Preparative and structural studies on sulfur-linked carborane icosahedra: 2-Phenyl-ortho-carboranyl-sulfur systems (2-Ph-1,2-C2B 10H10)2X (X = S, S2 or SO), and ortho-carboran-di-yl systems (1,2-C<sub

Article abstract of DOI:10.1016/j.poly.2005.06.046

Details are reported of the preparation and X-ray structural characterisation of the new compounds (PhCb^o)₂X, where PhCb^o = 2-Ph-1,2-C₂B₁₀H₁₀ and X = S (1) or SO (3), prepared from PhCb

Full text of DOI:10.1016/j.poly.2005.06.046

Polyhedron 25 (2006) 300–306
www.elsevier.com/locate/poly
Preparative and structural studies on sulfur-linked
carborane icosahedra: 2-Phenyl-ortho-carboranyl-sulfur systems
(2-Ph-1,2-C2B10H10)2X (X = S, S2 or SO), and
ortho-carboran-di-yl systems (1,2-C2B10H10Y)2 (Y = S or SO)
a
b
a
a,
*
Andrei S. Batsanov , William Clegg , Royston C.B. Copley , Mark A. Fox
,
a
a
a
a
Wendy R. Gill , Rachel S. Grimditch , Thomas G. Hibbert , Judith A.K. Howard ,
a
a
J.A. Hugh MacBride , Kenneth Wade
a
Chemistry Department, Durham University Science Laboratories, South Road, Durham, DH1 3LE, UK
School of Natural Sciences (Chemistry), University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK
b
Received 20 April 2005; accepted 30 June 2005
Available online 24 August 2005
Dedicated to Malcolm Chisholm on the occasion of his 60th birthday.
Abstract
Details are reported of the preparation and X-ray structural characterisation of the new compounds (PhCbo)2X, where
PhCbo = 2-Ph-1,2-C2B10H10 and X = S (1) or SO (3), prepared from PhCboLi and SCl2 or SOCl2 respectively, as well as the known
compound with X = S2 (2). Hydrogen in the presence of palladium/carbon reduced (3) to (1). Features of their structures (exo C–S
and cage C–C distances and substituent orientations) are consistent with significant exo S@C dative p-bonding from their sulfur
atoms to the cage hypercarbon atoms and weak exo p-bonding from the phenyl groups. Attempts to prepare systems (CboY)2,
in which two ortho-carboran-di-yl residues Cbo are linked through two bridging units Y (S, SO) are also reported, as are their cal-
culated structures.
ꢀ 2005 Elsevier Ltd. All rights reserved.
Keywords: Carborane; Sulfur; Thionyl chloride; Cycles; Crystal structure
1. Introduction
sulfur halides were used primarily to prepare derivatives
of formula types HCB10H10CSR, RCB10H10CSR0 or
RSCB10H10CSR0, where R and R0 = H, alkyl or aryl
[1–8]. Derivatives Cbo(SR)2 of ortho carborane have at-
tracted particular interest, in part in connection with
their ligand potential, whether as bidentate chelating li-
gands, or as components of macrocycles when the sub-
stituents R are linked through successive ether or
thioether units [9,10]. Where SR is SH they can be used
as precursors to form [closo-RC2B10H10S]ꢀ or [closo-
C2B10H10S2]2ꢀ anionic residues [11–18]. They have also
Researches into carboranes with cage C–sulfur sub-
stituents were originally developed in the 1960s [1–4]
and after a quiet period have acquired renewed momen-
tum recently. Reactions between alkali metal (normally
lithium) carborane derivatives and elemental sulfur or
*
Corresponding author. Tel.: +0191 374 3138; fax: +0191 384 4734.
E-mail address: m.a.fox@durham.ac.uk (M.A. Fox).
0277-5387/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2005.06.046

A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
301
been used as precursors from which [nido-
2. Results and discussion
C2B9H9(SR)2]2ꢀ anionic residues, offering yet further li-
gand potential, can be prepared [19–22].
2.1. Preparative aspects
Although many C–sulfur ortho-carboranes are now
listed in the Cambridge Structural Database [23], it is
perhaps surprising to find that there is only one reported
compound, [CboSCboSiMe2] [24], in which two ortho-
carboran-di-yl residues are linked through their carbon
atoms by a single sulfur atom. This compound also con-
tains a dimethylsilyl bridge between the two carboran-
di-yl residues [24]. One other compound, (MeCbo)2S,
with a sulfur bridge between ortho-carboranyl residues
has been reported [4] but it was not structurally
characterised.
