Synthetic and X-ray structural and reactivity studies of Cp*Ru IV complexes containing bidentate dithiocarbonate, xanthate, carbonate, and phosphinate ligands (Cp* = η5-C 5Me5)

Article abstract of DOI:10.1021/ic061781t

The reaction of [Cp*RuCl₂]₂ (1; Cp* = η⁵-C₅Me₅) with tetraalkyldithiuram disulfides (R₂NC(S)SS(S)CNR₂, R = Me, Et), isopropylxanthic disulfide ([ⁱPrOC(S)S]₂

Full text of DOI:10.1021/ic061781t

Inorg. Chem. 2007, 46, 1440
−1450
Synthetic and X-ray Structural and Reactivity Studies of Cp*RuIV
Complexes Containing Bidentate Dithiocarbonate, Xanthate, Carbonate,
and Phosphinate Ligands (Cp* ) η5-C5Me5)
Elaine Phuay Leng Tay, Seah Ling Kuan, Weng Kee Leong,* and Lai Yoong Goh*
Department of Chemistry, National UniVersity of Singapore, Kent Ridge, Singapore 117543,
Singapore
Received September 20, 2006
The reaction of [Cp*RuCl2]2 (1; Cp* ) η5-C5Me5) with tetraalkyldithiuram disulfides (R2NC(S)SS(S)CNR2, R
)
Me,
Et), isopropylxanthic disulfide ([iPrOC(S)S]2), and bis(thiophosphoryl) disulfide ([(iPrO)2P(S)S]2) led to the isolation
of dark-red crystalline solids of Cp*RuIVCl2(
Et), S2COiPr (3), and S2P(iPrO)2 (4)]. Dichlorido substitution in 2 and 3 with DTCEt and S2COiPr anions
yielded RuIV derivatives containing bis(DTC) and mixed DTC
dithiocarbonate ligands. These are the first
η ) S2CNR2, DTCR (2a, R ) Me; 2b,
2-dithiolate) complexes [dithiolate
R
)
−
organoruthenium complexes of such ligands. The reaction of monophosphines with 2a resulted in monochlorido
substitution, whereas the analogous reaction with 3 resulted in displacement of both chlorido ligands and reduction
of the metal center to RuII. Reduction at Ru was also observed in the reaction of 2a with [CpCr(CO)3]2. Of these
complexes, only 2 and 3 are air-stable in the solid state for an extended period. All of the complexes have been
spectrally characterized, and selected compounds are also crystallographically characterized.
Introduction
[Ru(DTCMe)(CO)(PPh3)(µ-SPh)]24+ 4a and Ru(DTCEt)2(Ts2N4)
(Ts2N4 ) ditosyltetrazene).4b Non-DTC RuIV compounds are
rare, with examples being Ru(chbae)(PPh3)(py) [H4(chbae)
) 1,2-bis(3,5-dichloro-2-hydroxybenzamido)ethane],5a and
Ru(bipy)(NHCMe2CMe2NH)2 reported by Che and co-
workers, Ru(PCy3)(“S2N2”) [“S2N2”4- ) 1,2-ethanediamide-
The lower (2+ to 0) oxidation states dominate the
organometallic chemistry of Ru.1 Higher oxidation states are
still uncommon, though inorganic compounds of RuIII and
RuIV are found quite frequently in the coordination environ-
ment of thiolate (-SR) ligands2 and 1,1′-dithiolate ligands
like dithiocarbamate (DTC). RuIV(DTC) coordination com-
pounds were extensively studied in the 1970s by Pignolet,
who reported examples of both the “binary” and “mixed-
ligand” types, with halogeno coligands.3 Other RuIV(DTC)
complexes with various types of coligands include dimeric
5b
(2) (a) Koch, S. A.; Millar, M. J. Am. Chem. Soc. 1983, 105, 3362. (b)
Millar, M.; O’Sullivan, T.; deVries, N.; Koch, S. A. J. Am. Chem.
Soc. 1985, 107, 3714. (c) Soong, S.-L.; Hain, J. H.; Millar, M.; Koch,
S. A. Organometallics 1988, 7, 556. (d) Satsangee, S. P.; Hain, J. H.,
Jr.; Cooper, P. T.; Koch, S. A. Inorg. Chem. 1992, 31, 5160. (e) See
the following chapters in Vol. 5 in ComprehensiVe Coordination
Chemistry II; McCleverty, J. A., Meyer, T. J., Eds.; Constable, E. C.,
Dilworth, J. R., Vol. Eds.; Pergamon: Oxford, U.K., 2004 and
references cited therein: (i) Chapter 5, pp 555-731 (Housecroft, C.
E.); (ii) Chapter 6, pp 733-847 (Che, C.-M.; Lau, T.-C.).
(3) See, for instance, the following and references cited therein: (a) Duffy,
D. J.; Pignolet, L. H. Inorg. Chem. 1974, 13, 2045. (b) Mattson, B.
M.; Heiman, J. R.; Pignolet, L. H. Inorg. Chem. 1976, 15, 564. (c)
Wheeler, S. H.; Mattson, B. M.; Miessler, G. L.; Pignolet, L. H. Inorg.
Chem. 1978, 17, 340. (d) Miessler, G. L.; Pignolet, L. H. Inorg. Chem.
1979, 18, 210.
(4) (a) Kawano, M.; Uemura, H.; Watanabe, T.; Matsumoto, K. J. Am.
Chem. Soc. 1993, 115, 2068. (b) Leung, W.-H.; Chim, J. L. C.; Hou,
H.; Hun, T. S. M.; Willams, I. D.; Wong, W.-T. Inorg. Chem. 1997,
36, 4432.
(5) (a) Che, C.-M.; Cheng, W.-K.; Leung, W.-H.; Mak, T. C. W. J. Chem.
Soc., Chem. Commun. 1987, 418. (b) Chiu, W.-H.; Peng, S.-M.; Che,
C.-M. Inorg. Chem. 1996, 35, 3369. (c) Sellmann, D.; Ruf, R.; Knoch,
F.; Moll, M. Inorg. Chem. 1995, 34, 4745. (d) Maiti, R.; Shang, M.;
Lappin, A. G. Chem. Commun. 1999, 2349.
* To whom correspondence should be addressed. E-mail: chmlwk@
nus.edu.sg (W.K.L.), chmgohly@nus.edu.sg (L.Y.G.).
(1) (a) Seddon, E. A.; Seddon, K. R. The Chemistry of Ruthenium;
Elsevier: Amsterdam, The Netherlands, 1984. (b) Bruce, M. I.
ComprehensiVe Organometallic Chemistry (I); Wilkinson, G., Ed.;
Pergamon: Oxford, U.K., 1982; Vol. 4, pp 661-690 and 843-929.
Bennett, M. A.; Bruce, M. I.; Matheson, T. W. ComprehensiVe
Organometallic Chemistry (I); Wilkinson, G., Ed.; Pergamon:
Oxford, U.K., 1982; Vol. 4, pp 691-841. (c) See the following
chapters in Vol. 7 in ComprehensiVe Organometallic Chemistry II;
