вход по аккаунту


Ninth Lyons-Tbingen Chemical Meeting.

код для вставкиСкачать
Ninth Lyons-Tubingen Chemical Meeting
The Ninth Lyons-Tubingen Chemicai Meeting took place on
September 27-29, 1967, at Tubingen on the invitation of the
Tubingen Academic Chemical Staff. Three plenary lectures
and twenty-five short papers were read.
Extracts from the lectures and papers:
(with the positive charge on a carbon atom) that is adsorbed
on aluminum oxide as intermediate usually undergoes heterolysis of the C - 0 bond. However, for conformations that
are only slightly hindered sterically and thus favor trunselimination, cleavage of C-C occurs. On heterolysis of
threo-(1) (R1 = R2 = H; R3 -+ H) the latter applies exclusively and leads to dihydropyrans (2) and (31, as well as ( 4 ) and
The Structure of Some Fluorides, Oxides, and Oxide
Fluorides : the RbNiCrF6 Type
By D. Babel (Lecturer), G. Pausewang, and W. Viebahn[*l
Among the oxide systems there are compounds AM206 that
crystallize in the perovskite lattice with only half the A cation
sites occupied, e.g., CaNb206 = Cao.sNbO3. An analogous
structure was at first expected for corresponding fluorides
AIMIIMIIIF6 where AT = large alkali ions, MIT and MI1' =
small ions, in particular of the first transition series, since
many of the components required, e.g., KNiF3 + CrF3, are
already known to crystallize with the perovskite lattice or
with closely related structures.
A number of new compounds AIMrrM1rrF6 were prepared,
where A1 = K, Rb, or Cs, MI1 = Mg, Ni, Cu, Co, Fe. or Mn,
and MI11 = Al, Ga, Cr, Fe, or V, by heating mixtures of the
binary fluorides AHFz MF2 + M'F3 in stoichiometric
amounts under a n inert atmosphere. However, X-ray structure analysis of the crystalline powders showed that these
were not perovskites but belonged to a hitherto unknown
face-centered cubic structure type (RbNiCrF6 type).
Further, numerous oxides A1MV'MVx06 with A' = K, Rb,
or Cs, as well as oxide fluorides have this structure, whose
relations to the perovskite type o n the one hand and to the
pyrochlore type o n the other were illustrated.
The isomerizations (2) e ( 3 ) and ( 4 ) e ( 5 ) depend on
complex intra- and inter-molecular migrations of hydride
ions which are hindered if the substituents are bulky or are in
cis-relation to the hydroxylated chain.
Analogous isomerizations are observed among tetrahydropyrans.
[*I Dr. G. Descotes
Faculti des Sciences,
Laboratoire de Chimie Organique I1
43 Boulevard du 11 Novembre
Lyon (France)
A N e w Method for Estimating Thermodynamic
Properties of Crystalline Substances: Alkali Halides and
Hydrides (NaC1 System)
[*I Dr. D. Babel, Dr. G . Pausewang, and
Dipl.-Chem. W. Viebahn
Laboratorium fur Anorganische und Analytische Chemie
der Universitat
74 Tubingen, Wilhelmstrasse 33 (Germany)
Catalytic Elimination and Isomerization Reactions of
By G. Descotes [*I
The mechanism and stereochemistry of ring-expansion of aalkylfurfuryl alcohols ( I ) are determined by the number,
position, and steric relations of the substituents. The cation
By J . Bousquet, J. Cl. David (Lecturer), M . Diot, and
A . Guillon I+]
The dependence of the following thermodynamic parameters
(referred to the standard state) on molar volumes was studied:
lattice energy, enthalpy of formation, entropy of formation
( 1 . elements in the ideal monoatomic gas state; 2. alkali
elements in the standard state, halogens in the gas state), and
free energy of formation. Linear functions of the logarithm
of the molar volume resulted; the lines representing them are,
in general, characteristic of each cation.
For the alkali hydrides, which crystallize in the NaCl system,
the representative points lie distinctly off these lines and it is
assumed that the hydrides occur as trimers M+(M2H3)-.
With such assumptions it is possible to supplement and interpret the experimentally observed thermodynamic results.
Agreement with previously estimated analogous values is
very good.