In previous studies of the derivative chemistry of ico-
sahedral carboranes, we have explored the effect on the
2-phenyl-ortho-carborane cage of the attachment of
more strongly p-donor substituents to the cage hyper-
carbon atom C1 and found that the cage opens up from
a closo to a near nido geometry as the exo bond order
increases [25–27]. Our own published work so far has
concentrated on one-cage systems and here we extend
our investigation to the effect of one p-donating atom
connected to two ortho-carborane cages. We prepared
systems (PhCbo)2X (X = S (1), S2 (2) or SO (3)) in which
the second cage carbon atom bore a phenyl substituent
[26,28], choosing 2-phenyl-ortho-carborane derivatives
because they generally form suitable crystals for X-ray
crystallographic studies (over fifty such compounds have
been structurally characterised) [29–34]. We also ex-
plored the synthesis of heterocyclic systems (CboY)2
(Y = S (4) or SO (5)) in which two C–S–C or C–S(O)–C
bridges link pairs of ortho carborane icosahedra, and
report calculated structures of (4) and (5). (See Fig. 1
for representative structures of (1)–(5).)
The new compounds (1) and (3) prepared in the pres-
ent work were made from the lithio-carborane PhCboLi
with SCl2 and SOCl2, respectively, and characterised by
NMR spectroscopic, elemental analytical and X-ray
crystallographic study. To our knowledge, thionyl chlo-
ride has not been used to make carboranyl sulfur com-
pounds previously. Compound 3 represents the first
example containing an SO link between two ortho-carb-
oranyl residues. It is easily reduced to compound 1 with
hydrogen in the presence of palladium-carbon. It is,
however, quite susceptible to deboronation. While
compound 1 is stable in wet DMSO, compound 3 in
wet DMSO ꢀ gave
a mixture of derivatives with
nido-C2B9H12 residues detected by NMR spectroscopy,
and C–S cleavage was also evident. Some carboranyl
derivatives are known to be susceptible to deboronation
with mild solvents such as DMSO and alcohols [36–38].
Here, carboranes with C–S(O)R substituents were found
to be much more susceptible to C–S bond cleavage and
deboronation than those with C–SR substituents, as ex-
pected because the S(O)R residue is more electron-with-
drawing than SR, facilitating nucleophilic attack on the
most positive boron atom at B3 (or B6). The known
compound 2 was made from PhCboLi with sulfur and
then oxidised with iodine [4].
Attempts to prepare and characterise (4) and (5),
from reactions between dilithio-ortho-carborane and
sulfur dichloride and thionyl chloride, respectively, were
less successful in that, although the reactions appeared
to proceed to formation of lithium chloride and the in-
tended products (4) and (5) (obtained as colourless
microcrystalline materials analysing correctly for the ex-
pected products), attempts to grow crystals suitable for
X-ray characterisation were unsuccessful. Unlike 4,
compound 5 could not be purified further due to its fac-
ile deboronation and C–S bond cleavage with certain
solvents.
A very recent paper [35] by Vinas, Teixidor et al. on
˜
synthesis and structural characterisation of carborane
mono- and di-sulfides appeared during submission of
this work. While our synthetic route to the monosulfide
differed from theirs, their structural findings and inter-
pretations broadly agree with ours.
2.2. Structural aspects
1
2
3
X = S
2.2.1. Systems (PhCbo)2S, (PhCboS2, (PhCboS)2S and
(PhCbo)2SO
Compounds 1–3, like the related trisulfide
(PhCboS)2S we have described elsewhere [27], all adopt
orientations of their exo-SR units, and have cage C–C
and exo C–S distances, consistent with significant dative
X = S2
X = SO
C
X
C
C
C
S
C p-bonding from their exo-sulfur atoms to their
Y
cage hypercarbon atoms (see Figs. 2–4 and Table 1,
which lists selected bond distances and angles for com-
pounds 1–3 and the trisulfide (PhCboS)2S). For com-
pound 1 the exo bonds C–S–C lie in a plane roughly
perpendicular to the C(2)–C(1)–S plane whereas for 2,
C
C
4
Y = S
Y = SO
5
C
C
Y
Fig. 1. Representative structures of the title compounds (1)–(5).

302
A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
Fig. 4. Molecular structure of 3.
other substituent on C(1), and maximises the opportu-
nity for dative p-bonding from the p-system of the phe-
nyl group to the carborane cage [39,40].
Fig. 2. Molecular structure of 1, showing thermal ellipsoids at 50%
The cage carbon–carbon distance, C(1)–C(2), of ortho
carborane is the cage edge link known to be most sensi-
tive to the presence of p-bonding substituents on the cage
hypercarbon atoms [27,41–43]. Its length increases as exo
p-bonding increases. Steric effects have previously been
invoked to explain the lengthening of the cage C–C bond
in various disubstituted-ortho-carboranes [29–34]. In
ortho carborane itself, HCboH, the C(1)–C(2) distance
probability level.
