B-substituted (arene)ruthenacarborane-sulfonium, -thioether and -mercaptan complexes: Mild single and double dealkylation and structural implications in the antipodal distance

Article abstract of DOI:10.1002/ejic.200500470

Reactions of [RuCl₂(η⁶-arene)]₂ (arene = benzene, p-cymene) with nido-[7-R-10-L-7,8-C₂B₉H ₉]^- in THF at room temperature for 3 d give the (arene)ruthenacarborane complexes closo-[3-Ru(η⁶-arene)-1-R-8-L- 1,2-C₂B₉H₉]⁺ {arene = benzene, R = H [L = Me₂S (1a), THT (1b), EtPhS (1c)], R = Me [L = Me₂S (2a)]; arene = p-cymene, R = H [L = Me₂S (3a)]} and mercaptan closo-[3-Ru(η⁶-arene)-1-R-8-HS-1,2-C₂B ₉H₉] [arene = benzene, R = H (4), Me (5); arene = p-cymene, R = H (6)] in yields of 20-40% and 22-29%, respectively. The asymmetric ligand nido-[9-Me₂S-7,8-C₂B₉H ₁₀]^- leads to the thioether complex closo-[3- Ru(η⁶-benzene)-7-MeS-l,2-C₂B₉H ₁₀] (8) in 34 % yield under the same reaction conditions. The crystal structure of 1a is described and compared with those of 4 and 8. The fully assigned ¹¹B NMR spectroscopic data for a whole series of ruthenacarboranes having B-substituted sulfonium, thioether and mercaptan groups are presented. These data show a relation between antipodal cluster atom distances (antipodal distance) and antipodal effect (AE) in the crystal structures of these complexes and for other families of heteroboranes such as closo-[EB₁₁H₁₁] and closo-[EB₉H₉]. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Full text of DOI:10.1002/ejic.200500470

FULL PAPER
B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and
–Mercaptan Complexes: Mild Single and Double Dealkylation and Structural
Implications in the Antipodal Distance
José Giner Planas,[a] Clara Viñas,[a] Francesc Teixidor,*[a] Mark E. Light,[b]
Michael B. Hursthouse,[b] and Helen R. Ogilvie[b]
Keywords: Antipodal effect / (Arene)ruthenacarboranes / Carboranes / Charge-compensated ligands / Dealkylation
Reactions of [RuCl2(η6-arene)]2 (arene = benzene, p-cymene)
with nido-[7-R-10-L-7,8-C2B9H9]– in THF at room tempera-
ture for 3 d give the (arene)ruthenacarborane complexes
tions. The crystal structure of 1a is described and compared
with those of 4 and 8. The fully assigned 11B NMR spectro-
scopic data for a whole series of ruthenacarboranes having
B-substituted sulfonium, thioether and mercaptan groups are
presented. These data show a relation between antipodal
cluster atom distances (antipodal distance) and antipodal ef-
fect (AE) in the crystal structures of these complexes and for
other families of heteroboranes such as closo-[EB11H11] and
closo-[EB9H9].
closo-[3-Ru(η6-arene)-1-R-8-L-1,2-C2B9H9]+ {arene
= ben-
zene, R = H [L = Me2S (1a), THT (1b), EtPhS (1c)], R = Me [L
= Me2S (2a)]; arene = p-cymene, R = H [L = Me2S (3a)]} and
mercaptan closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9] [ar-
ene = benzene, R = H (4), Me (5); arene = p-cymene, R =
H (6)] in yields of 20–40% and 22–29%, respectively. The
–
asymmetric ligand nido-[9-Me2S-7,8-C2B9H10
thioether complex
]
leads to the
closo-[3-Ru(η6-benzene)-7-MeS-1,2-
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2005)
C2B9H10] (8) in 34% yield under the same reaction condi-
tain a sulfur atom attached to a boron atom.[5] Of these,
only 5 correspond to ruthenacarboranes all having a
“charge-compensated” ligand, i.e. closo-[3-Ru(Cp*)-7-
Me2S-1-R-2-R1-1,2-C2B9H8] (R/R1 = H/H, H/Ph, Ph/H),[3g]
closo-[3-Ru(η6-benzene)-7-Me2S-1,2-C2B9H10][6] and closo-
[3-Ru-3-H-3,3-(PPh3)2-8-Me2S-1,2-C2B9H10].[3i] The latter
type of (phosphane)ruthenacarborane complexes have
proven to be very efficient catalysts in various types of ole-
fin-related catalytic reactions surpassing, in some cases, the
Cp-type complexes.[7] As part of our systematic work on
monoanionic o-carboranes as alternatives to the cyclopen-
tadienide ligand in transition metal complex catalysts,[7] we
became interested in the synthesis of (arene)ruthenacarbor-
ane complexes. Here we report the syntheses and characteri-
sation of the new symmetrically B-substituted (arene)ru-
thenacarborane–sulfonium complexes closo-[3-Ru(η6-ar-
ene)-1-R-8-L-1,2-C2B9H9]+ {arene = benzene, R = H [L =
Me2S (1a), THT (1b), EtPhS (1c)], R = Me [L = Me2S (2a)];
arene = p-cymene, R = H [L = Me2S (3a)]} and of the
unprecedented (arene)ruthenacarborane–mercaptan com-
plexes closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9] {arene
= benzene, R = H (4), Me (5); arene = p-cymene, R = H
(6)} and the asymmetric thioether complex closo-[3-Ru(η6-
benzene)-7-MeS-1,2-C2B9H10] (8), formed by double and
single dealkylation of the sulfonium groups in the starting
nido-carboranes, respectively. A pathway for the dealky-
lation reaction is proposed. The structure for [1a]PF6 is now
reported and compared with those of complexes 4 and 8
Introduction
Metal complexes having the dicarbollide ligand nido-[7-
R-8-R1-7,8-C2B9H9]2– constitute the most widely studied
class of metallacarboranes since they were first reported by
Hawthorne in the 1960s.[1] These dicarbollide ligands have
planar binding faces and are isolobal and isoelectronic ana-
logues of the cyclopentadienide ligand [C5H5]– (Cp), both
behaving as 6-electron donors in transition metal com-
plexes.[1,2] Introduction of substituents such as amines,
ethers, sulfides and phosphanes etc. at the boron atoms re-
duces the cluster charge, thereby producing “charge-com-
pensated” ligands such that a better comparison with the
classical (Cp)metal complexes can be made.[3] In particular,
sulfides are widely used as substituents in polyhedral B-sub-
stituted carboranes affording “charge-compensated” li-
gands of the type nido-[9- or 10-L-7,8-RR1C2B9H8]– (L =
SR2R3).[4] Interestingly, whereas nearly 500 structures of
icosahedral cages of the type closo-[3,1,2-MC2B9] have been
determined by X-ray crystallography, only 33 of those con-
[a] Institut de Ciència de Materials de Barcelona (CSIC), Campus
de la U.A.B,
08193 Bellaterra, Spain
Fax: +34-935805729
E-mail: teixidor@icmab.es
[b] School of Chemistry, University of Southampton,
Highfield, Southampton SO17 1BJ, UK
Fax: +44-2380596723
E-mail: M.B.Hursthouse@soton.ac.uk
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DOI: 10.1002/ejic.200500470
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J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
which were published in a preliminary communication.[8] of double dealkylation of all sulfonium salt derivatives un-
We present here the fully assigned 11B NMR spectroscopic der very mild conditions regardless of the nature of the sub-
data for a whole series of ruthenacarboranes having B-sub- stituents at the sulfur atom. Small amounts of sandwich
stituted sulfonium, thioether and mercaptan groups. The complexes of the type closo-[3,3Ј-Ru-(8-L-1,2-C2B9H10)2]
study reveals clear trends in the 11B NMR spectra and the were also detected in the reaction mixtures in some cases.
antipodal effect (AE)[9] which, to date, had only been re- Synthesis of the latter has been reported in a separate pa-
lated to NMR spectroscopic data. We have found that the per.[11] As an example, the sandwich complex closo-[3,3Ј-
AE can be clearly observed in the crystal structures for the Ru-(8-Me2S-1,2-C2B9H10)2] was obtained in 8% yield after
new complexes and other previously reported heterobor- workup of the reaction mixture of nido-[10-Me2S-7,8-
anes of the type EB11H11 and EB9H9. We have adopted in C2B9H10]– with (benzene)ruthenium dichloride. Fortu-
this work the carborane numbering system shown in nately, the latter type of sandwich complexes could, in most
Scheme 1.
cases, be easily removed by column chromatography (see
Exp. Sect.). The reactions shown in Scheme 2 have been
1
conclusively established by spectroscopic (11B, H and 13C
NMR) and analytical characterisation of all compounds
and crystallographic characterisation of [1a]PF6 and 4.
Scheme 1. Carborane numbering.
Results
1. Reactions of [RuCl2(η6-arene)]2 with Charge-
Compensated Carboranes nido-[7-R-10-L-7,8-C2B9H9]– and
nido-[9-Me2S-7,8-C2B9H10]–
According to protocols established in our group, tBuOK
was employed as the base for in situ deprotonation of the
neutral “charge-compensated” o-carboranes nido-[7-R-10-
L-7,8-C2B9H10] (R = H, L = Me2S, THT, EtPhS; R = Me,
L = Me2S) (THT = tetrahydrothiophene) affording the po-
tassium salt of the anionic “charge-compensated” o-carbor-
anes nido-[7-R-10-L-7,8-C2B9H9]–.[10] Exclusive deproton-
ation of the bridge BHB proton is confirmed by disappear-
ance of its resonance signal in the 1H{11B} NMR spectrum.
