The 16-electron dithiolene complexes (p-cymene)M[S2C2(B10H10)] (M=Ru, Os) containing both η6-(p-cymene) and η2-(ortho-carborane-dithiolate): Adduct formation with Lewis bases, and X-ray crystal structures of (p-cymene)Ru[S2C2(B10H10)](L) (L=PPh3).

Article abstract of DOI:10.1016/S0022-328X(99)00692-0

The reaction of the η⁶-arene complexes [(p-cymene)MCl₂]₂ (M=Ru, Os; p-cymene=4-isopropyl-toluene) with dilithium 1,2-dicarba-closo-dodecaborane-1,2-dithiolate (a) leads to the new 16e dithiolene complexes (p-cymene)M[S₂C₂(B₁₀H₁₀)] (M=Ru (1), Os (1A)). Addition of monodentate Lewis bases (L) to 1 gives 18e dithiolate complexes of the type (p-cymene)Ru[S₂C₂(B₁₀H₁₀)](L) (L=PPh₃ (2), P(OMe)₃ (3), NH₃ (4), NC₅H₅ (5), CO (6), CN^tBu (7), SEt₂ (8), SC₄H₈ (9), CN^- (10) and SCN^- (11)), whereas bidentate bridging Lewis bases (LL) give centrosymmetric binuclear analogues, {(p-cymene)Ru[S₂C₂(B₁₀H₁₀)]} ₂(LL) (LL=Ph₂PCH₂CH₂PPh₂ (12), N₂H₄ (13) and 4,4′-dipyridine (14)). The stability of the Lewis base adducts depends on the nature of the ligating atom and decreases in the order C>P>N>S>O. The adducts were characterized by their ¹H-, ¹³C- and ¹¹B-NMR spectra, and X-ray crystal structures were determined for 2, 12 and 13. The phosphane ligands in 2 and 12 cause stronger folding of the planar dithiolene ring RuS₂C₂ in 1 along the SS vector (by 25.6° in 2 and 21.0° in 12) than the hydrazine ligand in 13 (7.5°).

Full text of DOI:10.1016/S0022-328X(99)00692-0

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 598 (2000) 142–149
The 16-electron dithiolene complexes (p-cymene)M[S2C2(B10H10)]
(M=Ru, Os) containing both h6-(p-cymene) and
h2-(ortho-carborane-dithiolate): adduct formation with Lewis
bases, and X-ray crystal structures of (p-cymene)-
Ru[S2C2(B10H10)](L) (L=PPh3) and {(p-cymene)-
Ru[S2C2(B10H10)]}2(m-LL) (LL=Ph2PCH2CH2PPh2 and N2H4)
Max Herberhold *, Hong Yan, Wolfgang Milius
Laboratorium fu¨r Anorganische Chemie, Uni6ersita¨t Bayreuth, Postfach 101251, D-95440 Bayreuth, Germany
Received 22 September 1999; received in revised form 29 October 1999
Abstract
The reaction of the h6-arene complexes [(p-cymene)MCl2]2 (M=Ru, Os; p-cymene=4-isopropyl–toluene) with dilithium
1,2-dicarba-closo-dodecaborane-1,2-dithiolate (a) leads to the new 16e dithiolene complexes (p-cymene)M[S2C2(B10H10)] (M=Ru
(1), Os (1A)). Addition of monodentate Lewis bases (L) to
1 gives 18e dithiolate complexes of the type (p-
cymene)Ru[S2C2(B10H10)](L) (L=PPh3 (2), P(OMe)3 (3), NH3 (4), NC5H5 (5), CO (6), CNtBu (7), SEt2 (8), SC4H8 (9), CN−
(10) and SCN− (11)), whereas bidentate bridging Lewis bases (LL) give centrosymmetric binuclear analogues, {(p-
cymene)Ru[S2C2(B10H10)]}2(LL) (LL=Ph2PCH2CH2PPh2 (12), N2H4 (13) and 4,4%-dipyridine (14)). The stability of the Lewis
base adducts depends on the nature of the ligating atom and decreases in the order C\P\N\S\O. The adducts were
characterized by their 1H-, 13C- and 11B-NMR spectra, and X-ray crystal structures were determined for 2, 12 and 13. The
phosphane ligands in 2 and 12 cause stronger folding of the planar dithiolene ring RuS2C2 in 1 along the S···S vector (by 25.6°
in 2 and 21.0° in 12) than the hydrazine ligand in 13 (7.5°). © 2000 Elsevier Science S.A. All rights reserved.