Abel, E. W., Stone, F. G. A., Wilkinson, G., Shriver, D. F., Bruce,
M. I., Eds.; Pergamon: Oxford, U.K., 1995 and references cited
therein: (i) Chapter 5, pp 291-298 (Bruce, M. I.); (ii) Chapter 7, pp
441-472 (Bennett, M. A.); (iii) Chapter 8, pp 473-548 (Bennett,
M. A.; Khan, K.; Wenger, E.); (iv) Chapter 9, pp 549-602 (Bennett,
M. A.).
1440 Inorganic Chemistry, Vol. 46, No. 4, 2007
10.1021/ic061781t CCC: $37.00
© 2007 American Chemical Society
Published on Web 01/18/2007

Studies of Cp*RuIV Complexes
N,N′-bis(2-benzenethiolate)(4-)] from Sellmann’s group,5c
and [Ru(mnt)3]2- [mnt2- ) 1,2-dicyanoethylenedithiolate-
(2-)] reported by Lappin et al.5d
Wewereinterestedinexploringthereactivityof[Cp*RuCl2]n
toward disulfides of the [Z(S)S]2 types [Z ) R2NC, tet-
i
raalkyldithiuram disulfide for R ) Me or Et; Z ) PrOC,
isopropylxanthic disulfide; Z ) (iPrO)2P, bis(thiophosphoryl)
disulfide]. It has been established that these disulfides readily
undergo oxidative addition at transition-metal moieties,
leading to complexes with dithio derivatives, of which the
most common are the DTCs.18 In earler work with some of
these disulfides, we had isolated CpCr complexes containing
DTC, dithiocarboxamide, and dithiophosphinate ligands.19
Other possible outcomes may include adduct formation and
disulfide ligand oxidation.18 In this present study, it is
anticipated that further variation of products can arise from
no, partial, or total substitution of the chlorido ligands by
the derivative dithio ligands, with or without oxidation state
changes at the metal center. The resultant S-containing
complexes of Cp*Ru will be of interest with regard to
industrial and biochemical/biological processes.20 The ob-
servation of reversible one-step four-electron redox reactions
The first organoruthenium(IV) complex was the µ-dichlo-
ridobis(allyl) complex [RuCl(µ-Cl)(η3:η3-C10H16)]2, formed
by oxidative trimerization of butadiene or dimerization of
isoprene at RuII in the mid-1960s.6 The following 2 decades
saw sporadic reports of other organoruthenium(IV) com-
plexes commonly obtained from RuII species by oxidative
addition of hydrogen,7 halogens,8 quinones,9 and allylic
halides.10 The use of the ruthenium(III) halide [Cp*RuCl2]n,
first synthesized by Bercaw and Suzuki and their co-workers
in 1984,11 was exploited by Itoh as a new precursor to
Cp*RuIV complexes via treatment with allylic halides,
alcohol, ether, acetate or sulfides,12a and halogens.12b Other
routes to Cp/Cp*RuIV complexes include alkylation, for
instance, of Cp/Cp*Ru(η3-C3H5)X2 (X ) Cl, Br), which
yielded Cp/Cp*Ru(η3-C3H5)(Me)X, Cp/Cp*Ru(Me)L2X in
the presence of ligand L (phosphines or dienes),13a or [CpRu-
(η3-C3H5)2]+ when treated with silver(I) triflate in the
presence of propene.13b The oxidation of [Cp*RuCl2]n with
the ferrocenium ion in the presence of tetrahydrothiophene
led to [Cp*RuCl2(SC4H8)2]+.14 The reaction of [RuCl(µ-Cl)-
(η3:η3-C10H16)]2 with RSH (R ) alkyl or aryl) led to the
doubly thiolate-bridged complex [RuIVCl(µ-SR)(η3:η3-
C10H16)]2.15 Recently, Leung reported the syntheses of Cp*Ru
complexes containing S- and Se-donor ligands from the RuII
complexes [Cp*Ru(NO)Cl2] and [Cp*Ru(MeCN)3]+ 16 and
a ruthenium(IV) acetylide complex [Ru(SR)3Cl(CtCPh/
tol)]- (R ) 2,6-dimethylphenyl, tol ) 4-tolyl) from [Ru-
(SR)3(MeCN)Cl].17
21
in the RuII complex [Ru(DTC)(CO)(PPh3)(µ-SPh)]2 indi-
cates that electron-rich Ru(DTC) complexes are potential
candidates as multielectron catalysts.
Our studies resulting in Cp*RuIV(dithiolato) complexes are
described in this paper.
Experimental Section
All manipulations were carried out under purified N2 using
conventional Schlenk techniques or under an inert atmosphere of
Ar in an M. Braun Labmaster 130 Inert Gas System glovebox.
NMR spectra were measured on a Bruker 300-MHz Fourier
transform (FT)-NMR spectrometer (1H at 300.14 MHz, 13C at 75.43
MHz, and 31P at 121.49 MHz) or a Bruker AMX500 500-MHz
FT-NMR spectrometer (1H at 500.13 MHz, 13C at 125.77 MHz,
and 31P at 202.45 MHz) if so stated, with chemical shifts referenced
to residual solvent peaks in the respective deutero solvents or to
external H3PO4. IR spectra were measured in the range 4000-350
cm-1 on a BioRad FTS-165 FTIR machine. Mass spectra were
obtained on a Finnigan Mat 95XL-T (fast atom bombardment, FAB)
or Finnigan-MAT LCQ (electrospray ionization, ESI) spectrometer,
and elemental analyses were performed in the microanalytical
laboratory in-house.
(6) (a) Lydon, J. E.; Nicholson, J. K.; Shaw, B. L.; Truter, M. R. Proc.
Chem. Soc. London 1964, 421. (b) Porri, L.; Gallazzi, M. G.; Colombo,
A.; Allegra, G. Tetrahedron Lett. 1965, 47, 4187. (c) Nicholson, J.
K.; Shaw, B. L. J. Chem. Soc. A 1966, 807.
(7) (a) Ito, T.; Kitazume, S.; Yamamoto, A.; Ikeda, S. J. Am. Chem. Soc.
1970, 92, 3011. (b) Ashworth, T. V.; Singleton, E. J. Chem. Soc.,
Chem. Commun. 1976, 705. (c) Wilzcynski, R.; Fordyce, W. A.;
Halpern, J. J. Am. Chem. Soc. 1983, 105, 2066. (d) Davies, S. G.;
Moon, S. D.; Simpson, S. J. J. Chem. Soc., Chem. Commun. 1983,
1278.
All solvents were of analytical grade and were dried and freshly
distilled before use according to standard techniques. Deutero
solvents were vacuum-transferred after drying: CDCl3 using P2O5
(8) (a) Nowell, I. W.; Tabatabaian, K.; White, C. J. Chem. Soc., Chem.
Commun. 1979, 547. (b) Bruce, M. I.; Tomkins, I. B.; Wong, F. S.;
Skelton, B. W.; White, A. H. J. Chem. Soc., Dalton Trans. 1982, 687.
(9) Balch, A. L.; Sohn, Y. S. J. Organomet. Chem. 1971, 30, C31.
(10) (a) Nagashima, H.; Mukai, K.; Itoh, K. Organometallics 1984, 3, 1314.
(b) Albers, M. O.; Liles, D. C.; Robinson, D. J.; Shaver, A.; Singleton,
E. J. Chem. Soc., Chem. Commun. 1986, 645.
(18) Victoriano, L. I. Coord. Chem. ReV. 2000, 196, 383 (review) and
references cited therein.
(11) (a) Tilley, T. D.; Grubbs, R. H.; Bercaw, J. E. Organometallics 1984,
3, 274. (b) Oshima, N.; Suzuki, H.; Moro-oka, Y. Chem. Lett. 1984,
1161.
(12) (a) Nagashima, H.; Mukai, K.; Shiota, Y.; Ara, K.; Itoh, K.; Suzuki,
H.; Oshima, N.; Moro-oka, Y. Organometallics 1985, 4, 1314. (b)
Oshima, N.; Suzuki, H.; Moro-oka, Y.; Nagashima, H.; Itoh, K. J.
Organomet. Chem. 1986, 314, C46.
(13) (a) Nagashima, H.; Yamaguchi, K.; Mukai, K.; Itoh, K. J. Organomet.
Chem. 1985, 291, C20. (b) Itoh, K.; Masuda, K.; Ikeda, H. Organo-
metallics 1993, 12, 2752.
(14) Manzano, B. R.; Jalon, F. A.; Lahoz, F. J.; Chaudret, B.; de Montauzon,
D. J. Chem. Soc., Dalton Trans. 1992, 977.
(19) (a) Goh, L. Y.; Weng, Z.; Leong, W. K.; Leung, P. H. Angew. Chem.
2001, 40, 3236. (b) Goh, L. Y.; Weng, Z.; Leong, W. K.; Leung, P.
H. Organometallics 2002, 21, 4398. (c) Goh, L. Y.; Weng, Z.; Leong,
W. K.; Leung, P. H.; Haiduc, I. J. Organomet. Chem. 2000, 607, 64.
(d) Goh, L. Y.; Weng, Z.; Leong, W. K.; Haiduc, I.; Lo, K. M.; Wong,
R. C. S. J. Organomet. Chem. 2001, 631, 67.
(20) See, for instance, the following and the references cited therein: (a)
Mu`ller, A., Krebs, B., Eds. SulfursIts Significance for Chemistry;
for the Geo-, Bio- and Cosmosphere and Technology; Elsevier:
Amsterdam, The Netherlands, 1984. (b) Stiefel, E. I., Matsumoto, K.,
Eds. Transition Metal Sulfur Chemistry: Biological and Industrial
Significance; ACS Symposium Series 653; American Chemical
Society: Washington, DC, 1996. (c) Dai, S.; Schwendmayer, C.;
Schu¨rmann, P.; Ramaswamy, S.; Eklund, H. Science 2000, 287, 655.
(d) Sellmann, D.; Sutter, J. Acc. Chem. Res. 1997, 30, 460. (e)
Bianchini, C.; Meli, A. Acc. Chem. Res. 1998, 31, 109.
(15) Blechem, G.; Steed, J. W.; Tocher, D. A. J. Chem. Soc., Dalton Trans.
1994, 13, 1949.
(16) Zhang, Q.-F.; Cheung, F. K. M.; Wong, W.-Y.; Williams, I. D.; Leung,
W.-H. Organometallics 2001, 20, 3777.
(17) Zhang, Q.-F.; Lai, C.-Y.; Wong, W.-Y.; Leung, W.-H. Organometallics
2002, 21, 4017.
(21) Kawano, M.; Uemura, H.; Watanabe, T.; Matsumoto, K. J. Am. Chem.
Soc. 1993, 115, 2068.
Inorganic Chemistry, Vol. 46, No. 4, 2007 1441

Tay et al.
and CD3CN using CaH2. Silica gel (Merck Kieselgel 60, 230-400
mesh) was dried at 140 °C overnight before use. The tetraalky-
ldithiuram disulfides [R2NC(S)S]2 (R ) Me, Et), isopropylxanthic
disulfide [iPrOC(S)S]2, and RuCl3‚nH2O were purchased from
Merck and used as supplied. [Cp*RuCl2]n (1),22 [Cp*RuCl2(S2-
at -30 °C for 30 min, did not give any solid product. Then the
solution was evacuated to dryness and redissolved in 1 mL of
toluene. The addition of hexane (1 mL) gave microcrystalline 4
(50 mg, 0.096 mmol, 59%). Anal. Calcd for C16H29Cl2O2P1Ru1S2:
C, 36.9; H, 5.6; S, 12.3; P, 6.0. Found: C, 37.4; H, 5.7; S, 12.0; P,
24
1
CNMe2)] (2a),23 and bis(thiophosphoryl) disulfide [(iPrO)2P(S)S]2
5.8. H NMR (500 MHz, CD3CN): δ 1.31 (s, 15H, Me5C5), 1.34
3
3
were prepared according to published procedures.
