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Cyclization of Acid Chlorides by Polyphosphoric Acid.

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+IcR,) and additional conjugative back-donation of electrons Sid + C,. The relative energy changes of the highest
occupied and lowest unoccupied molecular orbitals caused
by interaction with the substituents can be measured individually be means of e.g. half-wave potentials [I], electron spin
densities [21, or charge-transfer band maxima [31, while the
resulting total energy differences can be determined from the
corresponding transitions in the electronic spectrar2.31. Of
the cross-conjugated [I], cyclic [2,31, and linear n-electron
systems containing R3Si-groups, ethylene derivalives were
the first for which we were able t o determine ionization
energies by mass spectroscopy (41 and thence t o obtain, by
means of the Koopman theorem [51, direct information about
the highest occupied (x)-levels “51.
The hitherto unknown [71 tris(trimethylsilyl)ethylene (2) can
be prepared as shown :
-R3St -
+ HSiClzR
[*] Priv.-Doz. Dr. H. Bock and Dip1.-Chem. H. Seidl
and applying the usual model of the Si-Cs,2 bond this
provides further evidence [1-31 in favor of a conjugative
Sid + C, electron back-donation. A minimum value for the
+ I s ~ R , effect follows from the ionization energy of t-butylethylene which is 0.8 eV higher than that of l-trimethylsilyl2-propene where the P-situated R3Si group is separated
from the x-electron system by a tetrahedral C atom.
The d-orbital interactions demonstrated by the ionization
energies for the ground state of silylethylenes were used
previously t o explain why the N M R signals of the ethylene
protons are shifted to lower field in comparison with the
alkyl derivatives 191 and why the C = C stretching frequencies
are lowered [lo]. In this connection, extreme differences are
shown by the values for tris(trimethylsily1)- and trimethylethylenes, where a difference of 5000 cm-1 = 14 kcal/mole in
the x + x* excitation energies also indicates considerable
x*/d splitting 1111. Smaller, but similar, differences between
the properties of silyl- and alkyl-polyenes and -poIyynes 1111
confirm the d-orbital effects for silyl substituted linear x electron systems.
[ Z 635 IE]
Received: October 13th, 1967
German version: Angew. Chem. 79, 1106 (1967)
60 mmoles of dichloro(methy1)silane is added dropwise and
slowly to an equimolar amount of bis(trimethy1silyl)acetylene
to which has been added 0.3 ml of a 0.1 N solution of HzPtC16
in 2-propanol. After 20 hours’ boiling under reflux, distillation affords 1 3 % of ( I ) , b.p. 57-60°C/0.5 mm, which
affords 47% of (2), b.p. 43--45 OC/O.5 mm, by a Grignard
reaction. The product is purified by gas chromatography
(SE-30 column). The 1H-NMR-spectrum contains three
singlets in the ratio 1 :18:9 at T = 2.67, 9.86, and 9.91; the
C = C stretching frequency appears at 1499 cm-I. Comparison
with the corresponding data for trimethyl ethylene‘s]
(IH-NMR signal of the ethylene proton: 4 . 8 3 ~ ; C = C
stretching frequency 1667 cm-1) illustrates t o what extent
characteristic properties of the ground state of simple R3Siand R3C-substituted x-electron systems may differ.
Institut fur Anorganische Chemie der Universitat
Meiserstr. 1
8 Miinchen 2 (Germany)
[**I Part IV of d-Orbital Effects in x-Electron Systems Containing Silicon Substituents. - Part 111 [31.
[l] H. Bock and H . Alr, Angew. Chem. 79, 941 (1967); Angew.
Chem. internat. Edit. 6 , 932 (1967).
[2] H . Alt, H . Bock, F. Gerson, and J . Heinzer, Angew. Chem.
79, 933 (1967); Angew. Chem. internat. Edit. 6 , 941 (1967).
[3] H. Bock and H. All, Angew. Chem. 79, 934 (1967); Angew.
Chem. internat. Edit. 6, 942 (1967).
[4] We thank Mr. M . Fochler for measuring the appearance
potentials. According to R . I . Reed (Ion Production by Electron
Impact. Academic Press, London 1962), the “vertical” ionization
energies determined in this way for alkylated ethylenes are in
good agreement with the “adiabatic” counterparts. In the series
studied, the individual values were scattered by at most 50.04 eV.
