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Cpi2TiS5O and Cp2TiOS5ЧIsomeric Titanocene Complexes with Two Novel S-O Chelate Ligands (Cp = 5-CH3C5H4).

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varied iteratively in the refinement until an equivalent isotropic displacement factor comparable with that at the other positions resulted. For each
ring position in the disorder model so obtained the C:P ratio was fixed, an
anisotropic displacement factor refined together with the atomic positions,
and-corresponding to the C fraction-an H atom was introduced
“riding” at a calculated position with a common isotropic displacement
factor (I/ = 0.09 A’). The refinement converged well and led (considering
the positional disorder) to reasonable displacement factors. Using the
weights w = I/02(Fo)and after introduction of an extinction correction the
residuals R = 0.054, wR = 0.037 resulted for 920 observed reflections with
Fo > 4a. Further details of the crystal structure investigation are available
on request from the Fachinformationszentrum Karlsruhe, Gesellschaft
fur wissenschaftlich-technische Information mbH, W-7514 EggensteinLeopoldshafen 2 (FRG), on quoting the depository number CSD-55147,
the names of the authors, and the journal citation.
[I91 Whereas the N atom in 1 occupies the 1,3 positions (SOjSO ratio) and in 2
As occupies the 1,4 positions, the electron density distribution in the ring
of 7 (Fig. 4) shows that the P atom, like in the As-analogue of chromium,
is preferentially located at the 1.4-positions, but that differing and smaller
fractions of P are located on all other ring positions. Because of superposition of several orientations of a distorted six-membered ring, varying
bond lengths from 148 to 159 pm are encountered, whereby the mean value
(155.4pm) lies well above the mean of the bond lengths in free phosphabenzene (150.7 pm) [2]. This is plausible since, because of its higher
number ofelectrons the P atom “prevails” more strongly during the superposition of C and P atoms than corresponds to its percentage. The deviations of a “best plane” through the six ring atom positions o f 7 are less than
0.3 pm and thus indicate planarity. The V atom is located 166(1) pm above
the ring plane, its distance from the ring atoms is on the average 227.4 pm.
The second ring is generated through the symmetry center in the V atom,
i.e. is parallel to the other ring and is in the eclipsed orientation. Since
pairwise oppositely disposed positions in the ring are occupied to about the
same extent by P, the disorder model is compatible both with the assumption-with varying contribution-of differently oriented molecules with
antiperiplanar and with synperiplanar conformation. The exclusive presence of a synclinal conformation is ruled out by the different extent of
occupation of the ‘‘mela” positions; an admixture cannot by ruled out,
[20] C. Batich, E. Heilbronner, V. Hornung, A. J. Ashe 111, D. T.Clark, U. T.
Cobley, D. Kilcast, I. Sanlan, .
Am. Chem. SOC.98 (1973) 928.
Cp;TiS,O and Cp’,TiOS,-Isomeric Titanocene
Complexes with Two Novel S-0 Chelate Ligands
(Cp’ = $-CH,CSHJ **
By R a y Steudel,* Andreas Prenzel, and Joachim Pickardt
S,O and other cyclic sulfur oxides can be prepared by
oxidation of sulfur rings with trifluoroperoxoacetic acid
They contain the group -S-S(OkS-, which can
also be incorporated into organic compounds by condensation of thiols or thiolates with thionyl chloride, whereby
sulfane oxides are formed [Eq. (b)].Iz1
C ~ c f o - S , CF3C03H--t S,O
n = 6-10
group -S-S(0)-according to Equation (a) or of chain-like
sulfane oxides with essentially more than three sulfur atoms
according to Equation (b). We report here on the first synthesis of a polysulfide oxide complex of titanocene, which
should enable the -S,O- group to be incorporated into chainlike or ringlike compounds, i.e. analogously to the use of
Cp,TiS, (Cp = q5-C5H5)for the synthesis of ring- and
chain-like polysulfur compounds.[3]
The dinuclear titanocene complex Cp,Ti,S, lt4]reacts
spontaneously with thionyl chloride in the ratio 1:1 at 0°C
in CS, to give the titanocene dichloride 2 and the pentasultide oxide complex 3, which is sparingly soluble in CS, and
precipitates in the form of red crystals (m.p. 105 “C, dec ~ m p . )[Eq.
‘ ~ ~(c)].
