2. anorg. allg. Chem. 621 (1995) 1513-1516

Zeitschrift fur anorganische und allgemeine Chemie 0 Johann Ambrosius Barth 1995

Sulfur Compounds. 183 [I]

A Derivative of Perthiocarbonic Acid H,CS,: X-Ray Structural Analysis of Bis(triphenylmethy1) Perthiocarbonate (Ph,C),CS,

Vera Munchow and Ralf Steudel*

Berlin, Technische Universitat Berlin, Institut fur Anorganische und Analytische Chemie

Jiirgen Buschmann and Peter Luger

Berlin, Freie Universitat Berlin, Fachbereich Chemie, Institut fur Kristallographie

Received April 5th, 1995.

Abstract. The molecular structure of Ph,CSSC(S)SCPh, . CS, 96.3". (Ph3C),CS4 was obtained by reaction of TosNSC1, has been determined by X-ray structural analysis. The substance (Tos = p-MeC6H,S0,) with Ph,CSH in CS, in the presence of crystallizes in the triclinic crystal system [a = 884.9(2) pm, triethylamine. The reaction mechanism is discussed. b = 1039.5(2) pm, c = 2064.6(3) pm, (Y = 75.8p(l)O, /? = 79.83(2)", y = 77.31(5)", Z = 2, space group PI]. The CS, Keywords: Perthiocarbonic acid diester; X-ray structural group is planar; the S-S-bond (201.4 pm) forms an angle of analysis; perthiocarbonate; bis(triphenylmethy1) perthiocar- 5.7" with the CS, plane. The torsional angle CSSC equals bonic acid diester

Ein Derivat der Perthiokohlensaure H,CS,: Rontgenstrukturanalyse von Bis(triphenylmethy1)perthiocarbonat (Ph,C),CS, Inhaltsiibersicht. Die Molekiilstruktur von Ph,CSSC(S)SCPh, * einen Winkel von 5,7". Der CSSC-Torsionswinkel betragt 96,3". CS, wurde durch eine Rontgenstrukturanalyse bestimmt. Die (Ph3C),CS4 wurde durch Umsetzung von TosNSClz (TOS = p- Substanz kristallisiert im triklinen Kristallsystem [a = 884,9(2)pm, MeC,H4S0,) mit Ph,CSH in CS, in Gegenwart von b = 1039,5(2) pm, c = 2064,6(3) pm, (Y =-75,86(1)", /3 = 79,83(2)", Triethylamin erhalten. Der Reaktionsmechanismus wird y = 77,31(5)", Z = 2, Raumgruppe Pl]. Die CS3-Gruppe ist diskutiert. planar; die S-S-Bindung (201,4 pm) bildet mit der CS,-Ebene

1 Introduction MeS0,SMe. However, no structural analysis has so far been reported. The related asymmetrical compounds

The chemistry of thiocarbonic acids has been extensively RSC(S)SSTos (R = methyl, phenyl, benzyl) have been studied [2]. There are organic derivatives like trithiocar- obtained from the reactions of the corresponding bonates RSC(S)SR, bis(alkanesulfeny1)trithiocarbonates chlorodithioformates RSC(S)CI with potassium RSSC(S)SSR, polymers with the backbone -C(S)- 4-toluene-thiosulfonate, TosSK, and in the case of S,-C(S)-S,-, and thioanhydrides of thioxanthic acid, R = PhCH, also from PhCH,SC(S)S- and TosSTos [4]. RSC(S)SC(S)SR. The unsubstituted Perthiocarbonic acid H,CS, ' has' been isolated and its -structure has been shown to be HSSC(S)SH 12 bl. Several perthiocarbonates Results and Discussion

have been reported. K,CS, - CH30H, for example, con- Reacting TosNSC1, with Ph,CSH in CS, in the presence tains the planar anion CS?- [2b]. To our knowledge, of Et,N we were able to isolate bis(triphenylmethy1)per- only one symmetrically substituted diorganyl derivative thiocarbonate as yellow-orange crystals which are stable of this acid is known, the ester MeSSC(S)SMe [2c, 31, at room temperature, The diester (Ph,C),CS, was which has been synthesized from KSC(S)SMe and characterized by IR and Rarnan spectroscopy. The wave-

1514 Z. anorg. allg. Chem. 621 (1995)

number of u(C=S) = 1074 cm-' (IR) is similar to those of PhSC(S)SSTos [4a] and Me,CS, [3].