Keywords: Ruthenium; Osmium; p-Cymene complexes; ortho-Carborane–dithiolato complexes; X-ray
thiolene complexes CpCo[S2C2(B10H10)] [10] and
Cp*Rh[S2C2(B10H10)] [11] are of particular interest be-
1. Introduction
cause they contain an almost planar pseudoaromatic
metallacycle MC2S2; two diselenolene analogues,
Cp*M[Se2C2(B10H10)] (M=Rh [11], Ir [12]) have also
been described. We now extend the series of 16-electron
dithiolenes to the h6-arene complexes (p-cymene)-
M[S2C2(B10H10)] (M=Ru (1), Os (1A), p-cymene=4-
isopropyl–toluene). The 16-electron complexes take up
Lewis bases to give coordinatively saturated 18-electron
adducts, in which the dihedral angle MS2/S2C2 at the
S···S vector is apparently smaller than 180°. In the
present paper, we describe a series of adducts of 1 with
selected two-electron ligands; in three typical cases the
molecular structure has been confirmed by X-ray struc-
ture analyses.
The voluminous and chemically robust chelate ligand
1,2-dicarba-closo-dodecarborane-1,2-dithiolate (ortho-
carborane dithiolate) has been repeatedly used in coor-
dination compounds, and complexes of Mo [1], Re [1],
Co [2], Ni [2,3], Pd [1,4], Pt [5] and — in particular —
Au [6–9] have been characterized. However, only a few
organometallic complexes are known, in general half-
sandwich cyclopentadienyl or pentamethylcyclopentadi-
enyl metal compounds with CpMo [1], CpCo [10] and
Cp*Rh [11] moiety. Among them, the 16-electron di-
* Corresponding author. Tel.: +49-921-552540; fax: +49-921-
552157.
E-mail address: max.herberhold@uni-bayreuth.de (M. Herberhold)
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00692-0

M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
143
2. Results and discussion
2.1. Syntheses
The dilithiated o-carborane dithiolate Li2[S2C2-
(B10H10)] (a) is conveniently prepared by insertion of
Fig. 2. Molecular structure of {(p-cymene)Ru[S2C2(B10H10)]}2(m-
Ph2PCH2CH2PPh2) (12) (hydrogen atoms are omitted for clarity).
Fig. 3. Molecular structure of {(p-cymene)Ru[S2C2(B10H10)]}2(m-
N2H4) (13) (hydrogen atoms are omitted for clarity except at N2H4).
Scheme 1.
sulfur into the CꢀLi bonds of the dilithiated o-carbo-
rane (Scheme 1). Stoichiometric reaction of a with the
binuclear h6-(p-cymene) complexes [(MeꢀC6H4ꢀiPr)-
MCl2]2 (M=Ru, Os) in THF solution leads in a
straightforward way to the 16-electron complexes 1 and
1A which are thermally stable up to 200°C.
1
Both the H- and the 13C-NMR data of 1 and 1A are
consistent with the monomeric, coordinatively unsatu-
rated 16-electron structure. The electron impact mass
spectra (EI-MS) show the mononuclear molecular ion
as the parent peak and very little fragmentation. It is
known that metalladithiolene 16-electron half-sandwich
complexes can dimerize in order to reach the coordina-
tively saturated 18-electron configuration, if the steric
situation allows it. Thus, a monomer–dimer equi-
librium has been reported for the benzene–1,2-dithio-
lato complexes CpCo[S2C6H4] [13] and (p-cymene)-
Ru[S2C6H4] [14,15], although the X-ray structure
Fig. 1. Molecular structure of (p-cymene)Ru[S2C2(B10H10)](PPh3) (2)
(hydrogen atoms are omitted for clarity).

144
M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
analysis of (C6Me6)Ru[S2C6H4] indicates a monomer
[14]. Dimeric structures have also been characterized
for ferrocene–1,1%-dithiolato and –diselenolato com-
plexes such as Cp*Ir[(EC5H4)2Fe] (E=S, Se) [16] in
the solid state. However, in the case of the bulky
ortho-carborane–dithiolate ligand, the dimerization ap-
pears to be excluded for steric reasons [10].
