Reactivities and structural and electrochemical studies of coordinatively unsaturated arene(dithiolato)Ru(II) complexes

Article abstract of DOI:10.1021/om020259l

The addition reactions of 16-electron complexes [(η⁶-arene)Ru(Cab^S,S′)] [3: arene = p-cymene (3a), C₆Me₆ (3b); Cab^S,S′ = 1,2-S₂C₂B₁₀H₁₀-S,S′] with the nucleophiles PEt₃, CNBu^t, and CO lead to the formation of the corresponding 18-electron complexes 4-6 [(η⁶-arene)-Ru(Cab^S,S′)(L)] (L = PEt₃, CNBu^t, CO), which have been characterized by X-ray crystallography. Investigation of the redox process in a series of these base-adduct metalladithiolene complexes by cyclic voltammetry reveals a large dependence of the redox potentials on the nature of the ancillary η⁶-arene and incoming L ligand. In an analogous manner, the reactivity of 3a toward arylamines (7) has been found to produce [(η⁶-p-cymene)Ru(Cab^S,S′)-(L)] (8) [L = η¹-NH₂(CH₂CH₂)Ar, Ar = C₆H₅ (8a); C₆H₄OMe (8b); C₆H₃(OMe)₂ (8c); C₈H₆N (8d)], having molecular structures closely related to those of 4 and 5, as deduced by an electrochemical analysis and NMR studies. In addition, complex 3 reacts with a variety of substrates such as alkynes and a diazoalkane, generating a new class of dithiolato ruthenium-(II) complexes incorporating alkene and alkylidene units. Thus, the syntheses of the half-sandwich ruthenium(II) complexes [(η⁶-arene)Ru{η³-(S,S,C′)-SC₂B ₁₀H₁₀SC′R₂}] [C′R₂ = (COOMe)C=C(COOMe) (9: arene = p-cymene (9a), C₆Me₆ (9b)), HC=CPh (10: arene = C₆Me₆ (10b)), CH₂SiMe₃ (11: arene = p-cymene (11a), C₆Me₆ (11b))] are reported, and the structure of lib has been established by an X-ray diffraction study. The formation of 9 and 10 has also been electrochemically investigated.

Full text of DOI:10.1021/om020259l

Organometallics 2002, 21, 5703-5712
5703
Rea ctivities a n d Str u ctu r a l a n d Electr och em ica l Stu d ies
of Coor d in a tively Un sa tu r a ted Ar en e(d ith iola to)Ru (II)
Com p lexes [(η6-p-cym en e)Ru (1,2-S2C2B10H10-S,S′)] a n d
[(η6-C6Me6)Ru (1,2-S2C2B10H10-S,S′)]
J e-Hong Won,† Hong-Gyu Lim,† Bo Young Kim,‡ J ong-Dae Lee,†
Chongmok Lee,*,‡ Young-J oo Lee,† Sungil Cho,§ J aejung Ko,*,† and
Sang Ook Kang*,†
Department of Chemistry, Korea University, 208 Seochang, Chochiwon, Chung-nam 339-700,
Korea, Department of Chemistry, Ewha Womans University, Seoul 120-750, Korea, and
Department of Chemical Engineering, J unnong-dong 90, Seoul City University,
Seoul 130-743, Korea
Received April 2, 2002
The addition reactions of 16-electron complexes [(η6-arene)Ru(CabS,S′)] [3: arene )
p-cymene (3a ), C6Me6 (3b); CabS,S′ ) 1,2-S2C2B10H10-S,S′] with the nucleophiles PEt3, CNBut,
and CO lead to the formation of the corresponding 18-electron complexes 4-6 [(η6-arene)-
Ru(CabS,S′)(L)] (L ) PEt3, CNBut, CO), which have been characterized by X-ray crystal-
lography. Investigation of the redox process in a series of these base-adduct metalladithiolene
complexes by cyclic voltammetry reveals a large dependence of the redox potentials on the
nature of the ancillary η6-arene and incoming L ligand. In an analogous manner, the
reactivity of 3a toward arylamines (7) has been found to produce [(η6-p-cymene)Ru(CabS,S′)-
(L)] (8) [L ) η1-NH2(CH2CH2)Ar, Ar ) C6H5 (8a ); C6H4OMe (8b); C6H3(OMe)2 (8c); C8H6N
(8d )], having molecular structures closely related to those of 4 and 5, as deduced by an
electrochemical analysis and NMR studies. In addition, complex 3 reacts with a variety of
substrates such as alkynes and a diazoalkane, generating a new class of dithiolato ruthenium-
(II) complexes incorporating alkene and alkylidene units. Thus, the syntheses of the half-
sandwich ruthenium(II) complexes [(η6-arene)Ru{η3-(S,S,C′)-SC2B10H10SC′R2}] [C′R2
)
(COOMe)CdC(COOMe) (9: arene ) p-cymene (9a ), C6Me6 (9b)), HCdCPh (10: arene )
C6Me6 (10b)), CH2SiMe3 (11: arene ) p-cymene (11a ), C6Me6 (11b))] are reported, and the
structure of 11b has been established by an X-ray diffraction study. The formation of 9 and
10 has also been electrochemically investigated.
In tr od u ction
of our previous work, we also found that the 16-electron
complexes showed a reversible 0/-1 reduction with
much less reversible 0/+1 oxidation, and the reversibil-
ity of the 0/+1 oxidation improved upon the addition of
a donor ligand, i.e., the 18-electron complex. Conse-
quently, the Cp* complex II displayed the enhanced
reversibility of the 0/+1 oxidation compared with that
of the Cp complex I. The differences shown in these
reactions have stimulated our interest to investigate
this area since they stem from the small difference in
the ligand, i.e., Cp vs Cp* as shown in Chart 1.
We have recently reported the new coordination
modes for the coordinatively unsaturated half-sandwich
metal complexes1 possessing an ancillary dithio-o-car-
boranyl ligand,2 where the redox stability of the com-
plexes showed a dependence on the ancillary ligand Cp
or Cp*. For example, (η5-Cp)Co(CabS,S′) (I) reacts with
BH3‚THF to give a dinuclear complex of [(η5-CpCo)2-
(CabS,S′)], while (η5-Cp*)Co(CabS,S′) (II) was suppressed
from making the dinuclear complex.3 During the course
Electrochemistry is the best method to monitor oxida-
tion and reduction reactions.4 However, not many
studies have been done on the electrochemical behavior
accompanying o-carboranyl complexes, especially those
involving the o-carboranyl dithiolate. Therefore, we hope
to develop and generalize this electrochemical method-
ology for the product analysis of o-carboranyl dithiolates.
In the present study, we synthesized the (η6-p-cymene)-
† Korea University.
‡ Ewha Womans University.
§ Seoul City University.
(1) (a) Ko, J .; Kang, S. O. Adv. Organomet. Chem. 2001, 47, 61. (b)
Bae, J .-Y.; Lee, Y.-J .; Kim, S.-J .; Ko, J .; Cho, S.; Kang, S. O.
Organometallics 2000, 19, 1514. (c) Kim, D.-H.; Ko, J .; Park, K.; Cho,
S.; Kang, S. O. Organometallics 1999, 18, 2738. (d) Bae, J .-Y.; Park,
Y.-I.; Ko, J .; Park, K.-I.; Cho, S.-I.; Kang, S. O. Inorg. Chim. Acta 1999,
289, 141.
(2) (a) Base, K.; Grinstaff, M. W. Inorg. Chem. 1998, 37, 1432. (b)
Crespo, O.; Gimeno, M. C.; J ones, P. G.; Laguna, A. J . Chem. Soc.,
Dalton Trans. 1997, 1099. (c) Crespo, O.; Gimeno, M. C.; J ones, P. G.;
Laguna, A. J . Chem. Soc., Chem. Commun. 1993, 1696. (d) Contreras,
J . G.; Silva-trivino, L. M.; Solis, M. E. J . Coord. Chem. 1986, 14, 309.
(e) Smith, H. D., J r.; Robinson, M. A.; Papetti, S. Inorg. Chem. 1967,
6, 1014. (f) Smith, H. D., J r.; Obenland, C. O.; Papetti, S. Inorg. Chem.
1966, 5, 1013. (g) Smith, H. D., J r. J . Am. Chem. Soc. 1965, 87, 1817.
(3) Won, J .-H.; Kim, D.-H.; Kim, B. Y.; Kim, S.-J .; Lee, C.; Cho, S.;
Ko, J .; Kang, S. O. Organometallics 2002, 21, 1443.
