[B(3,5-C6H3Cl2)4]- as a useful anion for organometallic chemistry

Article abstract of DOI:10.1002/ejic.201000686

We highlight the use of the robust [B(3,5-C₆H₃Cl ₂)₄]^- anion in organometallic chemistry. When partnered with organometallic cations, compared with [BAr^F ₄]^- it presents desirable solubility properties, a lack of anion disorder in the solid-state, different coordinating properties with metal fragments and convenient metathetical routes for utilisation in synthesis. The use of the robust [B(3,5-C₆H₃Cl₂) ₄]^- anion in organometallic chemistry is described; this anion partnered with organometallic cations presents desirable solubility properties, a lack of anion disorder in the solid-state, different coordinating properties with metal fragments and convenient metathetical routes for utilisation in synthesis.

Full text of DOI:10.1002/ejic.201000686

FULL PAPER
DOI: 10.1002/ejic.201000686
[B(3,5-C6H3Cl2)4]– as a Useful Anion for Organometallic Chemistry
Adrian B. Chaplin*[a] and Andrew S. Weller*[a]
Keywords: Rhodium / Boranes / Organometallic complexes / Weakly coordinating anions / Structure elucidation
We highlight the use of the robust [B(3,5-C6H3Cl2)4]– anion
in organometallic chemistry. When partnered with organo-
metallic cations, compared with [BArF4]– it presents desirable
solubility properties, a lack of anion disorder in the solid-
state, different coordinating properties with metal fragments
and convenient metathetical routes for utilisation in synthe-
sis.
by the synthesis of two sets of complexes that use the
Introduction
recently reported [Rh{κ3-PtBu2CH2CH(CH2)2}]+[8] and
Weakly coordinating anions are commonplace in the
synthesis of cationic organometallic and main-group salts,
as well as organic synthetic routes that use cationic transi-
tion metal catalysts. They are used when vacant, or latent,
sites are required at a metal centre, either as an integral
part of the desired structure or for onward reactivity, either
stoichiometric or catalytic.[1] The design of such anions thus
incorporates noncoordinating peripheries, in which the
overall negative charge is buried within the molecule. As the
desired cationic species that partner these anions are often
rather reactive, any associated anion is also required to be
robust to metal-promoted reactivity. Thus, the anions
[PF6]– and [BF4]–, although ubiquitous, are often not the
choice for demanding applications due to hydrolysis by ad-
ventitious water or fluoride abstraction.[2] Although the
range of possible anions is large, only a handful are used
routinely (Scheme 1). The anions [B{3,5-C6H3(CF3)2}4]–
(A) and [B(C6F5)4]– (B) (and derivatives[3]) are perhaps the
most widely used, but other anions have also found popu-
larity: [Al{OC(CF3)3}4]– (C[4]) and [closo-CB11H6Cl6]– (D[5])
(and derivatives thereof[6,7]). Of the fluorinated anions (e.g.,
A and C), rotational disorder of the CF3 groups or the for-
mation of clathrates can potentially hamper the accurate
structural determination of the resulting complexes in the
solid-state – especially when any structural study involves a
charge-density analysis in which electron density has to be
precisely modelled. We report here the use of an easily pre-
pared anion, [BArCl24]– (ArCl2 = 3,5-C6H3Cl2), that shows
no disorder in the solid-state for the complexes isolated
[Rh(BINOR-S)(PiPr3)]+[9]
fragments
(BINOR-S
=
endo,cis,endo-heptacyclo[5.3.1.1.2,61.4,121.9,110.3,508,10]tetra-
decane). The former is a 12-electron RhIII fragment that
binds arenes (e.g., fluorobenzene) in an η6-manner, whereas
the latter is formally a 12-electron RhIII centre with a sup-
porting C–C σ-bond and an agostic C–H interaction. Al-
though the [BArCl24]– anion was originally reported in the
open literature by Pacey as the Cs+ salt,[10] with a refine-
and, importantly, is readily substituted into a synthetic
–
pathway in place of anions such as [BArF
]
[ArF
=
4
C6H3(CF3)2]. We demonstrate its coordinating properties
[a] Department of Chemistry, Inorganic Chemistry Laboratories,
University of Oxford,
Oxford, OX1 3QR, United Kingdom
E-mail: andrew.weller@chem.ox.ac.uk
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.201000686.
Scheme 1.
