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Crystal Structure of Te5O4F22.

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cis-helix. The differing strength of the bonding between solvent
and peptide carbonyl groups could be determined from small
differences in the T values of the C,-H resonances (CF,COOD:
5.10ppm; CD,COOD:
5.19ppm; D z O : 5.24ppm;
C F 3 C D 2 0 D : 5.26ppm; C D 3 0 D : 5.31 ppm). In CD,COOD
and CF3COOD all oligopeptides have the trans-configuration.
We found that there is a distinct dependence of the configuration on chain length in the other solvents, di- and triprolines
behaving differently from the higher oligoprolines: in D 2 0 ,
di- and triproline are in cis-trans equilibrium; from n = 4
onwards only trans peptide bonds are formed. In CD,OD,
diproline is completely and triproline extensively cis configurated, respectively. The proportion of cis bonds (T= 5.50ppm)
passes through a minimum at n = 4 and increases rapidly
with increasing chain length; the all-cis configuration is
reached at ri>10. The reverse behavior was observed in
C F 3 C D 2 0 D : here diproline is likewise completely cis configurated; in the oligomers with r1=3 to 10, both cis and trans
peptide bonds occur. From n = 12 onwards we found exclusively trans peptide bonds. In the case of C- and N-protected
oligoprolines, however, apart from in the first disordered four
members, only all-trans peptide bonds a r e foundL4].The
ability of di- and triprolines to form cis peptide bonds is
consistent with the pronounced tendency to form cyclotriprolyls and, particularly, cyclodipr~lyls[~~.
While only the signal .of the cis- or trans-isomer appears
in the range of C, protons in the 'H-NMR spectra of the
polyproline and the oligomers with n > 15, the spectra of the
lower oligomers coptain additional resonances which arise
from the N- and C-terminal proline residues. The T values
of the C-terminal proline residue depend on the position
of the dissociation equilibrium of the carboxyl group, and
hence on the solvent (CF3COOD: 5.1 ppm; CD,COOD:
5.4 ppm; D 2 0 , C F 3 C D 2 0 D ,C D 3 0 D : 5.7 ppm).
Received: September 23, 1976 [Z 563 IE]
German version: Angew. Chem. X X . 844 (1976)
CAS Registry numbers:
Proline polymer, 2519 1 - 1 3-3; proline repeating unit, 2521 3-33-6
[I]
M. Rofhe and R. T h e w h i , Tetrahedron Lett. 1970, 4063; M. Rorhe
and J. Maidiiek, ;bid. 1972, 3795.
[2] !l Gniiser, J . Eiiyel, D. Wiriklniair. and G. K ~ ~ i i i sBiopolymers
r.
9, 329
(1970).
[3] M. Rorhe, W Sdiiiid1er. R. Piidill. M . KO.W:EII.(I. R. T/ie!.so/iii, and
R . Sreiriherqrr: Proceedings of the 1 I th European Peptide Symposium.
North Holland. Amsterdam 1971, p. 388.
Crystal Structure of Te5O4FZ2
[**I
By Hans Pritzkow and Konrad Seppelt"]
Sulfur and selenium form the monomeric compounds SOF4
and SeOF4['a1,whereas in the case of tellurium only polymeric
(TeOF4), and oligomers of the type F5Te--(OTeF4),--OTeFS
have been described"b1. Little is known about the structures
of these compounds. Previously it had been assumed that
they contained 0-TeF4-0
octahedra coupled via oxygen
and it is unclear whether the two oxygen atoms occupy the
cis or trans position. Polymeric (TeOF,)" is formed in
the pyrolysis of B(OTeF5)3[lb1and in the fluorination of
As(OTeF,),rZ1.
-
As(OTeF5)3 2 [ A s F ~ ( O T ~ F ~ ) ~AsF,
]
+ (TeOF4).
Anorganisch-chemisches Institut der Universitiit
Im Neuenheimer Feld 270, D-6900 Heidelberg (Germany)
[**I This work was supported by the Fonds der Chemischen Industrie.
Chrm. I n r . Ed. Engl. 1 Vol. 15 ( 1 9 7 6 ) No. 12
Fig. I . Molecular structure of TeS04F21
corners to a central octahedron. Limiting tellurium to an octahedral environment and allowing no oxygen double bonds,
there are still twelve possible isomers for a molecule of formula
Te504F22.Surprisingly, the substance under investigation
occurs only in the highly symmetric arrangement. This finding
is in accord with the I9F-NMR spectrum of Te504F22.
Since no short intermolecular distances occur, the geometry
of the molecule is determined only by intramolecular forces.