(4) Review: (a) Geiger, W. E. Acc. Chem. Res. 1995, 28, 351. (b)
Tyler, D. R. Acc. Chem. Res. 1991, 24, 325. (c) Connelly, N. G. Chem.
Soc. Rev. 1989, 18, 153. (d) Astruc, D. Chem. Rev. 1988, 88, 1189.
10.1021/om020259l CCC: $22.00 © 2002 American Chemical Society
Publication on Web 11/23/2002

5704 Organometallics, Vol. 21, No. 26, 2002
Won et al.
Ch a r t 1
Ch a r t 2
F igu r e 1. Absorption spectra of 0.25 mM of (η6-p-cymene)-
Ru(CabS,S′) (3a ) and (η6-C6Me6)Ru(CabS,S′) (3b) in CH2Cl2
(light path length 1.0 cm). (1) 0.25 mM 3a in 0.025 M TBAB
CH2Cl2 solution, 350 nm, ꢀ ) 7.0 × 103 M-1 cm-1; 628 nm,
ꢀ ) 1.6 × 103 M-1cm-1. (2) 0.25 mM 3b in 0.025 M TBAB
CH2Cl2 solution, 346 nm, ꢀ ) 7.6 × 103 M-1 cm-1; 608 nm,
ꢀ ) 1.5 × 103 M-1cm-1
.
coordinatively stabilizes the unsaturated metal centers,6
as shown in Figure 1. By changing the ligand from
p-cymene to hexamethylbenzene, the absorption band
of the Ru complex shows a blue shift by 20 nm to near
600 nm. The latter ligand is also expected to be more
electron-donating than the former ligand on the basis
of the results of our previous study.3 Such an intense
blue color corresponds to the LMCT band of the coor-
dinatively unsaturated ruthenium(II) complexes [(η6-
arene)Ru(SAr)2] (arene ) C6H6, p-cymene, C6Me6),7
[(Cp*)Ru(µ-SR)]2,8 and [Ru(SC6F5)2(PPh3)2],9 as well as
the related [(η6-p-cymene)Os(CabS,S′)]5 and [(Cp*)Ir-
(CabS,S′)].1d These 16-electron metal complexes 3 are
stable in solution; no dimerization is observed in the
NMR spectra. In the 1H NMR spectra, even a week after
the crystal was dissolved, only one singlet peak of the
methyl protons for the p-cymene ligand of 3a or one
peak for the protons for the hexamethylbenzene ligand
of 3b was observed. Thus, the analytical and spectro-
scopic data support the formulation of 3 as a mono-
nuclear 16-electron o-carboranyl dithiolate metal com-
plex, and this formulation has been confirmed by an
electrochemical study of 3, which showed coordinative
unsaturation in the steric sense around the ruthenium
center in the two-legged piano-stool geometry (Chart 2).
Figure 2 shows cyclic voltammograms (CVs) of 3a (A)
and 3b (B) in CH2Cl2 containing 0.1 M TBAB at the
scan rate (v) of 0.1 V s-1. The CV of 3a shows two major
redox responses, i.e., a reversible 0/-1 reduction wave
Sch em e 1. Syn th esis of 16-Electr on Meta l
Com p lexes 3a
a
(i) 1/2 [(p-cymeme)Ru(µ-Cl)Cl2]2 2a , THF, 0 °C; (ii) 1/2
[(C6Me6)Ru(µ-Cl)Cl]2 2b, THF, 0 °C.
Ru(CabS,S′) (3a ) and (η6-C6Me6)Ru(CabS,S′) (3b) com-
plexes and explored the chemistry of these complexes
in terms of coordination chemistry and redox chem-
istry. The comparison of the two complexes depending
on the arene ancillary ligands is our main interest
because they possess differences in their symmetry and
electron-donating ability as well as structural bulkiness
(Chart 2).
(5) Herberhold, M.; Yan, H.; Milius, W. J . Organomet. Chem. 2000,
598, 142.
Resu lts a n d Discu ssion
(6) (a) Michelman, R. I.; Ball, G. E.; Bergmen, R. G.; Anderson, R.
A. Organometallics 1994, 13, 869. (b) Garcia, J . J .; Torrens, H.;
Adames, H.; Bailey, N. A.; Scacklady, A.; Matlis, P. M. J . Chem. Soc.,
Dalton Trans. 1993, 1529. (c) Michelman, R. I.; Anderson, R. A.;
Bergman, R. G. J . Am. Chem. Soc. 1991, 113, 5100. (d) Garcia, J . J .;
Torrens, H.; Adams, H.; Bailey, N. A.; Maitlis, P. M. J . Chem. Soc.,
Chem. Commun. 1991, 74. (e) Klein, D. P.; Kloster, G. M.; Bergman,
R. G. J . Am. Chem. Soc. 1990, 112, 2022.
(7) Mashima, K.; Kaneyoshi, H.; Kaneko, S.; Mikami, A.; Tani, K.;
Nakamura, A. Organometallics 1997, 16, 1016.
(8) (a) Takahashi, A.; Mizobe, Y.; Matsuzaka, H.; Dev, S.; Hidai, M.
J . Organomet. Chem. 1993, 456, 243. (b) Koelle, U.; Rietmann, C.;
Englert, U. J . Organomet. Chem. 1992, 423, C20.
Syn th esis of Coor d in a tively Un sa tu r a ted Meta l
Com plexes. Mononuclear 16-electron arene-ruthenium-
(II)-dithiolate complexes of the general formula [(η6-
arene)Ru(CabS,S′)] [η6-arene ) p-cymene (3a ),5 C6Me6
(3b)] have been prepared by treatment of the arene
ruthenium chloride dimer (2) with 2 molar equiv of the
corresponding dilithium dithiolato ligand Li2CabS,S′ (1),
as shown in Scheme 1.
All these monomeric complexes show an intense blue
color of the LMCT band due to the donation from the
filled S(pπ) orbital to the empty Ru(dπ*) orbital, which
(9) Catala, R.-M.; Cruz-Garritz, D.; Sosa, P.; Terreros, P.; Torrens,
H.; Hills, A.; Hughes, D. L.; Richards, R. L. J . Organomet. Chem. 1989,
359, 219.

Arene(dithiolato)Ru(II) Complexes
Organometallics, Vol. 21, No. 26, 2002 5705
the redox properties of the electron-deficient 16-electron
complexes.3 In contrast to the CV of (η6-p-cymene)Ru-
(CabS,S′), an enhancement in the chemical reversibility
of the 0/+1 couples is demonstrated in the CV of (η6-
C6Me6)Ru(CabS,S′) in CH2Cl2 (Figure 2B) due to the
stronger electron-donating ability of hexamethylbenzene
than p-cymene. In Figure 2B, the ratio of ipa/ipc depend-
ing on the scan rate is a diagnostic of the EC mecha-
nism,12 and the kY value (defined in eq 1) is determined
as ca. 0.1 s-1 by assuming first-order kinetics;13 that is,
the lifetime of the -1 state is ca. 10 s, whereas the kX
value is too small to be determined by the CV technique.
However, the CV of 3b in CH3CN shows good chemical
reversibility in both the oxidation and reduction waves
(Figure 2C), where the shifts in redox potentials seemed
to be ascribed to the fact that the relative stability of
the +1 and -1 states compared with the 0 state
increases in a polar solvent.
Syn t h esis a n d Ch a r a ct er iza t ion of Com p lexes
[(η6-a r en e)Ru (Ca bS,S′)(L)] (a r en e ) p-cym en e (a ),
C6Me6 (b); L ) P Et3 (4), CNBu t (5), CO (6)). The
reaction of the 16-electron complex 3 with two-electron
donor molecules such as triethylphosphine, tert-butyl
isocyanide, and carbon monoxide proceeded to give
various 18-electron complexes, as shown in Scheme 2.
Our results are closely related to those of the re-
ported 16-electron cobalt, ruthenium, rhodium, osmium,
and iridium complexes such as (η5-Cp)Co(CabS,S′),3
(η6-p-cymene)Ru(CabS,S′),5 (η5-Cp*)Rh(CabS,S′),3 (η6-p-
cymene)Os(CabS,S′),5 and (η5-Cp*)Ir(CabS,S′).1d
The reaction of 3 with an excess of PEt3 in toluene
afforded red crystals of 4 in 85-93% yield. The 31P{1H}
NMR of 4 exhibited a singlet signal at around δ 22-28.