The 16-electron complexes 1 and 1A react with
Lewis bases (L) to give 18-electron adducts in which
the pseudoaromatic metalladithiolene structure is more
or less disturbed. This leads to bending of the origi-
nally planar MS2C2 ring along the S···S vector, as was
shown by X-ray structure analysis in the case of the
comparable adduct formation of the iridadiselenolene
complex Cp*Ir[SeC2(B10H10)] with trimethylphosphane
[12].
A series of adducts was prepared starting from the
blue ruthenium complex 1 and various two-electron
ligands with phosphorus (2, 3, 12), nitrogen (4, 5, 13,
14), carbon (6, 7), and sulfur (8, 9) as ligating atoms
(Scheme 1). Attempts to isolate adducts with oxygen-
ligands (e.g. 4-picoline-N-oxide, dimethylsulfoxide) un-
der comparable conditions were unsuccessful, although
reversible adduct formation clearly takes place in
CH2Cl2 solution, as indicated by the color change from
blue to brown–red. The sulfur ligands (diethylsulfide
and tetrahydrothiophene) give brown–red adducts (8,
9) which can be isolated, but the color of their CH2Cl2
solution is blue due to 1 unless an excess of the sulfide
ligand is added. The more volatile dimethylsulfide eas-
ily evaporates from its solid adduct, and the blue
powder of 1 remains back. The anionic adduct of 1
with thiocyanate (11) could only be studied in the
presence of an excess of NaSCN in the NMR tube in
CD3CN solution.
The 18-electron adducts (p-cymene)Ru[S2C2(B10-
H10)](L) (with labile ligands L=NH3 (4), NC5H5 (5),
SEt2 (8), SC4H8 (9)) can be considered as the coordina-
tively stabilized derivatives of the 16-electron complex
1 which is easily reformed under vacuum or in solu-
tion. In a similar manner, the 16-electron 1,2-dithiolate
complex (C6Me6)Ru[S2C6H4] [14] undergoes reversible
adduct formation, and the chiral 16-electron hydro-
genation catalyst (p-cymene)Ru[HNꢀCH(Ph)CH(Ph)ꢀ
NSO2C6H4ꢀp-CH3] may also be generated from suit-
able 18-electron precursors [17].
Table 1
Characterization
Complex
Yield
IR (KBr) w(B,H)
[cm−1
Hetero-NMR
NMR-solvent
]
l(11B)
Ligand L
(p-Cymene)-
Ru[S2C2(B10H10)] (1)
(p-Cymene)-
56% dec. 205°C
80% dec. 210°C
2613, 2589, 2578,
2549
2613, 2592, 2580,
2562
−6.4, −7.5, −9.2
−5.5, −7.4, −8.6
CDCl3
CDCl3
Os[S2C2(B10H10)] (1A)
(p-Cymene)Ru[S2C2(B10H10)](L)
L=PPh3 (2)
P(OMe)3 (3)
89% dec. 196°C
95% dec. 147°C
2592, 2576, 2561
2599, 2586, 2574,
2563, 2553
−5.3, −7.0, −9.1, −11.3
−1.1, −5.9, −9.5, −10.6
33.2 (31P)
CD2Cl2
CDCl3
137.4 (31P)
NH3 (4)
56% dec.
\110°C
66% dec. 178°C
100% dec. 130°C
2586, 3333 and
3306 (NH3)
2569
2632, 2587, 2560
2012 (CO)
−8.1, −9.9, −11.9
CDCl3
Pyridine (5)
CO (6)
−6.7, −8.7, −11.6
−1.9, −4.0, −5.4, −7.0, −8.6,
−9.7, −11.6
CDCl3
CD2Cl2
194.8 (13C)
CꢁNtBu (7)
SEt2 (8)
90%
2563
−5.6, −7.3, −8.7, −9.8, −11.7
30.8, 58.2 (13C)
CDCl3
CDCl3
2148 (CNtBu)
2622, 2592, 2564,
2542
\90%
−7.3, −9.3, −11.4
SC4H8 (9)
\90%
83%
2578, 2557
−7.2, −9.2, −11.3
CDCl3
CN− (10)
2576, 2080 (CN−
)
−2.6, −7.7, −9.4, −11.8, −13.0
−2.9, −7.4, −9.1, −11.2, −13.1
−6.2, −11.1 (br)
CD3CN
CD3CN
CD2Cl2
SCN− (11) a
LL=Ph2P(CH2)2PPh2
(12)
101.5 (13C)
35.6 (31P)
92% dec. 225°C
66% dec. 155°C
90% dec. 220°C
2585, 2556
N2H4 (13)
2583, 3315 and
3219 (NH)
2634, 2576
−6.4, −8.0, −9.5, −11.2
−7.1, −9.5, −11.8
CDCl3
4,4%-Bipyridine (14)
CD2Cl2
a NMR tube experiment.