˚
has been shown to be 1.62 A by both X-ray studies of
crystalline hydrogen-bonded adducts [44–47] and by
gas-phase electron diffraction and calculational studies
[48]. Attachment of a phenyl substituent to one carbon
atom, oriented (as here) so that its ring plane is roughly
perpendicular to the C(1)–C(2)–C(phenyl) plane, in-
˚
creases the cage C(1)–C(2) distance by some 0.04 A to
˚
1.66 A [49]. In compound 2 (Table 1), where the orienta-
tions of the sulfur and phenyl substituents offer greater
exo p-bonding effects compared to the trisulfide, the
˚
C(1)–C(2) distance is 1.755(4) A. The sulfur atom length-
˚
ens the C(1)–C(2) bond distance by some 0.1 A. The tri-
Fig. 3. Molecular structure of 2.
sulfide has a shorter C(1)–C(2) bond distance of 1.735(3)
A, as expected for orientations of the substituents which
˚
3 and the trisulfide these bond orientations depart
more from perpendicular (see torsion angle C–S–C/S
in Table 1). We recently showed, in our discussion of
a series of systems PhCboZ showing exo C Z p-bond-
ing (including the trisulfide (PhCboS)2S), that such a
perpendicular orientation optimised exo p-bonding [27].
The phenyl substituent on C(2) in compounds 2 and 3
also lies in a plane roughly perpendicular to the plane
C(2)–C(1)–S, whereas in 1 and the trisulfide the orienta-
tions depart more from perpendicular. A perpendicular
orientation minimises non-bonding repulsions with the
lead to less effective exo p-bonding.
Surprisingly, compounds 1 and 2 have similar C(1)–
C(2) and C(1)–S distances, suggesting a similar degree
of S C p-bonding in these two compounds. We had
expected there to be weaker S C p-bonding in 1, where
both carborane cages are attached to the same sulfur
atom, and so competing for p-electron density from
the same source. The C–S–C angle in 1 (112.8(1)ꢁ) is sig-
nificantly greater than the C–S–S angle in 2 (105.5(2)ꢁ)
which is due to steric repulsion between the two cages.
Intramolecular B–Hꢁ ꢁ ꢁH–B distances between the two

A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
303
Table 1
Selected bond distances (A) and angles (ꢁ) (averaged where variations are statistically insignificant) in X-ray structures of C–sulfur ortho-carboranes
˚
Compound
(PhCbo)2S (1)a
(PhCbo)2S2 (2)a
(PhCboS)2Sb
(PhCbo)2SO (3)a
PyCboSHc
PhCboSHb,d
C(1)–C(2)
C(1)–S
C(2)–C(Ph)
C(1)–B(3)/(6)
C(1)–B(4)/(5)
C(2)–C(1)–S
1.751(3)
1.789(2)
1.510(3)
1.725(10)g
1.714(11)g
116.1(2)
1.755(4)
1.796(3)
1.499(5)
1.709(5)
1.698(5)
114.6(2)
1.735(3)
1.788(3)
1.499(3)
1.716(4)
1.702(7)g
115.9(2)
117.6(2)
105.4(1)
123.3(2)
ꢀ96.1(2)
73.7(2)
1.729(3)
1.859(2)
1.505(3)
1.722(10)g
1.700(3)
110.7(1)
106.0(1)
106.2(1)
ꢀ124.2(1)
160.4(1)
87.6(1)
1.730(3)
1.775(2)
1.507(3)e
1.720(3)
1.709(3)
117.7(1)
1.729
1.782
1.495
1.705
1.700
117.5
C(1)–S–Ef
C(2)–C(1)–S–Ef
112.8(1)
99.1(2)
97.1(2)
74.5(3)
105.5(1)
108.0(2)
113.1(2)
81.7(3)
96(1)
99(2)
95.1
96.8
C(1)–C(2)/Phh
84.3(2)e
88.7
88.9(3)
89.0(1)
a
This work.
Ref. [27].
b
c
Ref. [50], low-temperature structure.
MP2/6-31G* calculation.
Py for Ph.
d
e
f
E = C (1, 3), S (2).
g
h
˚
Shows statistically significant variations, individual e.s.d.ꢀs 0.003–0.004 A, which relate to the orientation of the group at sulfur.
Calculated as the angle between the Ph (Py) ring and the C1–C2–C(Ph/Py) moiety.
˚
cages are 2.27, 2.40 and 2.49 A. Interestingly, the C(1)–
structures had separately been determined by X-ray
studies [27]. Selected bond distances and angles are listed
in Table 2, which also gives comparable bond distances
and angles determined crystallographically for the com-
pound (CboSCboSiMe2) [24].
o
˚
C(2) bond in 2 is some 0.03 A longer than in PyCb SH
(X-ray [50]) and PhCboSH (calc [27]) which suggests
that the disulfur bridge (S–S) is a more effective p-bond
donor to the ortho-carborane cage than is a thiol (S–H)
group.