The 1H NMR data for 4 conform to the structure
determined by the X-ray structural study. The ORTEP
diagram in Figure 3 shows the molecular structure of
4b and confirms the six-coordinate geometry about the
ruthenium atom, assuming that the hexamethylbenzene
ring serves as a three-coordinate ligand. The Ru atom
environment is transformed from a two-legged piano-
stool geometry in 3b to a three-legged version in 4b.
Overall, the structure is octahedral with an idealized
Cs molecular symmetry, similar to what is observed in
other related complexes such as [(η5-Cp)Co(CabS,S′)-
(PEt3)],3 [(η5-Cp*)Ir(CabS,S′)(PMe3)],1d and (η6-p-cy-
mene)Ru(CabS,S′)(L) (L ) PPh3, P(OMe)3, NH3, NC5H5,
CO, CNBut, SEt2, SC4H8, CN-, SCN-).5
F igu r e 2. Cyclic voltammograms of 1 mM 3a (A), 3b (B,
C) at a platinum disk electrode with negative initial scan
direction; in CH2Cl2 containing 0.1 M TBAB (A, B) and in
CH3CN containing 0.1 M TBAP (C); v ) 0.1 V s-1
.
at E1/2 ) -1.45 V and a virtually chemically irreversible
0/+1 oxidation wave at Epa ) 0.75 V. The chemical
reversibility of redox waves improved with the larger
scan rates; thus the 0/-1 and 0/+1 redox couples have
been assigned as shown in eq 1.10 The differences in the
peak potentials (Epa - Epc) are similar to that of the
Fc/Fc+ couples, i.e., one-electron processes.11
Treatment of the mononuclear 3 with an excess of
CNBut in toluene gave a reddish brown addition product
[(η6-arene)Ru(CabS,S′)(CNBut)] (5) in 87-91% yield.
Complex 5 exhibited a single CN stretching absorption
at around 2200 cm-1 in the IR spectrum, and this
wavenumber is quite normal for a terminal Ru-CNR
ligand and significant π-back-bonding of the isocyanide
1
ligand. The H NMR spectrum of 5 indicated a singlet
signal at δ 1.5 due to a tert-butyl moiety. The structural
analysis of 5b (Figure 4) reveals a molecular core with
similarities to that of complex 4b; the metal center is
in a distorted octahedral environment consisting of the
carbon atom of the isocyanide ligand with the Ru-C
interaction completing the coordination sphere.
This redox pattern is very similar to those of (η5-
Cp*)M(CabS,S′) (M ) Co, Rh, Ir), which was ascribed to
(10) Yang, K.; Bott, S. G.; Richimond, M. G. J . Organomet. Chem.
1994, 483, 7.
(11) A plot of E vs log[(il - i)/i] from the CV of the Fc+/Fc couple
using a microdisk (10 µm diameter) showed a slope of 60 mV. But the
peak potential difference increased in the present data probably due
to the solution resistance.
(12) Nicholson, R. S.; Shain, I. Anal. Chem. 1964, 36, 706.
(13) Kim, J . Y.; Lee, C.; Park, J . W. J . Electroanal. Chem. 2001,
504, 104.

5706 Organometallics, Vol. 21, No. 26, 2002
Sch em e 2. Ad d ition Rea ction of 16-Electr on Meta l Com p lexes 3a
Won et al.
a
(i) PEt3, toluene, 25 °C; (ii) CNBut, toluene, 25 °C; (iii) CO, toluene, 25 °C.
F igu r e 3. Molecular structure of 4b with atom labeling;
ellipsoids show 30% probability levels and hydrogen atoms
have been omitted for clarity.
The treatment of 3b at atmospheric pressure with
carbon monoxide in toluene resulted in the formation
of the mononuclear carbonyl adduct [(η6-C6Me6)Ru-
(CabS,S′)(CO)] (6b) in 95% yield. The structure of 6b was
determined on the basis of the spectral data as well as
an elemental analysis. The 1H NMR spectrum of 6b
exhibited a single proton signal assignable to a coordi-
nated hexamethylbenzene ligand. The IR spectrum
indicates that one carbon monoxide is bound to the
ruthenium atom in accordance with the strong ν(CO)
F igu r e 4. Molecular structure of 5b with atom labeling;
ellipsoids show 30% probability levels and hydrogen atoms
have been omitted for clarity.
to 3 and 4 except the direction of the potential shifts of
the 0/+1 waves.
Rea ction of 3a w ith Ar yla m in es (7). We are
interested in extending these studies to tethered arene-
ruthenium(II) complexes, from which it might be pos-
sible to generate, by replacing the p-cymene, the amine
strapped arene-ruthenium(II) analogous to the chela-
tion-stabilized phosphine complexes of (arene)ruthe-
nium(II), such as [RuCl2{η1:η6-R2P(CH2)3(aryl)}] (R )
Me, Ph; aryl ) Ph, 2,4,6-C6H2Me3, C6Me6),14 [RuCl2-
{η1:η6-Me2PCH2SiMe2C6H5}],14 [RuCl2{η1:η6-Me2P(CH2)3-
C6H5}],15 [RuCl2{η1:η6-Cy2P(CH2)3C6H5}],16 [RuCl2-
band at 1989 cm-1
.
The cyclic voltammetric data in CH2Cl2 containing 0.1
M TBAB with the scan rate of 0.1 V s-1 are summarized
in Table 4. The CVs of 4 and 5 show a fully reversible
0/+1 oxidation wave as expected for the 18-electron
complexes, and the E1/2 values for both 0/+1 and 0/-1
redox waves shift in the negative direction compared
with 3. Almost the same amount of potential shift is
observed whether the η6-arene moiety is η6-p-cymene
or η6-C6Me6. The CV patterns of 6a and 6b are similar
(14) Bennett, M. A.; Edwards, A. J .; Harper, J . R.; Khimyak, T.;
Willis, A. C. J . Organomet. Chem. 2001, 629, 7.
(15) Smith, P. D.; Wright, A. H. J . Organomet. Chem. 1998, 559,
141.

Arene(dithiolato)Ru(II) Complexes
Organometallics, Vol. 21, No. 26, 2002 5707
Ta ble 1. X-r a y Cr ysta llogr a p h ic Da ta a n d P r ocessin g P a r a m eter s for Com p ou n d s 4b, 5b, 8b, a n d 11b
4b
5b
8b
11b
formula
fw
cryst class
space group
Z
C
27H51B10PS2Ru
C19H37B10NS2Ru
C21H37B10NOS2Ru
C36H76B20S4Si2Ru2
679.99
monoclinic
P21/c
552.79
triclinic
P1h
592.81
triclinic
P1h
1111.73
monoclinic
P21/n
4
2
2
4
cell constants
a, Å
b, Å
8.9166(4)
15.912(2)
22.492(1)
3191.0(4)
11.484(1)
11.6254(7)
11.7828(7)
1364.6(2)
66.884(5)
82.193(6)
70.602(6)
7.37
10.8507(7)
11.7209(8)
13.3027(9)
1441.6(2)
106.870(6)
97.023(6)
112.586(6)
7.06
20.8410(2)
10.5570(7)
25.670(2)
5492.2(8)
c, Å
V, Å3
R, deg
â, deg
90.381(4)
103.490(6)
γ, deg
µ, cm-1
cryst size, mm
6.87
7.74
0.35 × 0.35 × 0.4
0.3 × 0.3 × 0.4
0.35 × 0.4 × 0.5
0.25 × 0.25 × 0.4
D
calcd, g/cm3
1.415
1.345
1.366
1.344
F(000)
1300
568
608
2288
radiation
θ range, deg
h, k, l collected
no. of reflns collected/unique
no. of data/restraints/params
goodness-of-fit on F2
final R indices [I > 2σ(I)]a,b
Mo KR (λ ) 0.7107 Å)
1.57-25.97
+11, +19, (27
6664/6251
6251/0/331
0.962
R1 ) 0.0592
wR2) 0.1402
R1 ) 0.1487
wR2 ) 0.1775
1.221 and -0.985
1.88-25.98
+14,(14, (14
5674/5353
1.66-25.97
+13, (14, (16
5971/5652
1.14-25.97
+25,+13, (31
11 046/10 740
10 732/0/615
0.907
5353/0/317
0.872
5652/0/347
1.599
R1 ) 0.0409
wR2 ) 0.1069
R1 ) 0.0589
wR2 ) 0.1201
1.345 and -0.741
R1 ) 0.0842
wR2 ) 0.2207
R1 ) 0.1157
wR2 ) 0.2331
2.746 and -3.792
R1 ) 0.0438
wR2 ) 0.1161
R1 ) 0.0999,
wR2 ) 0.1559
0.573 and -0.397
R indices (all data)a,b
largest diff peak and hole, e/Å3
R1 ) ∑||Fo| - |Fc|| (based on reflections with Fo > 2σF2). wR2 ) [∑[w(Fo - Fc2)2]/∑[w(Fo2)2]]1/2; w ) 1/[σ2(Fo2) + (0.095P)2]; P )
a
2
b
2
[max(Fo2, 0) + 2Fc2]/3 (also with Fo > 2σF2).