The crystal and molecular structure of (Ph,C),CS, - CS, was determined by X-ray diffraction on a single crystal prepared by slow evaporation of a CS, solution of the perthiocarbonate at 4°C. The compound crystallizes with one solvent molecule per molecule of (Ph,C),CS,. The rather compact molecules of (Ph,C),CS, (Fig. 1) contain a planar CS, group con- sisting of C(4), S(3), S(4) and S ( 5 ) as shown by PLATON calculations [5 ] and by the sum of the three SCS angles which amounts to 359.9". However, S(2) is located slight- ly above this plane with an angle of 5.7(2)" between the CS, plane and the bond S(2)-S(3). For comparison: in K,CS, - CH,OH CSt- is planar [2b]. This salt exists in two forms, one with a localized n bond (d,=, = 165.9 pm) and the other with delocalisation of this bond. The length of the S-S bonds are 202.1 pm and 203.2pm, respectively. In the present case the S-S bond (201.4 pm) is shorter than in H,S, (205.6pm) and in most organic disulfanes [6, 71, but similar to those in the two potassium perthiocarbonate samples. The torsional angle at the S-S bond of (Ph,C),CS, (96.3") is slightly larger than in H,S, (90.6") [6]. As usual in triphenylmethyl compounds [8] the C-S bonds at the four-coordinated carbon atoms are much longer (ca. 190 pm) than normal single bonds. In contrast, the bonds C(4)-S(3) (177 pm), C(4)-S(4) (163 pm), and C(4)-S(5) (170 pm) all show significantly smaller bond lengths. The bond distance C(4)-S(3) neighboring the S-S bond is by 7 pm longer than the distance between C(4) and S(5).

The diester was obtained in an attempt to prepare a new type of branching in sulfur chains reacting TosNSCl, with Ph,CSH in the presence of Et,N in CS, as solvent hoping to obtain Ph,CSS(=N-Tos)SCPh, in analogy to the preparation of trisulfane-2-oxides, RSS( =O)SR, from thiols and thionylchloride [9]. HPLC analysis of the reaction solution showed, however, that the solvent has been attacked in the course of the reaction and thus the diorganyl perthiocarbonate (Ph,C),CS, is one of the three main products (40%), in addition to the trisulfane (30%) and the tetrasulfane (1 3 To) [ 101. There are a number of additional yet unidentified products in small concentrations. (Ph,C),CS, was isolated in low yield only. TosNSC1, obviously functions as an oxidant and as a sulfur transfer reagent resulting in the formation of various bis(triphenylmethy1)polysulfanes and of the perthiocarbonate which may be explained as follows:

2Ph3CSH + TosNSC~~+TOSNH~ + Ph3CSCl + Ph3CSSCl (1)

PhiCSH + Et3N + Ph3CS- + Et3NH +

Ph3CS- + CS2 + Ph,CSC(S)S-

Ph3CSSCl + Ph3CS- + (Ph;C)& + C1-

(2)

(3)

(4)

Ph3CSC(S)S- + Ph,CSCl+ Ph,CSSC(S)SCPh, + C1- ( 5 )

Ph,CSC(S)S- + (Ph,C)&+Ph3CSSC(S)SCPh3 + Ph;CSS- (6)

To check whether the smaller peaks in the chromato- grams may be assigned to likely products of the reaction mixture we have prepared Ph,CSCl, Ph,CSSCl and (Ph,C),S, (n = 2-4) [lo, 11, 121 as reference samples. In addition, Ph,CC1 was obtained commercially and the previously unknown trithiocarbonate (Ph,C),CS, (which may be formed from Ph,CS- and the perthiocarbonate) was obtained from sodium trithiocarbonate and Ph,CCl in benzene. Comparison of the retention times of all reference compounds with the chromatograms of the reaction mixture showed that Ph3CC1, Ph,CSSCl and (Ph,C),CS, were not present, while Ph,CSCI was observ- ed only in low concentrations. Whether or not the disulfane (Ph,C),S, is formed depends on the temperature: at a reaction temperature of 0 "C it was only found in neglible concentrations. At low temperatures (- 78 "C) no perthiocarbonate was formed, perhaps due to the limited production of Ph,CSC(S)S-.

