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New Metal - Pentafluorothiophenol Compounds D. M. Kaminaris and A. G. Galinos Department of Inorganic Chemistry, University of Patras, Greece

Z. Naturforsch. 33 b, 149-150 (1978); received November 17, 1977

Pentafluorothiophenol, Iron, Alluminium, Rhodium In the present paper the reactions of pentafluorothiophenol with nonaqueous solutions

(absolute n-hexane) of anhydrous AICI3, FeBr3, RI1CI3 and CrCl3 are described. Analytical data, some physical and chemical properties and the IR spectra of the new compounds are reported and discussed.

It is known that pentafluorothiophenol, being similar in properties to pseudohalogens, forms com-pounds with various metals and their compounds. Thus Cleason [1] reported the preparation of various mercaptides. Peach [2, 3], likewise, reported the reactions of pentafluorothiophenol with aqueous and alcoholic solutions of metal compounds. Derivatives of transition metals and complex ions of the forms M(SC6F5)42- (M = Co, Cd, Hg) and M(SC6F5)2- (M = Cu+, Ag+, Au+) have been precipi-tated from aqueous solutions [4], as well as the compound K(SC6F5) • 1.5 H 2 0 [5], R. S. Nyholm et al. [6] prepared compounds of pentafluorothio-phenol with the metals Pt, Pd, Pb and Ni in water-acetone solutions.

These reactions of the C Ö F S S - ion as well as those with the elements of Groups IVa and V a of the Periodic Table clearly show that indeed the CeFsS-ion is very similar to the pseudohalides [7-10].

In the present work we report the preparation, for the first time, and study of properties of compounds of pentafluorothiophenol with Fe3+ , Al3+ and Rh 3 + ions. The reaction was carried out in an inert solvent (w-hexane) with a total replacement of the halide ions by the anion CeFsS-, as we have shown in other cases [11, 12]. We also report the failure of the preparation of the compound with the Cr3+ ion.

Experimental All the reactions were carried out under anhydrous

conditions. The pentafluorothiophenol and the anhydrous salts of FeBr3, AICI3, RI1CI3 and CrCl3 used, were commercially available. The solvent /i-hexane was rendered absolute just before use.

The compounds were prepared by prolonged heating (14 days for the case of FeCl3, 16 days for

Requests for reprints should be sent to Prof. Dr. A. G. Galinos, Department of Inorg. Chem., University of Patras, Korinthou St. 231, Patras, Greece.

the case of AICI3, 7 days for the case of RI1CI3 and 22 days for the case of CrCls) and continuous stir-ring (magnetic stirrer) under reflux, of the mixture of the anhydrous salt and pentafluorothiophenol (mole ratio 3:1 salt to ligand) in absolute w-hexane under dry nitrogen atmosphere. The apparatus was connected to a vacuum line for the removal of hydrogen chloride or hydrogen bromide which is evolved during the formation of the products.

The compounds formed are partially soluble in the solvent and contaminated with a second material (a common sidereaction product of penta-fluorothiophenol) .

On the basis of its IR spectrum and chemical analysis this contaminant appears to be bis(penta-fluorophenyl)disulfide, an oxidation-reduction prod-uct. Its formation necessitates purification for its removal.

The replacement of the halide ions by the C Ö F S S -ion takes place in steps and is accompanied by a change of color of the solution as the reaction progresses. Thus, in the case of the compound A1(C6F5S)3 the following colors appear gradually: white-light orange-dark orange-brown. In the case of the iron compound the color changes are: dark red-orange-brown-black. In the case of the rhodium compound the colour changes from red-violet to yellow, pale yellow and finally to brown. (No color change is observed in the case of the chromium compound.)

The total replacement of the halide ion by the CeFöF- group is shown not only by the IR spectra and chemical analysis but also by the fact that aqueous solutions of the prepared compounds give no reaction with a AgN03 solution.

The reaction of preparation of the new compounds may be represented in the final form by the equation:

MX 3 + 3 C6F5SH -> M(C6F5S)3 + 3 H X Reactions of this type take place slowly and require heating, continuous stirring for long periods of time and anhydrous environment because of the great hygroscopicity of the prepared compounds which, on hydrolysis, give hydroxides or sulfides.

For purification we used the method of vacuum sublimation at a temperature of about 65 °C. The solvent was removed by vacuum distillation and

150 D. M. Kaminaris-A. G. Galinos • New Metal - Pentafluorothiophenol Compounds

Table. Products and analyses.