2
Ta ble 2. Selected In ter a tom ic Dista n ces (Å) in 4b, 5b, 8b, a n d 11b
Compound 4b
Ru(1)-S(1)
Ru(1)-C(4)
Ru(1)-C(7)
S(2)-C(2)
2.3854(18)
2.221(7)
2.246(7)
1.796(7)
Ru(1)-S(2)
Ru(1)-C(5)
Ru(1)-P(1)
2.3975(18)
2.358(7)
2.320(2)
Ru(1)-C(3)
Ru(1)-C(6)
S(1)-C(1)
2.291(7)
2.352(8)
1.784(7)
Compound 5b
Ru(1)-S(1)
Ru(1)-C(4)
Ru(1)-C(7)
S(1)-C(1)
2.3762(10)
2.226(4)
2.318(4)
1.787(3)
1.450(6)
Ru(1)-S(2)
Ru(1)-C(5)
Ru(1)-C(8)
S(2)-C(2)
2.3639(9)
2.232(4)
2.234(4)
1.785(3)
Ru(1)-C(3)
Ru(1)-C(6)
Ru(1)-C(15)
N(1)-C(15)
2.234(4)
2.316(4)
1.926(4)
1.146(5)
N(1)-C(16)
Compound 8b
Ru(1)-S(1)
Ru(1)-C(4)
Ru(1)-C(7)
S(2)-C(2)
2.381(2)
2.208(8)
2.182(9)
1.801(8)
Ru(1)-S(2)
Ru(1)-C(5)
Ru(1)-C(8)
N(1)-C(13)
2.385(2)
2.219(8)
2.183(8)
1.494(10)
Ru(1)-C(3)
Ru(1)-C(6)
S(1)-C(1)
2.243(7)
2.227(8)
1.784(8)
Compound 11b
Ru(1)-S(1)
Ru(1)-C(4)
Ru(1)-C(7)
S(1)-C(1)
2.3185(14)
2.260(6)
2.223(6)
1.820(5)
1.877(6)
Ru(1)-S(2)
Ru(1)-C(5)
Ru(1)-C(8)
S(2)-C(2)
2.4049(15)
2.191(6)
2.197(6)
1.776(6)
Ru(1)-C(3)
Ru(1)-C(6)
Ru(1)-C(15)
S(1)-C(15)
2.267(6)
2.239(6)
2.142(5)
1.781(5)
Si(1)-C(15)
{η1:η6-1,4-Cy2P(CH2)2C6H4(CH2OH)}],17 and [RuCl2-
{η1:η6-R2P(CH2)2C6H5}] (R ) Ph, Cy).18 However, we
were unable to reproduce Smith and Wright’s prepara-
tion of [RuCl2{η1:η6-Me2P(CH2)3C6H5}]15 from the p-
cymene complex 3a in chlorobenzene at 130 °C.
cymene)Ru(CabS,S′)(arylamine)] (8), which, however,
decomposed upon prolonged reflux. Contrary to Smith
and Wright, we find that the ruthenium dithiolate of
an arene, in our case, the p-cymene complex 3a , is not
a suitably labile precursor to tethered arene complexes.
It reacts with the arylamine ligands (7) in a 1:1 mole
ratio in dichloromethane at room temperature to quan-
titatively give the corresponding N-bonded adducts 8,
which do not lose the p-cymene upon heating in dichlo-
romethane or dichloromethane/THF at 120 °C for 72 h.
Therefore, simple base-adducts can be isolated after
recrystallization of the crude reaction mixtures in yields
1
The H NMR spectrum showed a broad singlet at δ
5.6. This can be attributed to an intermediate [(η6-p-
(16) (a) Fu¨rstner, A.; Liebl, M.; Lehmann, C. W.; Picquet, M.; Kunz,
R.; Bruneau, C.; Touchard, D.; Dixneuf, P. H. Chem. Eur. J . 2000, 6,
1847. (b) J an, D.; Delaude, L.; Simal, F.; Demonceau, A.; Noels, A. F.
J . Organomet. Chem. 2000, 606, 55. (c) Simal, F.; J an, D.; Demonceau,
A.; Noels, A. F. Tetrahedron Lett. 1999, 40, 1653.
(17) (a) Therrien, B.; Ward, R. Angew. Chem., Int. Ed. 1999, 38, 405.
(b) Therrien, B.; Ko¨nig, A.; Ward, T. R. Organometallics 1999, 18, 1565.
(c) Therrien, B.; Ward, T. R.; Pilkington, M.; Hoffmann, C.; Gilardoni,
F.; Weber, J . Organometallics 1998, 17, 330.
(18) Abele, A.; Wurshe, R.; Klinga, M.; Rieger, B. J . Mol. Catal. A
2000, 160, 23.

5708 Organometallics, Vol. 21, No. 26, 2002
Won et al.
Ta ble 3. Selected In ter a tom ic An gles (d eg) in 4b, 5b, 8b, a n d 11b
Compound 4b
P(1)-Ru(1)-S(1)
C(1)-S(1)-Ru(1)
C(17)-P(1)-Ru(1)
87.38(7)
106.5(2)
117.7(3)
P(1)-Ru(1)-S(2)
C(2)-S(2)-Ru(1)
C(19)-P(1)-Ru(1)
89.52(7)
106.2(2)
116.5(3)
S(1)-Ru(1)-S(2)
C(15)-P(1)-Ru(1)
86.78(6)
114.7(3)
Compound 5b
C(15)-Ru(1)-S(2)
C(1)-S(1)-Ru(1)
N(1)-C(15)-Ru(1)
88.75(12)
105.77(12)
176.1(4)
C(15)-Ru(1)-S(1)
C(2)-S(2)-Ru(1)
87.07(12)
106.06(12)
S(2)-Ru(1)-S(1)
C(15)-N(1)-C(16)
89.99(3)
176.9(5)
Compound 8b
N(1)-Ru(1)-S(1)
C(1)-S(1)-Ru(1)
N(1)-C(13)-C(14)
C(20)-C(15)-C(14)
85.1(2)
106.7(2)
114.1(6)
121.6(7)
N(1)-Ru(1)-S(2)
C(2)-S(2)-Ru(1)
C(15)-C(14)-C(13)
82.46(1)
106.6(2)
112.5(7)
S(1)-Ru(1)-S(2)
C(13)-N(1)-Ru(1)
C(20)-C(15)-C(16)
88.83(7)
122.2(5)
119.0(8)
Compound 11b
C(15)-Ru(1)-S(1)
C(15)-S(1)-C(1)
C(2)-S(2)-Ru(1)
Si(1)-C(15)-Ru(1)
46.85(14)
108.8(3)
106.0(2)
139.9(3)
C(15)-Ru(1)-S(2)
C(15)-S(1)-Ru(1)
S(1)-C(15)-Si(1)
85.94(15)
61.4(2)
113.2(3)
S(1)-Ru(1)-S(2)
C(1)-S(1)-Ru(1)
S(1)-C(15)-Ru(1)
87.59(5)
108.9(2)
71.8(2)
Ta ble 4. Cyclic Volta m m etr ic Da ta for 3 a n d Th eir
Der iva tivesa
In ser tion of Ru -S Bon d s of 3. It is recognized that
π donation by a lone pair of electrons on the coordinated
sulfur atom alleviates such an electron deficiency and
thus the coordinative unsaturation around the transi-
tion metal center. Consequently, this geometry suggests
that some multiple-bond character is present in the
Ru-S bonds of complex 3. To verify the nature of the
Ru-S bonds, the insertion reactions of several organic
and organometallic compounds to 3 have been investi-
gated. Indeed, complex 3 was found to be a good
precursor for other insertion reactions.19,20 The treat-
ment of 3 with 1-2 equiv of an alkyne in refluxing
benzene for 2 h gave the alkyne insertion complexes
redox coupleb 0/+1
redox coupleb 0/-1
Epc pa/ipc
-1.39 -1.51
Epa
Epc
i
pc/ipa E1/2
Epa
i
E1/2
3a
3b
4a
4b
5a
5b
6a
6b
9a
9b
0.75 0.65
0.65 0.54
0.37 0.28
0.31 0.21
0.57 0.48
0.44 0.35
0.70
1
-1.45
1
0.60
0.33
0.26
0.53
0.40
-1.65 -1.75 0.70 -1.70
1
1
1
1
c
e
c
c
c
c
-2.41
e
-2.21
-2.41
-1.70
-2.26
-2.35d
e
e
-2.16d
-2.36d
-1.65d
-2.21d
-1.84
-2.12d
-2.41d
0.97
0.89 0.76
0.58 0.50 0.51 0.54
c
0.21 0.93d
1
0.83
-1.76 -1.91
0.47 0.36
10b 0.16 0.07
1
1
0.42
0.12
c
c
-2.17
-2.46
[(η6-arene)Ru{η3-(S,S,C′)-SC2B10H10SC′R2}] [C′R2
)
a
All cyclic valtammograms were recorded at rt at a scan rate
(COOMe)CdC(COOMe) (9: arene ) p-cymene (9a ),
C6Me6 (9b)), HCdCPh (10: arene ) C6Me6 (10b))], in
moderate yield (Scheme 4).