Solid 3, in contrast to the decomposable cyclo-sulfur oxides S,O, is stable at 20°C in air. The IR spectrum of 3 (KBr
pellet) shows the SO stretching vibration as a very
strong band at 1094 cm-’, an unequivocal indication of the
-S-S(OkS- group, as v ( S 0 ) for S,O appears at almost exactly the same wave number.r6l Since the SSO deformation
vibration of 3 (380 cm- ’) also appears at exactly the same
wave number as in S,O, it can be assumed that the 0 atom
in 3, as in S,O, is in the axial position, which is stabilized by
the anomeric effect.
The EI mass spectrum of 3 (sample temperature 140°C)
does not show a peak for the molecular ion M e , but peaks for
the characteristic fragments [ M - S,O]@ and [M - S,O]@;
the base peak is S,”. The elimination of S,O and S,O is also
typical for cyclo-sulfur oxides S,O.I’l The ‘H-NMR spectrum of 3 in CDCI, (400 MHz) shows two singlets at
6 = 2.012 and 2.466 for the methyl groups and four triplets
at 5.863, 5.91 1, 6.277 and 6.398 for the aromatic ring protons. Thus, with respect to the number of lines, this spectrum
corresponds exactly to the ’H-NMR spectrum of
Cp;TiS,,[’] i.e. the TiS,O ring in 3 must have a mirror plane.
As to be expected from the synthesis, 3 is present as Cp;Ti(p
S,),S=O and not as Cp;Ti(p-S)(p-S,)S=O, since the ring
protons of the unsymmetrical compound would have to give
eight quartet signals.
3 is readily soluble in CHCI,, CH,CI, and THF, but the
solutions decompose within 45 min at 20°C, whereby 3 is
converted via ring expansion into the isomeric complex 4
[Eq. (41‘
Cp;TiS,O 2
+ 2 HCl
R = Aryl
Unfortunately these reactions are not suitable for the
preparation of inorganic or organic heterocyles with the
[*I Prof. Dr. R. Steudel, Dipl.-Chem. A. Prenzel, Prof. Dr. J. Pickardt
Institut fur Anorganische und Analytische Chemie der
Technischen Universitat, Sekr. C 2
Strasse des 17. Juni 135, W-1000 Berlin 12 (FRG)
[**I Sulfur Compounds, Part 137. This work was supported by the Deutsche
Forschungsgemeinschaft and by the Verband der Chemischen Industrie.
Jakupovicr and Dip1.-Chem. J. Albertsen for
We thank Priv.-Doz. Dr. .
recording the NMRand massspectra.-Part 136: R. Steudel, B. Plinke, D.
Jensen, F. Baumgart, Polyhedron, in press.
0 VCH Verlagsgesellschafl mbH.
W-6940 Weinheim, 1991
This reaction can be monitored by means of reversed
phase HPLC,[81since 4 has a significantly greater retention
time than the obviously more polar 3; further reaction products are not formed (eluent: CH,OH; stationary phase: octadecylsilane). The UV absorption spectra of 3,4,and-for
comparison-of CpiTiS, 5 were measured immediately after
the chromatographic separation.[’I Whereas the spectra of 3
and 5 are, as expected, very similar, that of 4 shows a marked
shift of the absorption at ca. 300 nm (Table 1).
4 crystallizes from CH,Cl,/hexane in the form of darkbrown, rhomboidal, monoclinic, air-stable crystals,[9]which
05?0-0833/9110505-0550 $3.50+ ,2510
Angew. Chem. Inr. Ed. Engl. 30 (1991) No. 5
Table 1. Absorption spectra of 3-5 in methanol (range: 220-600 nm, relative
extinctions in brackets).
240 (100)
310 (33; shoulder)
484 (4)
240 (100)
328 (38)
482 (3)
240 (100)
310 (41)
486 (8)
were characterized X-ray crystallographically.[lo]
The novel
chelate ligand OS, in 4 is bound to the metal via the 0 atom
and one S atom, whereby a seven-membered ring with C,
symmetry is formed (Fig. 1.). In this ring the torsion angles
vary between 22.5" (Ti-0-S-S) and 88.0" (SI-S2-S3-S4),
the motif (signs of the torsion angles) is + + - + - + -.
Other than in the case of cyclo-heptasulfur["] there is no
torsion angle close to 0".
conformationally rigid. The appearance of eight quartets is
characteristic for unsymmetrical titanocene complexes with
two CH,C,H, ligands (e.g. Cp',TiSe,S,['61 and Cpz'(p-S)(pS3)CHZt1']).In the IR spectrum of 4 the SO stretching vibration is observed at 868 cm-' (KBr pellet).