˚
The C–C bond length of 1.62 A in the calculated
The C(1)–C(2) and C(1)–S distances in compound 3,
(PhCbo)2SO (Table 1), differ from those in 1 and 2,
though less than expected. The electron-withdrawing
oxygen atom on the bridging sulfur atom in 3 was
expected to reduce its capacity for S C exo p-bonding
relative to the lower oxidation state bridging sulfur atoms
in 1 and 2. Compound 3 appears to be affected (though to
a lesser extent than 1) by repulsive interactions between
the cages; shortest intramolecular B–Hꢁ ꢁ ꢁH–B contacts
structure of 4 (see Fig. 5) is identical to that of parent
ortho-carborane [48]. This may reflect both ring strain
in the C4S2 heterocycle and inappropriate orientations
of the bonds at sulfur for exo dative p-bonding to the
cage C–C bond. The reported crystal structure of a re-
lated heterocycle, CboS2C@S, has a cage C–C bond
˚
length of 1.632(3) A [53]. These lengths contrast with
˚
long cage C(1)–C(2) distances of 1.80 A reported for
neutral Cbo(SR)2 systems (R = Me or Ph) [43,54]. In
5, the two SO moieties may exist in trans or the more
stable cis configuration. The cis-configuration is lower
by only 0.1 kcal molꢀ1. As expected, the C–S distance
in the sulfoxy compound is longer than that in the
sulfide.
˚
in 3 are 2.25 and 2.37 A, and the C–S–C angle is
106.2(1). The exo-C–S bond distance in 3 is some
˚
0.07 A longer (less p-bonding) than that in 1. Interest-
ingly, 1 and 3 differ in their conformations, 1 is trans
and 3 is cis. Besides our derivatives and those in the very
recent report [35], only two neutral RCboSR0 systems
have been structurally characterised: HCboSpy [51]
(Py = 20-pyridyl) and MeCboSPh [52] with C–S distances
Table 2
o
o
˚
˚
Selected bond distances (A) and angles for the compounds (Cb SCb -
SiMe2), (CboS)2 and (CboSO)2
of 1.78 A and cage C(1)–C(2) distances of 1.64 and
˚
1.71 A, respectively.
Compound
(CboSCboSiMe2)a (CboS)2 (CboSO)2 HCboHc
(4)b (5)b
2.2.2. Systems (CboS)2 and (CboSO)2
C(1)–C(2)
C(1)–S
C(1)–B(3)/(6)
C–S–C
1.652(4)
1.794(3)
1.721(6)
111.2(2)
126.2(3)
1.621 1.637
1.62
Although our attempts to prepare crystalline samples
of these species suitable for X-ray characterisation were
unsuccessful, we carried out calculations to determine
their likely structures, encouraged by our previous expe-
rience of the reliability of such calculations for calculat-
ing the structures of derivatives of ortho-carborane
containing dative p-bonding substituents for which
1.800
1.734
1.873
1.716
1.71
106.9
126.6
101.5
129.2
C–C–S
a
Ref. [24].
b
This work, calculated at MP2/6-31G*.
Refs. [44–48].
c

304
A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
a Varian Unity 300 MHz spectrometer equipped with
the appropriate decoupling accessories. Chemical shift
values for 11B NMR spectra were referenced to external
1
BF3 Æ OEt2, those for H- and 13C{1H} NMR spectra
1
were referenced to SiMe4. H NMR spectra were refer-
enced to residual protio impurity in the solvent (CDCl3,
7.26 ppm). 13C NMR spectra were referenced to the sol-
vent resonance (CDCl3, 77.0 ppm). Chemical shifts are
reported in units of parts per million downfield from ref-
erence. Mass spectra (MS) were recorded on a VG
Micromass 7070E instrument under E.I conditions
(EI) at 70 eV.
4.2. Preparation of 1
Phenyl-ortho-carborane (0.71 g, 3.2 mmol) was dis-
solved in diethyl ether (20 ml) and BuLi (2.4 ml of
1.6 M solution in hexane, 3.8 mmol) was added under
a nitrogen atmosphere at 0 ꢁC. Sulfur dichloride
(0.1 ml, 1.6 mmol) in diethyl ether (5 ml) was added.
The solution was stirred at ambient temperature for
2 h. The solution was diluted with ether (60 ml). A white
precipitate (0.22 g) was filtered off. The solution was
washed with water (3 · 50 ml) and dried over MgSO4.
The solvent was removed under reduced pressure to
yield white crystals. The crystals were washed with 60–
80ꢁ petroleum ether to remove unreacted carborane,
then recrystallised from a 50:50 benzene–hexane mixture
(0.36 g, 49%). M.p. 237 ꢁC. Anal. Calc. for C16H30B20S:
C, 40.8; H, 6.4. Found: C, 41.0; H, 6.5%. EI-MS 452–
476 (with characteristic carborane isotope pattern). dH
7.6–7.2 (phenyl), 3.8–0.8 (BH). dB ꢀ1.3 (1B), ꢀ3.2
(1B), ꢀ9.8 (6B), ꢀ12.0 (2B).
