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Investigations of Reactions and Phase Transformations with a Novel X-Ray Camera.

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R'
R2
Products
Overall yield
(%) PI
COOC,H,
COOCH,
CH,OCH,
CH3
c
d
e
f
C,H,
C,H,
CH,OCH,
CH3
1I
-14 d )
76 t a l
The conditions of the catalytic reaction exert a considerable influence on the course of the reaction. If phenylacetylene, for example, is added dropwise at 40°C to a
benzene solution of the catalyst rNi'-P(C,H,),] that is
saturated with butadiene, the yield of ( 1 a ) can be increased
from 25 to 78 %['I.
1,4-Dimethoxy-2-butyne reacts with
(le)
I If)
0
[a] The yields are 80-95%, based on reacted butadiene at 15 to 20%.
All the tricycl0[2.2.2.O~~~]oct-7-enes( 5 ) -(S) prepared
from butadiene and alkynes via ( 1 ) - ( 4 ) have a plane of
symmetry. Their IR, 'H-NMR, and mass spectra confirm
the structures given (see Table).
,0,
I
~
(
butadiene in the presence of Nio-tricyclohexylphosphanecatalyst at 20°C to give ( I e ) in 26% yield. In the presence
of a nickel catalyst having no phosphorus-containing
ligandd7],slow addition of butadiene to 2-butyne at 30°C
gives ( 1f ) in about 20% yield.
I
R
R
4
)
(5)-f8)
analogous to ( 1 ) - ( 4 )
Table. Chemical shifts of the protons in the three-membered ring and
the methylene groups of tricyclo [2.2.2.02.6]oct-7-ene (HA-100). The
coupling of the methylene protons amounts to z 11-12 Hz. In a number
of compounds a weak coupling ( z1 Hz) of one proton of the methylene
groups with the protons of the three-membered ring could be detected
by extension of the spectrum. Compound ( 7 d ) was not isolated: assignment on the basis of the retention behavior in the gas-chromatographic
examination of the reaction product prior to recrystallization.
Cpd.
Protons in threemembered ring 7 (ppm)
Protons in methylene
groups 7 (ppm)
(Sa)
(5b)
(6b)
(Sc)
(6c)
(Sd)
(6d)
(8dj
(Se)
8.09
7.96
7.84
7.96
7.84
7.69
7.55
7.94
8.53
8.98
8.02 and 8.13; 8.65 and 8.76
8.10 and 8.22; 8.73 and 8.84
8.48 and 8.60; 8.93 and 9.04
8.04 and 8.16; superimposed
8.43 and 8.55 ; superimposed
7.78 and 7.90; 8.27 [a] and 8.39 [a]
7.87 and 7.98; 8.16 and 8.27
7.78 and 7.90; 8.27 [a] and 8.39 [a]
8.40 and 8.52; 9.10 and 9.22
8.75 and 8.86; 9.19 and 9.30
(Sf)
i 101
[a] Weak splitting.
Both the 5-vinylcyclohexa-1,3-dienesand the tricyclo[2.2.2.02,6]oct-7-enes react with dienophiles. At 20"C,
(If) reacts with maleic anhydride to give the adduct ( 9 ) .
(5f) reacts at 40°C with dimethyl acetylenedicarboxylate
to give (10) ; any possible intermediates have so far defied
detection.
Received: December 21, 1970 [Z 339 IE]
German version: Angew. Chem. 83,285 (1971)
[I] W Brenner, P. Heimbach, K.-J. Ploner, and F . Thornel, Angew.
Chem. 81, 744 (1969); Angew. Chern. internat. Edit. 8, 753 (1969).
[2] Yields based on reacted alkyne at approx. 100% conversion.
[3] Part of Dissertation by F. Thome/, Universitat Bochum 1970.
[4] W uon E. Doering and W R . Roth, Tetrahedron 19,715 (1963).
[5] W R . Rorh and B. Peltzer, Liebigs Ann. Chem. 68S, 56 (1965).