M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
145
Table 2
1H- and 13C-NMR data
Compound
1H-NMR
13C-NMR
p-Cymene
L
p-Cymene
Carborane
L
a
a,g
CH3
CHMe2
C6H4
7.32s
5.54s
CH3 CHMe2 C6H4
p-Cymene b
2.53s 1.46d(6.9)
3.08sp(6.9)
2.18s 1.14d(7.0)
2.57sp(6.9)
2.37s 1.27d(6.9)
2.55sp(6.9)
2.08s 1.14d(7.0)
20.9 24.1
33.7
20.2 23.1
31.9
20.7 23.4
32.4
17.5 23.1
126.3, 129.0
{135.1, 145.8}
79.4, 81.3
{93.88, 104.1}
72.5, 74.9
1 b
33.7
93.7
95.9
93.7
1A b
2 c
5.92, 5.93
(AA%BB%)
5.19, 5.22
{87.6, 97.5}
92.8d[5.5],
7.4m
128.2, 130.5
95.5d[5.5]
2.52sp(7.0)
2.13s 1.11d(6.9)
(AA%BB%)
5.49d(6.3)
30.8
17.9 22.6
{104.2s, 114.2s}
93.78, 93,86
93.90, 94.03
{110.9d[5.4],
113.5}
83.9, 86.6
{100.5, 106.5}
83.4, 84.4
134.6, 135.2
54.2[7.9]
3 b
3.70d
92.7
2.76sp(6.9)
5.62d(6.3)
(3J(P,H) 10.8
Hz)
n.o.
30.5
4 b
5 b
2.06s 1.06d(7.0)
2.57sp(7.0)
2.02s 1.17d(7.0)
2.54sp(7.0)
5.00d(6.0)
5.21d(6.0)
5.17d(6.0)
5.28d(6.0)
18.3 22.6
30.7
18.6 22.65
30.7
94.1
93.8
7.28
7.73
8.82
124.3
137.3
153.8
194.8
{ꢀ99(?), 106.1}
6 c
7 b
8 b
9 b
2.27s 1.22d(7.0)
2.73sp(6.9)
2.18s 1.17d(6.9)
2.58d(6.9)
2.17s 1.23d(7.0)
2.65sp(7.0)
2.18s 1.22d(7.0)
2.68sp(7.0)
5.78d(6.5)
6.01d(6.5)
5.31(6.1)
5.50(6.1)
5.46s
18.9 23.2
32.3
18.1 22.95
31.65
19.9 23.0
31.6
19.7 22.7
30.8
96.7, 99.3
{119.9, 123.5}
90.3, 92.5
{111.9, 114.5}
80.3, 82.4
{94.9, 105.3}
81.4, 83.1
91.6
93.3
94.0
94.0
1.51s
30.8,
58.2
14.6(CH3)
26.2(CH2)
30.8,
1.22t
2.57q (7.3)
1.96m
5.44(6.2)
5.46(6.2)
(AA%BB%)
5.05d(6.0)
5.30d(6.0)
4.98d(6.0)
2.84m
{not observed}
31.5
10 d
2.03s 1.14d(6.9)
2.69sp(6.9)
18.0 23.0
31.8
18.2 22.6
88.1, 89.3
{108.4, 108.8}
85.3, 87.1
97.8
97.7
n.o.
(138.9 free CN−
n.o. (133.4 free
)
11 d e
1.99
1.10d(6.9)
SCN−
)
2.62sp(6.9)
0.57d(6.6)br
2.40sp(6.9)
5.24d(6.0)
5.09br
5.22br
31.2
17.2 21.4br
30.1
{100.8, 107.1}
92.4br, 96.1br 94.3
{100.6, 113.7}
12 c
1.86
2.56br
7.4m
18.8(C2H4)
129.1, 129.2
131.1, 132.3
13 b
14 c
2.20s 1.21d(7.0)
2.83sp(7.0)
2.10s 1.22d(7.0)
2.56sp(7.0)
5.17d(5.8)
5.42d(5.8)
5.46s
n.o.