(51 T. Koopmans: Physica. Nijhoff, DenHaag 1934, Vol. I, p. 704.
[6] M . 5.Robin, R. R. Hart, and N . A. Kuebler, J. chem. Physics
44, 1803 (1966).
I71 R . West and G. R . Husk synthesized the compound by a
similar route (personal communication at the IUPAC Syrnposium on Organometallic Chemistry, Miinchen (Germany) 1967).
[S] Possibly, non-bonding interactions between the bulky cis
(CH&Si-groups play a part. It is impossible to build a StuartBriegleb model for a tris(t-butyl)ethylene, in the model of the
tris(trimethylsily1) derivate (dR,Si-c
dR3C-c) rotation of the
cis-R3Si groups 1s sterically hindered.
[91 R . T . Hobgood, J . H. Goldstein, and G . S. Reddy, J. chem.
Physics 35, 2038 (1961); cf. also R. Summit, J. J. Eisch, J. T.
Trainor, and M . T . Rogers, J. physic. Chem. 67, 2362 (1963).
[lo] J. Knizek, M . Horak, and V. Chvalovsky, Coll. czechoslov.
chem. Commun. 28, 3097 (1963).
[ l l j H. Bock and H. Seidl, unpublished work.
Cyclization of Acid Chlorides by
Polyphosphoric Acid
Fig. 1. Ionization energies (IE) of silyl- and alkyl-ethylenes.
The diagram (Fig. 1) for the highest occupied (x)-molecular
orbitas 161 of silyl- and alkyl-ethylenes permits the following
conclusions : (+I)-Substituents such as R3Si- and R3Cgroups lower the ionization energy of the ethylene x-electron
system, corresponding to a rise of the x-level, which for
the silyl derivatives CnH4-n(SiR3)n is linearly proportional,
within a good approximation, to the number of substituents.
The effect of the R3Si-groups is, however, in all cases less
than required for inductive polarization ( I s ~ R>~ +IcRJ,
By A . Bhati and
We have cyclized arylalkanecarbonyl chlorides ( I ) , namely,
4-phenylbutyryl, 5-phenylvaleryl, 4-(2-chloro-5-methoxyphenyl)butyryl, and 4-(5-chloro-2-methoxyphenyl)butyryl
chloride, with polyphosphoric acid and thus obtained the
cyclic ketones (2) in excellent yield.
Angew. Chem. internat. Edit. f Vol. 6 (1967) 1 No. 12
Syntltrsis of I-tetralone (2):
The acid chloride obtained from 1.65 g of 4-phenylbutyric
acid and thionyl chloride was treated with 23 g of
freshly prepared [ I ] polyphosphoric acid with exclusion of
moisture, and the whole was stirred at 70°C for 15 min. HCI
was evolved. The mixture was poured into water and extracted with ether. After washing with 1 0 % sodium hydroxide
solution and drying, the ether was removed, leaving 1.38 g
(94.6 %) of 1-tetralone.
Under the same conditions I-indanone is formed from 3phenylpropionyl chloride, but with only 57.3 % yield.
Received: September 18th. 1967
[Z 637 IEI
German version: Angew. Chem. 79, 1100 (1967)
[*I Dr.
A. Bhati and N. Kale
Department of Chemistry and Biology,
Regional College of Technology
Byrom Street
Liverpool 3 (England)
1 1 ) S. Dev, J . Indian chem. SOC.32, 262 (1955).
Irregularities in the Partial Molar Enthalpies of
Mixing of Water and Water-Alcohol Mixtures
at Constant Temperature
By G. Korfiim and K . A . Steinerr*]
I n the neighborhood of specific temperatures, irregularities
(called “kinks” in the Anglo-Saxon literature) occur in the
temperature-dependance of numerous properties of water
and aqueous solutions [I]. They are interpreted as indicating
that such systems contain various mixed phases that are
arranged in the manner of clathrates and are transformed
into one another a t specific temperatures. The best known
example of such a liquid structure if the “water hydrate”
( H 2 0 ) 2 , proposed by Pading, in which one molecule is
surrounded by 20 other molecules, after the manner of a
clathrate; as in gas hydrates, these 20 molecules form the
corners of a dodecahedron. The transition temperatures are
considered t o depend o n the nature and concentration of the
material dissolved in the water, whence it is concluded that
the anomalies denote sudden changes in the structure of the
water and have nothing to d o with interactions between water
and the solutes.