of 0.1 V s-1, and potentials are in volts vs Fc+|Fc couple. Epa and
b
Epc refer to the anodic and cathodic peak potentials for a given
redox couple. c No reverse redox peaks was observed. E1/2 is
d
calibrated with E1/2 ) Epa - (∆Ep, Fc+|Fc)/2 e Reduction wave
The IR spectra of 9 exhibit one ν(CdC) stretching
1
outside the solvent window
band, and the H NMR spectra of 9 display the char-
acteristic resonances of a coordinated olefin. Thus, for
9, the OMe groups of the ester give rise to two sing-
lets centered at δ 3.72 and 3.83, respectively. For the
13C{1H} NMR spectra of 9, it is sufficient to point out
that the resonances due to the π-bound olefin carbons
are characteristically upfield-shifted. The spectroscopic
data of the ruthenium complexes are in complete agree-
ment with the proposed structure of 9. Although the
process outlined in Scheme 4 proved quite general, there
were, however, structural limitations observed for the
metallabicyclic complexes 10.1b,21 For example, several
attempts to synthesize the complexes 10a with phenyl
acetylene were unsuccessful, yielding only decomposi-
tion under prolonged reflux conditions. The conver-
sion of 3 to the corresponding metallabicyclic complexes
ranging from 86 to 91% for [(η6-p-cymene)Ru(CabS,S′)-
(L)] (8) [L ) η1-NH2(CH2CH2)Ar, Ar ) C6H5 (8a );
C6H4OMe (8b); C6H3(OMe)2 (8c); C8H6N (8d )], as shown
in Scheme 3.
The NMR spectra of the arylamine complexes show,
in addition to resonances characteristic of the coordi-
nated NH2 group, resonances due to the protons of the
free arene ring in the region of δ 6.7-7.6 and corre-
sponding resonances due to the aromatic carbon atoms
in the region of δ 110-160. The N-methyl groups in 8
are nonequivalent because of the diasterotopicity of the
arylamines and appear as two doublets in the 13C{1H}
and 1H NMR spectra. The molecular structure of the
arylamine-coordinated ruthenium dithiolates 8b has
been determined by a single-crystal X-ray analysis and
is shown with atom labeling in Figure 5. It confirms the
six-coordinate geometry about the ruthenium center,
assuming that the arylamine ligand functions as a
monodentate ligand. The N-methylene chain is not in
a fully extended conformation but is nonetheless ori-
ented such that the aminoalkyl unit is held remote from
the ruthenium fragment. The CVs of 8a ,b,d showed an
apparently reversible reduction and a more prominent
but chemically irreversible oxidation; however, the
instability of 8 limited electrochemical studies (see
Supporting Information).
(19) (a) Takayama, C.; Takeuchi, K.; Kajitani, M.; Sugiyama, T.;
Sugimori, A. Chem. Lett. 1998, 241. (b) Sakurada, M.; Kajitani, M.;
Dohki, K.; Akiyama, T.; Sugimori, A. J . Organomet. Chem. 1992, 423,
141. (c) Sakurada, M.; Okubo, J .; Kajitani, M.; Akiyama, T. Sugimori,
A. Phosphorus, Sulfur, Silicon, Relat. Elements 1992, 67, 145. (d)
Kajitani, M.; Sakurada, M.; Dohki, K.; Suetsugu, T.; Akiyama, T.;
Sugimori, A. J . Chem. Soc., Chem. Commun. 1990, 19. (e) Sakurada,
M.; Okubo, J .; Kajitani, M.; Akiyama, T.; Sugimori, A. Chem. Lett.
1990, 1837.
(20) (a) Kajitani, M.; Suetsugu, T.; Takagi, T.; Akiyama, T.; Sugi-
mori, A.; Aoki, K.; Yamazaki, H. J . Organomet. Chem. 1995, 487, C8.
(b) Sakurada, M.; Kajitani, M.; Dohki, K.; Akiyama, T.; Sugimori, A.
J . Organomet. Chem. 1992, 423, 141. (c) Kajitani, M.; Suetsugu, T.;
Wakabayashi, R.; Igarashi, A.; Akiyama, T.; Sugimori, A. J . Orga-
nomet. Chem. 1985, 293, C15.

Arene(dithiolato)Ru(II) Complexes
Organometallics, Vol. 21, No. 26, 2002 5709
Sch em e 3. Ad d tion Rea ction of 16-Electr on Meta l Com p lex 3a a
a
(i) CH2Cl2, 25 °C; (ii) Ch2Cl2/THF, 120 °C.
imply that -CHdCPh- acts as a stronger ligand than
-COOMeCdCCOOMe-.
Similar to the reactions between 3 and alkynes, the
ruthenadithia-o-carborane ring in 3 undergoes the
insertion of a methylene group between Ru and S in its
reaction with a diazoalkane. The reaction of 3 with
SiMe3CHN2 rapidly occurred at 0 °C, accompanied by
the vigorous evolution of N2 to yield the methylene unit
inserted product [(η6-arene)Ru{η3-(S,S,C′)-SC2B10H10
-
SCH2SiMe3}] (11: arene ) p-cymene 11a , C6Me6 11b),
as shown in Scheme 4. The 1H NMR spectrum of
complex 11 exhibits resonances for a trimethylsilyl
group at δ 0.2 and methine proton δ 3.5. The 13C NMR
spectrum also corresponds to the Ru-S-inserted struc-
ture: two types of alkyl carbons of the p-cymene ring
and carbon atoms of the Ru-S-substituted trimethyl-
silyl methine unit.
To establish the exact conformation of the adduct, the
structure of 11b was determined by a single-crystal
X-ray analysis (Figure 6). The X-ray structure of 11b
shows that the ruthenium takes a three-legged piano-
stool configuration with a bicyclometallacyclic ring. This
is due to the insertion of the coordinated dithiolato
ligand at the ruthenium(II) metal center. In 11b, the
trimethylsilyl group is located in the anti-position with
respect to the ruthenadithia-o-carborane ring. The
formation of a methylene bridge between a metal and
a chalcogen in the reaction with a diazoalkane com-
pound is a typical result due to unsaturation.20 These
cycloaddition reactions suggest that a certain degree of
multiple-bond character is present in the Ru-S bond
of complex 3b.
F igu r e 5. Molecular structure of 8b with atom labeling;
ellipsoids show 30% probability levels and hydrogen atoms
have been omitted for clarity.
9 or 10 is generally favored by the electron-rich ru-
thenium complex; therefore, we decided to investigate
the reactivity of 3b toward the less reactive phenyl
acetylene. Indeed, complex 10b was produced in high
yields from the direct two-carbon insertion reaction of
1
phenyl acetylene with complex 3b. The H NMR spec-
trum of 10b shows the terminal proton at δ 6.42 and
multiplet signals (δ 7.30) of the phenyl group of the
acetylene.
At v of 0.1 V s-1, the CV of 9a does not show an entire
chemical reversibility of 0/+1 oxidation, while that of
9b does show a fully reversible 0/+1 oxidation wave
(Table 4). The same trend is shown in the CVs of 10b.