At present one can only speculate on the mechanism of the
isomerization 3 + 4: during a transition of the presumably
chair-shaped TiS, ring of 3 into the boat conformation, Ti0 contacts can occur, which lead to rupture of a Ti-S bond
and the rearrangement of some S-S bonds, whereby the oxophilicity of the titanium atom is apparently the driving
force. Preliminary experiments show that 3 reacts similarly
to Cp,TiS, with S-CI compounds, affording access to comgroups which could not
pounds containing -S-S-S(0)-S-S
be prepared hitherto. These reactions proceed more rapidly
than the isomerization.
Received: December 14, 1990 [Z 4328 IE]
German version: Angew. Chem. 103 (1991) 586
Fig. 1 . Structure of 4 in the crystal. Selected bond lengths [pm). angles and
torsion angles ["I: Ti-01 194.6, Ti41 246.7, S1-S2 204.5, S2-S3 204.4, S 3 4 4
208.1, S4-S5 199.9, S5-01 152.9; 01-Ti41 92.3, Ti-Sl-S2 111.8, Sl-S2-S3 106.5,
S2-S3-S4 105.7, S 3 4 4 - S 106.2, S4-S5-01 110.9, S5-01-Ti 154.8; Ol-Ti-SI-S2
- 70.8, T i 4 1 4 2 4 3 84.9, Sl-S2-S3-S4 - 81 .O, S2-S3-S4-S5 88.0, S3-S4-S5-01
-79.5, S4-SS-Ol-Ti 22.5, S5-01-Ti31 39.8.
The seven covalent bonds in the ring are of different bond
order: the Ti-S bond (246.7 pm) is somewhat longer than in
Cp,TiS, (243 pm);['21 the T i 4 bond (194.6 pm) is substantially longer than in (Cp,CITi),O (184 pm) or analogous
Cp,Ti alkoxy compounds.[' 31
The S-0 bond (152.9 pm) lies between S-0 single bonds
(e.g. 163-165 pm in (CH,O),S and (CH,0),S,['4]) and
S=O double bonds (e.g. 143pm in SO,). The S-S bond
lengths (199.9-208.1 pm) fluctuate about the value of the
single bond (205 pm)," '1 whereby, as usual,[' I * Is) the
longest bond (S3-S4) is adjacent to the shortest bond (S4SS).
The 'H-NMR spectrum of 4 in CD,Cl, at 20 "C shows a
single sharp singlet at 6 = 2.14 for the two methyl groups,
which can only be explained in terms of a rapid inversion
(pseudorotation) of the TiOS, ring on the NMR time scale.
At - IO'C, this singlet is strongly broadened, and at
- 40 "C two sharp singlets are observed at 6 = 2.0 and 2.1 as
well as eight quartets in the range 6 = 5.4-7.5 for the aromatic ring protons.[g1At this temperature the metallacycle is
Angew. Chem. Int. Ed. Engl. 30 (1991) No. 5
[I] R. Steudel, J. Latte, Angew. Chem. 86 (1974) 648; Angew. Chem. Int. Ed.
Engl. 13 (1974) 603; R. Steudel, &id. 88 (1976) 854-855 and I5 (1976)
772-773; R. Steudel, J. Steidel, ibid. 90 (1978) 134-135 and 17 (1978)
134-135; R. Steudel, T. Sandow, ibid. 90 (1978) 644-645 and 17 (1978)
611 -612; R. Steudel, T.Sandow, J. Steidel, Z . Naturforsch. B40 (1985)
594 - 600.
[2] L. Field, W. B. Lacefield, J. Org. Chem. 31 (1966) 3555-3561; P. W.
Schenk, R. Steudel, J. Bilal, Angew. Chem. 78 (1966) 717; Angew. Chem.
h t . Ed. Engl. 5 (1966) 613; Z . Anorg. Allg. Chem. 353 (1967) 250-258; R.
Steudel, G. Scheller, Z. Naturforsch. B 2 4 (1969) 351-352; H. E. Simmons, R. D. Vest, D. C. Blomstrom, J. R. Roland, T. L. Cairns, J: Am.
Chem. Soc. 84 (1962) 4746-4756, 4772-4781; R. Steudel, P. Luger, H.
Bradaczek, Chem. Ber. 110 (1977) 3553-3560; R. Steudel, Phosphorus
Sulfur 23 (1985) 33-64.
[3] Reviews: M. Schmidt, Angew. Chem. 85 (1973) 474-484; Angew. Chem.