Using a very sensitive differential calorimeter [21 we have
measured the intermediate enthalpy of mixing of water with
water-alcohol mixtures at 30 “C, and from the results have
determined the partial molar enthalpies of mixing as a function of the molar fraction of the components. In contrast to
the measurements by other authors the molar fraction was
varied by very small amounts. Surprisingly, we observed
numerous irregularities which exceeded the experimental
Fig. 1. Partial molar enthalpy of mixing A H E 2 0 of water with warerethanol mixtures. o = our measurements at 30°C; < = calculated
from measurements by Bose 141 at 21 OC. Analogous irregularities were
observed at 20 and 40 “C.
error in the measurements by an order of magnitude. Figure 1
shows some of our results. From them there is no doubt that
structured mixed phases occur also in ethanol-water mixtures,
a fact that may be important for the still IittIe understood
structure of liquids.
It is true that participation of dissolved gases ( 0 2 , N2) in
these structures [31 cannot be excluded with certainty, but
such participation is very unlikely at the temperatures
selected for o u r work. Our measurements further show that
the iregularities in the properties of aqueous solutions are
not determined solely by the structure of the water and its
temperature-dependance, since they are observed at almost
constant temperatures (temperature variations o n mixing
amounted to about 0.01 “ C ) .
Received: October loth, 1967
[Z 638 IE]
German version: Angew. Chem. 79, 1105 (1967)
[ * ] Prof. Dr. G. Kortum and Dipl.-Phys. K. A. Steiner
Institut fur Physikalische Chemie der Universitat
Wilhelmstr. 56
74 Tiibingen (Germany)
[I] M . J . Blundumer, M . F. Fox, and M . C . R. Symons, Nature
(London) 214, 163 (1967); C. Saluma and D. A. I. Goring, J.
physic. Chem. 70, 3838 (1966); W. Drost-Hunsen, Ann. N.Y.
Acad. Sci. 125, 471 (1965).
[2] G. Korriim and H . Schreiber, 2. Naturforsch. 20~7,1030
[31 Cf. M . Y. Stuckelberg and W. Meinhold, Z . Elektrochem. Ber.
Bunsenges. 58, 40 (1954).
[4] E . Bose, Nachr. Akad. Wiss. Gottingen, math.-physik. KI.
1906, 278, 316; Z.physik. Chem. 58, 585 (1907).
Preparation and Properties of Inorganic
By J . Junder[*l
Inorganic halogenoamines have recently been obtained by
disproportionation of halogens with ammonia at about
-75 “C. That the reddish-brown NI3.NH3 isolated, inter
ulia, actually has the structure corresponding to this formula
and is not, e.g., a 1:l adduct of NHI2 and NHpI follows
from the reaction (studied analytically and by IR spectroscopy) with pyridine or quinoline, in which the ammonia is
replaced by the nitrogenous bases without destruction of the
NI3 component r11. The structure, which was clarified by BurAngew. Chem. internat. Edit.
Vol. 6 (1967) J No. I2
nighuusen and Hurtl[21 by X-ray analysis shows NI4 tetrahedra which are joined together into chains by common
iodine atoms. One iodine atom of each NI4 tetrahedron is
additionally attached t o one ammonia molecule by a chargetransfer bond.
In order t o explain the decomposition of monochloramine
NH2C1 by way of the unstable imene or nitrene NH, monochloramine was treated with phenyl-lithium in dimethyl-2butene at -75 O C . The expected a-elimination took place in
good yield, as shown by the benzene formed, but only 3
of 2,2,3,3-tetramethylaziridine was obtained. During the
reaction a white precipitate was formed, which evolved NZ
and NH3 when warmed. The precipitate is moderately
soluble in ether at -75OC; LiCl separates from the clear
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acid, polyphosphoric, cyclization, chloride
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