18.6 22.8
30.8
83.5, 85.5
{101.5, 107.8}
93.8
7.58d(6.0)
8.82d(6.0)
f
a Coupling constants J(H,H) in parentheses, J(P,C) in square brackets; d=doublet, sp=septet; n.o.=not observed.
b In CDCl3 solution.
c In CD2Cl2 solution.
d In CD3CN solution.
e NMR tube experiment.
f Not observed due to low solubility in CD2Cl2.
g The 13C signals of the p-cymene carbon atoms without hydrogen are given in curly brackets; the carbon bearing the isopropyl substituent
appears at lower field.
As expected, the ammonia complex 4 tends to lose
NH3 unless kept under an atmosphere of ammonia,
both in the solid state and in solution. The hydrazine
complex 13 is binuclear and more stable than 4. The
higher stability of the binuclear products 12–14 is
apparently due to their low solubility. The yellow ad-
duct with pyridine (5) gives a green solution in CH2Cl2,
indicating an equilibrium between 5 and the blue start-
ing compound 1. The binuclear 4,4%-bipyridine complex
14 precipitates from CH2Cl2 as a yellow powder,

146
M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
whereas the supernatant, bright green solution con-
tains a mixture of the yellow product 14 and the blue
starting complex 1. If methanol is used as a solvent, a
brown solution of 14 is formed in the case of LL=
4,4%-bipy. The chelate ligand 2,2%-bipy did not react
with 1 under comparable conditions.
The addition reactions of 1 with various Lewis bases
indicate a qualitative order of decreasing stability ac-
cording to the ligating atom L=C\P\N\S\O.
The EI mass spectra of all addition compounds 2–14
contain the educt 1 as the highest peak together with
the ligand L, after dissociation of the adduct under
high vacuum.
The 1H- and 13C-NMR spectra of the com-
plexes 1–14 show the expected patterns (Table 2).
With respect to free p-cymene, the signals of the aro-
matic protons and of the arene ring carbon atoms are
shifted upfield due to p-coordination. It appears that
adduct 6 which contains the acceptor ligand L=CO
has the 1H and 13C signals of the aromatic part
of p-cymene at lowest fields. The 13C carborane signal
can be recognized among the p-cymene signal mani-
fold because it is broadened slightly as a result of
partial relaxation of the scalar 13C-11B spin–spin cou-
pling. The l(13C) values observed for the two equiva-
lent carborane carbons in the [S2C2(B10H10)] ligand
of the neutral ruthenium complexes 2–9 and 12, 13
remain within a narrow range (between 91 and
95 ppm in CDCl3 or CD2Cl2 solution); the high-field
end (91.6) is represented by the carbonyl complex
6.
Table 3
Selected bond lengths [pm] and angles [°]
2
12
13
(L=PPh3) (LL=Ph2P(CH2)2PPh2) (LL=N2H4)
Bond distances
RuꢀP
RuꢀN
RuꢀS(1)
RuꢀS(2)
RuꢀC(3)
RuꢀC(4)
RuꢀC(5)
RuꢀC(6)
RuꢀC(7)
RuꢀC(8)
RuꢀZ a
235.0(1)
233.31(9)
218.8(2)
237.85(9)
237.55(10)
224.7(3)
220.4(3)
221.4(3)
223.5(3)
220.4(3)
221.5(3)
170.8
238.9(1)
239.5(1)
226.1(4)
225.7(4)
226.3(4)
229.9(3)
224.9(3)
224.6(3)
177.0
240.25(10)
239.30(12)
226.6(4)
222.2(4)
224.7(4)
227.4(4)
226.1(4)
224.4(4)
175.4
2.2. X-ray structure determinations
The molecular structures of the mononuclear com-
plex 2 and the binuclear analogues 12 and 13 are
given in Figs. 1–3; characteristic bond lengths and
angles are compared in Table 3. The complexes under
study possess a (p-cymene)–ruthenium half-sandwich
tripod structure in which two legs are sulfur atoms
from the o-carborane dithiolato chelate ligand and the
third leg is either P or N.