(d, JHH ) 6.3 Hz, 12H, CH(CH3)2), 4.76 (d of septet, JHH ) 6.3
Hz, 3JPH ) 10.7 Hz, 1H, CH(CH3)2) and 5.00 (d of septet, 3JHH
)
Reactions of [Cp*RuCl2]2 (1). (a) With [Et2NC(S)S]2. Syn-
thesis of [Cp*RuCl2(S2CNEt2)] (2b). To an orange-red solution
of 1 (0.54 g, 0.88 mmol) in acetonitrile (10 mL) was added [Et2-
NC(S)S]2 (0.26 g, 0.88 mmol) with stirring. The solution turned
purple instantly. The resultant solution was filtered through a disc
(2 cm) of silica gel. Concentration of the filtrate in vacuo to ca. 3
mL, followed by the addition of ether (5 mL) and subsequent
cooling at -30 °C for 30 min, gave a microcrystalline solid of 2b
(0.67 g, 1.46 mmol, 85%). Anal. Calcd for C15H25Cl2NRuS2: C,
39.6; H, 5.5; N, 3.1; S, 14.1; Cl, 15.6. Found: C, 39.7; H, 5.7; N,
6.3 Hz, 3JPH ) 13.3 Hz, 1H, CH(CH3)2). 13C{1H} NMR (500 MHz,
3
CD3CN): δ 9.0 (Me5C5), 24.1 and 24.2 (each d, JPC ) 4.6 Hz,
CH3), 75.7 and 76.1 (each d, JPC ) 7.3 and 5.0 Hz, respectively,
2
CH), 108.8 (Me5C5). 31P NMR (500 MHz, CD3CN): δ 95.2 (dd,
3JPH ) 10.4 and 12.4 Hz). IR (KBr, cm-1): ν 2979m, 2930w,
2909w, 2868vw, 1475mbr, 1376s, 1173w, 1143w, 1097m, 983vs,
961vs, 890wsh, 771s, 640m (PdS). FAB+-MS: m/z 480 [M - iPr
+ 3H)]+, 449 [M - 2Cl]+, 366 [M - S2P(OiPr)]+, 351 [M -
S2P(OiPr) - Me]+, 300 [Cp*RuS2]+, 268 [Cp*RuS], 234 [Cp*Ru
- 2H]+, and significant unassigned higher mass fragments, 557,
588, and 663. The compound is very soluble in all organic solvents
and, unlike 2 and 3, is very air-sensitive even in the solid state.
Dichlorido Substitution. (a) Using Et2NC(S)S-. Synthesis of
[Cp*Ru(S2CNMe2)(S2CNEt2)]Cl (5a). To a purple solution of 2a
(46 mg, 0.11 mmol) in acetonitrile (4 mL) was added Na(S)SCNEt2
(24 mg, 0.11 mmol) with stirring. The solution turned red in 1 h.
The resultant solution was filtered through a disc (2 cm) of Celite.
Concentration of the filtrate in vacuo to ca. 1 mL, followed by the
addition of ether (2 mL) and subsequent cooling at -30 °C for 30
min, gave a microcrystalline solid of 5a (40 mg, 0.074 mmol, 69%).
Anal. Calcd for C18H31ClN2RuS4: C, 40.0; H, 5.8; N, 5.2; S, 23.7.
Found: C, 39.9; H, 6.1; N, 5.0; S, 23.9. 1H NMR (CDCl3): δ 1.60
1
3.3; S, 14.4; Cl, 16.4. H NMR (CDCl3): δ 1.30 (t, J ) 7.2 Hz,
6H, 2CH3), 1.41 (s, 15H, Me5C5), 3.73 (q, J ) 7.2 Hz, 4H, 2CH2).
13C{1H} NMR (CDCl3): δ 8.2 (Me5C5), 12.5 (CH3), 42.7 (CH2),
106.3 (Me5C5), 204.3 (CS). IR (KBr, cm-1): ν 1517vs (C-N),
1089s, 1010m (NC2), 859m, 783m (C-S). FAB+-MS: m/z 415
[M - Et - Me + 2H]+ 385 [M - 2Cl]+, 370 [M - 2Cl - Me]+,
352 [M - 2Cl - 2Me - 3H]+, 313 [M - 2Cl - NEt2]+, 300
[Cp*RuS2]+, 268 [Cp*RuS]+, 236 [M - 2Cl - SCNEt2
)
Cp*Ru]+, and higher mass fragments, the significant ones of which
are 492 [M + Cl]+ and 522 [M + Cl + 2Me]+. The complex is
sparingly soluble in toluene and ether, moderately soluble in
tetrahydrofuran, and highly soluble in acetonitrile and chloro
solvents. Solid samples are air-stable, and solutions in CD3Cl were
found unchanged when checked after 3 days at room temperature.
3
(s, 15H, Me5C5), 1.31 (t, JHH ) 7.2 Hz, 6H, CH2CH3), 3.37 (s,
6H, CH3), 3.76 and 3.73 (each dq, 2JHH ) 14.4 Hz, 2H, CH2CH3).
13C{1H} NMR (CDCl3): δ 8.8 (Me5C5), 12.3 (CH3), 38.0 (CH2CH3),
43.8 (CH2CH3), 105.7 (Me5C5), 204.3 and 205.2 (each CS). IR
(KBr, cm-1): ν 1560vs, 1527vs (C-N), 1156m, 1086m, 1018m
(NC2), 851w, 784w (C-S). FAB+-MS: m/z 505 [M - Cl]+, 477
[M - Cl - Et], 385 [M - Cl - (S2CNMe2)]+, 357 [M - Cl -
(S2CNEt2)]+, 300 [Cp*RuS2], 281 [M - Cp* - Cl - CNEt2 -
5H]+, 268 [Cp*RuS], 236 [Cp*Ru], and a higher mass fragment
533 [M - Cl + Et - H]+.
(b) With [iPrOC(S)S]2. Synthesis of [Cp*RuCl2(S2COiPr)] (3).
Similarly, from the reaction of 1 (0.40 g, 0.66 mmol) with [iPrOC-
(S)S]2 (0.18 g, 0.66 mmol) was obtained microcrystalline 3 (0.53
g, 1.20 mmol, 89%). Anal. Calcd for C14H22Cl2ORuS2: C, 38.0;
H, 5.0; S, 14.5; Cl, 16.0. Found: C, 37.6; H, 4.7; S, 14.9; Cl, 16.4.
3
1H NMR (CDCl3): δ 1.45 (s, 15H, Me5C5), 1.50 (d, JHH ) 6.0
Hz, 6H, CH(CH3)2), 5.64 (septet, 1H, CH(CH3)2). 1H NMR (CD3-
3
CN): δ 1.37 (s, 15H, Me5C5), 1.49 (d, JHH ) 6.0 Hz, 6H, CH-
(CH3)2), 5.69 (septet, 1H, CH(CH3)2). 13C{1H} NMR (CDCl3): δ
8.4 (Me5C5), 21.9 (CH3), 107.2 (Me5C5), 222.8 (CS), CH not
observed (presumably obscured by the solvent peaks at δ 77.0).
IR (KBr, cm-1): ν 1460s, 1372vs, 1280vs (C-O), 1094s 1041m,
900m (C-S), 811m (C-S). FAB+-MS: m/z 442 [M - 2H]+, 407
[M - 2H - Cl]+, 372 [M - 2H - 2Cl]+, 329 [M - 2H - 2Cl -
(iPr)]+, 300 [M - 2Cl - (COiPr) ) Cp*RuS2]+, 268 [Cp*RuS]+,
234 [Cp*Ru - 2H]+, and higher mass fragments, the significant
ones of which are 479 [M + Cl]+, 511 [M + Cl + S]+, 539 [M +
Cl + SCO]+, 610 [M + 3Cl + SCO]+, and 851. The complex is
similar to 2 in solubility and stability.
Synthesis of [Cp*Ru(S2CNEt2)2]Cl (5b). A similar reaction of
2b (50 mg, 0.11 mmol) with Na(S)SCNEt2 (25 mg, 0.11 mmol),
followed by a similar workup, gave microcrystalline 5b (60 mg,
0.11 mmol, 96%). Anal. Calcd for C20H35ClN2RuS4‚CH3Cl: C,
40.8; H, 6.2; N, 4.5; S, 20.7. Found: C, 41.0; H, 6.2; N, 4.8; S,
20.2. 1H NMR (500 MHz, CD3CN): δ 1.52 (s, 15H, Me5C5), 1.24
(t, 3JHH ) 6.9 Hz, 12H, CH3), 3.73 and 3.69 (each dq, 2JHH ) 14.5
Hz, 4H, CH2CH3). 13C{1H} NMR (CDCl3): δ 8.9 (Me5C5), 12.4
(CH3), 43.8 (CH2), 105.8 (Me5C5), 204.4 (CS). IR (KBr, cm-1): ν
1532vs, 1443s (C-N), 1075m, 1014w (NC2), 857w, 786w (C-S).