The 11B{1H} NMR spectra show the typical highfield dis-
placement of the antipodal boron B-1 signal after hydrogen
bridge deprotonation (see Figure 1 for one example). Treat-
ment of the nido-[7-R-10-L-7,8-C2B9H9]– compounds with
a suspension of the (arene)ruthenium complexes [RuCl2(η6-
arene)]2 (arene = benzene, p-cymene) in THF at room tem-
perature for 3 d afforded the new cationic ruthenacarborane
complexes closo-[3-Ru(η6-arene)-1-R-8-L-1,2-C2B9H9]+ Cl–
(1–3) as insoluble solids (Scheme 2). A Cl– exchange reac-
Figure 1. NMR monitoring for the deprotonation of nido-[10-
Me2S-7,8-C2B9H11]: (top) NMR spectra before addition of tBuOK
(1.0  solution in THF); (bottom) after addition of 1 equiv. of
tBuOK (Ͼ99% nido-K[10-Me2S-7,8-C2B9H10]).
–
tion in 1–3 using PF6 afforded the readily soluble com-
plexes
closo-[3-Ru(η6-arene)-1-R-8-L-1,2-C2B9H9][PF6]
(1a–c and 3a) in yields of 20–40% but only traces of 2a
were obtained. Detailed analysis of the remaining solution
showed, in all cases, the presence of starting anionic
“charge-compensated” o-carboranes nido-[7-R-10-L-7,8-
C2B9H9]– which could be recovered. In addition, we unex-
pectedly found that (mercaptan)ruthenacarborane com-
plexes of the type closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-
Scheme 2. Syntheses of new (arene)ruthenacarborane complexes.
Interestingly, the asymmetric isomer of 1a, namely closo-
C2B9H9] (4–6) were also formed in yields of 22–29% [3-Ru(η6-benzene)-7-Me2S-1,2-C2B9H10]+ (7), has been pre-
(Scheme 2). Although yields for the latter complexes were viously reported in an analogous reaction of [RuCl2(η6-ben-
low, their formation is remarkable since they are the result zene)]2 with the anionic nido-[9-Me2S-7,8-C2B9H10][Na] in
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B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
FULL PAPER
44% yield but no other species were reported to be resonances with relative intensities of 1:1:2:1:1:2:1. The
formed.[6] Based on our present results, we have examined asymmetry can also be observed in the 13C{1H} NMR
this reaction in more detail in order to determine whether spectrum which shows two different Cc–H resonances (two
C–S bond cleavage of Me2S was also possible in this case. broad singlets at δ = 49.2 and 49.9 ppm). The asymmetry
We found that the new soluble neutral complex closo-[3- of 2a results in all the B signals being inequivalent such that
Ru(η6-benzene)-7-MeS-1,2-C2B9H10] (8) is formed, in ad- extensive overlap can be observed. In addition, all cationic
dition to the previously reported 7, in 34% yield [Equa- complexes [1–3]PF6 show typical septuplets in their 31P
1
tion (1)]. Complex 8 has been identified by 11B, 1H and NMR spectra at δ Ϸ –143 to –146 ppm, due to JP,F coup-
13C{1H} NMR spectroscopy and structurally characterised ling (ca. 710 Hz).
by X-ray diffraction.
b. closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9]
The 11B NMR spectrum for the neutral mercaptan deriv-
ative 4 closely resembles that of 1a with an even larger
downfield resonance for the B–SH vertex (δ = 14.3 ppm).
The corresponding 1H NMR spectrum shows a broad reso-
nance at δ = 0.87 ppm which is consistent with an SH
group, a situation similar to that found in the related (mer-
captan)cobaltacarborane complex closo-[3-Co(Cp)-8-HS-
1,2-C2B9H10].[14] In addition, the H and 13C{1H} NMR
1
signals for the η6-benzene moiety and the cage Cc–H for
(1)
this complex appear at higher field than in the cationic
complex 1 and are consistent with other neutral ruthenacar-
borane complexes.[13a] Complexes 5 and 6 exhibited very
similar NMR characteristics to 4 so that their multinuclear
NMR spectroscopic data were assigned accordingly.
2. Characterisation of the New Complexes
a. closo-[3-Ru(η6-arene)-1-R-8-L-1,2-C2B9H9]+
c. closo-[3-Ru(η6-benzene)-7-MeS-1,2-C2B9H10]
The 1H NMR spectra for all cationic complexes 1–3
The resonance for the substituted B atom in the 11B
NMR spectrum is more shielded than in 4 (δ = 6.4 ppm)
and, unlike the latter, a signal for an MeS fragment can be
(anion for all cationic complexes throughout the text is
–
PF6 , unless otherwise noted) show diagnostic signals for
coordinated (η6-arene) fragments to Ru at δ = 6.62–
6.82 ppm.[12] Signals for the cage C–H protons (Cc–H) ap-
pear as broad resonances at δ = 4.61–4.67 ppm for the un-
substituted carborane compounds (1 and 3) and at δ =
4.97 ppm for the methylcarborane complex 2a, all data be-
ing consistent with those of other (arene)ruthenacarborane
complexes.[6,13] The 13C{1H} NMR spectra for all com-
plexes also show characteristic peaks for the benzene or p-
cymene ligands, two cage-carbon vertices and the L groups
(see Exp. Sect.). The 11B{1H} NMR spectra for all com-
plexes are consistent with a closo-icosahedral geometry for
the cage and are similar to those found for related metall-
1
observed in the H and 13C{1H} NMR spectra. These data
are in agreement with cleavage of only one of the C–S
bonds of the Me2S moiety affording the new neutral thio-
ether complex 8 as outlined in Equation (1). The asym-
metry of the complex is also evident in the 1H and 13C{1H}
NMR spectra which display two resonances for the Cc–H
atoms.
3. Crystal Structures
The structures for [1a]PF6, 4 and 8 have been unequivo-
acarborane species.[3i,11] The fully coupled 11B NMR spec- cally established by X-ray crystallography (Figures 2, 3 and
tra of these complexes show a singlet for the L–B boron 4). The Exp. Sect. contains the crystal and data collection
vertex whereas the rest of the boron atoms appear as doub- parameters for [1a]PF6. Figure 2 clearly shows that the ru-
lets due to 11B-1H coupling. For example, complex 1a dis- thenium atom in 1a is sandwiched between the benzene and
plays six resonances in a 1:1:2:2:2:1 ratio in its 11B NMR nido-[10-Me2S-7,8-C2B9H10]– ligands giving the cluster the
1
spectrum at δ = 7.1 (s, B-8), 1.9 (d, JB,H = 148 Hz, B-10), expected closo-[3,1,2-MC2B9] geometry. The Ru–(C2B3
1
1
–6.9 (d, JB,H = 153 Hz, B-4,7), –9.8 (d, JB,H = 144 Hz, B- plane) and Ru–(C6 plane) distances are 1.629 and 1.724 Å,
9,12), –17.5 (d, 1JB,H = 155.1 Hz, B-5,11), –22.0 (d, JB,H
=
respectively, and these values are similar to those of the di-
1
169 Hz, B-6) ppm. The assignments for each boron atom carbollide-containing neutral complex closo-[3-Ru(η6-ben-
have been unequivocally determined by 2D 11B{1H}- zene)-1,2-C2B9H11].[13c] Interestingly, the C6 benzene ring
11B{1H} COSY for all complexes. These data are consistent and C2B3 plane angle is 1.59° in 1a which is significantly
with Cs symmetry for the complexes as shown in Scheme 2. smaller than that for the related complex closo-[3-Ru(η6-
However, the symmetry is disrupted in complexes 1c and benzene)-1,2-C2B9H11] (4.1°).[13c] Notably the C1–C2 dis-
2a due the presence of the compensating EtPhS group at tance is 1.637(4) Å which is similar to that in other closo
B(8) and a methyl group at one of the carbon cage vertexes. structures.[3] The B8–S1 distance of 1.899(2) Å is consistent
Thus, the 11B{1H} NMR spectrum for 1c displays seven with that in other B-substituted sulfonium salts.[15]
Eur. J. Inorg. Chem. 2005, 4193–4205
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J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
–
Figure 2. Molecular structure of [1a]PF6 (thermal ellipsoids shown at the 50% probability level). The PF6 anion has been omitted for
clarity. Selected interatomic distances [Å]: Ru3–C1 2.169(2), Ru3–C2 2.177(2), Ru3–B4 2.212(2), Ru3–B7 2.215(2), Ru3–B8 2.217(2), Ru3–
C3 2.219(2), Ru3–C4 2.218(2), Ru3–C5 2.228(2), Ru3–C6 2.236(2), Ru3–C7 2.230(2), Ru3–C8 2.226(2), C1–C2 1.637(4), C2–B7 1.719(3),
B7–B8 1.798(3), B4–B8 1.794(3), B8–S1 1.899(2).
The neutral complex 4 also displays a closo-[3,1,2-
MC2B9] geometry for the cluster (Figure 3). The ruthenium
Discussion
1. Reactions of [RuCl2(η6-arene)]2 with Charge-
atom is sandwiched between the benzene and nido-[10-HS-
Compensated Carboranes nido-[7-R-10-L-7,8-C2B9H9]– and
7,8-C2B9H10]– ligands, thus supporting the structure for the
nido-[9-Me2S-7,8-C2B9H10]–
complex in solution and confirming that double demethyl-
ation occurs from the starting charge-compensated ligand.