Remarkably, the tellurium-fluorine bonds in the central octahedron are somewhat longer (1.849 A) than the others (1.798
angle ( 1 39.4") could be due
to 1.819 A).The large Te-0-Te
to repulsion between the tellurium atoms[31. In the related
compounds Xe(OSeFS)2 and U(OTeF& the corresponding
angles are 125" and 170", respectively[41. From these large
differences it may be assumed that double bonding leads
to stretching ofthe angle. It would then follow that the d-orbital
participation in the case of tellurium is greater than in the
case of selenium, while in the case of uranium even f-orbitals
participate in the bonding.
Received: September 28. 1976 [Z 567 IE]
German version: Angew. Chem. X X . X46 (1976)
CAS Registry numbers:
60788-79-6; TeF2(0TeFS),. 60788-8 1-0
~
[*] Dr. H. Pritzkow and Priv.-Doz. Dr. K . Seppelt
Aiiyew.
From the polymeric mixture obtained by the latter reaction
we were able to isolate a component having the composition
Te504F2z.It is a crystalline, sublimable solid which melts
at 76°C; it was characterized by its vibrational, mass, and
NMR spectrar2].A crystal structure analysis has now been
carried out on this apparently complicated oxide fluoride
of tellurium.
Te5O4FZ2crystallizes tetragonally, space gfoup I4'/a with
the cell parameters a = 8.81 6(2), c= 20.341 (6)A and Z = 4 formula units in the unit cell. The structure was solved with
Patterson and difference Fourier syntheses and refined by
the method of least squares (1 178 independent reflections
with I > 0,all atoms anisotropic) to R = 0.049.
The compound is made up of isolated TeF2(OTeFs)4octahedra (Fig. l). Four outer octahedra are coupled via their
"I
a ) H . J o i i a s , 2. Anorg. Allg. Chem. 265. 273 (1951); K . Seppelr. Angew.
Chem. 86, 103 (1974); Angew. Chem. Int. Ed. Engl. 13. 91 (1974); 2.
Anorg. Allg. Chem. 406, 287 ( 1 9 7 4 ) : h ) F . Sludky, H. Kropsliofer. and
0. Left-ke, J . Chem. Soc. Chem. Commun. 1973. 134.
121 K . Seppelr, Chem. Ber., in press.
[31 C. Glidewell, Inorg. Chim. Acta 12, 219 (1975).
[41 L. K . Trmpleroii, D. H . Tenipleron, N. Borlletr. and K . Srppelt, Inorg.
Chem.. in press.
771
Table I . Properties o f c o m p o u n d s ( 3 ) and ( 4 ) [a] ' H - N M R
111 C,,H,.
" ' P - N M R in C H 2 C l z
.. .
<<"I'
M.p. ["C]
[ppnl]
lllll
[il.
& ' H [ppm]
'JI.I, [HI]
NCIi.,
c]
I)'
[ii.
h]
JPII[Hz]
c'(('ll.,iz
PNCH
PCCH
-1lY4
- 1.15
- 1.08
- 1.19
12.3
9.0
14.5
17.3
12.8
11.2
19.6
IY.3
-
-2
(311)
-410
(.(hi
11oto I l l
144 to 145
(411)
(4 h )
- 201 7
-?XI 7
SLIbl. a bob e 705
- 120.1
- 105')
2x.o [d]
- 7 5 5 (I)
24.3 [d]
72.7 [d]
Y.5 [d]
-7.51 (I)
-7.39 It1
-1.15 ( I )
[c]
[c]
[c]
[c]
.
[q
[q
[f3
[q
-- -
Shift r e l ~ t i v eto X5 l'sl FiAPO1 c'xternaI or T M S internal atandard. 6 " ' P and d ' H ha\e negatibe signs for downfield
\lifts. [h] In C',,H,. [c] 111 C'H2CII. [d] Cnlciilated and read off from the [AX,2]I-spin system of the ' H - N M R
spectrum. In the case of ( 3 i i i and ( 3 h ) only 'JPF could he ca1ciil;ited. s o ii liiryc error range resulted. [el [AX,,]I-spin
system. [f] N = JJPCcH
+ Jp,pCcH/.
[:I]
Synthesis and Isolation of cis- and trans-1,3,2h3,4h3Diazadiphosphetidine
By Otto J . Sclierer and Giiiiter Schiicrbl[*I
I n contrast to the cis- and f~ui~.s-l,3,2hs,41~5-diazadiphosphetidine-2,4-dithiones already characterized by crystal structure analysis"] and the 1,3,2h3,4h5-diazadiphosphetidin-4ones or 4-thiones, some of which are detectable in solution
as mixtures of cis- and fruii.s-isomers[21,all the 1 ,3,2h3,4h3diphosphetidines that have been synthesized thus far and investigated N M R spectroscopically exist in only one isomeric
form[']. With the isolation of (2)14) we have now been able
to demonstrate for the first time the existence of the postulated
intermediate^'^^. in some 1 ,3,2h',4h3-diphosphetidine syntheses and have found a method for preparation of cis- and
rrtriis-l ,3.2h',4A3-diazadiphosphetidines [ ( 3 L I ) and ( 3 h ) ] .