FAB+-MS: m/z 533 [M - Cl]+, 385 [M - Cl - (S2CNEt2)]+.
Synthesis of Cp*Ru(S2CNEt2)(S2CO) (6b). A similar reaction
of 3 (30 mg, 0.068 mmol) with Na(S)SCNEt2 (15 mg, 0.068 mmol),
followed by a similar workup, gave microcrystalline 6b (30 mg,
0.063 mmol, 93%). Anal. Calcd for C16H25NORuS4: C, 40.3; H,
(c) With [(iPrO)2P(S)S]2. Synthesis of Cp*RuCl2(S2P(OiPr)2)
(4). To an orange-red solution of 1 (50 mg, 0.081 mmol) in
acetonitrile (4 mL) was added [(iPrO)2P(S)S]2 (35 mg, 0.081 mmol)
with stirring. The solution gradually turned maroon in color. After
1 h, the resultant solution was filtered through a disc (2 cm) of
silica gel. Concentration of the filtrate in vacuo to ca. 1 mL,
followed by the addition of ether (2 mL) and subsequent cooling
1
5.3; N, 2.9; S, 26.9. Found: C, 39.9; H, 5.4; N, 2.8; S, 27.5. H
3
NMR (CD3CN): δ 1.49 (s, 15H, Me5C5), 1.23 (t, JHH ) 7.2 Hz,
6H, CH2CH3), 3.78-3.59 (overlapping dq, resembling ABX3
spectrum of 5a, total 4H, CH2CH3). 13C{1H} NMR (CDCl3): δ
8.5 (Me5C5), 12.4 (CH2CH3), 43.0 (CH2CH3), 102.9 (Me5C5), 202.7
and 206.8 (CS, S2CO). IR (KBr, cm-1): ν 1704m (CdO), 1593vs,
1513vs (C-N), 1076s, 1018s (NC2), 850s (C-S). FAB+-MS: m/z
478 [MH]+, 417 [M - 2Et - 2H]+, 385 [M - (S2CO)]+, 300
(22) Koelle, U.; Kossakowski, J. Inorg. Synth. 1992, 29, 225.
(23) Kuan, S. L.; Tay, E. P. L.; Leong, W. K.; Goh, L. Y.; Lin, C. Y.;
Gill, P. M. W.; Webster, R. D. Organometallics 2006, 25, 6134.
(24) (a) Kuchen, W.; Mayatepek, H. Chem. Ber. 1968, 101, 3454. (b)
Higgins, Wm. A.; Vogel, P. W.; Craig, W. G. J. Am. Chem. Soc. 1955,
77, 1864.
1442 Inorganic Chemistry, Vol. 46, No. 4, 2007

Studies of Cp*RuIV Complexes
[Cp*RuS2]+, 268 [Cp*RuS]+, 234 [Cp*Ru - 2H]+, and an intense
higher mass fragment at 533 [M - (S2CO) + S2CNEt2]+.
(b) Using iPrOC(S)S-. Synthesis of Cp*Ru(S2CNMe2)(S2CO)
(6a). To a purple solution of 2a (50 mg, 0.12 mmol) in acetonitrile
(4 mL) was added K(S)SCOiPr (20 mg, 0.12 mmol) with stirring.
The solution turned red in 1 h. The resultant solution was filtered
through a disc (2 cm) of Celite. Concentration of the filtrate in
vacuo to ca. 1 mL, followed by the addition of ether (2 mL) and
subsequent cooling at -30 °C for 30 min, gave microcrystalline
6a (43 mg, 0.10 mmol, 82%). Anal. Calcd for C14H21NORuS4: C,
37.5; H, 4.7; N, 3.1; S, 28.6. Found: C, 37.7; H, 4.7; N, 3.0; S,
28.4. 1H NMR (CDCl3): δ 1.54 (s, 15H, Me5C5), 3.24 (s, 6H, CH3).
1H NMR (CD3CN): δ 1.49 (s, 15H, Me5C5), 3.27 (s, 6H, CH3).
13C{1H}NMR (CDCl3): δ 8.6 (Me5C5), 37.5 (CH3), 103.0 (Me5C5),
205.7 and 208.1 (CS, CO). IR (KBr, cm-1): ν 1701m (CdO),
1598vs, 1548s (C-N), 1158m (NC2), 845s (C-S). ESI+-MS: m/z
450 [MH]+, 390 [MH - (SCO)]+, 356 [M - (S2CO)]+, and higher
mass fragments at 492 [M + CO + Me]+ and 477 [M + CO]+.
The product 6b (32 mg, 0.067 mmol, 68%) isolated above was
also formed by reacting 2b (45 mg, 0.099 mmol) in acetonitrile (4
mL) with K(S)SCOiPr (17 mg, 0.099 mmol).
Synthesis of Cp*Ru(S2COiPr)(S2CO) (7). To a purple solution
of 3 (50 mg, 0.11 mmol) in acetonitrile (4 mL) was added K(S)-
SCOiPr (20 mg, 0.11 mmol) with stirring. The solution turned red
in 1 h. The resultant solution was filtered through a disc (2 cm) of
Celite. Concentration of the filtrate in vacuo to ca. 1 mL, followed
by the addition of ether (2 mL) and subsequent cooling at -30 °C
for 30 min, gave microcrystalline 7 (52 mg, 0.11 mmol, 99%). Anal.
Calcd for C15H22O2RuS4: C, 38.9; H, 4.8; S, 27.7. Found: C, 38.6;
1
H, 4.8; S, 27.9. H NMR (CDCl3): δ 1.58 (s, 15H, Me5C5), 1.46
3
3
(d, JHH ) 6.4 Hz, 6H, (CH(CH3)2), 5.55 (septet, JHH ) 6.4 Hz,
1H, (CH(CH3)2). 13C{H} NMR (CDCl3): δ 8.8 (Me5C5), 21.4 (CH-
(CH3)2), 103.5 (CH(CH3)2), 107.3 (Me5C5), 201.7 (CS), 225.0 (CO).
IR (KBr, cm-1): 1695m (CdO), 1606s (C-O), 842w (C-S).
FAB+-MS: m/z 463 [M]+, 404 [M - OiPr]+, 328 [M - (S2COi-
Pr)]+, 300 [Cp*RuS2]+, 268 [Cp*RuS]+, 234 [Cp*Ru - 2H]+, and
significant higher mass fragments at 537 [Cp*2Ru2S2H], 568 [Cp*2-
Ru2S3], 775 [M2 - O - (S2COiPr)], 807 [(M - OiPr)2H]+, and
869 [M2 - OiPr + 2H].
To detect all components of the product mixture, an NMR tube
reaction was carried out as follows: CDCl3 (0.50 mL) was added
to a mixture of 3 (5 mg, 0.011 mmol) and K(S)SCOiPr (2 mg,
0.011 mmol) in an NMR tube. After the tube was shaken for 30
1
min, the H NMR spectrum of the red mixture was scanned.
Reaction with Phosphines. (a) Synthesis of [Cp*Ru(S2CNMe2)-
(PPh3)Cl]Cl (8a). To a purple solution of 2a (30 mg, 0.070 mmol)
in acetonitrile (12 mL) was added PPh3 (18 mg, 0.070 mmol) with
stirring. The solution turned red after 4 h and was stirred for 17 h.
Concentration of the resultant solution in vacuo to ca. 3 mL,
followed by the addition of ether (2 mL) and subsequent cooling
at -30 °C for 30 min, gave microcrystalline 8a (36 mg, 0.052
mmol, 75%). Anal. Calcd for C31H36Cl2NPRuS2‚3H2O: C, 50.1;
H, 5.7; N, 1.9; S, 8.6; P, 4.2. Found: C, 49.9; H, 5.7; N, 1.8; S,
8.8; P, 4.0. 1H NMR (CD3CN): δ 1.46 (s, 15H, Me5C5), 3.03 and
3.17 (each s, 3H, CH3), 6.8-7.8 (m, 15H, PPh3). 13C{1H} NMR
(CD3CN): δ 8.9 (s, Me5C5), 38.0 and 38.2 (each s, CH3), 110.6 (s,
Me5C5), 129.4 (s, br, PPh), 132.2 (s, PPh), 134.4 (s, br, PPh), 201.9
(s, CS). 31P{1H} NMR (CD3CN): δ 35.2 (s, PPh3). IR (KBr, cm-1):
ν 1559vs (C-N), 1091m (NC2), 750w, 698s (C-S). FAB+-MS:
m/z 654 [M - Cl ) Cp*Ru(S2CNMe2)(PPh3)Cl]+, 619 [M - 2Cl]+,
497 [M - 2Cl - (S2CNMe2) - 2H]+, 392 [M - Cl - PPh3]+,
357 [M - 2Cl - PPh3]+, and 297 [M - 2Cl - PPh3 - CNMe2 -
Inorganic Chemistry, Vol. 46, No. 4, 2007 1443

Tay et al.
Figure 1. Molecular structures of the dications of 2b and 3. Thermal ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity.
Scheme 1
4H]+. HRMS. Calcd for [C31H36ClNPRuS2]+: 654.0759. Found:
654.0745 (ESI+) and 654.0776 (FAB+).
(c) Synthesis of [Cp*Ru(S2CNMe2)(PMe3)Cl][BPh4] (8c). To
a purple solution of 2a (30 mg, 0.070 mmol) in acetonitrile (10
mL) was added PMe3 (5.3 mg, 7 µL, 0.070 mmol) with stirring.