View this journal online at
wileyonlinelibrary.com
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[B(3,5-C6H3Cl2)4]– as a Useful Anion for Organometallic Chemistry
ment in the synthesis by Serwatowski and co-workers in analogous to the previously reported [Rh(BINOR-S)-
2003,[11] as far as we are aware it has not been utilised in (PiPr3)][BArF4] salt,[9] and contains a C–C σ and a C–H
organometallic chemistry to generate and stabilise poten- agostic interaction. It cannot be synthesised by using anions
tially reactive metal cations.[12] We believe that this anion such as [BF4]– or [PF6]– due to decomposition. Thus, the
will be of use to the organometallic and catalysis communi- anion [BArCl24]– supports potentially reactive late transition
ties as well as those interested in the structural determi- metal centres. Figure 1 shows the solid-state structure of
nation of cationic species given its ease of preparation, at- 1[BArCl24], which demonstrates that there are no close con-
tractive solubility properties, lack of anion disorder in the tacts between the anion and the metal centre (Rh···Cl dis-
solid-state, comparable coordinating properties to C6H5F tances longer than 4.5 Å). It also demonstrates no anion
and [BArF4]–, and its expedient use in synthesis. This paper disorder, a highly desirable property for charge-density
demonstrates these properties and the comparison with the analysis in which the rotational disorder in [BArF4]–-type
[BArF4]– anion and C6H5F arene ligand/solvent.
anions is problematic. The NMR spectroscopic data for the
cation are as reported previously,[9] and the anion reso-
1
nances in the H NMR spectrum are essentially unchanged
from those of the [Bu4N][BArCl24] salt.
Results and Discussion
The anion [B(3,5-C6H3Cl2)4]– is best prepared as the Na+
salt, Na[BArCl24], by a slight modification of the published
route,[11] in that additional drying is necessary to obtain
anhydrous material necessary for organometallic chemistry.
This is simply achieved by heating under vacuum overnight.
Metathesis (CH2Cl2, filtration) with [Bu4N][BH4] affords
the corresponding ammonium salt, for which the solid-state
structure is described in the Supporting Information. No
anion disorder is apparent in the structure. In solution
Scheme 2.
1
[Bu4N][BArCl24] shows sharp resonances in the H NMR
spectrum (CD2Cl2) that show complicated, presumably sec-
ond-order, coupling in the aromatic region (δ = 7.05–7.00
With a more open coordination environment the
ppm). The 13C{1H} NMR spectrum is simpler, with four [BArCl24]– anion can bind in an η6-motif to the metal cen-
resonances observed, as expected, for the anion between δ tre, as we have recently reported for the [BArF4]– anion in
= 165.2 and 123.6 ppm. The 11B NMR spectrum (CD2Cl2) both rhodium and iridium complexes with a chelating
indicates a single, relatively sharp, environment at δ = phosphane–alkene ligand [M{P(C5H9)2(η2-C5H7)}({η6-
–6.9 ppm.
C6H3(CF3)2}BArF3)] (M = Rh,[13a] Ir[13b]). Here we use
–
To demonstrate that [BArCl2
]
can support complexes the closely related RhIII complex [Rh(η6-C6H5F){κ3-
4
that show weak and unusual interactions, we have PtBu2CH2CH(CH2)2}][BArF
]
(2[BArF4]) as a suitable
[8]
4
synthesised the complex [Rh(BINOR-S)(PiPr3)][BArCl2
]
starting material as this provides an open coordination site
4
(1[BArCl24]) by the addition of Na[BArCl24] to a mixture of on displacement of the weakly bound fluoroarene ligand.
RhCl(PiPr3)(NBD)/excess NBD (Scheme 2) and precipi- The addition of [Bu4N][BArCl24] to 2[BArF4] in a solution
tation of NaCl (NBD = norbornadiene). This new salt is of CH2Cl2 results in the displacement of the bound fluo-
Figure 1. Solid-state structure of 1[BArCl24]. Thermal ellipsoids drawn at the 50% probability level. Most H atoms and the solvent
molecule (CH2Cl2) are omitted for clarity.
Eur. J. Inorg. Chem. 2010, 5124–5128
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5125

A. B. Chaplin, A. S. Weller
FULL PAPER
–
roarene ligand by the [BArCl2
zwitterionic
]
anion and formation of 3 results in the displacement of the anion and the formation
4
[Rh{κ3-PtBu2CH2CH(CH2)2}{(η6-C6H3Cl2)- of the arene adduct 4[BArCl4] (Scheme 3) (see the Support-
BArCl23}] (3) (Scheme 3). Alternatively, 3 can be prepared ing Information for the solid-state structure).