The yields of the new cationic (arene)ruthenacarborane
The average Ru–(C2B3 plane) and Ru–(C6 plane) distances complexes 1–3 (Scheme 2) and the reported 7[6] [Equa-
are similar to those in 1a (1.613 and 1.718 Å). The C6 ben- tion (1)] are usually below 50% (Table 1). As demonstrated
zene ring and the C2B3 planes are nearly parallel, the dihe- in this work, these low yields can be partially accounted
dral angle of 2.74° is slightly larger than that for the sulfo- for by the formation of the (mercaptan)ruthenacarborane
nium derivative 1a. The C1–C2 distance is 1.644(4) Å and complexes 4–6 in the case of the symmetric ligands nido-[7-
the B8–S1 bond [1.836(3) Å] is shorter than that of 1a R-10-L-7,8-C2B9H9]– (isomer-10) or the thioether complex
thereby being consistent with a thiol fragment attached to 8 for the related asymmetric ligand nido-[9-Me2S-7,8-
a boron atom.[16]
C2B9H10]– (isomer-9). Since the starting (arene)ruthenium
As can be seen in Figure 4, the structure of 8 exhibits a dichloride and isomer-10 ligand were also detected during
similar sandwich-type geometry with the ruthenium atom workup of the reactions, we initially thought that insolubil-
flanked both by the benzene ring and the C2B3 face of the ity of the benzene(chloro)ruthenium dimer was responsible
nido-[9-MeS-7,8-C2B9H10]– cage. The Ru–(C2B3 plane) and for the low yields of the complexes (Table 1, Entries 1–2
Ru–(C6 plane) distances are 1.719 and 1.606 Å, respectively, and 4–5). However, yields for the cationic complexes did
the angle between planes of 3.68° is similar to that for the not increase when using the more soluble chloro(p-cymene)
related
complex
closo-[3-Ru(η6-benzene)-7-Me2S-1,2- ruthenium dimer (Table 1, Entry 3). Heating was avoided
C2B9H10]+ (7) (4.4°).[6] The C1–C2 [1.627(3) Å] and B4–S1 to minimise the formation of the unwanted sandwich com-
distances [1.855(3) Å] are also consistent with the above plexes closo-[3,3Ј-Ru-(8-L-1,2-C2B9H10)2] mentioned ear-
data.
lier.[11]
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B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
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Figure 4. Molecular structure of 8 (thermal ellipsoids shown at the
50% probability level). Selected interatomic distances [Å]: Ru3–C1
2.153(2), Ru3–C2 2.163(2), Ru3–B4 2.202(3), Ru3–B7 2.198(3),
Ru3–B8 2.215(3), Ru3–C3 2.228(3), Ru3–C4 2.199(3), Ru3–C5
2.188(3), Ru3–C6 2.199(3), Ru3–C7 2.214(3), Ru3–C8 2.235(3),
C1–C2 1.627(3), C2–B7 1.721(4), B7–B8 1.801(4), B4–B8 1.815(4),
B4–S1 1.855(3), C9–S1 1.810(3).
Figure 3. Molecular structure of 4 (thermal ellipsoids shown at the
50% probability level). Selected interatomic distances [Å]: Ru3–C1
2.157(3), Ru3–C2 2.164(3), Ru3–B4 2.202(3), Ru3–B7 2.198(3),
Ru3–B8 2.215(3), Ru3–C3 2.242(3), Ru3–C4 2.229(4), Ru3–C5
2.206(3), Ru3–C6 2.197(3), Ru3–C7 2.221(4), Ru3–C8 2.238(3),
C1–C2 1.644(4), C2–B7 1.727(4), B7–B8 1.810(4), B4–B8 1.808(4),
B8–S1 1.836(3).
has been previously reported in thioethers coordinated to
electron-withdrawing W or Pt centres, cleavage of only one
C–S bond (single dealkylation) was observed in those
cases.[17] Double demethylation has only been observed in
polyhedral boranes having the charge-compensated Me2S
group but, in this case, a large excess of Li was needed as
the reducing agent.[18] Two crucial questions then arise: (i)
Does the C–S bond cleavage take place prior to or after
coordination of Ru to the open face of the monoanionic
carboranes and (ii) does Ru participate in the double C–S
bond cleavage? In order to address these points, we first
attempted the reaction of complex [1a]PF6 with a Cl–
source such as [Bu4N]Cl. The latter did not cleave any C–S
Table 1. Yield distribution of closo-[3-Ru(η6-arene)-1-R-8-L-1,2-
C2B9H9]+ (1–3) and closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9]
(4–6) formed for each reaction.
Entry
R
H
L
Arene
1–3 [%]
4–6 [%]
22 (4)
1
2
3
4
5
Me2S
benzene
benzene
p-cymene
benzene
benzene
40 (1a)
Ͻ1 (2a)
40 (3a)
20 (1b)
17 (1c)
Me Me2S
29 (5)
[a]
H
H
H
Me2S
THT
EtPhS
–
(6)
26 (4)
28 (4)
[a] Spectroscopically characterised (see Exp. Sect. for details).
Formation of complexes 4–6 is remarkable since they are bond. The only reaction observed was a single anion ex-
the result of double dealkylation of any of the sulfonium change reaction as shown in Equation (2). On the other
derivatives at room temperature regardless of the nature of hand, addition of an excess of the same Cl– source during
the groups attached to the sulfur atom. This was further the reaction of [RuCl2(η6-benzene)]2 with nido-[10-Me2S-
confirmed by detection of MeCl (Entry 1 in Table 1), 7,8-C2B9H10]– (Scheme 2) did not affect the ratio of species
Cl(CH2)4Cl (Entry 4) or PhCl and EtCl (Entry 5) during formed. These two observations are consistent with the cat-
the formation of 4. Elimination of the alkyl or aryl halides ionic complexes not being intermediates of the dealkylation
suggests that C–S bond cleavage takes place by means of reaction, a fact which is further supported by in situ NMR
nucleophilic addition of Cl– to the organic fragments of the spectroscopic studies of the formation of [1a]Cl and 4 (see
L groups. Similar yields for complexes 4–6, regardless of Exp. Sect.). In fact, the (arene)ruthenacarborane complexes
the starting sulfonium salt derivative, indicate that neither are so stable that they could be subjected to heating under
the electronic nor the steric nature of the carbon substitu- reflux or photolysis for days without alteration. This clearly
ents at the sulfur atom have an important role in the C–S suggests that the Cl– anion itself is not the nucleophile and
bond cleavage. Although this type of C–S bond activation that Ru must play some role in the cleavage reaction.
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J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
(2)
All the above data support the suggestion that cleavage
of the C–S bond in the sulfonium fragments takes place
prior to coordination of Ru to the open face of the cluster.
Since addition of an external Cl– source did not affect the
dealkylation reaction, formation of alkyl halides could then
only be explained by the occurrence of some type of nucleo-
philic addition of Cl– bonded to Ru. Taking into account
all experimental evidence, we propose the following path-
way for the dealkylation reactions: thioether–exo-nido-car-
boranes could be formed first (Scheme 3, proposed interme-
diate B) with release of 1 equiv. of either an alkyl or aryl
halide. In this way, only Cl– anions attached to Ru are able
to cleave the C–S bond by some type of sulfonium–Ru in-
teraction like that proposed in A. The first stepwise single
dealkylation is supported by the isolation and crystallo-
graphic characterisation of the neutral methyl thioether
complex closo-[3-Ru(η6-benzene)-7-MeS-1,2-C2B9H10] (8).
Observation of a resonance at δ = –4.27 ppm in the 1H
NMR spectrum during the double dealkylation reaction
provides evidence for the participation of some type of B–
HǞRu agostic interaction like that postulated in B.[19] We
have previously reported a series of exo-cluster monothio-
ether and monophosphanyl complexes having these types
of B–HǞM (M = Rh, Ru) agostic bonds (Scheme 4, I and
IVa).[20] Carbon–sulfur bond cleavage in (thioether)Ru
complexes, as could be the case in intermediate B, is known
to happen by means of π-back-donation from the metal to
the thioether C–S σ*-orbitals.[21] Thus, further dealkylation
by C–S bond cleavage in the thioether B would follow liber-
ation of a second equivalent of the halide and an exo-clus-
ter S-bonded (thiolato)ruthenium intermediate like C could
be formed (Scheme 3). Decoordination of the S-bonded thi-
olato complex C could then take place[22] thus forming the
more stable (η5-C2B3)ruthenacarborane complex which be-
comes protonated to give the mercaptan complex.
Scheme 3. Proposed pathway for the double dealkylation reaction.
Scheme 4. Other selected ruthenium complexes and reactions.