The binuclear complexes 12 and 13 are centrosym-
metric with the inversion center in the middle of the
CꢀC or NꢀN single bond. The dihedral angle
S(1)RuS(2)/S(1)C(1)C(2)S(2) is expected to be 180° in
the 16-electron educt 1, in analogy to the structurally
characterized compounds Cp*Co[S2C2(B10H10)] [10]
and Cp*Ir[Se2C2(B10H10)] [12]. This angle at the S···S
vector is reduced to 154.4° in the adduct (2) with PPh3
and to 159.0° in the adduct (12) with Ph2PCH2-
CH2PPh2 (cf. Cp*Rh[S2C2(B10H10)](PMe3) (155.1°)
[11], Cp*Ir[Se2C2(B10H10)](PMe3) (156.1°) [12]). How-
ever, the dihedral angle at the S···S vector is 172.5° in
the adduct (13) with hydrazine. The RuꢀP (or RuꢀN)
bond is nearly perpendicular to the S(1)RuS(2) plane
(2: 87.0°, 12: 85.7° and 13: 83.2°).
S(1)ꢀC(1)
S(2)ꢀC(2)
C(1)ꢀC(2)
C(1)ꢀB(3)
C(1)ꢀB(4)
C(1)ꢀB(5)
C(1)ꢀB(6)
C(2)ꢀB(3)
C(2)ꢀB(6)
C(2)ꢀB(7)
C(2)ꢀB(11)
C(25)ꢀC(25A)
NꢀN(0A)
178.9(3)
178.6(3)
164.0(5)
172.1(5)
171.8(5)
172.0(4)
174.6(6)
173.1(7)
174.6(6)
173.1(5)
173.5(5)
179.8(4)
177.6(4)
165.1(6)
172.7(7)
172.5(6)
171.8(6)
172.9(6)
172.8(6)
173.9(7)
172.5(7)
172.0(6)
152.5(7)
178.6(3)
178.5(3)
166.7(6)
172.0(4)
171.5(5)
172.1(4)
173.0(5)
171.6(5)
173.0(5)
171.0(5)
171.2(5)
146.4(5)
Bond angles
S(1)ꢀRuꢀS(2)
S(1)ꢀRuꢀP
S(1)ꢀRuꢀN
S(2)ꢀRuꢀP
S(2)ꢀRuꢀN
ZꢀRuꢀP
86.6(1)
87.1(1)
85.57(4)
92.01(3)
89.84(3)
84.34(7)
86.14(8)
90.5(1)
127.7
86.34(4)
127.4
ZꢀRuꢀN
130.0
125.6
127.0
106.49(12)
106.51(13)
ZꢀRuꢀS(1)
ZꢀRuꢀS(2)
RuꢀS(1)ꢀC(1)
RuꢀS(2)ꢀC(2)
RuꢀPꢀC(25)
RuꢀNꢀN(0A)
S(1)ꢀC(1)ꢀC(2) 116.9(2)
S(2)ꢀC(2)ꢀC(1) 117.7(2)
PꢀC(25)ꢀC(25A)
124.6
127.4
105.8(1)
105.4(1)
124.7
127.9
105.08(14)
106.02(15)
114.62(12)
The NꢀN distance (146.4(5) pm) in the binuclear
hydrazine complex 13 corresponds closely to the
analogous distance in {(C6Me6)Ru[S2C6H4]}2(m-N2H4)
(145.4(8) pm) [18] and is similar to the values in
related hydrazine-bridged ruthenium complexes [cf.
18]. The hydrogen atoms in 13 were localized, and
then refined according to the riding model with fixed
isotropic temperature factors.
121.4(3)
118.2(2)
118.3(2)
116.9(2)
116.5(3)
117.4(4)
a Z is the center of the p-cymene ring (C3–C8). The ring carbon
C(3) carries the methyl, C(8) the isopropyl substituent.