(Ph,C),CS, was also observed together with the disulfane in a reaction between Ph,CSCl and the thiol in carbon disulfide in the presence of Et,N. This alternative route to the diester verifies reactions (1) - (3) and (5). It was not possible to isolate the diester from this mixture since the reaction was not complete and unreacted Ph,CS- obviously destroys the diester. In addition, the formation of (Ph,C),CS, on reaction of alkali per- thiocarbonates with Ph,CC1 was observed, but the diorganyl perthiocarbonate was not stable in this reaction mixture. The identity of (Ph,C),CS, and the other pro- ducts in these mixtures was verified by HPLC analysis us- ing different eluents and reference injections.

3 Experimental

All reactions were carried out under dry nitrogen. The solvents were dried and distilled prior to use. - IR: grating infrared spectrometer 580 B (Perkin-Elmer) and F T spectrometer Magna IR 750 (Nicolet), KBr-discs. - Raman: krypton laser at 647 nm (Spectra Physics Model 2020-1 l), prism premonochromator (Anaspec), grating double-monochromator U 1000 (Jobin Yvon), GaAs photomultiplier R 943 (Hamamatsu), Mac 80A CPM computer (Spectradata), spectral slit width 2-3 cm-l. - M S double focusing spectrometer Varian MAT 3 1 IA. - elementary analysis: CHNS/O-Analyzer 2400 (Perkin-Elmer, Series 11) - m. p.: melting point apparatus 510 (Biichi), uncorrected values. - RP-HPLC: Chromatograph Varian 5000 pump, Valco loop injector (LO pl), UV photometer LCD 501 (Gamma Analysen Technik), HP 3390A integrator (Hewlett Packard), RCM 8 X 10 compression modules (Waters), radial compressed RP Radial PAK C18-column (10 pm, length = 10 cm, inside diameter = 8 mm, Waters), eluents: 100% MeOH; 95% (v) MeOH/5% (v) cyclohexane or 95% (v) MeOH/5% (v) water, flow 2mlrnin-', UV detected (A = 254 nm). - UV-spectra: on-line diode-array detector, model 990 (Waters). - NMR: ARX 200 (Bruker).

V. Miinchow et al., Bis(triphenylmethy1) Perthiocarbonate (Ph3C)2CS4 1515

Bis(tripheny1methyl)perthiocarbonate: A solution of triphenyl- methanethiol (3.93 g, 14.2 mmol) and triethylamine (1.87 ml, 1.37 g, 13.5 mmol) in CS2 (40 ml) was cooled to 0 "C and slowly a solution of TosNSCi, 1131 (1.84 g, 6.75 mmol in 20 mi CS,) was added dropwise over a period of 90 min. The colour of the solution changed from brown to orange, and NEt3 * HCl precipitated. After complete addition of TosNSCI2 the solution was stirred for another 30 min. The triethylamine hydrochloride was filtered off and the filtrate dried under vacuum. The re- maining residue was dissolved in 15 ml of CS2 and cooled to -78 "C. After 1 d a yellow oil had formed (containing mainly the trisulfane) which was separated. The remaining liquid was kept for 2d at - 18 "C. Another yellow oil was formed and removed. The decantate was cooled to - 18 "C. After 2 h a yellow-orange coloured precipitate was obtained which was isolated, washed with 2 ml of CS2, and recrystallized from CS2 (yield 2070, I I0 mg, 0.15 mmol). The product is not air-sensitive, it may be stored for several months at 20 "C without decomposi- tion. - m. p.: 104 - 112 "C (dec.). - IR (KBr): u = 1 074 cm-' (C=S, s). - Raman: u = 482cm-' (S-S, s), 1075 cm-' (C=S, m). - HPLC retention index (RS) [14]: 776. - MS (T, = 16OoC, EI, 70eV), m/z: 243 (base-peak) [Ph3C+j, 165 (89%) [Ph2C+], 76 (91%) [CS2+] - UV 216nm (100070), 323 nm (12%). C3yH30S4 . CS2 (703.04): C 68.28 (calcd. 68.33), H 4.59 (4.30), S 25.58 (27.36)%.