However, the amounts of the redox potential shifts
Con clu sion
Our electrochemical study of complex 3 with our
previous work3 provided the data pool of the electro-
chemical behavior accompanying o-carboranyl com-
plexes, 16-electron metalladithiolates, depending on the
arene or Cp/Cp* ancillary ligands. The π donation from
the filled pπ orbital of the sulfur atom to the empty dπ
orbital of the metal atom is found to significantly
stabilize this unsaturation. Thus, complex 3 is suscep-
tible to the insertion of organic and organometallic
compounds into the Ru-S bond of 3. In addition, this
compound exhibits a remarkable reactivity toward
(21) (a) Herberhold, M.; Yan, H.; Milius, W.; Wrackmeyer, B. J .
Chem. Soc., Dalton Trans. 2001, 1782. (b) Herberhold, M.; Yan, H.;
Milius, W.; Wrackmeyer, B. J . Organomet. Chem. 2001, 623, 149. (c)
Herberhold, M.; Yan, H.; Milius, W.; Wrackmeyer, B. Organometallics
2000, 19, 4289. (d) Herberhold, M.; Yan, H.; Milius, W.; Wrackmeyer,
B. J . Organomet. Chem. 2000, 604, 170. (e) Herberhold, M.; Yan, H.;
Milius, W.; Wrackmeyer, B. Chem. Eur. J . 2000, 6, 3026. (f) Herber-
hold, M.; Yan, H.; Milius, W.; Wrackmeyer, B. Z. Anorg. Allg. Chem.
2000, 626, 1627. (g) Herberhold, M.; Yan, H.; Milius, W.; Wrackmeyer,
B. Angew. Chem., Int. Ed. 1999, 38, 3689. (h) Herberhold, M.; J in, G.-
X.; Yan, H.; Milius, W.; Wrackmeyer, B. Eur. J . Inorg. Chem. 1999,
873. (i) Herberhold, M.; J in, G.-X.; Yan, H.; Milius, W.; Wrackmeyer,
B. J . Organomet. Chem. 1999, 587, 252.

5710 Organometallics, Vol. 21, No. 26, 2002
Sch em e 4. In ser tion Rea ction of 16-Electr on Meta l Com p lexes 3a
Won et al.
a
(i) (COOMe)CC(COOMe), toluene, 110 °C; (ii) HCCPh, toluene, 110 °C; (iii) Me3SiCHN2, toluene, 25 °C.
chemical shifts were measured relative to internal residual
benzene from the lock solvent (99.5% C6D6) and then refer-
enced to Me4Si (0.00 ppm). The 31P NMR spectra were recorded
with 85% H3PO4 as an external standard. IR spectra were
recorded on a Biorad FTS-165 spectrophotometer. Elemental
analyses were performed with a Carlo Erba Instruments
CHNS-O EA1108 analyzer. All melting points were uncor-
rected. All the electrochemical measurements were carried out
in CH2Cl2 or CH3CN solutions containing 1 mM metal complex
and 0.1 M tetrabutylammonium fluoroborate (TBAB), unless
otherwise specified, at room temperature using a BAS 100B
electrochemical analyzer. For use of CH3CN solution, tetrabu-
tylammonium perchlorate (TBAP) was used as supporting
electrolyte. A platinum disk (diameter 1.6 mm) and platinum
wire were used as a working and counter electrode. The
reference electrode used was Ag|AgNO3, and all the potential
values shown were calibrated vs Fc+|Fc redox couple, unless
otherwise specified. Epa and Epc denote anodic and cathodic
peak potential, respectively, and E1/2 value indicated is the
average of Epa and Epc for the reversible redox waves.
F igu r e 6. Molecular structure of 11b with atom labeling;
ellipsoids show 30% probability levels and hydrogen atoms
have been omitted for clarity.
o-Carborane was purchased from the Katechem (Czech
Republic) and used without purification. Complex CabS,S′ (1),22
[(η6-p-cymene)Ru(µ-Cl)(Cl)]2,23 and [(η6-C6Me6)Ru(µ-Cl)(Cl)]2
24
were prepared according to the literature methods.
various nucleophiles such as PEt3, CNBut, and CO. In
the present study, we tried to relate the electrochemical
behavior of the products with the structures analyzed
by other spectroscopic data, which can provide much
information about their structure at least in metalla-
dithiolate complexes.
P r ep a r a tion of [(η6-a r en e)Ru (Ca bS,S′)] [3: a r en e
)
p-cym en e (3a ), C6Me6 (3b); Ca bS,S′ ) 1,2-S2C2B10H10-S,S′].
Representative procedure: A 3.2 mmol solution of 1 in THF
(20 mL) was added to a stirred solution of [(η6-p-cymene)Ru-
(µ-Cl)(Cl)]2 (2a ) (0.92 g, 1.5 mmol) in THF (30 mL) cooled to
-78 °C. The reaction mixture was then allowed to react at 0
°C for 1 h, and the solution was stirred for another 2 h at room
temperature. The solution gradually turned dark blue, sug-
gesting the formation of an o-carboranyl dithiolato metal
complex. The solution was reduced in vacuo to about half its
original volume, and some insoluble material was removed by
filtration. The solution was removed under vacuum, and the
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations were performed
under a dry, oxygen-free, nitrogen or argon atmosphere using
standard Schlenk techniques or in a Vacuum Atmosphere
HE-493 drybox. THF was freshly distilled over potassium
benzophenone. Toluene was dried and distilled from sodium
benzophenone. Dichloromethane and hexane were dried and
distilled over CaH2. 1H, 13C, and 31P NMR spectra were
recorded on a Varian Mercury 300 spectrometer operating at
300.1, 75.4, and 121.4 MHz, respectively. All proton and carbon
(22) Smith, H. D., J r.; Obenland, C. O.; Papetti, S. Inorg. Chem.
1966, 5, 1013.
(23) Bennett, M. A.; Huang, T.-N.; Matheson, T. W.; Smith, A. K.
Inorg. Synth. 1982, 21, 74.
(24) Crochet, P.; Demerseman, B.; Rocaboy, C.; Schleyer, D. Orga-
nometallics 1996, 15, 3048.

Arene(dithiolato)Ru(II) Complexes
Organometallics, Vol. 21, No. 26, 2002 5711
resulting residue was taken up in a minimum of methylene
chloride and then transferred to a column of silica gel. The
crude residue was purified by column chromatography, af-
fording >98% pure complex as blue crystals. Dark blue crystals
of 3a were formed in 53% yield (0.70 g, 1.6 mmol). Data for
3a . Anal. Calcd for C12H24B10S2Ru: C, 32.64; H, 5.48. Found:
C, 32.72; H, 5.55. IR (KBr, cm-1): ν(B-H) 2589. 1H NMR
(300.1 MHz, ppm, CDCl3): 5.57 (s, 4H, C6H4), 2.90 (sp, 1H,
CHMe2), 2.20 (s, 3H, CH3), 1.26 (d, 6H, CHMe2, J H-H ) 6.9
Hz). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 104.2 (s, C6H4),
94.11 (s, C6H4), 81.75 (s, C6H4), 79.48 (s, C6H4), 33.8 (s, CHMe2),
31.97 (s, CH3), 24.23 (s, CHMe2).
3b. 3b was prepared from 1.00 g (1.5 mmol) of [(η6-C6Me6)-
Ru(µ-Cl)(Cl)]2. After flash chromatography on silica gel with
hexane/CHCl3 (90:10), 3b (0.92 g, 2.0 mmol, 65%) was isolated
as a blue solid. Data for 3b. Anal. Calcd for C14H28B10S2Ru:
C, 35.8; H, 6.01. Found: C, 35.92; H, 5.95. IR (KBr, cm-1):
ν(B-H) 2580. 1H NMR (300.1 MHz, ppm, CDCl3): 2.21 (s,
18H, C6Me6). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 91.88
(s, C6Me6), 17.61 (s, C6Me6).
An a lytica l Da ta for 8b. 8b was prepared from 2.0 mmol
(0.29 mL) of arylamine 7b. After recrystallization from toluene,
8b (0.52 g, 0.88 mmol, 88% yield) was isolated as a yellow solid.
Carbon atoms and the attached hydrogen atoms are numbered
as shown below. Anal. Calcd for C21H38B10S2NRuO: C, 42.55;
Gen er a l P r oced u r e for th e P r ep a r a tion of 18-Electr on
Com p lexes [(η6-a r en e)Ru (Ca bS,S′)(L)] (a r en e ) p-cym en e,
C6Me6; L ) P Et3, CNBu t, CO) (4-6). Under argon, ligand L
(2.0 mmol) was added to a blue solution of complex 3 (0.23
mmol) in 10 mL of THF. The resultant yellow solution was
stirred for 30 min and evaporated to dryness. The yellow
residue of the product was dried in vacuo. Spectroscopic data
are presented in the Supporting Information.