dition for B–HǞM agostic interactions to take place is the
existence of electron-enriched B–H bonds such as those in
the open-face (C2B3) boron atoms of nido-C2B9 clusters.[20d]
Therefore, existence of two hydridic B–H hydrogen atoms
in the postulated exo-nido intermediate B (Scheme 3), which
could interact indistinctly with Ru, might prevent fast iso-
merisation of B to the thioether and facilitate the second
dealkylation to give the observed mercaptan complex 4
(Schemes 2 and 5 left). In the presence of only one hydridic
hydrogen atom, the related isomer-9 might isomerise faster
from exo-nido to closo than its symmetrical analogue pre-
cluding the Ru from cleaving the second C–S bond
(Scheme 5, right). Such isomerisation has been shown to
take place in related Rh complexes of the type IV at room
temperature in CHCl3 solution (Scheme 3).[20d] Removal of
the bridging H in the nido-carborane in II also favours the
formation of the closo tautomer III.[23]
The stability of the thioether complex 8 towards further
cleavage to the corresponding (mercaptan)ruthenacarbor-
ane derivative could be related to the different electronic
nature of this isomer with regard to its symmetrical ana-
logue. Calculation of Mulliken charges at the Hartree-Fock
3-21G level clearly confirms that charge distribution is af-
fected by the position of C atoms in the C2B3 open face of
the nido-[10-MeS-7,8-C2B9H9]2– and nido-[9-MeS-7,8-
C2B9H9]2– carboranes as shown in Scheme 5. It is note-
worthy that whereas both hydrogen atoms in the BH ver-
texes besides the BSMe group are negatively charged in iso-
mer-10 (both have hydridic B–H hydrogen atoms), those for
2. Trends in 11B NMR Spectroscopy for the
Ruthenacarboranes
All compounds reported in this paper exhibit a closo-
the asymmetric isomer-9 have different charges (a hydridic [3,1,2-RuC2B9] geometry; thus, it is possible to compare the
B–H and a protic C–H hydrogen atom). The necessary con- differences in the boron chemical shifts caused by the dif-
4198
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B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
FULL PAPER
{Although the ruthenacarborane complex closo-[3-Ru(η6-
benzene)-1,2-C2B9H11] has been previously reported,[13a] as-
signment of the cluster 11B NMR spectroscopic data was
not published; the present assignments were made by
11B{1H}-11B{1H} COSY spectrosopy ([D6]acetone): δ = 1.3
1
(m, 2 B, B-8 and -10), –7.4 (d, JB,H = 117 Hz, 2 B, B-4
1
and -7), –8.7 (d, JB,H = 117 Hz, 2 B, B-9 and -12), –18.9
1
1
(d, JB,H = 152 Hz, 2 B, B-5 and -11) and –23.7 [d, JB,H
=
176 Hz, 1 B, B-6] ppm.} The most apparent effect observed
in Figure 5 is a large downfield displacement of chemical
shifts for the substituted B-8 with respect to our reference
complex, that of the HS derivative being larger than that of
the Me2S derivative. Whereas the signal for the Me2S–B
boron atom in 1a is shifted downfield by about 7 ppm, that
for the HS-B boron atom in 4 is displaced by 13 ppm. A
second significant effect apparent from Figure 5 is the so-
called antipodal effect (AE)[9] to the substituted boron atom
(B-6). Whereas the chemical shift for the boron atom antip-
odal to Me2S has moved downfield (Figure 5b), that of the
boron atom antipodal to HS is displaced upfield (Fig-
ure 5c). These two main effects have good precedent.[9,18]
As expected, smaller antipodal effects can also be observed
in the asymmetric complexes closo-[3-Ru(η6-benzene)-7-
Scheme 5. Representation of the C2B3 faces of the nido-[10-MeS-
7,8-C2B9H10]2– (left) and nido-[9-MeS-7,8-C2B9H10]2– ligands Me2S-1,2-C2B9H10]+ (7) and closo-[3-Ru(η6-benzene)-7-
(right) and corresponding postulated exo-nido Ru species prior to
MeS-1,2-C2B9H10] (8) due to the lack of a plane of sym-
the dealkylation reaction (below bold lines). Boron atoms in bold
metry crossing both the substituted and antipodal vertex[9]
correspond to the B-8 vertex in the closo-ruthenacarborane com-
{compound/δ(B-5): closo-[3-Ru(η6-benzene)-1,2-C2B9H11]/
plexes.
–18.9 ppm, 7/–18.7 ppm,[6] 8/–17.0 ppm}.
Other minor effects include a downfield/upfield butterfly
effect (BE)[9] analogous to the AE in our system (signals for
B-5, -10 and -11 have moved downfield with respect to the
reference in the case of the Me2S-substituted species 1a but
those for the HS analogue 4 are displaced upfield) and the
neighbouring effect (NE)[9] which only affects B-9 and -12
in the Me2S-substituted 1a.
ferent substituents at the boron atoms. Cationic 1–3 and 7
as well as the neutral ruthenacarborane complexes 4–6 and
8 can be considered as resulting from substitution of a hy-
dride ion in closo-[3-Ru(η6-benzene)-1,2-C2B9H11] by sulfo-
nium and thioether or thiol fragments, respectively. Figure 5
shows a comparison of the neutral closo-[3-Ru(η6-benzene)-
1,2-C2B9H11] which is taken as the reference, with substi-
tuted Me2S and HS at B-8 (Table 2; Entries 1, 2 and 7).
3. Crystal Structures and Antipodal Effect
The empirically observed AE has been previously ex-
plained through cooperation of atomic orbitals on antipo-
dally interacting vertices.[9] It is noteworthy that although
the AE has been extensively studied using calculations[24]
and by comparing various series of compounds,[9] the com-
parison has always been related to the 11B chemical shifts
as the only experimental evidence. Surprisingly, even
though such a hypothesis involves the transfer of part of
the electrons between antipodal boron atoms and, therefore,
through some type of interaction between atomic orbitals,
no other experimental evidence has ever been obtained
apart from NMR chemical shifts.
We were curious to see whether the AE obtained by
NMR spectroscopy, for neutral and cationic ruthenacar-
boranes, has any influence on their X-ray structures. A
comparison of the X-ray structures of the complexes closo-
[3-Ru(η6-benzene)-1,2-C2B9H11] (the reference compound)
with closo-[3-Ru(η6-benzene)-8-Me2S-1,2-C2B9H10]+ (1a)
Figure 5. Representation of the 11B{1H} NMR spectra for com-
plexes: (a) closo-[3-Ru(η6-benzene)-1,2-C2B9H11] (showing boron
assignment); (b) [1a]PF6; (c) 4.
and
closo-[3-Ru(η6-benzene)-8-HS-1,2-C2B9H10]
(4)
Eur. J. Inorg. Chem. 2005, 4193–4205
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J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
Table 2. Comparison of 11B NMR chemical shifts for closo-[3-Ru(η6-arene)-1-R-8-L-1,2-C2B9H10][PF6] (above bold line) and closo-[3-
Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9] (below bold line).[a]
Entry
Arene
L
R
Complex
B-8
B-10
B-4/B-7
B-9/B-12
B-5/B-11
B-6
1
2
3
4
5
6
benzene
benzene
benzene
benzene
benzene
p-cymene
H
H
H
H
H
Me
H
–
1.3
7.1
6.2
7.1
6.1
7.2
1.3
1.9
1.2
2.1
1.7
1.2
–7.4
–6.9
–8.0
–6.6
–8.7
–9.8
–10.7
–9.2/–9.6
–4.5 to –18.5
–9.8
–18.9
–17.5
–19.0
–17.6
–23.7
–22.0
–23.3
–21.7
–22.9
–21.6
Me2S
THT
EtPhS
Me2S
Me2S
1a
1b
1c
2a
3a
–5.7
–6.9
–17.6
7
8
9
benzene
benzene
p-cymene
HS
HS
HS
H
Me
H
4
5
6
14.3
15.0
13.6
–1.1
0.0
–2.9
–8.5
–3.5 to –9.4
–20.0
–15.1/-18.6
–20.9
–27.5
–22.0
–27.9
–7.7
–7.7
[a] See Scheme 1 for numbering.
(Table 3, polyhedral type V) shows a significant shortening of the chemical shift of the signal of this boron atom. Al-
of the distance between the substituted B atom and its an- though the magnitudes of both the downfield chemical shift
tipodal boron atom (Ad: antipodal distance) in the sulfo- and the shortening of Ad are quite small in our complexes,
nium salt derivative 1a with respect to the reference com- a relation between AE and the shortening of Ad can be
plex (0.061 Å). A smaller shortening can be observed for clearly seen when analysing the X-ray structures for the
the neutral complex 4 (0.023 Å). The same situation can polyhedral heteroboranes closo-EB11H11 and closo-EB9H9
be observed when comparing the structures of the related (Table 4).[25] The latter complexes are known to exhibit AE
substituted polyhedral boranes closo-[1-L-B12H11]z– with of at least one order of magnitude larger than the examples
the reference closo-[B12H12]2– molecule (Table 3, polyhedral in Table 3.[8] The data summarised in table 4 clearly show
type VII). In this case the shortening of Ad is slightly larger that the downfield AE and the shortening of Ad both follow
(0.093 Å) than in the related ruthenacarborane structures. the same order, E = MeAl2– Ͻ HB2– Ͻ HC– Ͻ HN, i.e.
In contrast, the shortening of Ad is hardly seen in the asym- with decreasing electron density at the E vertex. The short-
metric closo-[3-Ru(η6-benzene)-7-L-1,2-C2B9H10]+ (Table 3, ening of the antipodal distances Ad is really significant. The
polyhedral type VI) which is consistent with a smaller AE difference between the first compound in the closo-EB11H11
for these complexes as expected from the lack of sym- series (MeAl2–) and the last (HC–) is 0.637 Å (Table 4)! The
metry.[9] It is remarkable that the shortening of the antipo- shortening of Ad is clearly not driven by the charges on the
dal distance (Ad) is observed in those compounds having clusters, since closo-[MeAlB11H11]2– and closo-[B12H12]2– al-
strong electron-attracting substituents attached to boron ready show a significant shortening. To the best of our
atoms. According to the accepted hypothesis,[9] such sub- knowledge, this correlation has not been previously ob-
stituents are believed to decrease the electron density at the served.
antipodal boron atom with the consequent downfield shift
Table 4. Antipodal distances (Ad) for closo-EB11H11 (polydedral
type VIII) and closo-EB9H9 (type IX).[a]
Table 3. Antipodal distances (Ad) for closo-[3-Ru(η6-benzene)-8-L-
1,2-C2B9H10]+ (polyhedral type V), closo-[3-Ru(η6-benzene)-7-L-
1,2-C2B9H10]+ (type VI) and closo-[LB12H11]z– (type VII).