[8]
from the tetramer [RhCl{κ3-PtBu2CH2CH(CH2)2}]4 by
the addition of Na[BArCl24] in a solution of 1,2-C6H4F2.
The solid-state structure is shown in Figure 2, and the
structural metrics are unremarkable. The anion in 3 is coor-
dinated through one arene ring, similar to that observed
in the closely related complex [Rh{P(C5H9)2(η2-C5H7)}({η6-
C6H3(CF3)2}BArF )][13a] and for other RhI zwitterionic salts
3
of [B(C6H5)4]–.[14] In solution (CH2Cl2), the anion remains
coordinated, as demonstrated by the observation of a
1
6:3:1:2 set of resonances in the H NMR spectrum that are
all broadened compared with those of the free anion, and
which are spread over a wider chemical shift range than
those of the free anion (δ = 7.14–6.65 ppm). The higher-
field pair is assigned to the arene ring bound to the metal
centre. The 11B NMR spectrum of the reaction mixture
shows signals of free [BArF4]– and a broad resonance at δ
= –7.6 ppm for the coordinated anion in 3; this is shifted
upfield by 1 ppm from that of the free anion. Dissolution
of 3 in C6H5F results in an equilibrium being established
Figure 2. Solid-state structure of 3. Thermal ellipsoids are drawn
at the 50% probability level. Hydrogen atoms are omitted for clar-
ity. Rh1–C201 2.434(2), Rh1–C202 2.412(4), Rh1–C203 2.389(2),
Rh1–C204 2.380(2), Rh1–C205 2.290(2), Rh1–C206 2.286(2) Å.
with the arene adduct 2[BArCl24] (2:1, respectively, as mea-
1
sured by H, 31P and 11B NMR spectroscopy). Given the
large excess of C6H5F present as solvent, this result demon-
–
strates that [BArCl2
]
binds relatively strongly compared
4
with C6H5F. Complex 2[BArCl24] is less soluble than 3 and
crystallises out of solution on standing; a solid-state struc-
ture confirms the identity of this new species (see the Sup-
Conclusions
porting Information). In addition, complex 2[BArCl24] is
We highlight the use of the [B(3,5-C6H3Cl2)4]– anion in
organometallic chemistry. When partnered with organome-
significantly less soluble than the corresponding [BArF
]
–
4
salt and is readily isolated as crystalline material by mixing tallic cations, compared with [BArF4]– it presents different,
2[BArF4] and [Bu4N][BArCl24] in C6H5F, demonstrating the possibly desirable, solubility properties, a lack of anion dis-
potential versatility of the [BArCl2
]
anion for anion-ex- order in the solid-state, different coordinating properties
–
4
change reactions. Redissolving 2[BArCl24] in CD2Cl2 re- and convenient metathetical routes allowing for its utilis-
forms 3 as evidenced by 1H and 31P{1H} NMR spec- ation in synthesis. An approximate coordinating ability can
troscopy, as well as free C6H5F. Addition of mesitylene to also be established compared with [BArF4]– and C6H5F in
Scheme 3. [a] Equilibrium established between 2[BArCl24] and 3 in a solution of C6H5F. See text for details.
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[B(3,5-C6H3Cl2)4]– as a Useful Anion for Organometallic Chemistry
–
which [BArCl2
]
interacts with very open metal centres
suspension was stirred at room temperature for 1 h and then fil-
tered. The residue was extracted with CH2Cl2 (2 mL) and the prod-
uct precipitated as a yellow powder by the addition of excess hex-
ane. Yield: 0.043 g (33%). Crystals suitable for X-ray diffraction
were grown by layering a CH2Cl2 solution of the complex with
pentane at 5 °C. NMR spectroscopic data for the cation are in good
agreement with the literature values for the corresponding
4
more strongly than [BArF
]
but is competitive, although
–
4
,
more strongly binding, with the weakly coordinating sol-
vent C6H5F. With less available, albeit reactive, metal
centres, e.g., 1[BArCl24], the coordinating properties of the
anions are levelled and neither interact. Indeed in this re-
spect, [BArCl24]– has very recently been used in the isolation
of a two-coordinate-at-boron, 18-valence-electron, cationic,
iron–borylene complex, in which these desirable properties
of solubility, ease of synthesis and chemical robustness are
further highlighted.[12] Of course, in systems in which oxi-
dative addition to a metal centre of aryl chlorides is a
straightforward process,[15] such as in cross-coupling reac-
tions,[16] these anions might be of less use, although this
offers potential opportunities for derivatisation of the anion
itself.
