,"h~)/(0.96.0.5acuhfi) Zs
ctc~r,/~t,.ir
z
$fi
%
1.63
In comparison to the cubic KGe-type structure of the NPphases, the HP-phases are about 4% more densely packed.
Whether this increase in density is associated with a slight
increase in the coordination numbers must remain open
until an accurate determination of the positional parameters has been carried out. Thus, isolated tetrahedra are still
stable in the HP-phases of the alkali metal silicides and
germanides up to 4 GPa. A transformation into layer or
network arrays is probably rendered difficult here because
of the metal content being twice as high as in the alkaline
earth metal silicides and germanides.
Received: March 7, 1984 [Z 749 IE]
German version: Angew. Chem. 96 (1984) 512
[I] K. H. Janzon, H. Schafer, A. Weiss, Angew. Chem. 75 (1963) 451 ; Angew.
Chem. Int. Ed. Engl. 2 (1963) 393.
121 A. Betz, H. Schlfer, A. Weiss, R. Wulf, Z. Naturforsch. B 23 (1968)
878.
[3] J. Evers, A. Weiss, Muter. Res. Bull 9 (1974) 549.
141 J. Evers, G. Oehlinger, A. Weiss, Z. Naturforsch. B 34 (1979) 524.
[ 5 ] J. Evers, G. Oehlinger, A. Weiss, Angew. Chem. 89 (1977) 673; Angew.
Chem. I n t . Ed. Engl. 16 (1977) 659; ibid. 90 (1978) 562 and 17 (1978)
538.
[6] J. Evers, G. Oehlinger, A. Weiss, Z . Naturfowch. B 32 (1977) 1352; ibid.
35 (1980) 397.
[71 J. Evers, G. Oehlinger, H. R. Ott, J . Less-Common M e t 69 (1980) 389.
[8] E. Busmann, Z. Anorg. ANg. Chem. -113 (1961) 90.
[9] 1. F. Hewaidy, E. Busmann, W. Klemm, Z. Anorg. Allg. Chem. 328
(1964) 283.
[lo] R. E. Marsh, D. P. Shoemaker,Acta Crystallogr. 6 (1953) 197.
[ I l l K. Yvon, W. Jeitschko, E. Parthe, J . Appl. Crystallogr. 10 (1977) 73.
Hydridoplatinum(I1) Complexes with Phosphites
and Phosphonites and their Reactions with Methyl
Acrylate""
By Werner R. Meyer and Luigi M. Venanzi*
While hydrido complexes of the type trans-PtHXL2
(L= tertiary phosphane, X = halide) have been known for a
long time"], the analogous compounds with L = P(OR),,
PR'(OR),, or PR;(OR) have not been reported hitherto, although PtHC1[P(OPh),I2 has been postulated as a co-catalyst for the isomerization of randomly unsaturated to conjugated compounds'21. We report here the facile synthesis
of tr~ns-PtHCl[P(OMe)~],
1, tr~ns-PtHCl[PMe(OMe)~]~
2,
and their reactions with CH,=CH-C0,Me.
Compound 1 is formed in high yield by allowing cisPtC1,[P(OMe)3],[31to react with NaBH4 in acetonitrile. The
colorless solid product (v(Pt-H) = 2050 cm-') is obtained
[*I Prof. Dr. L. M. Venanzi, DipLNatw. W. R. Meyer
Laboratorium fur Anorganische Chemie der
Eidgenossischen Technischen Hocbschule
ETH-Zentrum, Universit2tstrasse 6, C'H-8092 Zurich (Switzerland)
[**I
Financial support for this work from Ciba-Geigy AG, Basel, and from
the Swiss National Science Foundation is gratefully acknowledged.
0 Verlag Chemie GmbH, 0-6940 Weinheim, 1984
0570-0833/84/0707-0529 $ 02.50/0
529
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