[*I Prof. J. Bousquet, Dr. J. CI. David, Dr. M. Diot, and
Dr. A. Guillon
Laboratoire de Chimie Minerale de J.N.S.A.
20 Avenue Albert Einstein
Villeurbanne (France)
Some Properties of 3-Phenoxyacrolein
By R. Gelin (Lecturer) and D. Makula[*1
3-Phenoxyacrolein is a stable starting material for preparation of malonaldehyde:
+ C6H50H
Hydrochlorides of the corresponding imino enamines are
obtained quantitatively on reaction with hydrochlorides of
primary aromatic arnines:
Angew. Chern. internat. Edit.
Voi. 7 (1968)
/ No. 3
With alcohols and a catalyst diacetals of malonaldehyde
(1,1.3,3-tetraalkoxypropanes) are obtained.
Other nucleophilic reagents (organomagnesium compounds,
secondary amines, and Na derivatives of compounds with
active rnethylene groups) react with addition-elimination.
With organomagnesiurn compounds a@-unsaturated aldehydes result; N a derivatives of compounds with active
methylene groups afford quantitative yields of dienolates:
Cyclization is not the only result of solvolysis of ( I ) when
R = H; the cyclobutanones are then accompanied by esters
of analogous structure.
[*I Priv.-Doz. Dr. M. Hanack, Dr. I.'Herterich,
V. Vott, and H. Ehrhardt
Chemisches Institut der Universitat
74 Tubingen, Wilhelmstrasse 3 1 (Germany)
cis-trans-Isomerism of N-Monosubstituted Amides
[*] Dr. R. Gelin and Dr. D. Makula
FacultC des Sciences,
Institut National des Sciences appliquees,
Laboratoire de Chimie Organique
69 Villeurbanne (France)
Microcalorimetric Investigation of Heterogeneous
Catalytic Reactions
By H. Kessler [*I
N-Monosubstituted amides exist mainly in the trans-form
(b) [I]. The cis-form (a) takes part in the equilibrium only to
the extent of < 1 % (the activation energy of the equilibration
(a) + (b) amounts to ca. 15-23 kcal/mole). But with formamides alone (R = H) (a) is preferred.
By P. C. Gruvelle[*l
In a catalytic reaction at least one reactant is adsorbed o n the
surface of the catalyst. The adsorbed species takes part in
surface reactions, and the final step in the reaction cycle is
desorption of the reaction product. All the partial processes
deliver or take up energy and can thus be followed directly
by calorimetry.
An apparatus was described for measurement of the heat of
adsorption of small quantities of gas. The curve showing the
dependence of the differential heats of adsorption on the
degree of occupation of the surface at a given temperature are
characteristic of the adsorbed gas o n the one hand and of the
solid adsorbent o n the other. Calorimetry discloses the change
of surface activity of a catalyst with respect to a gas o n variation, particularly, of the temperature of adsorption and of
the surface structure. The same applies to chemisorption
processes occurring on the surface. The calorimetric results
are refined by thermocbemical cyclic processes, and reaction
mechanisms and kinetic conclusions are derived from them.
[*] Dr. P. C. Gravelle
Institut de Recherches sur la Catalyse
Villeurbanne (France)
Conversion of Acetylene Compounds into Small-Ring
By M. Hanack (Lecturer), I. Herterich, V. Vott, and
H . Ehrhardt [*I
The C-C triple bond shows a n unexpected readiness to take
part in carbonium ion reactions, and this makes possible
novel types of synthesis of small-ring compounds.
If acetylene derivatives of structure (1) (R = CH3, C2H5, or
i-C3H7; X = m-OSOzC6H4N02) are solvolyzed in media of
high ionizing power (e.g. formic or trifluoroacetic acid), they
are converted completely into 2-alkylcyclobutanones ( 2 ) .
The direction of rearrangement can be controlled by changing
the reaction conditions: if acetylenes ( I ) are solvolyzed with
addition of catalytic amounts of Hg(rr) salts, then alkyl cyclopropyl ketones ( 3 ) are the preponderant products isolated.
