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Exchange of Ring Members in Cyclopolyphosphines.

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Exchange of Ring Members in Cyclopolyphosphines
twice, and the product was dried in a desiccator over P205.
The yield was about 45 %.
The compound ( I ) [m.p. 35.7 t 0.4OC; dj0 = 1.4796
0.001 g/crn3] is almost insoluble in nonpolarsolvents; the solubility increases with the polarity of the solvent. Chemical,
kinetic, infrared-spectroscopic, and X-ray investigations
showed that thermal decomposition of the acid ( I ) between
20 and 100 "C proceeds in two steps:
~~~
By Prof. Ulrich Schmidt, cand. chem. R. Schroer, and
Dr. H. Achenbach
Chemisches Laboratorium der Universitat,
Freiburg (Germany)
When heated with diethyl sulfide, pentaphenylcyclopentaphosphine (the so-called tetraphenylcyclotetraphosphinewas
recently found to be the pentamer) yields diethyl phenyldithiophosphonite, C S H ~ - P ( S C ~ H ~ This
) ~ . reaction was
interpreted as involving insertion of a phenylphosphinidene
(CsH5-P:) into the disulfide linkage[ll.
Thermal decomposition of cyclopolyphosphines into phosphinidenes should lead to "disproportionation" of two
different symmetrical cyclopolyphosphines. We have now
demonstrated such an exchange of ring members between
pentamethylcyclopentaphosphine ( I ) and pentaethylcyclopentaphosphine (2) [21:
2 SC(SHI(NH2)
+ NH4[SC(S)(NH2)1+ CS2
NH4[SC(S)(NHz)] + NH4SCN+ H2S
Infrared spectrum of ( I ) : 2170(m), 1551(w), 1519(st), 845(m)
cm-1 [41.
The equivalent conductivity (51 determined for aqueous solutions between 5 and 25 "C is described by the temperature
functions
11, = 5.87 T - 1348 for ( I )
Ro= 0.918 T - 222.8 for [SC(S)(NH2)]-
[A0 in cmZ(g-equiv)-l ohm-1; T in OK). The thermodynamic
dissociation constantr51 of ( I ) is Ka = (1.13 -L 0.03) x 10-3
at 20 "C.
Decomposition of the acid ( I ) in aqueous solution follows
first-order kinetics, with a half-life of 85.5 -C 1.5 min. at 20 OC
and an activation energy of 21.1 t 0.5 kcal/mole at 20°C.
Received: January 21st, 1966
IZ 141/971 IE]
German version: Angew. Cheni. 78, 334 (1966)
On simultaneous introduction of compounds (1) and (2)
into a mass spectrometer [31 superposition of the mass spectra
of these two compounds is observed. If, however, the mass
spectrum is registered under the same conditions for a mixture that has been previously distilled (150 "C bath temperature, 0.1 mm), then ions of mass 244, 258, 272, and 286
are observed, in addition to the molecule ions and fragments
of compounds ( I ) and (2). These masses correspond to the
molecule-ion weights of the mixed cyclopentaphosphines
(3 ) to (6).
Received: January 14th, 1966
IZ 136/968 IE]
German version: Angew. Chem. 78, 307 (1966)
[I] Part 2 of Phosphinidenes. - Part 1: U. Schmidt and Ch.
Osterroht, Angew. Chem. 77,455 (1965); Angew. Chem. internat.
Edit. 4, 437 (1965).
[2] Preparation: W. A . Henderson, M . Epstein, and F. S . Seichtw,
J. Amer. chem. SOC.85, 2462 (1963). According to these authors
the product is identical with a cyclophosphine obtained by K .
Isleib and B. Mitscherling [ Z . Naturforsch. 156, 267 (1960)] for
which the tetrameric structure was deduced from cryoscopic
measurements. According to mass-spectrometric results the
product is pentameric; the most important signals in the spectrum of (2) are at m/e = 300 (Et5P5+; 70 %) and 271 (Et4P5+;
100 Yo).
[3] Atlas-CH-4 mass spectrometer. The substances were introduced by the HTE system at 110 "C.
Synthesis of Free Dithiocarbamic
Acid, SC(SH) (NH*)L11
[I] Communication XXV on Chalkogenocarbonates. - Communication XXIV: A . Miiller, G. Gattow, and H . Seidel, Z . anorg.
allg. Chem., in the press.
[2] E. Mulder, J. prakt. Chem. 103, 178 (1868); Liebigs A n n .
Chem. 168, 228 (1873).
[3] G. Gattow and B. Krebs, Z . anorg. allg. Chem. 321, 143(1963).
[4] st = strong, m = medium, w = weak.
[5] Cf. A . Hantzsch and W. Buceriris, Ber. dtsch. chem. Ges. 59,
793 (1926).
Reductive Fragmentation of
1-Methyl-4-tosyloxybicyclo[2.2.2]octan-2-one[*I
By Dr. W. Kraus
Chemisches Institut der Universitat Tubingen (Germany)
Sulfonic esters of P-hydroxy ketones are fragmented on
hydrolysis with KOH [2,31 or treatment with a Grignard reagent 131. Reductive cleavage of such compounds has not previously been described.
4-Hydroxy-l-methylbicyclo[2.2.2]octan-2-one
[ 5 61, which is
readily accessible from 4-acetyl-4-methylpimelic acid 141 by
way of 4-acetyl-4-methylcyclohexanone [ 5 61, was converted
into its p-toluenesulfonate ( I ) ; (Ts = CH3C&&&),
m.p.
93.5-94.5 "C. This was stirred with LiAlH4 in ether for 2 h
at room temperature, leading to the previously unknown
(1-methyl-4-methylenecyclohexyl)methanol(2), b. p. 89 "C/
10 mm, in 8 3 % yield.
9
9
By Prof. Dr. G . Gattow and Dipl.-Chem. V. Hahnkamm
Anorganisch-Chemisches Institut der Universitat
Gottingen (Germany)
Although there have been numerous papers concerning esters
of dithiocarbamic acid, SC(SH)(NH2) ( I ) , and their N-substituted derivatives, as well as the ammonium salt, only the
probable existence of the free acid ( I ) has been shown
by Miilder's investigations [21. We have now prepared the
acid ( I ) by a method analogous to that used for synthesis
of trithiocarbonic acid, SC(SH)z (31 :
Concentratcd HC1 (1.4 ml, 0 "C) was dropped, with stirring,
into a solution of 2 g ofNH4[(SC(S)(NH2)] in 16.5 ml of H20,
previously cooled to 0 "C. The colorless acid (1) that crystallized was washed with ice-water, ligroin was poured over it
316
1
Angew. Chem. internat. Edit.
+
OOTS
J
/ Vol. 5 (1966) 1 No. 3
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exchanger, cyclopolyphosphines, ring, members
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