The solution turned red after 1 h. After 17 h, solid NaBPh4 (40
mg, 0.136 mmol) was added and the precipitated NaCl was removed
by filtration through a disc (2 cm) of Celite. Concentration of the
solution in vacuo to ca. 3 mL, followed by the addition of ether (2
mL) and subsequent cooling at -30 °C for 30 min, gave
microcrystalline 8c (43 mg, 0.055 mmol, 78%). Anal. Calcd for
C40H50BClNPRuS2: C, 61.0; H, 6.4; N, 1.8; S, 8.2; P, 3.9. Found:
(b) Synthesis of [Cp*Ru(S2CNMe2)(PPhMe2)Cl][PF6] (8b). To
a purple solution of 2a (30 mg, 0.070 mmol) in acetonitrile (10
mL) was added PPhMe2 (9.7 mg, 10 µL, 0.070 mmol). The solution
turned red after stirring for 2 h. After 17 h, solid NH4PF6 (30 mg,
0.184 mmol) was added and the precipitated NH4Cl was removed
by filtration through a disc (2 cm) of Celite. Concentration of the
filtrate in vacuo to ca. 3 mL, followed by the addition of ether (2
mL) and subsequent cooling at -30 °C for 30 min, gave
microcrystalline 8b (39 mg, 0.058 mmol, 83%). Anal. Calcd for
C21H32ClNRuS2P2F6: C, 37.4; H, 4.8; N, 2.1; S, 9.5; P, 9.2.
Found: C, 37.0; H, 4.8; N, 2.0; S, 9.7; P, 9.7. 1H NMR (CD3CN):
1
C, 61.0; H, 6.4; N, 1.3; S, 7.9; P, 3.9. H NMR (CD3CN): δ 1.56
2
(s, 15H, Me5C5), 1.54 (d, JPH ) 9.6 Hz, 9H, PMe3), 3.24 (s, 3H,
Me), 3.25 (s, 3H, Me), 6.8-7.3 (m centered at 6.85, 7.00, and 7.28
(1:2:2), total 20H, BPh4). 13C{1H} NMR (CD3CN): δ 8.9 (C5Me5),
13.4 (d, 1JPC ) 40.2 Hz, PMe3), 38.1 and 38.4 (each s, Me), 109.0
(C5Me5), 122.6, 126.4, and 136.6, with one peak probably obscured
by δ 118.1 of CD3CN (each s, BPh4), 202.9 (CS). 31P{1H} NMR
(CDCl3): δ 10.3 (PMe3). IR (KBr, cm-1): ν 1558s (C-N), 1159m
(NC2), 948s, 846m (C-S). ESI+-MS: m/z 468 [M - Cl ) Cp*Ru-
(S2CNMe2)(PMe3)Cl]+, 432 [M - 2Cl]+, 392 [M - Cl - PMe3]+,
356 [M - 2Cl - PMe3]+. ESI+-HRMS. Calcd for [C16H30-
ClNPRuS2]+: 468.0289. Found: 468.0276.
2
δ 1.56 (s, 15H, Me5C5), 1.82 (d, JPH ) 8.1 Hz, 3H, PMe), 1.85
(d, 2JPH ) 8.8 Hz, 3H, PMe), 3.05 and 3.16 (each s, 3H, Me), 7.3-
7.8 (m, 5H, PPh). 13C{1H} NMR (CD3CN): δ 9.1 (s, C5Me5), 12.6
1
and 13.2 (each d, JPC ) 38.6 Hz, PMe), 37.9 and 38.1 (each s,
1
Me), 109.5 (C5Me5), 134.3 (d, JPC ) 56.2 Hz, ipso-C), 132.3 (d,
3JPC ) 6.4 Hz, meta-C) and 131.6 (s, para-C), 128.4 (d, 2JPC ) 9.7
Hz, ortho-C) (PPh), 202.7 (CS). 31P{1H} NMR (CD3CN): δ 9.7
(s, PPhMe2), -142.9 (septet, J ) 703 Hz, PF6). IR (KBr, cm-1):
ν 1554m (C-N), 1015w (NC2), 840s (C-S). ESI+-MS: m/z 494
[M - Cl ) Cp*Ru(S2CNMe2)(PPhMe2)]+.
1444 Inorganic Chemistry, Vol. 46, No. 4, 2007

Studies of Cp*RuIV Complexes
Table 2. Selected Bond Lengths (Å) and Bond Angles (deg) of 2 and 3
2a
2b
3
Ru(1)-S(1)
2.3706(12)
2.3681(10)
1.712(5)
1.724(4)
1.304(5)
71.16(4)
106.7(2)
Ru(1)-S(1)
Ru(1)-S(1)#1
S(1)-C(1)
2.3644(7)
2.3644(7)
1.704(2)
1.704(2)
1.323(4)
70.70(3)
106.78(19)
Ru(1)-S(1)
2.3554(8)
2.3639(8)
1.682(3)
1.685(3)
1.300(4)
71.23(3)
109.40(17)
Ru(1)-S(2)
Ru(1)-S(2)
S(1)-C(11)
S(2)-C(11)
N(11)-C(11)
S(2)-Ru(1)-S(1)
S(1)-C(11)-S(2)
S(1)-C(11)
S(2)-C(11)
O(12)-C(11)
S(1)-Ru(1)-S(2)
S(1)-C(11)-S(2)
C(1)-S(1)#1
N(1)-C(1)
S(1)-Ru(1)-S(1)#1
S(1)#1-C(1)-S(1)
Table 3. Selected Bond Lengths (Å) and Bond Angles (deg) of 5a and 6a,b
5a 6a
6b
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-S(3)
Ru(1)-S(4)
S(1)-C(1)
2.3852(9)
2.3851(9)
3.3942(9)
2.3960(8)
1.709(4)
1.709(4)
1.709(3)
1.711(3)
1.317(5)
1.313(4)
71.24(3)
71.22(3)
108.77(19)
109.27(18)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-S(3)
Ru(1)-S(4)
S(1)-C(1)
2.3793(7)
2.3947(7)
2.3869(8)
2.3824(7)
1.711(3)
1.711(3)
1.755(3)
1.758(3)
1.315(4)
1.217(4)
71.19(2)
72.04(3)
108.60(15)
105.94(17)
Ru(1)-S(1)
2.3967(6)
2.3842(6)
2.3792(6)
2.3855(6)
1.712(2)
1.711(2)
1.754(3)
1.744(3)
1.322(3)
1.211(3)
71.03(2)
71.37(3)
108.49(12)
105.24(14)
Ru(1)-S(2)
Ru(1)-S(3)
Ru(1)-S(4)
S(1)-C(10)
S(2)-C(1)
S(2)-C(1)
S(2)-C(10)
S(3)-C(2)
S(3)-C(4)
S(3)-C(20)
S(4)-C(2)
S(4)-C(4)
S(4)-C(20)
N(1)-C(1)
N(1)-C(1)
N(10)-C(10)
O(20)-C(20)
S(2)-Ru(1)-S(1)
S(3)-Ru(1)-S(4)
S(2)-C(10)-S(1)
S(4)-C(20)-S(3)
N(2)-C(2)
O(1)-C(4)
S(2)-Ru(1)-S(1)
S(3)-Ru(1)-S(4)
S(1)-C(1)-S(2)
S(3)-C(2)-S(4)
S(1)-Ru(1)-S(2)
S(4)-Ru(1)-S(3)
S(2)-C(1)-S(1)
S(3)-C(4)-S(4)
(d) Synthesis of Cp*Ru(S2COiPr)(PPh3) (9). To a purple
solution of 3 (50 mg, 0.113 mmol) in acetonitrile (12 mL) was
added PPh3 (59 mg, 0.226 mmol). The solution was stirred for 4 h.
The resultant red solution was evacuated to dryness and the residue
redissolved in toluene (ca. 2 mL) and cooled at -30 °C for 30
min, giving microcrystalline 9 (43 mg, 0.068 mmol, 60%). Anal.
Calcd for C32H37OPRuS2: C, 60.6; H, 5.9; S, 10.1; P, 4.9. Found:
Crystal Structure Determinations. Diffraction-quality crystals
were obtained as follows: 2b, 3, 6b, 8a, and 8c from acetonitrile
solutions layered with ether after 2 days at -30 °C, 5a from a
CDCl3 solution after 2 days at -30 °C, 6a from acetonitrile-ether
after 2 h at 5 °C, and 4, 9, and 10 from a solution in toluene layered
with hexane after 2-3 days at -30 °C.
The crystals were mounted on glass fibers. X-ray data were
collected on a Bruker APEX AXS diffractometer, equipped with a
CCD detector, using Mo KR radiation (λ ) 0.710 73 Å), with the
SMART suite of programs.25a Data were processed and corrected
for Lorentz and polarization effects with SAINT25b and for absorp-
tion with SADABS.25c Structural solution and refinement were
carried out with the SHELXTL suite of programs.25d The crystal
data collection and processing parameters are given in Table 1.
The structures were solved by direct methods or Patterson maps
to locate the heavy atoms, followed by difference maps for the
light, non-H atoms. All non-H atoms were generally given
anisotropic displacement parameters in the final model. Refinements
were against F 2.