Fig. 5. MP2-optimised geometries for 4 and 5.
3. Conclusions
The monosulfide (PhCbo)2S and sulfoxide (PhCbo)2SO
in which two phenyl-ortho-carborane residues are linked
at the cage carbon through a sulfur atom were synthes-
ised simply by reactions of the lithio-ortho-carborane
PhCboLi with sulfur dichloride or thionyl chloride,
respectively. Their structures show significant cage
C(1)–C(2) bond lengthening relative to the parent carbo-
rane, an effect attributable mainly to p-bonding from the
sulfur atom and to a lesser extent to p-bonding from the
phenyl substituent. By contrast, the C(1)–C(2) bond
lengths in the heterocyclic system (CboS)2, in which
two C–S–C bridges link pairs of ortho carborane icosa-
hedra, are calculated to be similar to the parent ortho
carborane.
4.3. Preparation of 3
To a solution of 1-phenyl-ortho-carborane (925 mg,
4.2 mmol) in dry ether (40 ml) at 0 ꢁC was added nBuLi
in hexanes (1.6 ml, 2.7 M, 4.2 mmol), and this was stir-
red under N2 for 1 h. SOCl2 (0.19 ml, 2.1 mmol) was
added, forming a white precipitate (LiCl). After warm-
ing to room temperature, the solid was removed by fil-
tration, and the ether evaporated, leaving a white
solid. Pure 3 was obtained by recrystallisation from a
mixture of ethyl acetate and cyclohexane (1:9), affording
colourless crystals. (0.35 g, 34%). M.p. 262 ꢁC. Anal.
Calc. for C16H30B20SO: C, 39.5; H, 6.2. Found: C,
39.7; H, 6.3%. EI-MS 484-489 (with characteristic car-
borane isotope pattern). dH 7.4–7.2 (phenyl), 3.8–0.8
(BH). dB 1.5 (1B), ꢀ3.1 (1B), ꢀ8.6 (6B), ꢀ11.7 (2B).
dC 131.9, 131.3, 128.8, 128.5, 92.3, 87.3.
4. Experimental
4.1. General
All manipulations were carried out under dry, oxy-
gen-free N2. Commercial grade acetic acid, 10% palla-
dium on carbon, SCl2, SOCl2 and n-butyllithium in
hexanes were used without further purification. Dry
Et2O was obtained by reflux and distillation over Na
wire. Demineralised water was used in the aqueous
stages of syntheses. Compound 2 was prepared by the
literature method [4].
4.4. Reduction of 3
Elemental analyses were performed using Exeter
1
Analytical CE-440 apparatus. H, 11B, 13C NMR spec-
Hydrogen gas was slowly bubbled through a stirred
tra were recorded from room-temperature solutions on
suspension of 3 (84 mg, 0.17 mmol) and 10% palladium

A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
305
Table 3
Crystallographic data
on carbon (15 mg) in acetic acid (10 ml) for 15 h. Re-
moval of the solvent from the filtered solution gave crys-
1
2
3
talline 1 (54 mg, 66%).
Chemical formula
Formula weight
T (K)
C16H30B20
470.7
150
S
C16H30B20S2 C16H30B20OS
502.7
486.7
4.5. Preparation of 4
293
296
˚
k (A)
0.71073
1.54184
1.54178
ortho-Carborane (1.11 g, 7.72 mol) was dissolved at
0 ꢁC in dry ether (30 ml) under N2 and nBuLi in hexanes
(6.4 ml, 2.42 M, 15.4 mmol) was added, precipitating
white 1,2-dilithio-ortho-carborane. After 15 min stirring,
SCl2 (0.50 ml, 811 mg, 7.9 mmol) was added and the
reaction was left to warm to room temperature over
1 h. Water (30 ml) was added and the ether layer was
further washed before being isolated and dried over
MgSO4. Filtration and removal of the solvent gave a
white solid which was sublimed in vacuo at 40 ꢁC to re-
move unreacted ortho-carborane, then at 100 ꢁC to give
a white powder identified as pure 4. 73.6 mg (5%). M.p.
122 ꢁC. Anal. Calc. for C4H20B20S2: C, 13.8; H, 5.8.
Found: C, 14.0; H, 5.9%. EI-MS, 346–352 (typical car-
borane isotope pattern).