M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
147
Table 4
Crystal structure determinations
2
12
13
Empirical formula
C30H39B10PRuS2
C50H72B20P2Ru2S4·
C24H52B20N2Ru2S4
2CH2Cl2
Crystal shape
Crystal dimensions (mm)
Crystal system
Space group
Lattice parameters
a (pm)
b (pm)
c (pm)
h (°)
Dark red prism
0.25×0.18×0.12
Monoclinic
P21/c
Brown irregular
0.30×0.18×0.12
Triclinic
Red platelet
0.30×0.18×0.08
Triclinic
(
(
P1
P1
1159.2(2)
2965.6(3)
1102.6(2)
1073.37(11)
1163.07(10)
1552.02(14)
93.064(7)
1035.35(9)
1095.89(11)
1130.86(9)
77.438(7)
i (°)
k (°)
117.03(2)
106.573(7)
112.205(8)
1690.7(3); 1; 726
0.810
73.650(7)
78.805(8)
1189.58(18); 1; 546
1.061
V (106 pm3); Z; F(000)
3378.4(9); 4; 1440
0.657
Siemens P4(Mo–Ka, u=71.073 pm; graphite monochromator)
Absorption coefficient (mm−1
Diffractometer
)
Scan range [2q; °]; mode
Measured reflections
Independent reflections
Observed reflections
3–55; ꢀ
9465
7753
6572(F\2|(F))
SHELXTL-PLUS
V. 4.2 (against F)
Empirical („-scan)
0.4571/0.5179
398
3–55; ꢀ
8948
7702
6273(I\2|(I))
SHELXTL-PLUS
V. 5.1 (against F2)
Empirical („-scan)
0.5503/0.9645
397
3–55; ꢀ
4122
4001
3654(I\2|(I))
SHELXTL-PLUS
Solution and refinement
V. 5.1 (against F2)
Empirical („-scan)
0.3684/0.4621
263
0.094/0.038 (wR2/R1)
1.04/−1.48
Absorption correction
Min./max. transmission factors
Refined parameters
R values
0.044/0.037 (R/wR; w−1=|2(F)) 0.140/0.059 (wR2/R1)
0.56/−1.30 2.18/−1.26
Max./min. residual electron density (e 10−6 pm−3
)
3. Experimental
changed from orange to blue. The solvents were
removed under reduced pressure and the residue was
purified by column chromatography on silica. Elution
with hexane–CH2Cl2 (2:1) produced a blue zone
from which 250 mg (56%) 1 were isolated. Dec.
\205°C. EI-MS: m/z 442 (100%, M+; correct isotope
pattern).
The reactions were carried out under argon in care-
fully dried solvents. The starting materials Li2[S2C2-
(B10H10)] (a) [11], [(p-cymene)RuCl2]2 [19] and [(p-
cymene)OsCl2]2 [20] were prepared according to litera-
ture procedures.
Instrumentation: IR spectra: Perkin–Elmer, 983
G. Mass spectra: VARIAN MAT CH7, direct inlet (70
eV). NMR-spectra: Bruker ARX 250 and DRX
500; chemical shifts are given with respect to CHCl3–
CDCl3 (l(1H)=7.24; l(13C)=77.0), CHDCl2–CD2Cl2
(l(1H)=5.33; l(13C)=53.8), external Et2O–BF3
(l(11B)=0 for J(11B)=32.083971 MHz), and external
85% aq. H3PO4 (l(31P)=0 for J(31P)=40.480747 MHz).
3.2. (p-Cymene)Os[S2C2(B10H10)] (1A)
The osmium analogue of 1 was prepared starting
from 144 mg (1 mmol) o-carborane and 395 mg (0.5
mmol) [(p-cymene)OsCl2]2 in Et2O–THF, as described
above in Section 3.1. The violet osmium complex
was isolated in about 80% yield (425 mg). Dec.
\210°C. EI-MS: m/z 531 (100%, M+; correct isotope
pattern).
3.1. (p-Cymene)Ru[S2C2(B10H10)] (1)
o-Carborane, C2B10H12 (144 mg, 1 mmol), was dis-
solved in 40 ml of diethylether and lithiated by addition
of 1.4 ml (2.2 mmol) of the commercially available 1.6
M hexane solution of n-butyllithium. The addition of 70
3.3. General procedure to prepare the adducts
(p-cymene)Ru[S2C2(B10H10)](L); L=triphenylphosphane
(2), trimethylphosphite (3), pyridine (5), tert-butyl
isocyanide (7), diethyl sulfide (8), tetrahydrothiophene
(9)
mg (2.2 mmol) sulfur gave
a colorless solution
of Li2[S2C2(B10H10)] (a). Then a solution of 306 mg (0.5
mmol) [(p-cymene)RuCl2]2 in 120 ml THF was added.