–
–
[BArF
] ] are essentially un-
salt.[9] Resonances due to [BArCl2
4
4
changed from [nBu4N][BArCl24].
Preparation of [Rh{κ3-PtBu2CH2CH(CH2)2}(η6-BArCl24)] (3): 1,2-
C6H4F2 (2 mL) was added to a Schlenk flask charged with
[RhCl{κ3-PtBu2CH2CH(CH2)2}]4 (0.038 g, 0.028 mmol) and Na-
[BArCl24] (0.073 g, 0.118 mmol). After stirring for 1 h, the solution
was filtered and the filtrate concentrated to dryness in vacuo. Suc-
cessive recrystallisation of the residue from CH2Cl2/pentane/hexane
at –20 °C afforded the product as yellow needles. Yield: 0.052 (49%
yield). 1H NMR (CD2Cl2, 500 MHz): δ = 7.14 [br., 6 H, B(o-
C6H3Cl2)3], 6.95 [br., 3 H, B(p-C6H3Cl2)3], 6.74 [v. br., 1 H, η6-(p-
3
C6H3Cl2)], 6.65 [v. br., 2 H, η6-(o-C6H3Cl2)], 2.84 (dm, JPH
=
2
65.2 Hz, 1 H, CH), 1.75 (br. d, JPH = 7.8 Hz, 2 H, PCH2), 1.68
(apparent q, J = 3.4 Hz, 2 H, RhCH2), 1.54 (br., 2 H, RhCH2Ј),
1.38 (d, 3JPH = 13.7 Hz, 18 H, tBu) ppm. 13C{1H} NMR (CD2Cl2,
Experimental Section
General: All manipulations, unless otherwise stated, were per-
formed under argon by using Schlenk and glove-box techniques.
Glassware was oven-dried at 130 °C overnight and flamed under
vacuum prior to use. CH2Cl2, pentane and hexane were dried by
using a Grubbs-type solvent purification system (MBraun SPS-800)
and degassed by successive freeze-pump-thaw cycles.[17] CD2Cl2,
C6H5F and 1,2-C6H4F2 were dried with CaH2, vacuum-distilled
1
126 MHz): δ = 160.8 [q, JBC = 49 Hz, B(i-C6H3Cl2)3], 153.2 [br.,
η6-(i-C6H3Cl2)], 133–134 [m, B(o-C6H3Cl2)3 + m-C6H3Cl2], 125.1
[B(p-C6H3Cl2)3], 109.7 [η6-(o-C6H3Cl2)], 103.2 [η6-(p-C6H3Cl2)],
45.1 (m, CH), 38.7 [d, 1JPC = 17 Hz, tBu (C)], 31.2 [d, 2JPC = 3 Hz,
1
1
tBu (Me)], 26.1 (d, JPC = 24 Hz, PCH2), 13.6 (d, JRhC = 18 Hz,
RhCH2) ppm. 31P{1H} NMR (CD2Cl2, 202 MHz): δ = 126.4 (d,
1JRhP = 198 Hz) ppm. 11B NMR (CD2Cl2, 160 MHz): δ =
–7.6 ppm. C36H37BCl8PRh (898.0): calcd. C 48.15, H 4.15; found
C 47.49, H 4.16. See Supporting Information for selected NMR
spectra of the crystalline material.
and stored over molecular sieves (3 Å). [Rh(NBD)(PiPr3)Cl],[9]
[8]
[RhCl{κ3-PtBu2CH2CH(CH2)2}]4
and [Rh{κ3-PtBu2CH2CH-
(CH2)2}(C6H5F)][BArF
]
4
were prepared according to literature
[8]
methods. Na[BArCl24] was prepared according to a literature pro-
cedure[11] and dried at 120 °C under dynamic vacuum
(5ϫ10–3 Torr). All other chemicals are commercial products and
were used as received. NMR spectroscopic data were recorded with
a Varian Mercury VX 300 MHz, Varian Unity Plus 500 MHz or
Bruker AVC 500 MHz spectrometer at room temperature, unless
otherwise stated. Chemical shifts are quoted in ppm and coupling
constants in Hz. Microanalyses were performed by Elemental Mi-
croanalysis Ltd.