1
C, 60.8; H, 5.9; S, 10.3; P, 5.3. H NMR (CD3CN): δ 1.42 (s,
15H, Me5C5), 1.12 (d, 3JHH ) 6.0 Hz, 6H, CH(CH3)2), 4.95 (septet,
3JHH ) 6.0 Hz, 1H, CH(CH3)2), 7.2-7.6 (m, 15H, PPh3). 1H NMR
(C6D6): δ 1.55 (s, 15H, Me5C5), 0.97 (d, 3JHH ) 6.0 Hz, 6H, CH-
(CH3)2), 5.00 (septet, 3JHH ) 6.0 Hz, 1H, CH(CH3)2), 7.0-7.8 (m,
15H, PPh3). 13C{1H} NMR (C6D6): δ 11.0 (C5Me5), 22.3 (CH-
(CH3)2), 74.5 (CH(CH3)2), 86.6 (C5Me5), 138.0 (d, 1JPC ) 35.3 Hz,
ipso-C), 135.3, 135.2 (each s) and 134.8 (d, 2JPC ) 19.3 Hz, ortho-
C) (PPh), 227.1 (CS). 31P{1H} NMR (CD3CN): δ 54.5 (PPh3).
31P{1H} NMR (C6D6): δ 54.2 (PPh3). IR (KBr, cm-1): ν 1027m,
1097s (C-S), 1227vs (C-O). ESI+-MS: m/z 634 [M ) Cp*Ru-
(S2COiPr)(PPh3)]+, 499 [M - (S2COiPr)]+, 372 [M - PPh3]+, 329
Two chloroform solvent molecules were found in 5a. For 8a,
there were two acetonitrile molecules, with occupancies of 1.0 and
0.5, respectively, as well as a water molecule. There was disorder
of the chloride counterion, which was modeled over three sites,
with occupancies of 0.37, 0.37, and 0.26, respectively, with
appropriate restraints.
i
[M - PPh3 - Pr)]+, 300 [Cp*RuS2]+, 263 [PPh3H]+.
Reaction of 2a with [CpCr(CO)3]2. Synthesis of Cp*Ru-
(S2CNMe2)(CO) (10). To a green solution of [CpCr(CO)3]2 (24
mg, 0.059mmol) in toluene (10 mL) was added 2a (50 mg, 0.12
mmol). The solution was stirred for 2 h at room temperature. The
resultant greenish-blue solution was evacuated to dryness and the
residue extracted with hexane. The extract was concentrated to ca.
3 mL, and subsequent cooling at -30 °C for 30 min gave
microcrystalline moderately air-stable 10 (43 mg, 0.11 mmol, 92%).
Anal. Calcd for C14H21NORuS2: C, 43.7; H, 5.5; N, 3.6; S, 16.7.
Found: C, 44.0; H, 5.6; N, 3.3; S, 16.9. 1H NMR (CDCl3): δ 1.81
Results and Discussion
Reactions with Disulfides. Treatment of the RuIII complex
1 with the disulfanesstetraalkyldithiuram disulfides [R2NC-
(S)S]2 (R ) Me,23 Et), isopropylxanthic disulfide [iPrOC-
(S)S]2, and bis(thiophosphoryl) disulfide [(iPrO)2P(S)S]2s
resulted in facile cleavage of the bridging Ru-Cl and S-S
1
(s, 15H, Me5C5), 3.18 (s, 6H, 2CH3). H NMR (CD3CN): δ 1.78
(s, 15H, Me5C5), 3.14 (s, 6H, 2CH3). 13C{1H} NMR (CDCl3): δ
10.0 (Me5C5), 38.1 (CH3), 93.1 (Me5C5), 201.9 (CS) and 215.6
(CO). IR (KBr, cm-1): ν 1901vs (C-O), 1529s (C-N), 1153m
(NC2), 980m (C-S). FAB+-MS: m/z 385.0 [MH]+, 357.0 [MH -
CO]+.
(25) (a) SMART, version 5.628; Bruker AXS Inc.: Madison, WI, 2001.
(b) SAINT+, version 6.22a; Bruker AXS Inc.: Madison, WI, 2001.
(c) Sheldrick, G. M. SADABS; University of Go¨ttingen, Go¨ttingen,
Germany, 1996. (d) SHELXTL, version 5.1; Bruker AXS Inc.:
Madison, WI, 1997.
Inorganic Chemistry, Vol. 46, No. 4, 2007 1445

Tay et al.
Scheme 2
Scheme 3
Scheme 4
bonds with concomitant oxidation of the metal centers,
resulting in the formation of dichlorido-Cp*RuIV complexes
2, 3, and 4, respectively, which were isolated in high yields
as air-stable (2 and 3) and very air-sensitive (4) crystalline
solids (Scheme 1).
The complexes 2b and 3 possess similar structures,
showing coordination of Ru to Cp*, η2-DTC, and two
chlorido ligands, as illustrated in Figure 1 for 2b and 3.
Assuming that Cp* takes up three coordination sites, the RuIV
center is formally seven-coordinate. Bond parameters of these
complexes, together with those of 2a,23 are given in Table
2. It is seen that the C-S bond lengths [1.682(3)-1.724(4)
Å] fall intermediate between those for the C-S single bond
(1.81 Å) and the CdS double bond (1.61 Å). The C-N bond
distances [1.300(4)-1.304(5) Å] also fall intermediate
between those for a C-N single bond (1.47 Å) and a CdN
double bond (1.27 Å). In 3, the C-O bond length [1.300(4)
Å] also lies between those of a C-O single bond (1.43 Å)
and a CdO double bond (1.23 Å).26 The presence of a mirror
plane through the Ru(1), C(1), and N(1) atoms in 2b,
resulting from symmetrical bonding of the DTC ligand to
the Ru center, is reflected in the metric data in Table 2.
The spectral data are consistent with the molecular
structures. The Me groups of Cp* rings of 2b and 3 are seen
as singlets at δ 1.41 and 1.45, respectively, in their 1H NMR
spectra in CDCl3 and at δ 8.2 and 8.4 (methyl C’s) and δ
106.3 and 107.2 (ring C’s) in their 13C NMR spectra. The
proton resonances in CDCl3 of the DTC ligand of 2b are
observed as a triplet at δ 1.30 (CH3) and a quartet at δ 3.73
(CH2), consistent with the presence of a plane of symmetry
and possibly also rapid free rotation about the C-N bond.
The corresponding 13C NMR resonances of the DTC ligand
are found at δ 12.5 and 42.7, respectively, and that of the
CS moiety is found at δ 204.3. The isopropyl group of 3 is
observed in the 1H NMR spectrum in CDCl3 as a doublet at
δ 1.50 (CH3) and a septet at δ 5.64 (CH). Significant in the
IR spectra are the presence of stretching frequencies of C-S,
C-N, and NC2 in 2b and of C-S and C-O in 3. The mother
Scheme 5
ions of these complexes are not observed; the highest mass
fragment of 2b shows loss of Et and Me groups, while that
of 3 shows loss of two H atoms, with subsequent loss of
chlorido ligands.
The single-crystal X-ray diffraction analysis of 4 was not
obtained. However, a structure conforming to the formulation
shown in Scheme 1 is supported by microanalytical and
1
spectral data. Thus, the H NMR spectral data at 300 MHz
in CDCl3 shows a singlet for Cp* at δ 1.37, a doublet at δ
1.39 (CH3), and two septets at δ 4.76 and 5.09 (CH) for the
two iPr groups in the molecule; scanned at 500 MHz in CD3-
CN, these latter resonances are seen as symmetrical 9- and
10-line multiplets, which are comprised of P-coupled dou-
blets of proton-coupled septets. The proton-decoupled 31P
NMR spectrum shows a doublet of doublet at δ 95.2,
indicating coupling to two different CH protons. This is
consistent with the 13C NMR spectrum, which reveals two
CH moieties possessing slightly different P-C coupling
constants and two P-coupled doublets pertaining to Me
groups in two different environments; indeed, the underlying
reason for the absence of this effect in the 1H NMR spectrum
is not clear. The combined inference is the presence of
inequivalent OiPr moieties in the phosphinate ligand, an
expected consequence of a probable tetrahedral geometry at
(26) Pauling, L. The Nature of the Chemical Bond, 3rd ed.; Cornell
University Press: Ithaca, NY, 1960; Chapter 7.
1446 Inorganic Chemistry, Vol. 46, No. 4, 2007

Studies of Cp*RuIV Complexes
Figure 2. Molecular structures of the cations of 5a and 6b. Thermal ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity.
Figure 3. Molecular structures of 8a and 8c. Thermal ellipsoids are drawn at the 50% probability level, and the anions of the complexes are omitted. H
atoms are omitted for clarity.