Bis(triphenylmethy1)trithiocarbonate: Triphenylmethylchloride (9.95 g, 35.68 mmol) was dissolved in 50 ml of benzene and NazCS3 (2.76g, 17.84mmo1, finely ground in a mortar) was added. The suspension was stirred for about 24 h. Its colour turned from brown-yellow to raspberry-red. The suspension contained still a yellow sediment of unreacted sodium trithiocarbonate and now also a rose-coloured precipitate. The latter was separated (The mother liquor - remaining after the separation of the pink solid - was discarded because it con- tains the unreacted Ph,CCl.) and extracted several times with CS2 (- 100 ml), the residue (remaining Na2CS3) was filtered off. The clear red filtrate was kept at - 78 "C. After 15 h the CS2-solution showed a pink precipitate which was isolated. HPLC-analysis showed a single product. It was dried in air. Yield: 0.90 g (crystallizes without CS2) (1.51 mmol), 8.5%. - m.p.: 166-168°C (dec., colour change from pink to yellow). - IR (KBr): u = 1093cm-' (C=S, vs). - Raman: u = 1095 cm-' (C= S, m). - HPLC retention index (RS) [14]: 674. - U V 228nm (100%), 252.5 nm (48'70, sh), 327nm

(ppm) = 76.3 (Ph,C); 127.3, 127.8, 130.8, 142.5 (Ph,C) and 213.5 (CS,). - C3yHWS3 (594.87): C 78.32 (calcd. 78.74), H 4.80 (5.08), S 17.23 (16.17) Yo.

Crystal structure anafysis of (Ph,C),CS, . CS2: (see Fig. 1 and Tables 1 -3) C3yHJOS4 - CS2, M = 703.04, a = 884.9(2) pm, b = 1039.5(2) pm, c = 2064.6(3) pm, CY = 75.86(1)", = 79.83(2)", y = 77.31(5)", Z = 2, dcalcd. = 1.31Og~m-~, triclinic, Pi, STOE four circle diffractometer, CuKa radiation, orange- yellow prismatic crystal of dimension 0.25 x 0.1 1 x 0.09 mm3, 2 2 ° C m28scan technique, 28 = 6.0-100.0, hkl = 0-12, +_ 12, k 22, 3 964 reflections measured, 3 659 unique reflections, 2122unique reflections with F, > 30 (FJ, p = 36.1 cm-I, direct methods [15], no absorption correction, least-squares refinement [ 161 [full matrix, anisotropic, hydrogen positions found, 538 parameters refined, largest d/o = 0.42 (final cycle), largest residual peak 1.12 e A -;, anomalous dispersion in-

(47%). - "c NMR (Csz 60% (v)/c6D6 40% (V)): 6

Fig. 1 Molecular structure of (Ph,C)KS4 (SCHAKAL [fgl) and numbering of atoms

Table 1 Selected bond distances, bond angles and torsional angles

bond distances bond angles ["I

torsional angles C( l)-S(2)-S(3)-C(4) S(2)-S(3)-C(4)-S(4) S(2)-S(3)-C(4)-S(5) S(3)-C(4)-S(5)-C(6) S(4)-C(4)-S(5)-C(6)

191(1) 201.4(6) 177(1) 163(2) 170( 1) 187( 1) 147(2) 151(2) 162(2) 152(2) 151(2) 158(2)

["I 96.3(6)

174.9(6)

175.9(7) -7.1(8)

-7(I)

S(2)-C(l)-C(25) 11 1(1)