Polyhedral type
VIII
E
Cluster charge
δ[b]
Ad [Å]
MeAl
HB
HC
–2
–2
–1
–25.5
–15.3
–7.0
3.893
3.391
3.256
Polyhedral type
V
L
Compound charge
Ad [Å]
HB
HC
HN
–2
–1
0
–2.0
28.4
61.0
3.697
3.387
3.303
H
HS (4)
Me2S (1a)
0
0
+1
3.439[a]
3.416[b]
3.378[c]
3.387[a]
3.405[b]
3.354[c]
IX
[a] Ad values were measured from the structures in ref.[25] [b] 11B
H
0
0
+1
NMR chemical shift for antipodal B atoms taken from ref.[9]
VI
MeS (8)
Me2S
H
MeS
Me2S
–2
–2
–1
3.391[d]
3.374[e]
3.298[f]
VII
Conclusion
[a] Value measured from the structure in ref.[13c] [b] From ref.[8] [c]
In this study, we describe the formation of cationic ru-
This work. [d] From ref.[26] [e] From ref.[18a] [f] From ref.[15a]
thenacarborane complexes closo-[3-Ru(η6-arene)-1-R-8-L-
4200
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B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
FULL PAPER
1,2-C2B9H9]+ (L = Me2S, THT, EtPhS) (1–3) and neutral
mercaptan
closo-[3-Ru(η6-arene)-1-R-8-HS-1,2-C2B9H9]
tate. After stirring for at room temperature for 1 h, the remaining
ethanol was removed under reduced pressure and the resultant sus-
pension was allowed to settle without stirring in the refrigerator
for 1 h. The aqueous solution was separated by cannula and the
residue was washed with H2O (1 mL) and extracted with CH2Cl2
which was then evaporated and the residue dried by oil-pump vac-
uum to afford [1a]PF6 as a tan powder (101.3 mg, 0.196 mmol,
40%). C10H22B9F6PRuS: calcd. C 23.20, H 4.28, S 6.19; found C
22.92, H 3.92, S 5.86. MALDI-TOF m/z (%) = 373.53 (100) [M],
311.46 (43) [M – Me2S].
(4–6) and closo-[3-Ru(η6-benzene)-7-MeS-1,2-C2B9H10] (8).
The neutral complexes are the result of double or single
dealkylation of L groups in mono-anionic “charge-compen-
sated” o-carborane derivatives at room temperature. Such
facile C–S bond activations are unprecedented in polyhe-
dral carborane chemistry and open a new route to mercap-
tan metallocarboranes. A pathway for the dealkylation re-
actions is proposed. The findings also show, for the first
time, a relation between the empirical antipodal effect (AE)
and the structural antipodal distance (Ad) in the crystal
structures for the new complexes and other previously re-
ported 12- and 10-vertex heteroboranes. We are currently
working on an extension of this correlation to other closo-
heteroboranes.
[1a]Cl: 1H NMR ([D3]acetonitrile): δ = 6.58 (s, 6 H, η6-C6H6), 4.50
1
(br. s, 2 H, Cc-H), 2.45 (s, 6 H, Me2S) ppm. H{11B} NMR ([D3]
acetonitrile; only signals due to B-H protons are given): δ = 2.92
(br. s, 2 H), 1.90–1.60 (m, 6 H) ppm. 11B NMR ([D3]acetonitrile):
1
δ = 6.9 (s, 1 B, B-8), 1.7 (d, JB,H = 154 Hz, 1 B, B-10), –7.1 (d,
1
1JB,H = 150 Hz, 2 B, B-4 and -7), –10.0 (d, JB,H = 144 Hz, 2 B, B-
1
9 and -12), –17.6 (d, JB,H = 162 Hz, 2 B, B-5 and -11), –22.0 (d,
1JB,H = 175, 1 B, B-6) ppm. 13C{1H} NMR ([D3]acetonitrile): δ =
93.3 (s, η6-benzene), 50.8 (br. s, Cc-H), 25.7 (s, Me2S) ppm.
[1a]PF6: 1H NMR ([D6]acetone): δ = 6.80 (s, 6 H, η6-benzene), 4.64
Experimental Section
1
(br. s, 2 H, Cc-H), 2.63 (s, 6 H, Me2S) ppm. H{11B} NMR ([D6]
acetone; only signals due to B-H protons are given): δ = 3.40 (br.
General: All manipulations were carried out under N2. Chemicals
were prepared as follows: THF was distilled from Na/benzophe-
none; acetone was distilled from P2O5; tBuOK (95%, Aldrich or
1.0  solution in THF) and NaPF6 (98%, Aldrich) were used as
received. The following were prepared by literature procedures:
nido-[9-Me2S-7,8-C2B9H11],[4a] nido-[7-R-10-L-7,8-C2B9H10] (R =
H, L = Me2S, THT, EtPhS; R = H, L = Me2S)[4] and [RuCl2(η6-
arene)]2 (arene = benzene, p-cymene).[12] NMR spectra were ac-
quired with a Bruker ARX 300 MHz spectrometer and referenced
to the solvent (1H, residual signals of [D5]acetone, [D2]acetonitrile
or [D7]THF; 13C signals of [D6]acetone or [D3]acetonitrile),[26]
BF3·OEt2 (11B NMR) or PPh3 (31P NMR; a C6D6 solution in an
internal sealed capillary, δ = –5.00 ppm). Chemical shifts are re-
ported in ppm and coupling constants in Hz. Multiplet nomencla-
ture is as follows: s, singlet; d, doublet; t, triplet; sept, septuplet;
br., broad; m, multiplet. Chromatography was carried out using
ACROS silica gel (0.035–0.070 mm, pore diameter ca. 6 nm).
Microanalyses were conducted with a Carlo Erba EA1108 instru-
ment. The mass spectra were recorded in the negative ion mode
s, 1 H), 3.02 (br. s, 2 H), 1.86 (br. s, 2 H), 1.70 (m, 3 H) ppm. 11B
1
NMR ([D6]acetone): δ = 7.1 (s, 1 B, B-8), 1.9 (d, JB,H = 148 Hz,
1 B, B-10), –6.9 (d, 1JB,H = 153 Hz, 2 B, B-4 and -7), –9.8 (d, 1JB,H
1
= 144 Hz, 2 B, B-9 and -12), –17.5 (d, JB,H = 155 Hz, 2 B, B-5
1
and 11), –22.0 (d, JB,H = 169 Hz, 1 B, B-6) ppm. 13C{1H} NMR
([D6]acetone): δ = 92.6 (s, η6-benzene), 49.4 (br. s, Cc-H), 24.5 (s,
1
Me2S) ppm. 31P NMR ([D6]acetone): δ = –143.7 (sept, JP,F
=
708 Hz, PF6) ppm.
4: Concentration of the above-mentioned supernatant orange THF
solution afforded a mixture of 4 and closo-[3,3Ј-Ru-(8-Me2S-1,2-
C2B9H10)2] as an orange residue. Chromatographic separation on
silica gel using THF as the eluent afforded closo-[3,3Ј-Ru-(8-Me2S-
1,2-C2B9H10)2] (Rf = 0.63) as a yellow-orange solid (10.0 mg,
0.020 mmol, 8%) and 4 (Rf = 0.50) as a yellow solid after washing
with cold CH2Cl2 (36.4 mg, 0.106 mmol, 22%). C8H17B9RuS
(343.65): calcd. C 27.96, H 4.99, S 9.33; found C 28.09, H 4.74, S
8.39. 1H NMR ([D6]acetone): δ = 6.38 (s, 6 H, η6-benzene), 4.31
(br. s, 2 H, Cc-H), 0.87 (br. m, 1 H, SH) ppm. 1H{11B} NMR ([D6]
acetone; only signals due to B-H protons are given): δ = 3.09 (br.
s, 1 H), 2.91 (br. s, 2 H), 1.99 (br. s, 2 H), 1.53 (br. s, 2 H), 1.31
(br. s, 1 H) ppm. 11B NMR ([D6]acetone): δ = 14.3 (s, 1 B, B-8),
using a Bruker Biflex MALDI-TOF instrument [N2 laser; λexc
=
337 nm (0.5 ns pulses); voltage ion source 20.00 kV (Uis1) and
17.20 kV (Uis2)]. Photochemical reactions were performed in a
quartz Schlenk vessel equipped with a magnetic bar and condenser.
The unfiltered output of an in-house 76.8 W medium-pressure mer-
cury lamp was used as a light source.
1
1
–1.1 (d, JB,H = 140 Hz, 1 B, B-10), –6.9 (d, JB,H = 144 Hz, 2 B,
1
B-4 and -7), –8.5 (d, JB,H = 160 Hz, 2 B, B-9 and -12), –20.0 [d,
1JB,H = 155 Hz, 2 B, B-5 and -11), –27.5 (d, JB,H = 170 Hz, 1B,
1
B-6) ppm. 13C{1H} NMR ([D6]acetone): δ = 92.1 (s, η6-benzene),
46.2 (br. s, Cc-H) ppm.
closo-[3-Ru(η6-benzene)-8-Me2S-1,2-C2B9H10]+ (1a) and closo-[3-
Ru(η6-benzene)-8-HS-1,2-C2B9H10] (4). General Procedure:
A
Schlenk flask was charged with nido-[10-Me2S-7,8-C2B9H11]
(95.1 mg, 0.489 mmol), tBuOK (0.550 mL, 1.0 ) and THF
(10 mL). The mixture was stirred at room temperature for 30 min
giving a clear pale yellow solution. The flask was then charged with
[RuCl2(η6-benzene)]2 (122.4 mg, 0.245 mmol) and the resultant
heterogeneous brown mixture was stirred at room temperature for
3 d. Workup for 1a and 4 was as follows:
The synthesis was repeated in a modified form to identify the vola-
tile by-product MeCl. A Schlenk flask was charged with 10-Me2S-
7,8-nido-C2B9H11 (294.0 mg, 1.513 mmol), tBuOK (1.65 mL, 1.0 )
and THF (20 mL). The mixture was stirred at room temperature
for 30 min affording a clear pale-yellow solution. The flask was
then charged with [RuCl2(η6-benzene)]2 (369.9 mg, 0.740 mmol),
closed with a rubber stopper and the resultant heterogeneous
brown mixture was stirred at room temperature for 3 d. MeCl gas
was detected using gas chromatography by comparing the retention
time with that of an authentic sample. 1H NMR identification was
also carried out (see in situ NMR studies below).