Table 4. Selected Bond Lengths (Å) and Bond Angles (deg) of 8a, 8c, 9, and 10
molecule A
8a
8c
9
molecule B: 10
Ru(1)-S(2)
Ru(1)-S(3)
S(2)-C(1)
S(3)-C(1)
N(1)-C(1)
Ru(1)-P(1)
Ru(1)-Cl(4)
2.3981(12) Ru(1)-S(2)
2.3807(12) Ru(1)-S(3)
1.707(5) S(2)-C(1)
1.714(5) S(3)-C(1)
1.304(6) N(1)-C(1)
2.3968(13) Ru(1)-P(4)
2.4039(12) Ru(1)-Cl(1)
2.3833(14) Ru(1)-S(1)
2.3903(14) Ru(1)-S(2)
1.705(5) S(1)-C(1)
1.719(5) S(2)-C(1)
1.310(6) O(1)-C(1)
2.3562(15) Ru(1)-P(1)
2.4141(15)
2.4102(7) Ru(1)-S(1)
2.3974(7) Ru(1)-S(2)
1.689(3) S(1)-C(11)
1.692(3) S(2)-C(11)
1.325(3) N(1)-C(11)
2.3009(7) Ru(1)-C(1)
O(1)-C(1)
2.3964(6) Ru(2)-S(3)
2.3925(6) Ru(2)-S(4)
1.711(2) S(3)-C(21)
1.714(2) S(4)-C(21)
1.321(3) N(2)-C(21)
1.841(2) Ru(2)-C(2)
1.152(3) O(2)-C(2)
2.3986(6)
2.4103(6)
1.714(2)
1.715(2)
1.315(3)
1.833(2)
1.148(3)
S(3)-Ru(1)-S(2) 70.70(4) S(2)-Ru(1)-S(3) 70.70(5) S(2)-Ru(1)-S(1) 71.77(2) S(2)-Ru(1)-S(1) 72.107(19) S(3)-Ru(2)-S(4) 72.121(19)
S(2)-C(1)-S(3)
107.8(2) S(2)-C(1)-S(3)
107.5(3) S(1)-C(1)-S(2) 112.90(16) S(1)-C(11)-S(2) 110.75(12) S(3)-C(21)-S(4) 111.28(12)
O(1)-C(1)-Ru(1) 173.8(2) O(2)-C(2)-Ru(2) 174.8(2)
P. The mass spectral fragments are also consistent with the
proposed formulation. The PdS stretch is identified in the
IR spectrum.
results in the formation of a dithiocarbonato complex
[Cp*Ru(η2-S2COiPr)(η2-S2CdO)] (7).
The molecular structures of the bis(thiolato) complexes,
5a and 6a,b, have been determined. The ORTEP diagrams
of 5a and 6b are given in Figure 2, and that of 6a in Figure
S1 in the Supporting Information. The molecules all assume
a four-legged piano-stool configuration, with coordination
being to η5-Cp* and two bidentate dithiolate ligands. The
metric data are given in Table 3. Like in complexes 2, the
C-S and C-N bonds possess partial double-bond character.
The C-O bond lengths [1.217(4) Å in 6a and 1.211(3) Å in
6b] in the dithiocarbonate ligands are close to that of the
CdO double bond (1.23 Å).26 The DTC bite angles in these
complexes [range 71.03(2)-71.24(3)°] are slightly smaller
than those of the dithiocarbonate [71.37(3)-72.04(3)°].
Chlorido Substitution in 2 and 3. (a) Reaction with
i
Et2NC(S)S- and PrOC(S)S-. Complexes 2a and 2b
undergo dichlorido substitution with the DTCEt anion to give
bis(DTC) complexes 5a and 5b, respectively (Scheme 2a).
The similar reaction with isopropyl xanthate is accompanied
by loss of the isopropyl group, resulting in thiocarbonate
complexes [Cp*Ru(η2-S2CNR2)(η2-S2CO)] 6a and 6b (Scheme
2b). While this manuscript was in preparation, complex 5a
was reported to be isolated as the [N(Ph2PS)2] salt from the
27
oxidation of Cp*Ru{N(Ph2PS)2} with [Me2NC(S)S]2.
Complex 6b was also obtained from the reaction of 3 with
Et2NC(S)S- (Scheme 3a). The reaction of 3 with iPrOC(S)S-
The spectral data are consistent with the molecular
structures. The H NMR spectrum of 5a in CDCl3 shows
(27) Cheung, W.-M.; Zhang, Q.-F.; Williams, I. D.; Leung, W.-H. Inorg.
Chim. Acta 2006, 359, 782.
1
Inorganic Chemistry, Vol. 46, No. 4, 2007 1447

Tay et al.
Cp*, a doublet at δ 1.46 for CH3’s, and a septet at δ 5.55
for CH of the isopropyl xanthate ligand), its IR spectrum
(νCdO 1695 m), and its FAB-MS spectrum (m/z ) 463 for
the molecular ion).
These dithiocarbonate complexes are the first examples
of an organoruthenium, and notably of RuIV. The only other
such example among the transition metals was a (phenyl)-
rhodium complex reported by Bianchini.28 Coordination
compounds of dithiocarbonate are much more common,
mainly of PdII and PtII, with the first case reported by Fackler
and Seidel in 196929 and subsequent examples from the
groups of Stephenson,30 Beck,31 and Contreras.32 There are
a few dithiocarbonate compounds of NiII,33 and detailed
synthetic and reactivity studies of Rh, reported by the groups
of Bianchini and Stephenson.28,34 Very recently, the first such
RuII coordination compound, [Ru(S2CO)(dppm)2] (dppm )
Ph2PCH2PPh2), was reported by Wilton-Ely and Hogarth,
from a clean facile reaction of cis-[RuCl2(dppm)2] with CS2
and NaOH.35 Other synthetic routes to date have involved
the reaction of bromo/isocyanate complexes with CS231 and
xanthate anions,33b,34c oxidation of η2-CS2 complexes with
O2, S8, or Sen,33c and nucleophilic attack of ligated xanthate
(S2COR) with Lewis bases, e.g., phosphines,29,30,33a with
iodide,32 and with xanthate anions.30
Figure 4. Molecular structure of 9. Thermal ellipsoids are drawn at the
50% probability level. H atoms are omitted for clarity.
Stephenson and co-workers had postulated that the mech-
anism of xanthate-promoted formation of dithiocarbonato
complexes of Pd and Pt involves the intermediate formation
of a tris(dithiocarbonato) complex, followed by intramo-
lecular generation of a dithiocarbonate moiety, upon release
of a dithiocarbonate ester RS2COR.30 Indeed, in an NMR-
tube reaction of 3 with a stoichiometric amout of K(S)SCOi-
Pr in CDCl3, we observed in the product solution resonances
pertaining to the complex 7, as well as those assignable to
Figure 5. ORTEP diagram for one of the molecules in the unit cell of 10.
Thermal ellipsoids are drawn at the 50% probability level. H atoms are
omitted for clarity.
3
[iPrS2COiPr] (viz., δ 1.44 and 1.46 (each d, JHH ) 6 Hz,
singlets at δ 1.60 for the Cp* Me protons and at δ 3.37 for
the six NMe2 protons on the DTCMe ligand; the nature of
the latter is indicative of rapid rotation about the C(1)-N(1)
bond. The six Me protons of the DTCEt ligand are seen as a
triplet at δ 1.31 and the methylene protons as a doublet of
quartets (δ 3.76 and 3.73), in agreement with an AB system
3
3H, CH3), 3.79 and 5.76 (each septet, JHH ) 6 Hz, 1H,
CH(CH3)2).
(b) Reaction with Phosphines. The reaction of 2a with
phosphines PRR′2 resulted in the substitution of one chlorido
ligand, giving monocationic complexes 8a-c in high yields
(Scheme 4). By comparison, the reaction of 3 with PPh3
resulted in the displacement of both chlorido ligands and
the reduction of the metal center to the 2+ oxidation state
coupled to CH3 with coupling constants of 14.4 Hz (2JHH
)
and 7.2 Hz (3JHH). The 1H NMR spectrum of 5b in CD3CN
shows a singlet at δ 1.52 for the Cp* Me protons. The
resonances of the DTCEt ligands are observed as a triplet at
δ 1.24 for the CH3 protons and an overlapping doublet of
quartet (dq) at δ 3.77-3.65 for the CH2 protons, with
coupling closely resembling the ABX3 spectrum of 5a.
The 1H NMR spectra of 6a and 6b in CD3CN both showed
a singlet at δ 1.49 for the Me protons of the Cp* ring. The
Me protons of the η2-S2CNMe2 ligand in 6a are observed as
a singlet at δ 3.27, while the η2-S2CNEt2 ligand in 6b is
manifested as a triplet at δ 1.23 for the CH3 protons and
overlapping dq at δ 3.78-3.59 for the CH2 protons, with a
ABX3 coupling scheme as in 5a. The presence of νCdO
stretching frequencies (1701m in 6a and 1704m in 6b) in
their IR spectra is indicative of the dithiocarbonate ligand.
Their molecular [MH]+ ions were observed.
(28) Bianchini, C.; Meli, A.; Laschi, F.; Vizza, F.; Zanello, P. Inorg. Chem.
1989, 28, 227.
(29) Fackler, J. P., Jr.; Seidel, W. C. Inorg. Chem. 1969, 8, 1631.
(30) (a) Cornock, M. C.; Gould, R. O.; Jones, C. L.; Owen, J. D.; Steele,
D. F.; Stephenson, T. A. J. Chem. Soc., Dalton Trans. 1977, 496. (b)
Alison, J. M. C.; Stephenson, T. A. J. Chem. Soc., Dalton Trans. 1973,
254.
(31) Werner, K. v.; Beck, W.; Bo¨hner, U. Chem. Ber. 1974, 107, 2434.
(32) Contreras, R.; Valderrama, M.; Riveros, O.; Moscoso, R.; Boys, D.
Polyhedron 1996, 15, 183.
(33) (a) Perpin˜a´n, M. F.; Ballester, L.; Gonza´lez-Casso, M. E.; Santos, A.