Crystal system
Space group
Unit cell dimensions
monoclinic
P21/n
triclinic
triclinic
ꢀ
ꢀ
P1
P1
˚
a (A)
10.806(2)
17.727(4)
13.916(3)
90
97.81(3)
90
2641(1)
4
1.184
0.13
10.475(1)
11.549(1)
12.900(1)
85.070(5)
69.041(6)
77.637(5)
1423.5(2)
2
1.173
1.72
3569
3569
9.783(1)
10.360(1)
15.167(1)
91.94(1)
95.61(1)
116.10(1)
1368.7(2)
2
1.181
1.11
5900
4999
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
V, (A )
Z
Dcalc (g cmꢀ3
)
l (mmꢀ1
Reflections collected
)
6644
Independent reflections 6325
Rint
0.030
0.060
0.234
1.05
0.018
0.049
0.131
1.08
R (F, F2 > 2r)
Rw (F2, all data)
Goodness-of-fit on F2
El. density extremes
0.046
0.132
1.06
4.6. Attempted synthesis of 5
0.60, ꢀ0.49 0.18, ꢀ0.27
0.31, ꢀ0.42
ꢀ3
˚
(e A
)
Ortho-carborane (0.723 g, 5.02 mmol), was dissolved
at 0 ꢁC under N2 in dry ether (30 ml) and nBuLi in hex-
anes (4.3 ml, 2.42 M, 10.4 mmol) was added, precipitat-
ing white 1,2-dilithio-ortho-carborane. After 15 min
stirring, SOCl2 (0.37 ml, 5.07 mmol) was added and
the reaction was left to warm to room temperature over-
night. Water (30 ml) was added, dissolving the nascent
LiCl, and the ether layer was washed with further water
(2 · 30 ml) before being isolated and dried over MgSO4.
Removal of the solvent in vacuo gave a white solid. This
was sublimed in vacuo at 50 ꢁC to remove unreacted
ortho-carborane. The unsublimed material contained 5,
based on mass spectroscopy with a carborane peak pat-
tern observed at 375–381 (EI-MS). Purification attempts
of the white powder (458 mg) were unsuccessful – sev-
eral solvents were shown by boron NMR spectroscopy
to degrade the carborane cages.
ꢀ
ꢀ
operation ð001; 100; 010Þ to give the reduced cell
˚
˚
˚
a = 10.511(5) A, b = 11.579(3) A, c = 12.917(4) A,
a = 85.09(3)ꢁ, b = 69.05(3)ꢁ, c = 77.72(3)ꢁ. The volume
of this cell (1434.5(9) A ) is ca. 0.8% larger than found
3
˚
by us, although both experiments were carried out at
room temperature. Our data gave rather lower residual
electron density peaks near the sulfur atoms, but these
can be successfully refined also as part of a very minor
disorder component, with an occupancy of 0.059(3),
similar to that recently reported. This disorder has no
significant effect on the geometry of the molecule. Over-
all our results are of greater precision. Full crystallo-
graphic data, excluding structure factors, have been
deposited at the Cambridge Crystallographic Data Cen-
tre, CCDC Nos. 269295, 269296 and 269297.
4.7. Crystallography
4.8. Computational section
Single-crystal diffraction experiments (Table 3) for 1
and 3 were carried out on a Rigaku AFC6S 4-circle dif-
fractometer, for 2 on a Stoe STADI4 4-circle diffractom-
eter using graphite-monochromated Mo Ka (1) and Cu
Ka (2, 3) radiation. The structures were solved by direct
methods and refined by full-matrix least-squares meth-
ods with F2 of all unique data, using SHELXTL software.
Hydrogen atoms positions were freely refined (except
for the phenyl groups in 3, in which they were con-
strained with a riding model). Structure 2 has been re-
ported elsewhere [35]. The non-standard unit cell
setting used in that report can be transformed by the
The ab initio computations were carried out with the
GAUSSIAN 03 package [55]. The geometries of 4 and 5 (cis
and trans) were optimised at the HF/6-31G* level with
no symmetry constraints. Frequency calculations were
computed on these optimised geometries at the HF/6-
31G* level and revealed no imaginary frequencies. Opti-
misation of these geometries were then carried out at the
MP2/6-31G* level. Total energies at MP2/6-31G* are
ꢀ1454.57589 a.u. for 4 and ꢀ1604.55461 (trans) and
ꢀ1604.55479 (cis) for 5. The C4S2 rings in these geome-
tries are planar.

306
A.S. Batsanov et al. / Polyhedron 25 (2006) 300–306
[28] W. Clegg, H.M. Colquhoun, R. Coult, M.A. Fox, W.R. Gill,
Appendix A. Supplementary data
P.L. Herbertson, J.A.H. MacBride, K. Wade, Spec. Publ. – R.
Soc. Chem. 143 (1994) 232.
Supplementary data associated with this article can
be found, in the online version at doi:10.1016/j.poly.
2005.06.046.
[29] Z.G. Lewis, A.J. Welch, Acta Cryst. C 49 (1993) 705.
[30] T.D. McGrath, A.J. Welch, Acta Cryst. C 51 (1995) 646.
[31] T.D. McGrath, A.J. Welch, Acta Cryst. C 51 (1995) 651.
[32] T.D. McGrath, A.J. Welch, Acta Cryst. C 51 (1995) 654.
[33] T.D. McGrath, A.J. Welch, Acta Cryst. C 51 (1995) 649.