The color of the Et2O–THF solution immediately
The two-electron ligand L (0.5 mmol) was added to a
solution containing 133 mg (0.3 mmol) of the blue

148
M. Herberhold et al. / Journal of Organometallic Chemistry 598 (2000) 142–149
of the suspension gave an orange solution, over which
a layer of hexane was placed carefully. After 1 week at
room temperature the orange crystals which had been
formed were harvested. Yield 60 mg (66%). Elemental
analysis C24H52B20N2Ru2S4 (915.32), Anal. Calc. C,
31.49; H, 5.73; N, 3.06, found C, 30.80; H, 5.45; N,
3.09%.
16-electron dithiolene complex (p-cymene)Ru[S2C2-
(B10H10)] (1) in 20 ml CH2Cl2. The color changed
immediately, indicating adduct formation. The solvent
CH2Cl2 was evaporated and the residue washed with
hexane to remove excess L (yield: 80–90%). Recrystal-
lization from hexane–CH2Cl2 mixtures gave the desired
adduct (p-cymene)Ru[S2C2(B10H10)](L) in yields of 80–
90% (Table 1).
3.9. X-ray crystallography
3.4. (p-Cymene)Ru[S2C2(B10H10)](NH3) (4)
The intensity data for all three complexes were col-
lected on a Siemens P4 diffractometer using Mo–Ka
radiation (u=71.073 pm, graphite monochromator) at
room temperature (296 K). Crystals suitable for X-ray
structure determination were sealed in glass capillaries
under argon. The refinement of the structures was carried
out against F in the case of 2, and against F2 in the cases
of 12 and 13. All hydrogen atoms were placed in
Ammonia gas was bubbled through the blue solution
of 90 mg (0.2 mmol) 1 in 20 ml CH2Cl2, causing
an immediate color change to brown–red. A hexane
layer was placed on top of the brown–red solution and
the reaction tube kept under an atmosphere of NH3
at room temperature. After 1 week the red crystals of
4 were isolated, yield 52 mg (56%). Elemental analy-
sis C12H27B10NRuS2 (458.55), Anal. Calc. C, 31.34;
H, 5.91; N, 3.05, found C, 30.85; H, 6.04; N,
3.35%.
calculated positions and refined isotropically applying
2
,
the riding model with fixed temperature factors (0.08 A ).
A summary of the refinement parameters is given in
Table 4.
3.5. (p-Cymene)Ru[S2C2(B10H10)](CO) (6)
4. Supplementary material
In contact with CO the blue solution of 90 mg
(0.2 mmol) 1 in 20 ml CH2Cl2 turned yellow. The
yellow product 6 was isolated in nearly quantitative
yield.
Crystallographic data (excluding structure factors)
for the structures reported in this paper (2, 12 and 13)
have been deposited with the Cambridge Crystallo-
graphic Data Centre (CCDC) as supplementary publi-
cation no. CCDC 136420 (2), CCDC 136419 (12) and
CCDC 136418 (13). Copies of the data can be obtained
free of charge on application to CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (fax: +44-1223-
336033; e-mail: deposit@ccdc.cam.ac.uk).
3.6. K{(p-Cymene)Ru[S2C2(B10H10)]}(CN) (10)
An excess of KCN (20 mg, 0.3 mmol) was added to
the solution of 90 mg (0.2 mmol) 1 in 20 ml of
methanol. The deep brown slurry was brought to dry-
ness under reduced pressure and the residue redissolved
in CH2Cl2. Filtration gave a yellow solution which
contained 10.
Acknowledgements
3.7. Binuclear adducts {(p-cymene)Ru[S2C2-
(B10H10)]}2(v-LL) (LL=1,2-bis(diphenyl-phosphino)-
ethane (4), 4,4%-bipyridine (14)
Support of this work by the Deutsche Forschungsge-
meinschaft and the Fonds der Chemischen Industrie is
gratefully acknowledged. We thank Professor B.
Wrackmeyer, Bayreuth, for helpful discussions.
The bidentate bridging ligand LL (0.1 mmol) was
added to the blue solution of 90 mg (0.2 mmol) 1 (in
20 ml of dichloromethane for 4 and in 20 ml of methanol
for 14). The product was washed with hexane and (in
the case of 14) with methanol. The yields are around
90%.
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