Reaction of 3 with C6H5F: C6H5F (0.4 mL) was added to a J. Young
NMR tube charged with 3 (0.006 g, 0.007 mmol). Analysis by
NMR spectroscopy indicated the formation of a 1:2 mixture of
2[BArCl24] and 3. NMR spectroscopic data for the cation of
2[BArCl24] are in good agreement with the literature values for the
corresponding [BArF4]– salt.[8] Resonances due to [BArCl24] are es-
sentially unchanged from [nBu4N][BArCl24]. On standing at room
temperature, 2[BArCl24] crystallised from solution (0.006 g, 90%
yield). Dissolving this material in CD2Cl2 resulted in quantitative
reformation of 3 with the concomitant liberation of C6H5F, as ob-
served by NMR spectroscopy, and thus NMR spectroscopic data
for 2[BArCl24] could not be obtained. Complex 2[BArCl24] was also
prepared by the stoichiometric reaction between 2[BArF4] and
[nBu4N][BArCl24] in C6H5F. Crystals of 2[BArCl24] suitable for X-
ray diffraction were grown from C6H5F at –20 °C (see Supporting
Information for the solid-state structure).
Preparation of [nBu4N][BArCl24]: CH2Cl2 (3 mL) was added to a
Schlenk flask charged with [nBu4N][BH4] (0.208 g, 0.808 mmol)
and Na[BArCl24] (0.501 g, 0.810 mmol). The resulting suspension
was placed in an ultrasound bath for 20 min and then filtered. The
filtrate was concentrated to dryness under vacuum and then
washed with hexane (3ϫ 5 mL) to yield 0.54 g (80%) as a white
microcrystalline solid. Crystals suitable for X-ray diffraction were
grown from layering a CH2Cl2 solution of the complex with hexane
1
at room temperature (see the Supporting Information). H NMR
(CD2Cl2, 500 MHz): δ = 7.00–7.05 {m, 12 H, BArCl24 [δ = 7.04 (m-
CH), 7.01 (p-CH) ppm]}, 2.92–2.98 (m, 8 H, NCH2), 1.47–1.58 (m,
Reaction of 3 with C6H3Me3: C6H3Me3 (0.005 mL, 0.036 mmol)
was added to a solution of 3 (0.006 g, 0.007 mmol) in CD2Cl2
(0.4 mL) in a J. Young NMR tube. Analysis by NMR spectro-
scopy indicated the quantitative formation of [Rh{κ3-
PtBu2CH2CH(CH2)2}(C6H3Me3)][BArCl24] (4[BArCl24]); data for
the cation are in good agreement with the literature values for the
corresponding [BArF4]– salt.[8] Resonances due to [BArCl24]– are es-
sentially unchanged from [nBu4N][BArCl24]. Crystals suitable for X-
ray diffraction were grown from a CH2Cl2 solution of the complex
layered with pentane at 5 °C (see Supporting Information for solid-
state structure).
3
8 H, NCH2CH2), 1.35 (apparent sext, JHH = 7 Hz, CH2Me), 0.98
(t, JHH = 7.3 Hz, 12 H, Me) ppm. 13C{1H} NMR (CD2Cl2,
3
76 MHz): δ = 165.2 (q, JBC = 49 Hz, BArCl24), 133.6 [BArCl2 (m-
1
4
CH)], 133.4 (q, 3JBC = 4 Hz, BArCl24), 123.6 [BArCl24 (p-CH)], 59.5
(m, NCH2), 24.3 (NCH2CH2), 20.2 (CH2Me), 13.9 (Me) ppm. 11B
NMR (CD2Cl2, 160 MHz): δ = –6.9 ppm. C40H48BCl8N (837.3):
calcd. C 57.38, H 5.78, N 1.67; found C 57.38, H 5.81, N 1.69.
Preparation of [Rh(BINOR-S)(PiPr3)][BArCl24] (1[BArCl24]): A solu-
tion of NBD (0.040 mL, 0.393 mmol) in C6H5F (3 mL) was added
to a Schlenk flask charged with [Rh(NBD)(PiPr3)Cl] (0.050 g,
0.128 mmol) and Na[BArCl24] (0.077 g, 0.125 mmol). The resulting
Reaction of 2[BArF4] with [nBu4N][BArCl24]: CD2Cl2 (0.4 mL) was
added to a J. Young NMR tube charged with 2[BArF4] (0.010 g,
Eur. J. Inorg. Chem. 2010, 5124–5128
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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A. B. Chaplin, A. S. Weller
FULL PAPER
0.008 mmol) and [nBu4N][BArCl24] (0.066, 0.008 mmol). Analysis
by NMR spectroscopy indicated the quantitative formation of 3.