[34] R.L. Thomas, A.J. Welch, Polyhedron 18 (1999) 1961.
[35] A. Laromaine, F. Teixidor, R. Kiveka¨s, R. Sillanpa¨a¨, R. Benakki,
References
B. Gruner, C. Vinas, Dalton Trans. (2005) 1785.
¨
˜
[1] H.D. Smith Jr., C.O. Obenland, S. Papetti, Inorg. Chem. 5 (1966)
[36] F. Teixidor, P. Angles, C. Vinas, Inorg. Chem. 38 (1999) 3605.
˜
1013.
[37] J.J. Schaeck, S.B. Kahl, Inorg. Chem. 38 (1999) 204.
[38] Y.-J. Lee, J.-D. Lee, J. Ko, S.-H. Kim, S.O. Kang, Chem.
Commun. (2003) 1364.
[2] N.S. Semenuk, S. Papetti, H. Schroeder, Inorg. Chem. 8 (1969)
2441.
[3] L.I. Zakharkin, G.G. Zhigareva, Zh. Obshch. Khim. 37 (1967)
[39] W. Clegg, R. Coult, M.A. Fox, W.R. Gill, J.A.H. MacBride, K.
Wade, Polyhedron 12 (1993) 2711.
2781.
[4] L.I. Zakharkin, G.G. Zhigareva, Izv. Akad. Nauk SSSR, Ser.
[40] R. Kivekas, R. Sillanpaa, F. Teixidor, C. Vinas, R. Nunez, Acta
˜
˜
Khim. (1967) 1358.
Cryst. Sect. C C50 (1994) 2027.
[5] J. Plesˇek, S. Herˇmanek, Coll. Czech. Chem. Commun. 46 (1981)
687.
[41] L.A. Boyd, H.M. Colquhoun, M.G. Davidson, M.A. Fox, W.R.
Gill, P.L. Herbertson, T.G. Hibbert, J.A.H. MacBride, R.J.
Peace, G.P. Rivers, K. Wade, Spec. Publ. – R. Soc. Chem. 201
(1997) 289.
´
[6] C. Vinas, R. Benakki, F. Teixidor, J. Casabo, Inorg. Chem. 34
˜
(1995) 3844.
[7] F. Teixidor, C. Vinas, R. Benakki, R. Kiveka¨s, R. Sillanpa¨a¨,
˜
[42] F. Teixidor, C. Vinas, A. Demonceau, R. Nunez, Pure Appl.
˜
˜
Inorg. Chem. 36 (1997) 1719.
Chem. 75 (2003) 1305.
´
[8] F. Teixidor, C. Vinas, J. Casabo, A.M. Romerosa, J. Rius, C.
˜
[43] J. Llop, C. Vinas, J.M. Oliva, F. Teixidor, M.A. Flores, R.
˜
Miravitlles, Organometallics 13 (1994) 914.
Kiveka¨s, R. Sillanpa¨a¨, J. Organomet. Chem. 657 (2002) 232.
[44] M.G. Davidson, T.G. Hibbert, J.A.K. Howard, A. Mackinnon,
K. Wade, Chem. Commun. (1996) 2285.
´
[9] F. Teixidor, C. Vinas, J. Rius, C. Miravitlles, J. Casabo, Inorg.
˜
Chem. 29 (1990) 149.
´
[10] F. Teixidor, A.M. Romerosa, J. Rius, C. Miravitlles, J. Casabo,
[45] R.J. Blanch, M. Williams, G.D. Fallon, M.G. Gardiner, R.
Kaddour, C.L. Raston, Angew. Chem., Int. Ed. Engl. 36 (1997)
504.
C. Vinas, E. Sanchez, J. Chem. Soc., Dalton Trans. (1990) 525.
˜
[11] For examples, see M. Herberhold, H. Yan, W. Milius, B.
Wrackmeyer, Chem. Eur. J. 8 (2002) 388.
[46] M.J. Hardie, C.L. Raston, Cryst. Eng. Commun. 3 (2001) 162.
[47] M.A. Fox, A.K. Hughes, Coord. Chem. Rev. 248 (2004) 457.
[48] A.R. Turner, H.E. Robertson, K.B. Borisenko, D.W.H. Rankin,
M.A. Fox, Dalton Trans. (2005) 1310.
[12] D.-H. Kim, J. Ko, K. Park, S. Cho, S.O. Kang, Organometallics
18 (1999) 2738.
[13] X.-Y. Yu, G.-X. Jin, N.-H. Hu, L.-H. Weng, Organometallics 21
(2002) 5540.
[49] E.S. Alekseyeva, M.A. Fox, J.A.K. Howard, J.A.H. MacBride,
K. Wade, Appl. Organomet. Chem. 17 (2003) 499.
[14] O. Crespo, M.C. Gimeno, P.G. Jones, A. Laguna, J. Chem. Soc.,
Chem. Commun. (1993) 1696.