S(2)-C(I)-C(31) 11 1.9(9) C(31)--C(l)-C(37) 1 lO(1) C(25)-C(l)-C(37) 111(1) S(5)-C(6)-C(7) 113(1) S(5)-C(6)-C(I 3) 1 I2(1) S(5)-C(6)-C(19) 98(1) C(7)-C(6)-C(13) 113(2) C(7)-C(6)-C(I9) 1 10(1) C(13)-C(6)-C(19) 1 lO(1) S(3)-C(4)-S(4) 114.2(7) S(4)-C(4)-S(5) 130.9(8) S(3)-C(4)-S(5) I 14.8(9) C(l)-S(2)--S(3) 1 1 1.7(5) S(2)-S(3)-C(4) 107.5(5) C(4)-S(5)-C(6) 110.0(7)

S(2)-C( 2)-C(37) 97.7(8) C(25)-C(I)-C(31) 114(1)

Table 2 Selected atomic coordinates (Ueq and U in Az x 100)

atom x Y Z Ueq U

C(1) 0.186(2) 0.302(1) 0.9208(7) 3.9(6) C(4) 0.154(2) 0.146( 1) 0.7576(6) 4.9(6) C(6) 0.063(2) 0.377(1) 0.6494(7) 3.7(6) C(7) -0.114(2) 0.400(2) 0.6579(9) 4.4(7) C(13) 0.139(2) 0.289(1) 0.5996(8) 4 4 7 ) C(19) 0.120(2) 0.516(2) 0.6274(9) 5.2(8) C(25) 0.021(2) 0.327(2) 0.9049(7) 4.8(7) C(31) 0.207(2) 0.229(1) 0.9899(8) 3.8(7) C(37) 0.251(1) 0.441(1) 0.9042(8) 3.4(6) S(2) 0.3279(4) 0.2172(4) 0.8557(2) 5.2(2) S(3) 0.2420(5) 0.0728(4) 0.8321(2) 6.2(2) S(4) 0.0916(6) 0.0395(4) 0.7271 (2) 8.4(2) S(5) 0.1443(5) 0.3155(4) 0.7315(2) 5.4(2)

1516 Z. anorg. allg. Chem. 621 (1995)

cluded [17], R = 0.092, Rw = 0.058. As a result of CSz- evaporation during the measurements the intensity of the reflec- tions decreased to about 60% of their initial values. As soon as t,he intensity of any one of the standard reflections had dropped by more than 3% with respect to the previous maximum value the orientation reflections were automatically recentered, and thereby a new orientation matrix was determined. This happen- ed about every six hours [18].

Table Selected anisotropic displacement parameters (Uij and U in A’ x 100). The anisotropic displacement factor exponent takes the form: -2n’[U,,(h - a*)’ + U,,(k . b*)2 + Ua3(1 . c*)~ + 2U,, . h . k a* . b* + 2U13 * h - I . a* ’ c4 -t 2UZ3 . k isotropic displacement factor exponent takes the form: -2U . [271 ~in(zP)/A]~

b* . c*] and the

atom U,, U, Us, U,, UU u23

U

-0.6(8) - 2.7(9) - 1 S(8) - It11

0.3(9) )

-1(1) -2(1)

1.4(9) - 0.2(2) - 0.3(3) - 4.4(3) - 1.2(2)

- 1.4(9) - 2.5(9) - 0.7(9)

O(1) -1 (1 ) - 2(1) -1(1) - 1(1) - 1.4(8) - 0.7(2) -2.3(3) -2.3(3) -2.3(2)

- 1.7(9) 0.3(7)

-0.9(7) - 1.3(9) -0.6(9) -3(1) -0.6(9)

0.9(8) -1.1(9) - 1.7(2) - 0.8(2) - 0.5(3) - 0.7(2)

This work was supported by the Deutsche Forschungsge- meinschaft and the Verband der Chemischen Industrie.

