Neutral and anionic aryloxy halides of bismuth(III)

Article abstract of DOI:10.1039/a806647g

The preparation and crystal structures of the aryloxy bismuth halide compounds [Bi₂Cl₄(thf)₂(μ-OC₆H ₃Me₂-2,6)₂], [Bi₂Cl₄(thf)₂(μ-OC₆H ₂Me₃-2,4,6)₂], [NMe₄]₂[Bi₂(OC₆H₃Me ₂-2,6)₆(μ-Cl)₂] and [PPh₄]₂[BiBr₃(OC₆H ₂Me₃-2,4,6)₂] are described. The former two compounds, which are isostructural, are neutral and comprise loosely bound polymers of more strongly bound dimers. Within the dimeric unit, the two bismuth centres are bridged by two aryloxide groups with each bismuth additionally carrying two chlorine atoms and one thf ligand. Asymmetric chlorine bridges between dimers result in the polymeric structure. The latter two structures contain aryloxy bismuth halide anions. In the structure of [Bi₂(OC₆H₃Me₂-,6) ₆(μ-Cl)₂]^2- two chlorine atoms form bridges between Bi(OC₆H₃Me₂-2,6)₃ units whereas in [BiBr₃(OC₆H₂Me₃-2,4,6) ₂]_2- a monomeric species is present. Also reported are the preparations of the compounds [PPh₄]₂[Bi₂Br₂(OC₆H ₂Me₃-2,4,6)₄(μ-Br)₂], [PPh₄]₂[BiBr₂(OC₆H ₃Me₂-2,6)₃] and SbCl₂(OC₆H₂Bu^t₃-2,4,6).