1a: A solid residue was separated from the supernatant orange
solution and transferred into another Schlenk vessel for further
isolation of 4 (vide infra). The solid residue remaining in the flask
was dried by oil-pump vacuum to give [1a]Cl and KCl as a pale
brown powder. Addition of an aqueous solution of NaPF6
(176.7 mg, 1.052 mmol) to the heterogeneous brown mixture of
[1a]Cl in ethanol (10 mL) resulted in the formation of a tan precipi-
closo-[3-Ru(η6-benzene)-8-THT-1,2-C2B9H10]+ (1b) and 4: The ge-
neral procedure described above was applied using nido-[10-THT-
7,8-C2B9H11] (103.9 mg, 0.471 mmol), tBuOK (0.48 mL, 1.0 ),
Eur. J. Inorg. Chem. 2005, 4193–4205
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4201

J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
THF (5 mL), [RuCl2(η6-benzene)]2 (116.9 mg, 0.234 mmol) and
NaPF6 (165 mg, 0.982 mmol) to give [1b]PF6 (51.0 mg,
0.094 mmol, 20%). The neutral complex 4 was separated and puri-
fied by chromatography as described above (41.7 mg, 0.121 mmol,
26%).
(3 s, o-, m- and p-SPh), 124.4 (s, i-SPh), 92.5 (s, η6-benzene), 49.9
(s, Cc-H), 49.2 (s, CcЈ-H), 37.6 [s, S(CH2CH3)], 10.7 [s, S(CH2CH3)]
1
ppm. 31P{1H} NMR ([D6]acetone): δ = –142.7 (sept, JP,F
=
708 Hz, PF6) ppm.
The reaction was repeated in a modified fashion to identify the
by-products PhCl and EtCl. 10-Me2S-7,8-nido-C2B9H11 (14.8 mg,
0.055 mmol), [D8]THF (0.50 mL) and a THF solution of tBuOK
(0.066 mL, 1.0 ) were placed into an NMR tube. The clear solu-
tion rapidly turned light yellow. After 20 min, the solution was
transferred under N2 by syringe to another NMR tube containing
1
[1b]Cl: H NMR ([D3]acetonitrile): δ = 6.53 (s, 6 H, η6-benzene),
4.42 (br. s, 2 H, Cc-H), 3.45 [m, 2 H, S(CHHЈCHЈЈHЈЈЈ)2], 3.03 [m,
3
2 H, S(CHHЈCHЈЈHЈЈЈ)2], 2.12 [br. t, JH,H = 7.5 Hz, 2 H,
3
S(CHHЈCHЈЈHЈЈЈ)2], 2.10 ppm [br. t, JH,H
= 7.8 Hz, 2 H,
S(CHHЈCHЈЈHЈЈЈ)2]. 11B NMR ([D3]acetonitrile): δ = 7.4 (s, 1 B,
B-8), 2.2 (d, JB,H = 144 Hz, 1 B, B-10), –6.7 [d, JB,H = 151 Hz, 2
B, B-4 and -7), –9.7 (d, JB,H = 145 Hz, 2 B, B-9 and -12), –17.8
(d, JB,H = 160 Hz, 2 B, B-5 and -11), –22.1 (d, JB,H = 183 Hz, 1
B, B-6) ppm. 13C{1H} NMR ([D3]acetonitrile): δ = 93.4 (s, η6-ben-
zene), 51.0 (s, Cc-H), 44.5 [s, S(CH2CH2)2], 30.4 [s, S(CH2CH2)2]
ppm.
1
1
[RuCl2(η6-benzene)]2 (13.4 mg, 0.026 mmol). PhCl [δ = 7.34–7.18
1
3
(m) ppm] and EtPhS [δ = 7.30–7.35 (m, 5 H, Ph), 2.95 (q, JH,H
=
1
1
3
7.5 Hz, 2 H, Et), 1.26 (t, JH,H = 7.5 Hz, 3 H, Et) ppm] were de-
tected by 1H NMR spectroscopy. Signals for THF prevented identi-
fication of EtCl due to overlapping of signals (proton resonances
for terminal B-H groups appear as broad unresolved peaks in the
range δ Ϸ 3.5–1.0 ppm).
[1b]PF6: C12H24B9F6PRuS (543.72): calcd. C 26.51, H 4.45, S 5.90;
found C 26.72, H 4.46, S 6.00. MALDI-TOF: m/z (%) = 397.9 (74)
closo-[3-Ru(η6-benzene)-1-Me-8-Me2S-1,2-C2B9H9]+ (2a) and closo-
[3-Ru(η6-benzene)-1-Me-8-HS-1,2-C2B9H9] (5): The general pro-
cedure described above was applied using nido-[10-Me2S-7-Me-8-
C2B9H10] (104.8 mg, 0.502 mmol), tBuOK (0.55 mL, 1.0 ), THF
(10 mL), [RuCl2(η6-benzene)]2 (125.7 mg, 0.251 mmol) and NaPF6
(114.0 mg, 0.665 mmol) to afford traces of [2a]PF6. The neutral
complex 5 was purified by chromatography as described above
(52.0 mg, 0.145 mmol, 29%).
1
[M + 1], 309.8 (100) [M + 1 – (CH2)4S]. H NMR ([D6]acetone): δ
= 6.82 (s, 6 H, η6-benzene), 4.67 (br. s, 2 H, Cc-H), 3.72 [m, 2 H,
S(CHHЈCHЈЈHЈЈЈ)2], 3.20 [m, 2 H, S(CHHЈCHЈЈHЈЈЈ)2], 2.22 [br. t,
3
3JH,H = 7.5 Hz, 2 H, S(CHHЈCHЈЈHЈЈЈ)2], 2.20 ppm [br. t, JH,H
=
6.6 Hz, 2 H, S(CHHЈCHЈЈHЈЈЈ)2]. 1H{11B} NMR ([D6]acetone;
only signals due to B-H protons are given): δ = 3.42 (br. s, 1 H),
3.06 (br. s, 2 H), 1.78 (br. s, 2 H), 1.68 (br. s, 3 H) ppm. 11B NMR
1
([D6]acetone): δ = 6.2 (s, 1 B, B-8), 1.2 (d, JB,H = 147 ppm, 1 B,
[2a]PF6: Selected NMR spectroscopic data are given: 1H NMR
([D6]acetone): δ = 6.82 (s, 6 H, η6-benzene), 4.97 (br. s, 1 H, Cc-
1
1
B-10), –8.0 (d, JB,H = 152 Hz, 2 B, B-4 and -7), –10.7 (d, JB,H
=
1
144 Hz, 2 B, B-9 and -12), –19.0 (d, JB,H = 156 Hz, 2 B, B-5 and
-11), –23.3 (d, 1JB,H = 174 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D6]
acetone): δ = 92.4 (s, η6-benzene), 49.3 (s, Cc-H), 45.7 [s,
S(CH2CH2)2], 43.2 [s, S(CH2CH2)2] ppm. 31P{1H} NMR ([D6]ace-
H), 2.25 (s, 3 H, Cc-Me), 2.66 (s, 3 H, SMe2), 2.60 (s, 3 H, SMe2)
1
ppm. 11B NMR ([D6]acetone): δ = 6.1 (s, 1 B, B-8), 1.7 (d, JB,H
=
156 Hz, 1 B, B-10), –4.5 to –18.5 (m, 6 B, B-4, -5, -7, -9, -11 and
-12), –22.1 (d, 1JB,H = 177 Hz, 1 B, B-6) ppm. 31P{1H} NMR ([D6]
1
tone): δ = –146.0 (sept, JP,F = 705 Hz, PF6) ppm.
1
acetone): δ = –142.6 (sept, JP,F = 707 Hz, PF6) ppm.
closo-[3-Ru(η6-benzene)-8-EtPhS-1,2-C2B9H10]+ (1c) and 4: The ge-
neral procedure described above was applied using nido-[10-EtPhS-
7,8-C2B9H11] (116.6 mg, 0.431 mmol), tBuOK (0.47 mL, 1.0 ),
THF (15 mL), [RuCl2(η6-benzene)]2 (107.9 mg, 0.216 mmol) and
NaPF6 (82.9 mg, 0.494 mmol) to afford [1c]PF6 (44.0 mg,
0.074 mmol, 17%). The neutral complex 4 (41.7 mg, 0.121 mmol,
28%) was isolated by chromatography as in the previous procedure.
5: C9H19B9RuS (357.68): calcd. C 30.22, H 5.35, S 8.96; found C
1
30.15, H 5.20, S 9.10. H NMR ([D6]acetone): δ = 6.40 (s, 6 H, η6-
benzene), 4.60 (br. s, 1 H, Cc-H), 2.17 (s, 3 H, Cc-Me), 0.87 (br. m,
1 H, SH) ppm. 1H{11B} NMR ([D6]acetone; only signals due to B-
H protons are given): δ = 3.17 (br. s, 2 H), 3.02 (br. s, 1 H), 2.07
(br. s, 2 H), 1.82 (br. s, 1 H), 1.62 (br. s, 2 H) ppm. 11B NMR ([D6]
1
acetone): δ = 15.0 (s, 1 B, B-8), 0.0 (d, JB,H = 143 Hz, 1 B, B-
[1c]Cl: 1H NMR ([D3]acetonitrile): δ = 7.80–7.50 (m, 5 H, SPh),
6.34 (s, 6 H, η6-benzene), 4.35 (br. s, 2 H, Cc-H), 3.40–3.15 [m, 2
10), –3.5 to –9.4 (4 B, B-4, -7, -9 and -12) (these signals can be
clearly observed in the 11B{1H } NMR spectrum as singlets for 1
B each at δ = –4.2, –5.5, –7.8, –8.6 ppm), –15.1 (d, 1JB,H = 155 Hz,
H, S(CH2CH3)], 1.14 [t, 3JH,H = 7.2 Hz, 3 H, S(CH2CH3)] ppm.[27]
1
11B NMR ([D3]acetonitrile): δ = 7.0 (s, 1 B, B-8), 2.1 (d, JB,H
=
1
1 B, B-5 or -11), –18.6 (d, JB,H = 156 Hz, 1 B, B-11 or -5), –22.0
1
170 Hz, 1 B, B-10), –6.7 (d, JB,H = 139 Hz, 2 B, B-4 and -7), –9.4
(d, JB,H = 133 Hz, 1 B, B-9 or -12), –9.9 (d, JB,H = 122 Hz, 1 B,
B-12 or -9), –17.6 (d, JB,H = 162 Hz, 2 B, B-5 and -11), –21.8 (d,
1
(d, JB,H = 172 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D6]acetone):
1
1
δ = 93.02 (s, η6-benzene), 68.40 (br. s, Cc-Me), 55.03 (br. s, Cc-H),
35.15 (s, Cc-Me) ppm.