[6] K . Alder et a/., Liebigs Ann. Chem. 593, 1 (1955).
[7] B. Bogdanooic, P. Heimbach, M . Kroner, and G . Wilke, and E . G .
Hoflmann and J . Brandt, Liebigs Ann. Chem. 727, 143 (1969).
C O N F E R E N C E REPORTS
Investigations of Reactions and Phase Transformations with a Novel X-Ray Camera
By Arndt Simon"]
By suitable modification of the X-ray recording technique
it is also possible to use the high resolution Guinier
method for the investigation of substances that are extremely sensitive to air. The sample to be examined is fused
I'[
Dr. A. Simon
Anorganisch-chemisches Institut der Universitat
44 Miinster, Gievenbecker Weg 9 (Germany)
rl] E. Rengade, Bull. SOC.chim. France (4). 5,994 (1909).
Angew. Chem. internat. Edit. / Vol. 10 ( 1 9 7 1 )
No. 4
in a Mark tube which is arranged parallel to the focal line
of the monochromator on the focusing circle of the film
chamber. With the aid of a sensitive control device, structural changes in the sample with temperature can be
determined very accurately (+O.O2"C between - 190 and
400°C).
This method has been used in an investigation of the
phase transformations occurring in solid halogen hydrides.
With the modified apparatus it is possible, especially in
the case of HBr, to detect all the transformations expected
from the calorimetric behavior (orthorhombic % orthorhombic s cubic % cubic). Interpretation of the data
obtained by X-ray crystallography would suggest that
211
intermolecular interactions over a wide range play an important role in the course of these transformations.
The modified apparatus proved particulariy usefuI for the
investigation of the phases in alkali metal suboxides. With
additional aid of a sensitive DTA arrangement, existence
of all the suboxides designated by Rengade"] as Cs,O,
Cs,O, Cs,O,, and Cs,O could be established. The presently
found compositions deviate, in certain cases quite distinctly,
from those previously reported in the literature; the Cs,O
phase has a wide range of homogeneity. The occurrence
of such suboxides is not confined to cesium; well-defined
suboxides of rubidium have also been observed. In the
latter case, however, the investigation is rendered much
more difficult by the peritectic formation of Rb,O at ca.
40°C. In order to gain more detailed information about
the suboxide phases, we have begun a series of X-ray
crystallographic investigations on single crystals.
Lecture at Kiel on December 10, 1970 [VB 270 IE]
German version: Angew. Chem. 83,216 (1971)
Heterocycles from C, Systems and Sulfur
By Friedrich Boberg"'
1,2-Dithiacyclopenten-ones, -thiones, -imines, and 1,2dithiolium compounds can be prepared from ally1 compounds and sulfur. 1,2-Dithiacyclopentenimines are also
formed from 3-chloro-l,2-dithiolium compounds and
N,N-dichloro compounds having electron attracting
groups attached to the nitrogen (sulfonyl, alkoxycarbonyl,
carbonyl) with elimination of chlorine. The systems are
described by apolar and polar resonance structures
(positive charge on the heterocycle, negative charge on the
exocyclic heteroatom) in which electron shifts by substituents in position 5 have to be considered. Dipole
moments of 1,2-dithiacyclopentenones and -thiones confirm these concepts. Information about the distribution
of charge in the heterocycle is provided by chlorine
exchange with [36Cl]-SbC13 and [36Cl]-A1Cl,, which, in
the case of 3,4,5-trichloro-1,2-dithioliumchloride, preferentially takes place at the 3- and 5-positions.
1,2-Dithiacyclopentenonesreact with preservation of the
heterocycle and with ring cleavage. The position of
substitution is in agreement with theoretical concepts.