R = H, CH3, CzHs, i-C3H7, tert-CsH9
R', Rz, R3 = CH3, CzHs, i-C3H7
or tert-C4Hg
The position of the equilibrium and the height of the energy
barrier (a) + (b) have been studied by NMR spectrometry
for nuclear-substituted anilides ( I ) . In contrast to the case
with acetanilide (R = CH3; R1 = Rz = R3 = H) appreciable
amounts of (a) are found in ortho-substituted acetanilides 121;
the proportion of (a) increases with the size of the orthosubstituent [for 2,4,6-tri-tert-butylacetanilide the equilibrium
mixture contains (a):(b) = 45:551.
Simultaneously, the free activation enthalpy of establishment
of equilibrium increases with increasing steric hindrance. For
the tri-tert-butylacetanilide it amounts to 24 kcal/mole, sufficing to enable (a) and (b) to be isolated in quantity by thinlayer chromatography at O°C, and thus constituting the
first separation of cis- and trans-forms of a N-monosubstituted amide.
lncrease in the size of the group R (from H to tert-C4H9)
decreases the proportion of (a).
The effects observed are explained by twisting of the benzene
ring relative to the plane of the amide bond by means of the
ortho-substituents. The steric effect of the phenyl ring is
reduced in the twisted form.
[*I Dr. H. Kessler
Chemisches Institut der Universitat
74 Tiibingen, Wilhelmstrasse 33 (Germany)
[I] L. A . La Planche and M. T. Rogers, J. Amer. chem. SOC.86,
337 (1964).
[2] €3. Kesder and A . Rieker, Liebigs Ann. Chem. 708, 57 (1967).
Polarimetric Study of Simple and Mixed Metal-Amino
Acid Complexes
By M. R. Pdris (Lecturer) and M. Petit-Ramel[*I
The optical rotation is changed when a n optically active
ligand is coordinated to a metal ion. The specific rotation of
a species is a n additive property (in the same way as, for
example, absorption). The pH-dependence of the optical
Angew. Chem. internat. Edit. 1 Vol. 7 (1968) / No. 3
rotation permits determination of the stability constants and
the specific rotation of each of the complexes that are successively formed. For this purpose the p H values and the rotations of solutions (HC104:NaC104 a t constant ionic strength
0.5) containing originally the metal ion and the complexforming agent are measured simultaneously during progressive neutralization with NaOH. For determination of the
stability constants and specific rotations the graphical
method of Fronaeus- Yatsimirskii, plus the analytical method
of least squares, were applied, this being their first use in
polarimetry. Studies to date have been concerned with simple
complexes of Cu, Zn, Cd, and Ni with D-alanine, o-valine,
and L-proline, and mixed complexes of C u with these amino
acids and with glycine, the last named complex showing no
F o r m a t i o n of Sulfenes from Aliphatic Sulfonyl
Chlorides and Trialkylamines
By K . Rieth[*I
S,S-Dioxides of thioaldehydes are formed as intermediates
on reaction of tertiary bases with primary sulfonyl chlorides.
They can be detected indirectly by trapping with suitable
cycloaddition reagents (olefins with strongly polar double
bonds, such as enamines and ketene acetals). Derivatives of
thietane S,S-dioxide result.
[*I Dr. M. R. Pdris and M. Petit-Ramel
Chaire de Chimie Minerale,
Faculte des Sciences de l'universite de Lyon
4 3 Boulevard Du Onze Novembre
Villeurbanne (France)
The reactions are preferentially carried out in ether at room
temperature. Cycloaddition of thioketone S,S-dioxides from
secondary sulfonyl chlorides does not occur under these conditions, but it takes place smoothly in acetonitrile at -40 'C.
By A . Riekerf*l
Mesylsulfene is formed from methanesulfonyl chloride and
triethylamine under these conditions, and is detected as the
triethylamine adduct.
Aliphatic ethers of parrr-quinol ( I ) decompose on pyrolysis,
on acid fission, or in the mass spectrometer into isobutene,
2,4.6-tri-tert-butylphenol (31,and the p-hydroxyphenyl ether
(2) as main products. Aryl ethers of type ( 4 ) . however, are
cleaved by pyrolysis into o-hydroxydiphenyl ethers ( 5 ) and
isobutene, on acid fission into ( 5 ) or ( 6 ) according to the
conditions, and in the mass spectrometer into the radical
components (7) and (8).