Chem. Int. Ed. 2004, 43, 2066–2090; A. Macchioni, Chem. Rev.
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Crystallography: Relevant details about the structure refinements
of 1[BArCl24] and 3 are given in Table 1. Data were collected with
an Enraf Nonius Kappa CCD diffractometer by using graphite-
monochromated Mo-Kα radiation (λ = 0.71073 Å) and a low-tem-
perature device;[18] data were collected by using COLLECT, re-
duction and cell refinement were performed by using DENZO/
SCALEPACK.[19] The structures were solved by direct methods
using SIR2004[20] and refined by full-matrix least-squares on F2
using SHELXL-97.[21] All non-hydrogen atoms were refined aniso-
tropically. Hydrogen atoms were placed in calculated positions by
using the riding model. Graphical representations of the structures
were made by using ORTEP3.[22] CCDC-781556 (for 2[BArCl24]),
-781557 (for 3), -781558 (for 4[BArCl24]), -781559 (for [nBu4N]-
[BArCl24]) and -781946 (for 1[BArCl24]) contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.
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8958–8970; M. H. Hannant, J. A. Wright, S. J. Lancaster, D. L.
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2415–2426.
[4] I. Krossing, A. Reisinger, Coord. Chem. Rev. 2006, 250, 2721–
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Table 1. Crystallographic data for 1[BArCl24] and 3.
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5249; V. Geis, K. Guttsche, C. Knapp, H. Scherer, R. Uzun,
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1[BArCl2
]
4
3
[7] E. Molinos, S. K. Brayshaw, G. Kociok-Köhn, A. S. Weller, Or-
ganometallics 2007, 26, 2370–2382.
Empirical formula
M
T /K
Crystal system
Space group
a /Å
b /Å
c /Å
C48H51BCl10PRh C36H37BCl8PRh
1127.08
150(2)
897.95
150(2)
[8] A. B. Chaplin, A. S. Weller, Organometallics 2010, 29, 2332–
2342.
monoclinic
P21/c
monoclinic
P21/n
[9] S. K. Brayshaw, J. C. Green, G. Kociok-Kohn, E. L. Sceats,
A. S. Weller, Angew. Chem. Int. Ed. 2006, 45, 452–456.
15.54420(10)
13.39650(10)
23.9622(2)
95.6384(4)
4965.70(6)
4
12.56750(10)
16.1160(2)
20.0126(3)
106.8663(5)
3878.95(8)
4
[10]
[11]
G. E. Pacey, Anal. Chim. Acta 1980, 115, 417–420.
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During the preparation of this manuscript, we gifted a sample
β /°
V /Å3
[12]
of Na[BArCl2 ] for the use in the structural determination of
4
Z
Density /gcm–3
1.508
1.538
a reactive organometallic species: D. A. Addy, G. A. Pierce, D.
Vidovic, D. Mallick, E. D. Jemmis, J. M. Goicoechea, S. Ald-
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µ /mm–1
0.948
1.059
θ range /°
Reflections collected
Rint
5.11 Յ θ Յ 26.37 5.10 Յ θ Յ 26.37
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19586
15115
0.0262
99.2%
10071/0/556
0.0308
0.0702
1.014
0.0249
99.2%
7874/0/430
0.0295
0.0723
Completeness
Data/restraints/parameters
R1 [IϾ2σ(I)]
wR2 (all data)
GoF
1.033
Largest difference peak/hole /eÅ–3 0.606/–0.574
0.571/–0.496
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Supporting Information (see footnote on the first page of this arti-
cle): Solid-state structures of [nBu4N][BArCl24], 2[BArCl24] and
4[BArCl24]; selected NMR spectroscopic data.
Acknowledgments
The Engineering and Physical Sciences Research Council (EPSRC)
(Grant EP/E050743) and the University of Oxford are thanked for
their support.
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Received: June 23, 2010
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Published Online: September 29, 2010
5128
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Eur. J. Inorg. Chem. 2010, 5124–5128