4a . Yield: 0.12 g (0.21 mmol, 93%). Anal. Calcd for
H, 6.29; N, 2.36. Found: C, 42.65; H, 6.40; N, 2.40. IR (KBr,
cm-1): ν(B-H) 2580. 1H NMR (300.1 MHz, ppm, CDCl3):
7.31-6.71 (m, 4H, C8, C4-6), 5.22, 5.07 (AA′BB′, 4H, C6H4,
J Ha-Hb ) 6.0 Hz, J Ha′-Hb ) 6.0 Hz), 3.83 (s, 3H, OMe), 2.97 (t,
2H, C1, J H-H ) 6.0 Hz), 2.78 (t, 2H, C2, J H-H ) 6.0 Hz), 2.65
(sp, 1H, CHMe2), 2.17 (s, 3H, CH3), 1.13 (d, 6H, CHMe2, J H-H
) 6.9 Hz). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 160.27 (s,
C7), 138.57 (s, C3), 130.79 (s, C5), 121.92 (s, C4), 113.95 (s,
C8), 111.67 (s, C6), 107.50 (s, C6H4), 100.86 (s, C6H4), 93.95
(s, C6H4), 56.32 (s, OMe), 31.69 (s, C1), 29.98 (s, C2), 23.23 (s,
CHMe2), 22.50 (s, CH3), 18.84 (s, CHMe2).
An a lytica l Da ta for 8c. 8c was prepared from 2.0 mmol
(0.34 mL) of arylamine 7c. After recrystallization from toluene,
8c (0.54 g, 0.87 mmol, 87% yield) was isolated as a yellow solid.
Carbon atoms and the attached hydrogen atoms are numbered
as shown below. Anal. Calcd for C22H41B10S2NRuO2: C, 42.42;
C
18H39B10S2RuP: C, 38.62; H, 7.02. Found: C, 38.75; H, 7.10.
IR (KBr, cm-1): ν(B-H) 2585, ν(P-C) 1035.
4b: Yield: 85%. Anal. Calcd for C20H43B10S2RuP: C, 40.87;
H, 7.37. Found: C, 41.00; H, 7.48. IR (KBr, cm-1): ν(B-H)
2592.
5a . Yield: 91%. Anal. Calcd for C17H33B10S2RuN: C, 38.91;
H, 6.34; N, 2.67. Found: C, 39.00; H, 6.40; N, 2.73. IR (KBr,
cm-1): ν(B-H) 2580, ν(CdN) 2166. 5b: Yield: 87%. Anal.
Calcd for C19H37B10S2RuN: C, 41.28; H, 6.75; N, 2.53. Found:
C, 41.35; H, 6.83; N, 2.60. IR (KBr, cm-1): ν(B-H) 2595,
ν(CdN) 2208.
6a . Yield: 91%. Anal. Calcd for C13H24B10S2RuO: C, 33.25;
H, 5.15. Found: C, 33.40; H, 5.30. IR (KBr, cm-1): ν(B-H)
2632, 2587, 2560, ν(CO) 2012.
6b: Yield: 95%. Anal. Calcd for C15H28B10S2RuO: C, 36.20;
H, 5.67. Found: C, 36.28; H, 5.72. IR (KBr, cm-1): ν(B-H)
2598, ν(CO) 1989.
Gen er a l Rea ction s of 3a w ith Ar yla m in es. In a typical
run 3a (0.44 g, 1.0 mmol) and arylamines (7) were dissolved
in methylene chloride (15 mL) under argon, and the solution
was stirred for 8 h at room temperature. The blue color of the
solution slowly faded to give an orange-yellow solution, sug-
gesting the formation of an adduct. The completion of the
reaction was monitored by TLC. The solution was reduced in
vacuo to about half its original volume, and some insoluble
material was removed by filtration. Addition of hexane to the
resulting solution afforded 8 as a dark yellow precipitate.
An a lytica l Da ta for 8a . 8a was prepared from 2.0 mmol
(0.24 mL) of arylamine 7a . After recrystallization from toluene,
8a (0.48 g, 0.86 mmol, 86% yield) was isolated as a yellow solid.
Carbon atoms and the attached hydrogen atoms are numbered
as shown below. Anal. Calcd for C20H35B10S2NRu: C, 42.68; H,
6.26; N, 2.49. Found: C, 42.75; H, 6.30; N, 2.40. IR (KBr, cm-1):
ν(B-H) 2590. 1H NMR (300.1 MHz, ppm, CDCl3): 7.39-7.17
(m, 5H, C4-8), 5.22, 5.08 (AA′BB′, 4H, C6H4, J Ha-Hb ) 5.1 Hz,
J Ha′-Hb′ ) 6.0 Hz), 2.98 (t, 2H, C1, J H-H ) 6.9 Hz), 2.80 (t, 2H,
C2, J H-H ) 6.9 Hz), 2.62 (sp, 1H, CHMe2), 2.18 (s, 3H, CH3),
1.12 (d, 6H, CHMe2, J H-H ) 6.9 Hz). 13C{1H} NMR (75.4 MHz,
ppm, CDCl3): 137.02 (s, C3), 129.64 (s, C7), 129.40 (s, C5),
128.92 (s, C8), 128.31 (s, C4), 127.84 (s, C6), 107.50 (s, C6H4),
100.77 (s, C6H4), 93.91 (s, C6H4), 31.34 (s, C1), 30.01 (s, C2),
23.30 (s, CHMe2), 22.51 (s, CH3), 18.87 (s, CHMe2).
H, 6.31; N, 2.25. Found: C, 42.53; H, 6.45; N, 2.19. IR (KBr,
cm-1): ν(B-H) 2580. 1H NMR (300.1 MHz, ppm, CDCl3):
6.87-6.67 (m, 3H, C4, C7-8), 5.23, 5.09 (AA′BB′, 4H, C6H4,
J Ha-Hb ) 6.0 Hz, J Ha′-Hb′ ) 6.0 Hz), 3.91 (s, 3H, OMe), 3.88 (s,
3H, OMe), 2.95 (t, 2H, C1, J H-H ) 6.0 Hz), 2.75 (t, 2H, C2,
J H-H ) 6.0 Hz), 2.65 (sp, 1H, CHMe2), 2.18 (s, 3H, CH3), 1.14
(d, 6H, CHMe2, J H-H ) 7.8 Hz). 13C{1H} NMR (75.4 MHz, ppm,
CDCl3): 149.60 (s, C7), 148.48 (s, C6), 129.32 (s, C3), 121.89
(s, C4), 112.68 (s, C5), 111.16 (s, C8), 107.44 (s, C6H4), 100.77
(s, C6H4), 93.84 (s, C6H4), 56.76 (s, OMe), 55.60 (s, OMe), 31.80
(s, C1), 30.09 (s, C2), 23.24 (s, CHMe2), 22.53 (s, CH3), 18.92
(s, CHMe2).
An a lytica l Da ta for 8d . 8d was prepared from 2.0 mmol
(0.32 g) of arylamine 7d . After recrystallization from toluene,
8d (0.55 g, 0.91 mmol, 91% yield) was isolated as a yellow solid.

5712 Organometallics, Vol. 21, No. 26, 2002
Won et al.
Carbon atoms and the attached hydrogen atoms are numbered
as shown below. Anal. Calcd for C22H36B10S2N2Ru: C, 43.91;
toluene, 10b (0.26 g, 0.45 mmol, 45% yield) was isolated as a
yellow solid. Anal. Calcd for C22H34B10S2Ru: C, 46.21; H, 5.99.
Found: C, 46.28; H, 6.10. IR (KBr, cm-1): ν(B-H) 2600,
ν(CdC) 1488, ν(CdC) 1442. 1H NMR (300.1 MHz, ppm,
CDCl3): 7.30 (s, 5H, Ph), 6.42 (s, 1H, CdCH), 1.73 (s,
18H, C6Me6). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 192.05
(s, HCdCPh), 176.64 (s, HCdCPh), 127.58 (m, Ph), 86.70 (s,
C6Me6).
Rea ction of 3 w ith Me3SiCHN2. A solution of complex 3a
(0.1 g, 0.23 mmol) in toluene (20 mL) was treated with a 2.0
M hexane solution of (trimethylsilyl)diazomethane (0.2 mL,
0.4 mmol) at room temperature for 5 min. The blue color of
the solution quickly faded to give a yellow solution. The volatile
substances were then removed in vacuo, and the resulting solid
was extracted with CH2Cl2. Addition of hexane to the concen-
trated extract gave complex 11a as yellow-orange crystals.