The steric course of the cycloaddition of mesylsulfene to cisand trans-1-butoxy-1-butene can be recognized from the
IH-NMR spectra.
Specific Fragmentation of Cyclohexadienones
[ * ] Dipl.-Chem. K. Rieth
Chemisches Institut der Universitat
7 4 Tiibingen, Wilhelmstrasse 33 (Germany)
+ H,C=C(CH,),
(2)R = CH,
(6) R = A r y l
Ternary Oxides of Rutile Structure: Systems
containing W02, MoO2, V02, or Ti02
By W. Rudorf (Lecturer) and H. Kornelson [*I
(I) R
(4) R
The dioxides V02, MoO2. and W 0 2 crystallize in a monoclinic deformed rutile structure. In this structure the M-M
pair has a remarkably short separation (Mo-Mo = 2.50 A)
in the direction of the c-axis. These dioxides have only a
small, temperature-independent paramagnetism (TIP), which
indicates direct metal-metal bonding. The authors have
studied whether
a) the monoclinic structure is retained on formation of
mixed crystals among themselves or with TiOz,
b) M-M bonds still occur in the mixed crystals, and
c) electron transfer (change of valence) occurs between the
There is a complete series of mixed crystals having monoclinic structure in the series Mo02-WO2. The TIP is retained,
i.e., Mo-Mo, W-W, and Mo-W pairs occur.
Photolysis of para-quinol derivatives proceeds quite differently: thus compounds ( 3 ) , (91, ( l o ) ,and ( I I ) are formed
from (1) in ether (254nm), whereas irradiation of (12)
affords two stereoisomeric bicyclo[2.1.0]pentan-2-one derivatives having, probably, the structure (13).
[*I Priv.-Doz. Dr. A. Rieker
Chemisches Institut der Universitat
7 4 Tiibingen, Wilhelmstrasse 33 (Germany)
Angew. Chem. internat. Edit. 1 Vol. 7 (I968) 1 No. 3
Ti02 and W 0 2 form a tetragonal rutile phase (TixW1-x)02
with 1> x > 0.42, the magnetic behavior indicating that
the W atoms still occur mainly in pairs.
In the system VO2-WO2, however, x
= 0.95 to about 0 . 3 3
for the tetragonal rutile phase (V,W1-,)02. but at x < 0 . 3 3
the structure passes continously into the WOz structure. At
the composition (vO.67WO.33)02 (= VzWO6) the substance
has the trirutile structure with VIII and WVI; at the same
time the conductivity reaches a minimum. This compound is
antiferromagnetic, like the trirutiles crzw06, (VCr)W06,
(FeV)W06, and Cr2TeOg. At the transition trirutile-rutile
which occurs by inclusion of VOTor Ti02 im4 0 (V~!&w&)O2.
the paramagnetism increases greafly since fhe magnetically
active M3+ ions n o longer occupy neighbaring sites.
I*] Prof. Dr. W. Riidorff and Dipl.-Chem. H. K,ornelson
Laboratorium fur Anorganische und Analms che Chemie
der Universitat
74 Tubingen, Wilhelmstrasse 33 (Gexmny)\
Galvanic Metal-N&rnetal
cyanide, a series of unexpected reactions is observed, in which
always two molecules of isocyanide react with one of ketone.
When a n aromatic ring is present, indole derivatives are
formed .
tert-Butyl amides of 2-indolecarboxylic acids are formed
from aromatic ketones, such as acetophenone or benzophenone, and tert-butyl isocyanide:
By J . P. Soulier, D . Bouquet, and J . Gouthier (I .ectu‘er) [*I
The reaction
Metal + Non-metal
R ’ = (CH,),C
+ Salt
R = CH,, C,H5
in galvanic elements was studied for many combinations o f
elements by means of suitable electrolytes. The EMF is
independent of the concentration and to a certain extent also
of the nature of the electrolyte; it depends only o n the solubility product of the resulting difficultly soluble salt. E M F
measurements thus permit exact determination of solubility
[*I J. P. Soulier, D. Bouquet, and P r d Dr. J. Ciauthier
If, however, the aromatic substituent is in the isocyanide
component (e.g., phenyl isocyanide), cycloaliphatic ketones
afford 2-indoleninecarboxanilides 111.