S2-, OH-, RO-, and R,NH open the heterocycle between
the carbonyl group and ring suifur and reaction with
Grignard compounds leads to ring cleavage at the disulfide
bridge. The primary cleavage product reacts further to
give various types of compounds, the substituents in the
4- and 5-positions of the 1,2-dithiacyclopentenone being
of importance. The primary cleavage products from the
reaction of RO- with 1,2-dithiacyclopentenones containing C1 in position 4 or 5 undergo intramolecular or
intermolecular elimination of C1- to give other sulfur
heterocycles.The following products have been established:
1,2,S-trithiacycloheptadienes, 1,4-dithiacyclohexadienes,
1,2-dithiacyclohexadienesor the valence tautomeric dithioamides (unknown) and thiophenes from 4-chloro-1,2dithiacyclopentenones ;1,2,4,5-tetrathiacyclohexanes,
1,2,4tri thiacyclopentanes, 1,3-dithiacyclobutanes, and 1,3-dithiacyclopentenes from 5-chloro- or 5-sulfonyl-1,2-dithiacyclopentenones"]. The intermolecular mechanism is ex[*] Prof. Dr. F. Boberg
Lehrstuhl fur Erdolchemie der Technischen Universitat
3 Hannover. Am Kleinen Felde 30 (Germany)
278
cluded in the case of the 1,2-dithiacyclohexadienes.The
thiomalonic acid derivatives obtainable by reaction of
5-amino-1,2-dithiacyclopentenoneswith Grignard compounds are starting materials for the preparation of
aminopyrazolinones and methylenebenzothiazoles.
Attempts to prepare the thiacyclopropene system were
without success.
Lecture at Hannover on January 21,1971 [VB 269 IE]
German version: Angew. Chem. 83, 216 (1971)
[l] J . Bader, Helv. Chim. Acta 51, 1421 (1968)
Electronic and Molecular Structure of Coordination
Compounds of Transition Metals as Derived from
Their Optical Properties
By H.-H. Schmidtke"
The gain in energy on formation of chemical bonding
between central ions (electron acceptors) and ligands
(donors) of a complex resuits from resonance properties
of the electrons and from electrostatic interactions between
the atoms and ions participating in the molecule. While
the molecular orbital theory takes account of both effects,
ligand field theory can only describe the electrostatic
component of the bond. The ligand field theory satisfactorily accounts for the high- and low-spin behavior
of the complexes that finds experimental expression in,
for example, their magnetic behavior or their electronic
spectra. However, the utility of the theory is limited once
results are required that are not of a purely qualitative
nature. For instance, no explanation is forthcoming of
the existence of the spectrochemical series, in which some
neutral ligands possess a stronger ligand field than charged
ligands. The shortcomings of the theory are attributable
to the overemphasis placed on electrostatic effects in the
description of the electronic structure.
The angular overlap model, whose parameters are symmetry-orbital adapted and therefore better fitted to the
molecular orbital theory, provides a better interpretation
of experimental data. This model represents a semiempirical theory which takes into account second order
perturbation terms and which is of comparable quality to
the Pariser-Parr theory. It is particularly suitable for the
interpretation of spectra of low-symmetry coordination
compounds with significantly covalent bonding and for
the assignment of geometric isomers (e.g., interpretation
of the spectra of hydroxo complexes, assignment of the
three geometric isomers of bis(L-histidinato) complexes).
Mention should also be made of the assignment of
linkage isomers, such as S- and N-bonded thiocyanate,
on the basis of the electronic spectrum. Information about
the mode of bonding is provided by both the ligand field
theory and the charge transfer spectrum. The latter case
is concerned with the transfer of ligand electrons to the
d shell of the central ion. Assignment of linkage isomers
is possible on the basis of differing optical electronegativities for S- and N-bonded thiocyanate.
Lecture at Clausthal on January 8, 1971 [VB 271 IE]
German version: Angew. Chem. 83,295 (1971)
[*] Priv.-Doz. Dr. H.-H. Schmidtke
Institut fur Physikalische Chemie der Universitiic
6 Frankfurt (Main) 1, Robert-Mayer-Strasse 11 (Germany)
Angew. Chem. internat. Edit.
1 Vol. I0 (1971) J NO.4
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