Int. Ed. Engl. 12(1973)44-455; R. Steudel, Top. Curr. Chem. 102(1982)
149-176; R. Steudel in I. Haiduc and D. B. Sowerby (Eds.): "The Chemistry of Inorganic Homo- and Heterocycles", Vol. 2, Academic Press, London 1987, p. 737-768; H.Schmidt, R. Steudel, Z. Narurforsch. B 45 (1990)
557- 558.
[4] C. M. Bolinger, J. E. Hoots, T. B. Rauchfuss, Organometallics 1 (1982)
223 -225.
[5] Preparation of 3: a stirred solution of CpkTi,S, (100 mg, 0.185 mmol) in
CS, (28 mL) was treated at 0°C with a solution of SOCI, (22 mg,
0.185 mmol) in CS,. After 10min the precipitated Cp;TiS,O was recovered by suction, washed with n-pentane, and immediately dried in vacuo.
Yield 38 mg (54% of theory). Correct C,H analysis.
[6] R. Steudel, Z . Naturforsch. B25 (1970) 156-165; R. Steudel, M. Rebsch,
J. Mol. Spectrose. 51 (1974) 334-340; R. Steudel, D. F. Eggers, Spectrochim. Aera A 31 (1975) 871 -877.
[7] CpiTiS, shows singlets at 6 = 2.00 and 2.26 as well as four multiplets in the
range b = 5.92-6.18 (in CDCI,): C. M. Bolinger, T. B. Rauchfuss, Inorg.
Chem. 21 (1982) 3947-3954.
[8] Separatingcolumn: 1OC18 Radial-Rak (Waters): UV spectra: Diode array
detector 990 (Waters; 512 diodes, range 190-800 nm) with NEC-APC-Ill
191 Preparation of 4: a stirred solution of CpbTi2S4 (1 g, 1.85 mmol) in
CH,CI, (150mL) was treated with a solution of SOCI, (220mg,
1.85 mmol) in CH,CI, (3.5 mL). After 45 min the dark-brown solution
was separated chromatographically(150 g silica gel 40 (Merck), I = 60 cm)
and eluted with CH,CI,. The first 500 mL were evaporated down to 25 mL
in vacuo, treated with 25 mL hexane, and cooled to - 60T, whereupon
4 crystallized out. Yield: 142 mg (20% theoretical). Correct C,H analysis
EI-MS (180°C sample temperature): no molecular peak, [M-SOJe.
[M-S,O]" and [M-S,O]" observed, base peak: Sp. 'H NMR (CD,CI,,
- 40°C 400 MHz): b = 2.083, 2.036(s), 5.458, 5.645, 6.061, 6.438, 6.52,
6.734, 7.453 (9).
[lo] Crystal structure analysis of 4: space group P2Jn (No. 14); a =738.5(5),
b = 1606.8(6), c = 1317.8(7) pm, fi = 95.27(9)". V = 1557.1 x lo6 pm3,
Z = 4,
= 1.63 gcm-3, ~(Mo,.) = ll.Ocm-', diffractometer EnrafNonius CADI, room temperature, Mo, radiation (1 =71.069 pm).
28 I 50", 2436 independent reflections, 1694 with I > 2u(I), empirical absorption correction, solution of structure by Patterson methods, refinement with anisotropic temperature factors for all atoms except hydrogen.
the CH bonds were calculated and not refined: 180 parameters,
R = X(II FoI-IFcIl)/~lFo~
= 0.0436. Furtherdetailsof thecrystalstructure
Verlagsgesellschaft mbH, W-6940 Weinheim. 1991
investigation are available on request from the Fachinformationszentrum
Karlsruhe, Gesellschaft fur wissenschaftlich-technischeInformation mbH,
W-7514Eggenstein-Leopoldshafen 2 (FRG), on quoting the depository
number CSD-55148,the names of the authors, and !he journal citation.
[ll]R. Steudel, J. Steidel, J. Pickardt, F. Schuster, R. Reinhardt, Z . Naturforsch. B35 (1980)1378-1383.
[12]E. F. Epstein, I. Bernal, H. Kopf, J. Organomet. Chem. 26 (1971)229-245;
E. G.Muller, J. L. Petersen, L. F. Dahl, ibid. ifi (1976)91-112.
1131 Y.LePage, J. D. McCowan, B. K. Hunter, R. D. Heyding, J. Organornet.
Chem. 193 (1980)201-207; J. C. Huffman, K. C. Moloy, J. A. Marsella,
K. G. Caulton, 1 Am. Chem. SOC.f02(1980) 3009-3014.
[14]E. Baumeister, H. Oberhammer, H. Schmidt, R. Steudel, Heteroatom
Chem.. in press, and unpublished results.