[50] A.S. Batsanov, M.A. Fox, T.G. Hibbert, J.A.K. Howard, R.
[15] J.-H. Won, H.-G. Lim, B.Y. Kim, J.-D. Lee, C. Lee, Y.-J. Lee, S.
Cho, J. Ko, S.O. Kang, Organometallics 21 (2002) 5703.
[16] O. Crespo, M.C. Gimeno, P.G. Jones, A. Laguna, J. Chem. Soc.,
Dalton Trans. (1997) 1099.
Kiveka¨s, A. Laromaine, R. Sillanpa¨a¨, C. Vinas, K. Wade, Dalton
˜
Trans. (2004) 3822.
[51] O. Crespo, M.C. Gimeno, A. Laguna, Polyhedron 18 (1999) 1279.
[52] R. Kiveka¨s, M.A. Flores, C. Vinas, R. Sillanpa¨a¨, Acta Cryst.
˜
[17] J.D. McKinney, H. Chen, T.A. Hamor, K. Paxton, C.J. Jones, J.
Chem. Soc., Dalton Trans. (1998) 2163.
Sect. C58 (2002) o570.
[53] J.D. McKinney, T.A. Hamor, C.J. Jones, K. Paxton, Polyhedron
16 (1997) 1819.
[18] M. Herberhold, H. Yan, W. Milius, B. Wrackmeyer, Angew.
Chem., Int. Ed. Engl. 38 (1999) 3689.
[54] A. Laromaine, C. Vinas, R. Sillanpa¨a¨, R. Kiveka¨s, Acta Cryst.,
˜
[19] F. Teixidor, J.A. Ayllon, C. Vinas, J. Rius, C. Miravitlles, J.
˜
Sect. C60 (2004) o524.
´
Casabo, J. Chem. Soc., Chem. Commun. (1992) 1279.
[55] M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A.
Robb, J.R. Cheeseman, J.A. Montgomery Jr., T. Vreven, K.N.
Kudin, J.C. Burant, J.M. Millam, S.S. Iyengar, J. Tomasi, V.
Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G.A.
Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R.
Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O.
Kitao, H. Nakai, M. Klene, X. Li, J.E. Knox, H.P. Hratchian,
J.B. Cross, C. Adamo, J. Jaramillo, R. Gomperts, R.E. Strat-
mann, O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W.
Ochterski, P.Y. Ayala, K. Morokuma, G.A. Voth, P. Salvador,
J.J. Dannenberg, V.G. Zakrzewski, S. Dapprich, A.D. Daniels,
M.C. Strain, O. Farkas, D.K. Malick, A.D. Rabuck, K. Ragh-
avachari, J.B. Foresman, J.V. Ortiz, Q. Cui, A.G. Baboul, S.
Clifford, J. Cioslowski, B.B. Stefanov, G. Liu, A. Liashenko, P.
Piskorz, I. Komaromi, R.L. Martin, D.J. Fox, T. Keith, M.A.
Al-Laham, C.Y. Peng, A. Nanayakkara, M. Challacombe,
P.M.W. Gill, B. Johnson, W. Chen, M.W. Wong, C. Gonzalez,
J.A. Pople, GAUSSIAN 03, Revision C.02, Gaussian, Inc., Walling-
ford, CT, 2004.
´
[20] F. Teixidor, J. Casabo, C. Vinas, E. Sanchez, R. Kiveka¨s, L.
˜
Escriche, Inorg. Chem. 30 (1991) 3053.
[21] F. Teixidor, J.A. Ayllon, C. Vinas, R. Sillanpa¨a¨, R. Kiveka¨s, J.
Casabo, Inorg. Chem. 33 (1994) 4815.
[22] F. Teixidor, J.A. Ayllon, C. Vinas, R. Kiveka¨s, R. Sillanpa¨a¨, J.
˜
´
˜
´
Casabo, Inorg. Chem. 33 (1994) 1756.
[23] Search on the Cambridge Structural Database (CSD Version 5.26)
February 2005. See F.H. Allen, Acta Crystallogr., Sect. B 58
(2002) 380.
[24] L.I. Zakharkin, N.F. Shemyakin, A.V. Polyakov, A.I. Yanovskii,
Y.T. Struchkov, Zh. Obshch. Khim. 57 (1987) 611.
[25] D.A. Brown, W. Clegg, H.M. Colquhoun, J.A. Daniels, I.R.
Stephenson, K. Wade, J. Chem. Soc., Chem. Commun. (1987)
889.
[26] R. Coult, M.A. Fox, W.R. Gill, K. Wade, W. Clegg, Polyhedron
11 (1992) 2717.
[27] L.A. Boyd, W. Clegg, R.C.B. Copley, M.G. Davidson, M.A.
Fox, T.G. Hibbert, J.A.K. Howard, A. Mackinnon, R.J. Peace,
K. Wade, Dalton Trans. (2004) 2786.