Product Color m.p •[°C] Calculated [%] M C F S

Found [%] M C F

1 S

Solubility Yield [%]

A1(SC6F5)3 Rh(SC6F5)3 Fe(SC6F5)3 (C6FÖS)2

Brown Brown Black White

187 177 148 51-

> d. > d. > d. -52

4.32 34.61 45.67 15.38 14.71 30.85 40.70 13.71 8.58 33.07 43.64 14.70

36.10 47.71 16.00

4.21 34.73 14.42 30.25 8.42 33.22

36.28

15.32 14.03 14.38 15.78

1, 3, 4, 7, 8, 11 5, 9, 12 1, 3, 6, 7, 8, 11 1, 2, 3, 5

80-85 70-74 70-78

Solubilities: 1 = chloroform (h), 2 — benzene, 3 = acetone, 4 = diethyl ether, 5 = dichloromethane (h), 6 = dichloroethane, 7 = carbon tetrachloride (h), 8 — ethyl alcohol, 9 = hexane, 10 = petroleum ether, 11 = pyridine (h), 12 = carbon disulfide, (where h = hot).

the by-products by vacuum sublimation. Finally the compounds were recrystalliged twice from %-hexane.

Properties, IR Spectra and Discussion

The prepared new compounds are solids, very hygroscopic, insoluble in organic solvents at room temperature, but very soluble in hot solvents. They do not have a sharp or definite melting point. They are slightly soluble in cold pyridine while they dissolve appreciably in the hot solvent with a color change. The compound A1(C6F5S)3 gives a beautiful rose coloration while the iron and the rhodium compounds yield a yellow one. All the colorations disappear upon the addition of a few drops of water. The aforementioned property shows that these new compounds behave as Lewis acids in the presence

of bases, forming coordination compounds e.g. of the type C5H5N : M(C6F5S)3.

The I R spectra of these compounds were taken in a P. E. 577 spectrophotometer, in the region 4000-225 cm-1 .

The samples were used in the form of Nujol mulls. The spectra show absorption bands characteristic of the C6F5S- group as well as of the C-C and C-S bonds, at 1090, 985, 860 and 715 cm-1. These bands are in perfect agreement with other such bands mentioned in the literature [7, 13, 14, 15].

The absorption bands of the M-group bond appear at ca. 300 cm - 1 [2, 3, 15], while no bands charac-teristic of the metal-halogen bonds appear in the spectrum.

The following Table contains the melting points, analytical results, solubilities, yields, and colors.

[1] P. Claeson, J. Pract. Chem. 15, 193 (1877). [2] M. E. Peach, Can. J. Chem. 46, 211 (1968). [3] M. E. Peach, Can. J. Chem. 46, 2699 (1968). [4] W. Beck, K. H. Stetter, S. Trados, and K. L.

Schwarzhans, Chem. Ber. 100, 3944 (1967). [5] P. Robson, M. Stacen, R. Stephens, and J. C.

Tatlow, J. Chem. Soc. 1960, 4754. [6] R. S. Nyholm, J. F. Skinner, and M. H. B.

Stiddard, J. Chem. Soc. A 1968, 38. [7] W. Beck and K. H. Stetter, Inorg. Nucl. Chem.

Lett. 2, 388 (1966). [8] J. Cooke, M. Green, and F. G. A. Stone, J. Chem.

Soc. A 1968, 170. [9] B. R. Hollebone and R. S. Nyholm, J. Chem.

Soc. A 1971, 332.

[10] M. Muller, B. J. H. Clark, and B. S. Nyholm, J. Chem. Soc. (Dalton), to be published.

[11] R. J. H. Clark and D. M. Kaminaris, Inorganica Chimica Acta II (1974).

[12] D. M. Kaminaris and A. G. Galinos, Hungaria Chimica Acta 1977, in press.

[13] I. J. Hyan, E. R. Lippincott, and R. T. Bailey. Spectrochim. Acta A 22, 655 (1966).

[14] J. A. Donek and J. T. Speckett, J. Inorg. Nucl. Chem. 35, 511 (1973).

[15] L. J. Bellamy, The Infrared Spectra of Complex Molecules, London 1966.

[16] R. J. H. Clark and M. Coles, J. Chem. Soc. (Dalton) 1972, 2454.