J. Chem. Soc., Dalton Trans. 1987, 281. (b) Tenorio, M. J.; Puerta,
M. C.; Valerga, P. J. Chem. Soc., Dalton. Trans. 1996, 1935. (c)
Bianchini, C.; Ghilardi, C. A.; Meli, A.; Orlandini, A. J. Organomet.
Chem. 1985, 286, 259.
(34) (a) Bianchini, C.; Mealli, C.; Meli, A.; Sabat, M. J. Chem. Soc., Chem.
Commun. 1985, 1024. (b) Bianchini, C.; Meli, A.; Vizza, F. Angew.
Chem., Int. Ed. Engl. 1987, 26, 767. (c) Cole-Hamilton, D. J.;
Stephenson, T. A. J. Chem. Soc., Dalton Trans. 1974, 1818.
(35) Wilton-Ely, J. D. E. T.; Solanki, D.; Hogarth, G. Inorg. Chem. 2006,
45, 5210.
Likewise, spectral characterization of complex 7 was
1
via its H NMR spectrum in CDCl3 (a singlet at δ 1.58 for
1448 Inorganic Chemistry, Vol. 46, No. 4, 2007

Studies of Cp*RuIV Complexes
Scheme 6
(Scheme 5). The basis for this reactivity difference is
probably electronic in origin; DTC ligands are well recog-
nized for their ability to stabilize high oxidation states in
transition metals via extensive electron delocalization, which
results in delocalization of the positive charge toward the
periphery of the complex.18 It appears that the higher donor
capability of the xanthate ligand, arising from more localized
electron density at the S atoms, has facilitated a redox
reaction in which reduction occurred at Ru, while the
chlorido ligands are oxidized, releasing chlorine in the
process.
from 2.3554(8) to 2.3981(12) Å, while those of the RuII
complexes, 9 and 10, are longer [range: 2.3925(6)-2.4103-
(6) Å].
(c) Reaction of 2a with [CpCr(CO)3]2. Complex 2a was
reacted with dimeric [CpCr(CO)3]2 to test the ability of its
monomeric radical to extract S atoms from the DTC ligand,
a reactivity feature that had been demonstrated for DTC
ligands19a,38 and various other dithiolate- and S-containing
ligands in CpCr complexes.39 However, this reaction showed
that S abstraction from DTC at Cp*RuIV did not occur.
Rather, the reaction was influenced by the oxidizing tendency
of RuIV in 2a and the halophilicity of the resulting CrIII,40
producing the RuII complex 10 and CpCrCl2(solvent) with
loss of CO ligands (Scheme 6). CpCrCl2(CH3CN) was
characterized structurally and found to be identical with that
which we have reported before.41
The 1H NMR spectrum of the RuII complex 10 in CDCl3
possesses singlet resonances at δ 1.81 and 3.18 for the Cp*
and Me protons of the DTC ligand, respectively. Its IR
spectrum in KBr shows a terminal CO stretch at 1901 cm-1.
The mass fragment m/z 385 in the MS spectrum indicates a
protonated mother ion.
The structural formulation of all of the phosphine deriva-
1
tives of 2a and 3 is supported by their H NMR spectra,
which show a singlet for Cp* (δ 1.46 for 8a, δ 1.56 for
both 8b and 8c, and δ 1.42 for 9, in CD3CN). Complexes
8a-c show nonequivalent Me groups of the DTC ligand in
1
their H NMR spectra (singlets at δ 3.03 and 3.17 in 8a, δ
3.05 and 3.16 in 8b, and δ 3.24 and 3.25 in 8c), suggestive
of nonrotation about their C-N bonds. The Me substituents
1
on P are seen as doublets in the H NMR spectra at δ 1.82
and 1.85 in 8b and δ 1.54 in 8c, while Ph substituents are
found in the aromatic region at δ 6.8-7.8. The isopropyl
group of the xanthate ligand in 9 is observed as a doublet at
δ 1.12 for CH3 and a septet at δ 4.95 for CH. The P atoms
of PPh3 in 8a and 9, of PPhMe2 in 8b, and of PMe3 in 8c
resonate at δ 35.2, 54.5, 9.7, and 11.6, respectively.
The ORTEP diagrams for the molecular structures of the
phosphine derivatives 8a and 8c are shown in Figure 3. With
coordination to Cp*, bidentate DTC, a monophosphine, and
a chlorido ligand, the metal centers assume a four-legged
piano-stool configuration. The bond parameters are given
in Table 4, which also includes those of the RuII “three-
legged piano-stool” complex 9 (Figure 4), which is coordi-
nated to triphenylphosphine like 8a but unlike 8a does not
possess a chlorido ligand. 9 is structurally similar to CpRu-
(PPh3)(S2COR) (R ) Me, Et, or Pr), which was formed from
the reaction of CpRu(PPh3)2Cl with the sodium salt of
xanthate.36 As in all of the other structurally characterized
complexes discussed earlier, the C-S and C-N distances
are indicative of partial double-bond character.
Unlike 2a,b and 3, solid samples of 10 (Figure 5) lasted
only a day in air, those of 5a,b, 6a,b, 7, and 8a-c ca. 30
min, while those of 4 and 9 are very air-sensitive. In a CDCl3
solution under N2, 8a-c remained unchanged for a day,
while 9 only lasted a few hours.
Conclusions
The reaction of the µ-dichloro dinuclear RuIII complex,
[Cp*RuCl2]2 (1), with S-S-bonded substrates, [R2NC(S)S]2
(R ) Me, Et), [iPrOC(S)S]2, and [(iPrO)2P(S)S]2, resulted
in the formation of diamagnetic mononuclear dichloridoru-
thenium(IV) complexes containing η2-dithiolate ligands
(DTC, xanthate, and dithiophosphate, respectively). This is
the first instance of the oxidative role of disulfides in the
formation of RuIV complexes. The derived DTC and xanthate
(36) Coto, A.; Tenorio, M. J.; Puerta, M. C.; Valerga, P. Organometallics
1998, 17, 4392.
(37) Bruce, M. I.; Wong, F. S.; Skelton, B. W.; White, A. H. J. Chem.
Soc., Dalton Trans. 1982, 2203.
(38) Goh, L. Y.; Weng, Z.; Hor, A. T. S.; Leong, W. K. Organometallics
2002, 21, 4408.
(39) See references in: Weng, Z.; Goh, L. Y. Acc. Chem. Res. 2004, 37,
187.
(40) See, for instance, the following: (a) Ng, V. W. L.; Leong, W. K.;
Koh, L. L.; Tan, G. K.; Goh, L. Y. J. Organomet. Chem. 2004, 689,
3210. (b) Ng, V. W. L.; Kuan, S. L.; Leong, W. K.; Koh, L. L.; Tan,
G. K.; Goh, L. Y.; Webster, R. W. Inorg. Chem. 2005, 44, 5229. (c)
Ko¨hler, F. H.; Lachmann, J.; Muller, G.; Zeh, H.; Brunner, H.;
Pfauntsch, J.; Wachter, J. J. Organomet. Chem. 1989, 365, C15. (d)
Bra¨unlein, B.; Ko¨hler, F. H.; Strauss, W.; Zeh, H.; Z. Naturforsch.
1995, 50b, 1739.
The Ru-P distances increase in the order of 9 < 8c <
8a. The weaker bond in 8a as compared to 8c is probably
the combined effect of the steric bulk of PPh3 and its poorer
donor capability resulting from the presence of electron-
withdrawing Ph groups, whereas Me substituents in PMe3
are electron-releasing. The shortest Ru-P distance found in
9 is in agreement with the general observation of slightly
shorter Ru-P bonds (by 0.02-0.04 Å) in neutral Ru
complexes vis-a`-vis those in cationic Ru complexes.37 The
Ru-S distances of the RuIV complexes in this study range
(41) Goh, L. Y.; Hambley, T. W. J. Organomet. Chem. 1990, 395, 269.
Inorganic Chemistry, Vol. 46, No. 4, 2007 1449

Tay et al.
complexes underwent dichlorido substitution with DTC and
xanthate anions, with conversion of η2-xanthate to η2-
dithiocarbonate. Chlorido substitution of the DTC complex
with phosphines resulted in a monochloridophosphine de-
rivative. The dichloridoxanthate complex reacted with PPh3
with total displacement of the chlorido ligands and reduction
of Ru to the 2+ oxidation state, in agreement with previous
observations of the necessary donation of at least two
negative charges from anionic coligands for stabilization of
higher oxidation states of Ru.42 The reaction of the dichlo-
rido-DTC complex with [CpCr(CO)3]2 is strongly influenced
by the oxidizing tendency of RuIV and the halophilicity of
the resulting CpCrIII moiety.
Acknowledgment. Support from the National University
of Singapore under Academic Research Fund Grants R-143-
000-077-112 and R-143-000-209-112 to L.Y.G. and a
research scholarship to E.P.L.T. are gratefully acknowledged.
Supporting Information Available: Complete crystallographic
data in CIF format for 2a, 2b, 3, 5a, 6a, 6b, 8a, 8c, 9, and 10 and
an ORTEP diagram of 6a. This material is available free of charge
via the Internet at http://pubs.acs.org.
(42) References 6-8 in: Shin, R. Y. C.; Goh, L. Y. Acc. Chem. Res. 2006,
39, 301.
IC061781T
1450 Inorganic Chemistry, Vol. 46, No. 4, 2007