Yield: 0.10 g (0.19 mmol, 83%). Data for 11a . Anal. Calcd for
H, 6.03; N, 4.65. Found: C, 44.05; H, 6.00; N, 4.60. IR (KBr,
cm-1): ν(B-H) 2580. 1H NMR (300.1 MHz, ppm, CDCl3):
7.56-7.14 (m, 5H, C5-8, C10), 5.11, 5.00 (AA′BB′, 4H, C6H4,
J Ha-Hb ) 6.0 Hz, J Ha′-Hb′ ) 6.0 Hz), 3.05 (t, 2H, C1, J H-H ) 6.0
Hz), 2.95 (t, 2H, C2, J H-H ) 6.0 Hz), 2.36 (sp, 1H, CHMe2),
2.12 (s, 3H, CH3), 0.95 (d, 6H, CHMe2, J H-H ) 6.9 Hz).
13C{1H} NMR (75.4 MHz, ppm, CDCl3): 151.15 (s, C9), 145.52
(s, C4), 123.38 (s, C10), 121.27 (s, C6), 120.13 (s, C5), 118.77
(s, C7), 111.60 (s, C3), 110.24 (s, C8), 106.54 (s, C6H4), 101.02
(s, C6H4), 94.03 (s, C6H4), 46.23 (s, C1), 32.97 (s, C2), 23.20 (s,
CHMe2), 22.75 (s, CH3), 18.72 (s, CHMe2).
C
16H34B10S2RuSi: C, 36.41; H, 6.49. Found: C, 36.50; H, 6.55.
IR (KBr, cm-1): ν(B-H) 2582. 1H NMR (300.1 MHz, ppm,
CDCl3): 5.83, 5.73 (AA′BB′, 4H, C6H4, J Ha-Hb ) 6.0 Hz, J Ha′-Hb′
) 6.0 Hz), 3.53 (s, 1H, Me3SiCH), 2.54 (sp, 1H, CHMe2), 2.22
(s, 3H, CH3), 1.25 (d, 6H, CHMe2, J H-H ) 6.6 Hz), 0.16 (s, 9H,
SiMe3). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 104.47 (s,
C6H4), 95.52 (s, C6H4), 84.90 (s, C6H4), 43.88 (s, Me3SiCH),
32.18 (s, CH3), 23.94 (s, CHMe2), 0.31 (s, SiMe3).
11b. 11b was prepared from 0.21 mmol of 3b. After flash
chromatography on silica gel with hexane/CHCl3 (90:10), 11b
was isolated as an orange solid. Yield: 0.11 g (0.19 mmol, 90%).
Data for 11b. Anal. Calcd for C18H38B10S2RuSi: C, 38.89; H,
6.89. Found: C, 38.95; H, 6.94. IR (KBr, cm-1): ν(B-H) 2596,
ν(B-H) 2568. 1H NMR (300.1 MHz, ppm, CDCl3): 3.51 (s, 1H,
Me3SiCH), 2.15 (s, 18H, C6Me6), 0.18 (s, 9H, SiMe3). 13C{1H}
NMR (75.4 MHz, ppm, CDCl3): 94.69 (s, C6Me6), 87.53 (s,
C6Me6), 22.78 (s, Me3SiCH), 17.11 (s, C6Me6), 16.63 (s, C6Me6),
-0.05 (s, SiMe3).
X-r a y Cr ysta llogr a p h y. Suitable crystals of 4b, 5b, 8b,
and 11b were obtained by slow diffusion of hexane into a
methylene chloride solution of the complexes at room temper-
ature and were mounted on a glass fiber. Crystal data and
experimental details are given in Table 1. The data sets for
4b, 5b, 8b, and 11b were collected on an Enraf CAD4 auto-
mated diffractometer. Mo KR radiation (λ ) 0.7107 Å) was used
for all structures. Each structure was solved by the application
of direct methods using the SHELXS-96 program25a and least-
squares refinement using SHELXL-97.25b All non-hydrogen
atoms in compounds 4b, 5b, 8b, and 11b were refined aniso-
tropically. All other hydrogen atoms were included in calcu-
lated positions.
Gen er a l Syn th esis of [(η6-a r en e)Ru {η3-(S,S,C′)-
SC2B10H 10SC′R 2}] [C′R 2 ) (COOMe)CdC(COOMe) (9:
a r en e ) p-cym en e (9a ), C6Me6 (9b)), HCdCP h (10: a r en e
) C6Me6 (10b))]. In a typical run 3 (1.0 mmol) and alkynes
were dissolved in toluene (15 mL) under argon, and the
solution was stirred for 8 h at 110 °C. The blue color of the
solution slowly faded to give a yellow solution, suggesting the
formation of an adduct. The completion of the reaction was
monitored by TLC. The solution was reduced in vacuo to about
half its original volume, and some insoluble material was
removed by filtration. Addition of hexane to the resulting
solution afforded 9 and 10 as a dark yellow precipitate.
An a lytica l Da ta for 9a . 9a was prepared from 4.0 mmol
(0.48 mL) of dimethyl acetylenedicarboxylate. After recrystal-
lization from toluene, 9a (0.55 g, 0.94 mmol, 94% yield) was
isolated as a yellow solid. Anal. Calcd for C18H30B10S2RuO4:
C, 37.04; H, 5.18. Found: C, 37.12; H, 5.25. IR (KBr, cm-1):
ν(B-H) 2582, ν(CO) 2362, ν(CdC) 1631. 1H NMR (300.1 MHz,
ppm, CDCl3): 5.63, 5.50 (AA′BB′, 4H, C6H4, J Ha-Hb ) 6.0 Hz,
J Ha′-Hb′ ) 6.0 Hz), 3.81 (s, 3H, OMe), 3.72 (s, 3H, OMe), 2.66
(sp, 1H, CHMe2), 2.09 (s, 3H, CH3), 1.29 (d, 6H, CHMe2, J H-H
) 6.6 Hz). 13C{1H} NMR (75.4 MHz, ppm, CDCl3): 190.95 (s,
MeOCO), 171.84 (s, MeOCO), 157.55 (s, MeOCOCd), 123.00
(s, MeOCOCd), 99.77 (s, C6H4), 95.03 (s, C6H4), 89.07 (s, C6H4),
88.52 (s, C6H4), 53.59 (s, OMe), 52.39 (s, OMe), 30.99 (s,CH3),
22.99 (s, CHMe2).
Ack n ow led gm en t . The support of this research
by a Korea Science & Engineering Foundation Grant
(R01-2000-00050) is gratefully acknowledged. This work
was also supported by the Brain Korea 21 project in
2000.
An a lytica l Da ta for 9b. 9b was prepared from 4.0 mmol
(0.48 mL) of dimethyl acetylenedicarboxylate. After recrystal-
lization from toluene, 9b (0.48 g, 0.79 mmol, 79% yield) was
isolated as a yellow solid. Anal. Calcd for C20H34B10S2RuO4:
C, 39.27; H, 5.60. Found: C, 39.33; H, 5.70. IR (KBr, cm-1):
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data (excluding structure factors) for the structures (4b, 5b,
8b, and 11b) and CV data for complex 8a reported in this
paper. This material is available free of charge via the Internet
at http://pubs.acs.org.
1
ν(B-H) 2580, ν(CO) 1710, (CdC) 1579. H NMR (300.1 MHz,
ppm, CDCl3): 3.83 (s, 3H, OMe), 3.74 (s, 3H, OMe), 2.08 (s,
18H, C6Me6). 13C{1H}NMR (75.4 MHz, ppm, CDCl3): 190.84
(s, MeOCO), 157.60 (s, MeOCO), 145.62 (s, MeOCOCd), 123.06
(s, MeOCOCd), 99.78 (s, C6Me6), 94.96 (s, C6Me6), 53.09 (s,
OMe), 51.27 (s, OMe), 15.92 (s, C6Me6), 15.65 (s, C6Me6).
An a lytica l Da ta for 10b. 10b was prepared from 4.0 mmol
(0.40 mL) of phenylacetylene. After recrystallization from
OM020259L
(25) (a) Sheldrick, G. M. Acta Crystallogr. A 1990, 46, 467. (b)
Sheldrick, G. M. SHELXL, Program for Crystal Structure Refinement;
University of Go¨ttinen, 1997.