[lS]R. Steudel, Angew. Chem. 87(1975)683-692;Angew. Chem. Inl. Ed. Engl.
14 (1975)655-663.
[16] M. Papavassiliou, Disserlarion, Technische Universitat Berlin 1990.
[17]D. M. Giolando, T. B. Rauchfuss, Organometallics 3 (1984)487-489.
Proof of Strong S-H * S Bridges in
[Ru(SH,)(PPh,)('S,')] * THF, the First H,S
Complex Characterized by X-Ray Crystallography**
inversion center. In addition each H,S ligand is bound to a
THF molecule via one S-H . . .O bridge (Fig. 1, bottom).
The position of the H,S hydrogen atoms were localized by
difference Fourier synthesis.
The Ru atoms are each surrounded by five sulfur and one
phosphorus atom in a pseudo-octahedral geometry. The angles in the coordination polyhedron are all close to 90 or 180"
and do not exhibit anomalies. The Ru-S distances (236.1(5)239.7(5) pm) and the Ru-P distance (232.4(5) pm) are typical for these complexes. Only the Rul - S3 distance in trans
position to the H,S ligand is clearly shorter (229.3(5) pm);
comparison with other [Ru(L)(PPh,)('S,')] complexes16]
suggests a stronger Ru -+ S (thioether) IT acceptor bond.
The S-H . . . S bridges in 1.THF are of particular interest
(Fig. 1, bottom). For the first time the existence of these
bridges in H,S complexes could be proved by X-ray crystallography. They are very strong in comparison with the usu=
ally weak S-H ...S bridges (e.g., in H,S: AH';
7 kJ mol - '9.
By Dieter Sellman,* Peter Lechner, Falk Knoch,
and Matthias Moll
The interaction of H,S, HSe and SZo with transition
metals is a primary step in the formation of ores and in the
construction of the [M,S,] clusters in enzymes like ferredoxines or nitrogenases. Here, as in the metal-enzyme catalyzed
S04Ze/H,S transformation in the biological sulfur cycle,
H,S complexes are assumed to be intermediates. Because of
their extreme reactivity,".
such complexes could be detected,(zb*f*gl
or isolated,[2a-el only in exceptional cases in the
past, but never be studied by X-ray crystallography. In this
respect they differ from the numerous well-characterized
H,O complexes.
We have now succeeded in obtaining the H,S complex
1 from [Ru(PPh,)('S,')lr3I (eq. (a)),
which could be characterized by X-ray crystallography
(Fig. 1 a).t41Compound 1precipitates as 1.THF on recrystallization from H,S-saturated THF as yellow-orange crystals
and can be ionized in a mass spectrometer without decomposition. In contrast to the highly labile solvent-free 1, 1.THF
is stable at 25 "C and loses H,S slowly in vacuum only. Both
compounds are rapidly oxidized by 0, to turquoise-colored
[(P-S,){Ru(PPh3 )cs4')} 2 I t 5 ] (Eq. (b)).
In the unit cell of l.THF, two enantiomers are each associated via two S-H . . .S bridges to a cyclic dimer containing an
Prof. Dr. D. Sellmann, DipLChem. P. Lechner, Dr. F. Knoch, Dr. M.
Institut fur Anorganische Chemie I1 der Universitat Erlangen-Nurnberg
Egerlandstrasse 1, W-8520Erlangen (FRG)
= 2,2'-(ethylenedithio)bis(thiophenolate). Transition Metal Complexes with Sulfur-Containing Ligands, Part 64.This work was supported
by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and Degussa AG, Hanau (gift of RuCl,.xH,O). Part 63:D. Sellmann, M. Geck, F. Knoch, M. Moll, Inorg. Chim. Acfa, in press.
Verlagsgesellscha$t mbH, W-6940 Weinheim, 1991
Fig. 1. Top: Structure of 1,THF in the crystal (THF omitted); bottom:
S-H . . .S and S-H . . .O hydrogen bridges in ].THE
The strongest S-H . . .S bridges known as yet (AH:"
12 kJ mol- ['I) were found in dithiophosphinic acids, which
have S . . .S distances of 375 to 384 pm, v(SH) between 2340
and 2400 cm- ' (KBr) and S-H . . . S angles in the range 159
to 173".Ig1In comparison, the calculated S-H . . .S limiting
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