[VB 128 IE]
German version: Angew. Chem. 80, 199 (1968)
[*I Dr. B. Zeeh
Chemisches Institut der Universitat
74 Tiibingen, Wilhelmstrasse 33 (Germany)
[lI B. Zeeh, Angew. Chem. 79, 415 (1967); Angew. Chem.
internat. Edit. 6, 453 (1967).
Faculte des Sciences, Chimie Prop Adeutique
4 3 Boulevard de 1’Hippodrome
Villeurbanne (France)
Organic Syntheses in the Plasma of High VoltaDischarges
By H . Suhr[*]
When vapors of organic compounds are led at pressures of
a few torr through the plasma of cold discharges, various
processes can take place. The molecular ions that are primarily formed may recombine, decompose into smaller fragments, or undergo chemical reactions with neighboring
neutral molecules. At 25-50 V/cm and pressures of 1-10
torr reaction with neutral molecules predominates. The
behavior, in the glow discharge, of a great number of different
types of substance with molecular weights of 50 to 150 has
been studied: most of the compounds give mixtures in which
dimerization products (formed from molecular ions and
neutral molecules) predominate. F r ~ mthe proportions of
the isomers formed from, e.g., toluHE, information about
the lifetime of the molecular ions and about their reactive
behavior can be obtained. If vapors of different compounds
are fed together through the discharge tube, the proportions
in which the products are formed gives information about.
the selectivity of the molecular ions.
[*I Priv.-Doz. Dr. H. Suhr
Chernisches fnstitut der Universitat
7 4 Tiibingen, Wilhelmstrasse 33 (Germany)
A New Synthesis of IndoIe Derivatives
By B. ZeehC*l
Ketones are activated by Lewis acids such as BF3 (the polarity of the carbonyl group is greatly increased) and can then
react with nucleophilic reagents. If the nucleophile is an iso-
Quantum-mechanical Prediction of the Existence
and Properties of the Unknown Molecule BeHz
By W. Kutzelnigg and R. Ahlrichs[*]
Quantitative predictions of the properties of unknown molecules by “ub initio calculations” have so far been rarely possible because of the extraordinarily complicated quantummechanical equations to be solved. (By ab initio calculations
W t mean those in which only the number and kind of the
nuclei and the number of electrons are put in, and in which,
for instance, the equilibrium geometry of the molecule comes
out of the calculation.)
Almost all ub initio calculations are based on the “independent particle model”. This means that one orbital (one oneelectron wave function) is associated with each electron
and that the interaction between the electrons is calculated as the electrostatic repulsion between the electron
clouds that correspond to the orbitals. Since, however, the
electrons are not smeared charge distributions, and only a
probability distribution of all the electrons has any physical
meaning, this description in which the “electron correlation”
is neglected cannot be quite correct. However, it permits
certain properties, such as dipole moments, equilibrium
distances and angles, and force constants, to be obtained
surprisingly well. The independent particle model is, however,
quite insufficient to permit calculation of bond energies and
electron excitation energies.
A method developed by the authors[ll for calculation of a
major part of the electron correlation - the “electron pair
correlation” - now makes ab initio calculation of bond
energies possible. The procedure has been applied with success to some known small molecules and then to the unknown
molecule BeH2.
The BeH2 molecule is linear and symmetrical in the ground
state. The equilibirum Be-H separation (1.35 rt 0.01 A) is
almost the same as in the known[zJ BeH molecule (1.343 A);
valence force constants are also similar [fr= 2.23 (BeH2) and
2.26 (BeH) mdyn/A]. The Be atom is in almost the same
valence state in the two molecules. I n accord therewith the
dissociation energy for separation of one H atom from BeHz
(consideration being given to zero point vibrations) at
89 f 6 kca1,lmoIe is distinctly greater than that for separation
of the second H atom (53 f 6 kcal/mole) because bonding of
Angew. Chem. internat. Edit. 1 VoI. 7 (1968) 1 No. 3
Без категории
Размер файла
403 Кб
meeting, chemical, lyons, ninth, tbingen
Пожаловаться на содержимое документа