1
1JB,H = 190 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D3]acetonitrile):
δ = 134.2, 133.0, 131.7 (3 s, o-, m- and p-SPh), 93.2 (s, η6-benzene),
49.9 (s, Cc-H), 49.3 (s, CcЈ-H), 38.7 [s, S(CH2CH3)], 11.5 [s,
S(CH2CH3)] ppm.
closo-[3-Ru(η6-p-cymene)-8-Me2S-1,2-C2B9H10]+ (3a) and closo-[3-
Ru(η6-p-cymene)-8-HS-1,2-C2B9H10] (6): The general procedure de-
scribed above was applied using nido-[10-Me2S-7,8-C2B9H11]
(90.5 mg, 0.466 mmol), tBuOK (0.51 mL, 1.0 ), THF (15 mL),
[RuCl2(η6-p-cymene)]2 (143.1 mg, 0.234 mmol) and NaPF6
(78.8 mg, 0.469 mmol) to afford [3a]PF6 (107.3 mg, 0.187 mmol,
40%). From the procedure described above, a brown-orange oily
mixture, which was found to include the neutral complexes 6 (Rf =
0.69) and closo-[3,3Ј-Ru-(8-Me2S-1,2-C2B9H10)2] (Rf = 0.63), was
obtained and characterised spectroscopically.
[1c]PF6: MALDI-TOF: m/z (%) = 448.95 (77) [M], 310.93 (100)
1
3
[M – EtPhS]. H NMR ([D6]acetone): δ = 7.80 (d, JH,H = 6.9 Hz
3
3
2 H, o-SPh), 7.80 (d, JH,H = 7.2 Hz, 1 H, p-SPh), 7.73 (t, JH,H
=
6.9 Hz, 2 H, m-SPh), 6.62 (s, 6 H, η6-benzene), 4.61 (br. s, 2 H, Cc-
2
H), 3.50 [dq, JH,H = 13.2 Hz, 3JH,H = 7.3 Hz, 1 H, S(CHHЈCH3)],
3.41 [dq, 2JH,H = 13.2 Hz, 3JH,H = 7.3 Hz, 1 H, S(CHHЈCH3)], 1.27
[t, JH,H = 7.3 Hz, 3 H, S(CHHЈCH3)] ppm.[28] 11B NMR ([D6]
3
1
1
2
acetone): δ = 7.1 (s, 1 B, B-8), 2.1 (d, JB,H = 148 Hz, 1 B, B-10),
–6.6 (d, JB,H = 145 Hz, 2 B, B-4 and -7), –9.2 (d, JB,H = 141 Hz, H, m- of p-cymene), 6.33 (d, JH,H = 6.6 Hz, 2 H, o- of p-cymene),
[3a]Cl: H NMR ([D3]acetonitrile): δ = 6.38 (d, JH,H = 6.6 Hz, 2
1
1
2
1
3
1 B, B-9 or -12), –9.9 (d, JB,H = 132 Hz, 1 B, B-12 or -9), –17.6
4.30 (br. s, 2 H, Cc-H), 2.98 (sept, JH,H = 6.6 Hz, 1 H,
MeC6H4CHMe2), 2.46 (s, H, Me2S), 2.42 (S, H,
B, B-6) ppm. 13C{1H} NMR ([D6]acetone): δ = 133.3, 132.1, 130.7 MeC6H4CHMe2), 1.32 (d, JH,H = 6.9 Hz, 6 H, MeC6H4CHMe2)
1
1
(d, JB,H = 154 Hz, 2 B, B-5 and -11), –21.7 (d, JB,H = 172 Hz, 1
6
3
3
4202
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2005, 4193–4205

B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
FULL PAPER
ppm. 1H{11B} NMR ([D3]acetonitrile; only signals due to B-H pro-
tons are given): δ = 3.31 (br. s, 1 H), 2.64 (br. s, 2 H), 2.50–2.30
(m, 2 H), 1.79 (br. s, 1 H), 1.66 (br. s, 2 H) ppm. 11B NMR ([D3]
(br. s, 1 H), 1.64 (br. s, 2 H), 1.38 (br. m, 3 H) ppm. 11B NMR
([D6]acetone): δ = 6.4 (s, 1 B, B-7), 4.91 (d, JB,H = 114 Hz; this
1
resonance overlaps partially with the signal at δ = 6.36 ppm so that
1
1
acetonitrile): δ = 7.0 (s, 1 B, B-8), 1.0 (d, JB,H = 138 Hz, 1 B, B-
the coupling constant is an estimate, 1 B, B-8), 1.2 (d, JB,H
=
1
1
1
10), –5.8 (d, JB,H = 146 Hz, 2 B, B-4 and 7), –9.9 (d, JB,H
=
127 Hz, 1 B, B-10), –6.6 (d, JB,H = 159 Hz, 2 B, B-4 and -12),
–8.3 (d, JB,H = 171 Hz, 1 B, B-9), –17.0 (d, JB,H = 159 Hz, 1 B,
1
1
1
144 Hz, 2 B, B-9 and -12), –17.7 (d, JB,H = 165 Hz, 2 B, B-5 and
-11), –21.7 (d, 1JB,H = 169 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D3] B-5), –20.2 (d, 1JB,H = 169 Hz, 1 B, B-11), –22.1 (d, 1JB,H = 197 Hz,
acetonitrile): δ = 115.7 (s, CCHMe2), 106.4 (s, MeC), 92.1 (s, o- of 1 B, B-6) ppm. 13C{1H} NMR ([D6]acetone): δ = 91.0 (s, η6-ben-
p-cymene), 89.5 (s, m- of p-cymene), 49.5 (s, Cc-H), 31.3 (s,
MeC6H4CHMe2), 24.8 (s, SMe2), 21.8 (s, MeC6H4CHMe2), 18.0 (s,
MeC6H4CHMe2) ppm.
zene), 51.0 (br. s, Cc-H), 47.3 (br. s, CЈc-H), 14.7 (s, MeS) ppm.
Reaction of closo-[3-Ru(η6-benzene)-8-Me2S-1,2-C2B9H10][PF6]
([1a]PF6) with [Bu4N]Cl: A 5-mm NMR tube was charged with
solid [1a]PF6 (22.9 mg, 0.044 mmol), [Bu4N]Cl (13.6 mg,
0.046 mmol) and [D6]acetone (0.50 mL). A beige precipitate was
observed after a few minutes and a remaining pale yellow solution.
After 1 h, 1H and 11B NMR spectra showed no change in the chem-
ical shifts for all species but the ratio of [1a]+/[Bu4N]+ was found
to be 1:2. Addition of D2O (0.50 mL) was followed by dissolution
of the precipitate and the ratio between the latter species was re-
stored to 1:1. Whereas [1a]PF6 and [Bu4N]Cl are readily soluble in
[D6]acetone, [1a]Cl is only partially soluble. The NMR experiment
can be explained by a simple anion exchange reaction as shown in
Equation (2).
[3a]PF6: RuC14H30B9SPF6 (573.79): calcd. C 29.31, H 5.27, S 5.59;
found C 29.56, H 5.29, S 5.47. MALDI-TOF: m/z (%) = 429.00
1
(100) [M], 363.97 (22) [M – Me2S – 3 H]. H NMR ([D6]acetone):
2
2
δ = 6.63 (d, JH,H = 6.6 Hz, 2 H, m- of p-cymene), 6.58 (d, JH,H
= 6.6 Hz, 2 H, o- of p-cymene), 4.49 (br. s, 2 H, Cc-H), 3.11 (sept,
3JH,H = 6.8 Hz, 1 H, MeC6H4CHMe2), 2.65 (s, 6 H, Me2S), 2.53
3
(S,
3
H, MeC6H4CHMe2), 1.38 (d, JH,H
=
6.9 Hz,
6
H,
MeC6H4CHMe2) ppm. 1H{11B} NMR ([D6]acetone; only signals
due to B-H protons are given): δ = 3.38 (br. s, 1 H), 2.80–2.50 (br.
s, 2 H), 1.86 (br. s, 2 H), 1.69 (br. s, 3 H) ppm. 11B NMR ([D6]
1
acetone): δ = 7.2 (s, 1 B, B-8), 1.2 (d, JB,H = 144 Hz, 1 B, B-10),
1
1
–5.7 (d, JB,H = 146 Hz, 2 B, B-4 and -7), –9.8 (d, JB,H = 142 Hz,
Reaction of [RuCl2(η6-benzene)]2 with nido-[10-Me2S-7,8-
C2B9H10][K]. In situ NMR Studies: An analogous procedure for the
deprotonation of the carborane was applied: nido-[10-Me2S-7,8-
C2B9H11] (10.7 mg, 0.055 mmol), [D8]THF (0.50 mL) and a THF
solution of tBuOK (0.07 mL, 1.0 ) were mixed. The clear solution
rapidly turned light yellow. After 20 min, 1H and 11B NMR spectra
showed 100% conversion of nido-[10-Me2S-7,8-C2B9H11] to nido-
K[10-Me2S-7,8-C2B9H10] with concomitant formation of tBuOH.