N o transformation into the other isomer could be detected
by N M R spectroscopy on warming ( 3 0 ) or ( 3 b ) to cu. 140°C
for several hours.
E\-perimenftrl
Synthesis of ( 3 a ) and ( 3 h ) : A solution of phenyllithium
(52.8mmol) in ether (44mI) is added dropwise with stirring
to an ice-cold solution of (2)16] ( 1 3.0g, 48.0mmol) in pentane
(250 ml). The mixture is then allowed to warm to room temperature, stirred for a further 3 hours, and filtered on a G3
frit. The filtrate is concentrated in a vacuum and fractionally
distilled. ( 3 b ) sublimes on the cold finger, while ( 3 t r ) drips
into the receiver. (3 h ) is purified by resublimation (oil-pump
vacuum)and ( 3 t r ) by redistillation in a 10-cm Vigreux column.
B.p. 32-34"C/O.I torr ( ~ L I )subl.
,
temp. 55--70°C (bath temperature)/O. I torr (3 b ) .
Received: September 24, 1976 [Z 564 IE]
German jersion: Anpen. Chem. (88. 343 I19761
CAS Registry numbers.
(21.60746-25-0: ( 3 1 1 ) . 60746-26-1; ( 3 h ) . 60746-27-2: ( 4 0 ) . 60746-28-3: ( 4 h ) .
60746-29-4.
"P.
7123-14-0
[ I ] R. .4. Shim Cr d.. Phosphorus I , 153 11971).
[1] Examples- a ) 0. J . Schcr.i,r. and G . ScIiitiibI. Chem. Ber. IflY. 2996 (1976):
b ) G . B i d h ~ d iand R. Kecrr. .I Chem. Soc. Dalton Trans. IY76. I 113.
[ 3 ] a ) 0. J . SiIirriv and P. K / ~ ~ W I ~Angew.
I I ~ I I . Chem. 8 / . 743 119691: Angew.
Chem. Int. Ed. Engl. 8. 752 (1969): b ) C. BirIImIr and R. Keur. _I. Chem.
Soc. Dalton Trans. IY74, 2010: c ) K . W M i i i r . . _I. Chem. Soc Dalton
( 3 h ) , whose structure was confirmed by a crystal structure
analysis[*I, shows an unusual downfield shift in the 3'P-NMR
spectrum (Table 1). Compounds ( 3 0 ) and ( 3 h ) are oxidized
stereospecifically by elemental sulfur (in ice-cold pentane)
to the I ,3,2h5,4h5-diazadiphosphetidin-2,4-dithiones
( 4 u ) and
( 4 b ) . respectively, which also differ markedly in their melting
points.
Trans. IY75. 259: also Ref. [2].
[4] ( 2 j, which like all other compounds w'as characterized by elemental
analysis. ' H - N M R and massspectra.and molecular weight determination
[ ( 2 ) . (301. ( 3 h ) . and (411)cryoscoptcally in benzene, ( 4 h ) osrnometrically in methylene chloride] forms colorless crystals 1m.p. 6X to 70°C)
which reveal the presence of a mixture of rotamers (rotamer A. <(I.
XO",,. 'JPp=765 Hz: B . ~ ~ i i . 2 0 " ~ ~ . 2 J p p = 1 Y 0 H
the
~ )'iHt i- a n d "P-NMR
spectra (in ChH,).
[5] R. Ktwr cr <I/.. J. Chem. Soc. Dalton Trans IY73. 1414
[6] PI-epared fi-oni ( I ) [7] stid in.r-CIHqPCII in pentane ;it irooni ceiiiperatnre with triethylaiiiiiie iis HCI acceptor
[7] 0. J . S</tiwr and P. K / I I \ I I ~ U Z.
I ~ IAnorg.
~.
Allg Chem. 3711. 171 11969).
1x1 Dr. S. P ( J / ~Bielefeld.
/.
private communicatioii.
Synthesis of Cycloheptasulfur Oxide, S 7 0 r'I
1 4 a ~cis
= C(CH,),
By Rulf Strudel and Torsteri Sandow[*]
Compounds containing cumulated sulfur-sulfur bonds, such
as Ss, R2S3,or R2S4,canbe oxidized with trifluoroperoxyacetic
acid to sulfoxides (S,O; R2S,0, i i = 3 or 4)12'. We have now
..
[*] Prof. Dr. R. Steudel and DiplLChem. T. Sandow
[*] Prof. Dr. 0. J. Scherer a n d DiplLChem. G. Schnabl
Fachbereich Chemie der Universitiit
Pfaffenbergstrasse 95, D-6750 Kaiserslatitern (Germany)
772
lnstitut Kir Anorganische itnd Analytische Chemie
der Technischen Universitat
Strasse des 17. Juni 135. D-I000 Berlin 12 (Germany)
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