References

[ 11 Sulfur Compounds, Part 182: R. Steudel, J? Kriiger, I. Florian, M. Kustos, Z. anorg. allg. Chem. 621 (1995) 1021

[2] (a) A . D. Dunn, K-D. Rudorf, Carbon Disulphide in Organic Chemistry, Wiley, New York 1989; (b) G. Gartow, W; Behrendt, Carbon Sulfides and Their Inorganic and Complex Chemistry, in Topics in Sulfur Chemistry (Ed.: A . Senning), Vol. 2, Thieme, Stuttgart 1976; (c) G. Gat- tow, Sulfur Reports 14 (1993) 1

[3] W; Knoth, G. Gattow, Z. anorg. allg. Chem. 550 (1987) 109

[4] (a) H. C. Hansen, A . Senning, J. Chem. SOC., Chem. Commun. 1979, 1135; (b) H. C. Hansen, A. Senning, J. Chem. SOC., Chem. Commun. 1980, 692

[5] A. L. Sgek, PLATON 82 in Computational Crystallo- graphy (Ed.: D. Sayre), Clarendon Press, Oxford 1982, p. 528

~

[6] (a) G. Winnewisser, J. Mol. Spectros. 41 (1972) 534; (b) .I Hahn, I? Schmidt, K. Reinartz, Z. Naturforsch. B46 (1991) 1338

[7] (a) R. Steudel, Angew. Chem. 87 (1975) 683; Angew. Chem., Int. Ed. Eng. 114 (1975) 655; (b) l? b u r in Sulfur in Organic and Inorganic Chemistry (Ed.: A. Senning), Vol. 111, Dekker, New York 1972, p. 91

[8] (a)M. Ostrowski, J. Jeske, l? G. Jones, W-K du Mont, Chem. Ber. 126 (1993) 1355; (b)M. Kustos, J . Pickardt, .I Albertsen, R. Steudel, Z. Naturforsch. B48 (1993) 928

[9] (a)L. Field, W B. Lacefield, J. Org. Chem. 31 (1966) 3555; (b) R. Steudel, i? Luger, H. Bradaczek, Chem. Ber. 110 (1977) 3553; (c) R. Steudel, Phosphorus Sulfur 23 (1985) 33

[lo] (a) 7: Nakubayashi, .I Tsurugi, I: Yabuta, J. Org. Chem. 29 (1964) 1236; (b) R. Steudel, S. Forster, J . Albertsen, Chem. Ber. 124 (1991) 2357

[ l l ] D. Voritinder, E. Mittag, Ber. Dtsch. Chem. Ges. 46 (1913) 3450

1121 J. Albertsen, Doctoral Dissertation, Technische Univer- sitat Berlin 1993

[I31 (a) E. S. Levchenko, A . P! Kirsanov, J. Gen. Chem. USSR (Engl. Transl.) 32 (1962) 157; (b) G. Kresze, FK Wucher- pfennig, Angew. Chem. 79 (1967) 109

[14] For definition and determination of retention index values see: R. Steudei, E.-M. Strauss, D. Jensen, Z. Naturforsch. B45 (1990) 1282

[I51 G. M. Sheldrick, Acta Crystallogr. A46 (1990) 467 [I 61 S. R. Hall, J . M. Stewart, XTAL 2.2 User’s Manual,

University of Western Australia, Nedlands, WA, and University of Maryland, College Park, Md 1987

[17] J. A . Ibers, W; C. Hamilton, International Tables for X- Ray Crystallography IV, The Kynoch Press, Birmingham, England 1974, p. 148

[18] Further details of the crystal structure investigation are available on request from the Fachinformationszentrum Karlsruhe, Gesellschaft fur wissenschaftlich-technische In- formation mbH, D-76344 Eggenstein-Leopoldshafen, on quoting the depository number CSD-58 876

[t 91 E. Keller, SCHAKAL 88, Graphics program for molecular and crystallographic models, Albert-Ludwigs-Universitat, Freiburg, Germany 1988

Authors’ Addresses:

Prof. Dr. R. Steudel*, Dipl.-Chem. Vera Munchow Institut fur Anorganische und Analytische Chemie, Sekr. C2, Technische Universitat Berlin StraRe des 17. Juni 135 D-10623 BerlinXermany

Dr. J. Buschmann, Prof. Dr. P. Luger Institut fur Kristallographie, Fachbereich Chemie, Freie Universitat Berlin Takustralje 6 D-I 4195 BerlidGermany