The solution was then transferred by syringe to another NMR tube
containing [RuCl2(η6-benzene)]2 (13.7 mg, 0.028 mmol) under N2.
NMR spectra of the heterogeneous mixture were frequently re-
corded over a period of 6 d. Due to low solubility of the ruthena-
carborane [1a]Cl, no quantitative measure of concentration of the
species was obtained. However, the experiment clearly showed a
gradual and constant increase in 1a and 4, whereas nido-K[10-
Me2S-7,8-C2B9H10] decreased. A small amount of reprotonation of
the latter was observed, probably due to moisture in the solvent.
2 B, B-9 and -12), –17.6 (d, 1JB,H = 159 Hz, 2 B, B-5 and -11), –21.6
(d, JB,H = 195 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D6]acetone): δ
1
= 116.0 (s, CCHMe2), 106.8 (s, MeC), 92.5 (s, o- of p-cymene), 89.9
(s, m- of p-cymene), 49.5 (s, Cc-H), 31.7 (s, MeC6H4CHMe2), 24.9
(s, Me2S), 22.1 (s, MeC6H4CHMe2), 18.2 (s, MeC6H4CHMe2) ppm.
31P{1H} NMR ([D6]acetone): δ = –145.6 (sept, 1JP,F = 708 Hz, PF6)
ppm.
1
2
6: H NMR ([D6]acetone): δ = 6.17 (d, JH,H = 6.5 Hz, 2 H, m- of
2
p-cymene), 6.10 (d, JH,H = 6.5 Hz, 2 H, o- of p-cymene), 4.19 (br.
3
s, 2 H, Cc-H), 3.02 (sept, JH,H = 7.2 Hz, 1 H, MeC6H4CHMe2),
2.43 (s, 3 H, MeC), 1.35 (d, 3JH,H = 6.9 Hz, 6 H, MeC6H4CHMe2)
ppm. 11B NMR ([D6]acetone): δ = 13.6 (s, 1 B, B-8), –2.9 (d, JB,H
1
1
= 143 Hz, 1 B, B-10), –7.7 (d, JB,H = 137 Hz, 4 B, B-4, -7, -9 and
-12), –20.9 (d, JB,H = 154 Hz, 2 B, B-5 and -11), –27.9 (d, JB,H
1
1
=
183 Hz, 1 B, B-6) ppm. 13C{1H} NMR ([D6]acetone): δ = 113.2 (s,
CCHMe2), 104.1 (s, MeC), 92.9 (s, o- of p-cymene), 89.7 (s, m- of
p-cymene), 46.1 (s, Cc-H), 31.5 (s, MeC6H4CHMe2), 22.1 (s,
MeC6H4CHMe2), 18.0 (s, MeC6H4CHMe2) ppm.
1
MeCl (δ = 3.06 ppm) was also detected by H NMR spectroscopy
and a broad resonance at low field (δ = – 4.27 ppm) was observed
during the experiment which could be due to a B–HǞRu agostic
interaction. NMR spectroscopic data for nido-K[10-Me2S-7,8-
closo-[3-Ru(η6-benzene)-7-MeS-1,2-C2B9H10] (8): A Schlenk flask
was charged with tBuOK (52.5 mg, 0.408 mmol), nido-[9-Me2S-7,8-
C2B9H11] (64.9 mg, 0.334 mmol), THF (10 mL) and CH3CN
(1.0 mL). The mixture was stirred at room temperature for 30 min
giving a clear pale yellow solution. The flask was then charged
with [RuCl2(η6-benzene)]2 (81.5 mg, 0.167 mmol) and the resultant
heterogeneous brown mixture was stirred at room temperature for
3 d. The supernatant orange solution was filtered using a cannula
and transferred into another Schlenk vessel. The remaining solid
residue was washed with further THF (2×5 mL) and combined
with the orange solution. The orange residue obtained after evapo-
ration of the THF was then filtered through a short silica gel col-
umn using CH2Cl2 as eluent. Concentration of the eluate gave a
yellow-orange solid which was washed with Et2O (2×5 mL) to
eliminate of the remaining 9-Me2S-7,8-nido-C2B9H11 and complex
8 was obtained as a yellow solid (40.8 mg, 0.114 mmol, 34%).
C8H17B9RuS (343.65): calcd. C 30.22, H 5.35, S 8.96; found C
1
C2B9H10]: H NMR ([D8]THF): δ = 2.37 (s, 6 H, Me2S), 0.85 (br.
1
s, 2 H, Cc-H) ppm. H{11B} NMR ([D6]acetone; only signals due
to B-H protons are given): δ = 1.59 (br. s, 1 H), 1.0–0.6 (m, 6 H),
–0.16 (br. s, 1 H) ppm. 11B NMR ([D8]THF, 96 MHz): δ = –14.1
1
1
(br. s, 1 B, B-8), –18.2 (d, JB,H = 135 Hz, 3 B), –19.6 (d, JB,H
=
=
1
1
135 Hz, 2 B), –25.4 (d, JB,H = 132 Hz, 2 B), –45.9 (d, JB,H
134 Hz, 1 B, B-10) ppm.
Photolysis of closo-[3-Ru(η6-arene)-8-Me2S-1,2-C2B9H10][PF6]: An
acetonitrile solution (8.0 mL) of the benzene complex [1a]PF6
(36.4 mg, 0.070 mmol) or p-cymene complex [3a]PF6 (40.7 mg,
0.071 mmol) was irradiated with stirring for 3–5 d. Evaporation of
the solvent afforded unreacted starting material.
Calculation Details: The geometries for nido-[10- and 9-MeS-7,8-
C2B9H10]2– were obtained from the X-ray structures of nido-[10-
and 9-Me2S-7,8-C2B9H11].[4c,28] Geometries were then optimised
with AM1 semiempirical methods and a single-point UHF calcula-
tion at the 3-21G level using Hyperchem Release 7 for Windows
(Hypercube Inc.). A summary of selected charges is outlined in
Scheme 5.
1
30.24, H 5.37, S 8.71. H NMR ([D6]acetone): δ = 6.34 (s, 6 H, η6-
benzene), 4.51 (br. s, 1 H, Cc-H), 4.30 (br. s, 1 H, Cc-HЈ), 1.87 ppm
1
(s, 3 H, MeS). H{11B} NMR ([D6]acetone; only signals due to B-
H protons are given): δ = 3.22 (br. s, 1 H), 2.98 (br. s, 1 H), 2.49
Eur. J. Inorg. Chem. 2005, 4193–4205
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4203

J. G. Planas, C. Viñas, F. Teixidor, M. E. Light, M. B. Hursthouse, H. R. Ogilvie
FULL PAPER
[5]
A search of the February 2005 release of the Cambridge Struc-
tural Database revealed 498 examples of closo-[3-M-1,2-C2B9]
metallacarboranes, 33 of those having a B-attached sulfonium
group. With regards to the related ruthenacarboranes, 59 closo-
[3-Ru-1,2-C2B9] structures were found, 5 of which have a B-
attached sulfonium group.
A. R. Kudinov, D. S. Perekalin, P. V. Petrovskii, G. V. Grintse-
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Crystallography: Colourless crystals of [1a]PF6 were obtained from
acetone at room temperature. Cell parameters and intensity data
were collected with a Bruker Nonius Kappa CCD diffractometer
mounted at the window of a molybdenum rotating anode according
to standard procedures. Crystal data for 1a: Colourless block,
0.38×0.36×0.20 mm, C10H22B9F6PRuS, Mr
= 517.67, T =
[6]
[7]
120(2) K, monoclinic, P21/c, a = 6.6900(3), b = 30.6880(14), c =
9.4050(3) Å, β = 92.916(2)°, V = 1928.37(14) Å3, Z = 4, ρcalcd.
=
1.783 gcm–3, 2θmax = 27.47°, Mo-Kα (0.71073 Å) radiation, φ and
ω scans used to fill the asymmetric unit, 13685 reflections mea-
sured, 4324 independent reflections used in the refinement, Rint
=
0.0253, Lorentz polarisation corrections were made using Scale-
pack,[29] a multi-scan absorption correction was applied using SA-
DABS[30] (µ = 1.054 mm–1, min/max transmission factor ratio =
0.811856), the structure was solved by direct methods and refined
using full-matrix least squares with SHELX-97,[31] 253 parameters
were refined and hydrogen atoms were placed in calculated posi-
tions and refined using a riding model, final R indices [I Ͼ 2σ(I)]:
R1 = 0.0267, wR2 = 0.0818, R indices (all data): R1 = 0.0323. wR2
= 0.0860, largest difference peak/hole: 0.508/–0.486 eÅ–3. CCDC-
264406 contains the supplementary crystallographic data for this
paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
[8]
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J. G. Planas, C. Viñas, F. Teixidor, M. B. Hursthouse, M. E.
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Acknowlegments
We thank CICYT (Project MAT2004-01108), Generalitat de Cata-
lunya (2001/SGR/00337), CSIC (I3P contract to J. G. P.), and the
UK EPSRC for support.
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© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Eur. J. Inorg. Chem. 2005, 4193–4205

B-Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and –Mercaptan Complexes
FULL PAPER
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Received: May 24, 2005
Published Online: September 5, 2005
Eur. J. Inorg. Chem. 2005, 4193–4205
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4205