Full text of DOI:10.1039/a806647g

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Neutral and anionic aryloxy halides of bismuth(III)
Philip Hodge, Siân C. James, Nicholas C. Norman* and A. Guy Orpen
The University of Bristol, School of Chemistry, Cantock’s Close, Bristol, UK BS8 1TS.
E-mail: N.C.Norman@Bristol.ac.uk
Received 24th August 1998, Accepted 9th October 1998
The preparation and crystal structures of the aryloxy bismuth halide compounds [Bi2Cl4(thf)2(µ-OC6H3Me2-2,6)2],
[Bi2Cl4(thf)2(µ-OC6H2Me3-2,4,6)2], [NMe4]2[Bi2(OC6H3Me2-2,6)6(µ-Cl)2] and [PPh4]2[BiBr3(OC6H2Me3-2,4,6)2] are
described. The former two compounds, which are isostructural, are neutral and comprise loosely bound polymers of
more strongly bound dimers. Within the dimeric unit, the two bismuth centres are bridged by two aryloxide groups
with each bismuth additionally carrying two chlorine atoms and one thf ligand. Asymmetric chlorine bridges
between dimers result in the polymeric structure. The latter two structures contain aryloxy bismuth halide anions. In
the structure of [Bi2(OC6H3Me2-2,6)6(µ-Cl)2]2Ϫ two chlorine atoms form bridges between Bi(OC6H3Me2-2,6)3 units
whereas in [BiBr3(OC6H2Me3-2,4,6)2]2Ϫ a monomeric species is present. Also reported are the preparations of the
compounds [PPh4]2[Bi2Br2(OC6H2Me3-2,4,6)4(µ-Br)2], [PPh4]2[BiBr2(OC6H3Me2-2,6)3] and SbCl2(OC6H2But3-2,4,6).
A number of technologically useful and important materials
contain bismuth. With particular regard to oxo-species, these
include (an example is given in parentheses) bismuth-
containing copper oxide based superconductors (Bi2Sr2CaCu2-
O8),1 bismuthate superconductors (BaPb1 Ϫ xBixO3),2 ferroelec-
tric materials (SrBi2Ta2O9),3 oxide ion conductors (Bi2WO6) 4
and hydrocarbon oxidation and ammination catalysts (MoO3–
Bi2O3).5 In the last case, a number of bismuth–oxide–chloride
systems have also been investigated with regard to the oxidative
coupling of methane and dehydrogenation of ethane.6 Potential
precursors to all of the above materials are bismuth alkoxides,
alkoxy anions or oxo–alkoxides but detailed reports of such
compounds are still relatively scarce. Examples which have been
structurally characterised include Bi(OC6H3Me2-2,6)3,7
Bi(OBut)3,8 [Bi2{OCH(CF3)2}4{µ-OCH(CF3)2}2(thf)2] (thf =
tetrahydrofuran),9 [Bi2(OC6F5)4(µ-OC6F5)2(thf)4],9 [Bi2(OC6F-
the structures of a number of antimony complexes relevant
to this study have been reported, namely SbCl(OEt)2,22
23
SbCl2(OEt),22 SbCl(OBut)2,23 Sb4Cl(O)(OBut)3 and [Sb2Cl4-
(NHMe2)2(µ-OEt)2]24 together with the mixed bismuth–
vanadium alkoxy chloride complex [{BiCl3OV(OC2H4-
OCH3)3}2],25 and also because of the recent interest, noted
above, in bismuth–oxide–chloride based catalyst systems.
Results and discussion
The reaction between BiCl3 and one equivalent of either
Na[OC6H3Me2-2,6] or Na[OC6H2Me3-2,4,6] in thf solution
afforded, after work-up and crystallisation, orange crystals
of complexes which were shown by X-ray crystallography to
be [Bi2Cl4(thf)2(µ-OC6H3Me2-2,6)2]
1 and [Bi2Cl4(thf)2(µ-
OC6H2Me3-2,4,6)2] 2 respectively. Crystallographic data for
these and subsequent structures are presented in Table 1. The
two structures are very similar and consist primarily of dimeric
units as indicated in the formulas and shown in Figs. 1 and 2; in
each case the dimer resides on a crystallographic C2 axis which
runs perpendicular to the Bi2O2 mean plane. Within the dimer,
each bismuth centre is five-coordinate with the expected square-
based pyramidal geometry20,† in which the apical site is occupied
by a chlorine atom, Cl(1) [1, Bi(1)–Cl(1) 2.456(2); 2, Bi(1)–Cl(1)
2.4563(13) Å] (the C2 axis requires that the two apical chlorine
atoms adopt a syn rather than an anti arrangement with respect
to the Bi2O2 plane). The second chlorine, Cl(2), lies in the basal
plane trans to the aryloxide oxygen O(1), the Bi–Cl distance
being somewhat longer as a result of the trans influence of the
oxygen [1, Bi(1)–Cl(2) 2.585(2); 2, Bi(1)–Cl(2) 2.5695(13) Å].
The two Bi–O(1) distances [1, Bi(1)–O(1) 2.211(5), Bi(1)–O(1A)
2.463(5); 2, Bi(1)–O(1) 2.187(3), Bi(1)–O(1A) 2.497(3) Å] are
significantly different such that the aryloxide groups bridge the
bismuth centres asymmetrically, the longer Bi–O bond being
5)4(µ-OC6F5)2(tol)2]
(tol = toluene),9
[Bi(OSiPh3)3(thf)3],10
[Bi2(µ2,η1-OC2H4OMe)4(η1-OC2H4OMe)2]∞,10–12 K[Bi(OBut)4],13
Na[Bi(OC6F5)4(thf)],14 Na4[Bi2(µ6-O)(OC6F5)8(thf)4],14 [Bi6(µ3-
O)7(µ3-OC6F5){Bi(OC6F5)4}3(thf)2],15
[Bi6(µ3-O)7(µ3-OC6F5)-
{Bi(OC6F5)4}3]ؒ2tol,15 Na[Bi3(µ4-O)(OC6F5)8(thf)x] (x = 1 or
3),16 Na[Bi4(µ3-O)2(OC6F5)9(thf)2],16 Na2[Bi4(µ3-O)2(OC6F5)10-
(thf)2],16 [Bi6(µ3-O)2(µ4-O)(OC6F5)12(thf)2],16 [Bi6(µ3-O)2(µ4-O)-
(OC6F5)12(tol)],16 [Bi4(µ3-O)2(µ2-OBut)2(OBut)6]17 and [Bi6(µ3-
O)3(µ2-OR)7(OR)5] (R = 2,6-Cl2C6H3).18 Many of these com-
pounds and their relationship to bismuth oxide-based materials
and catalysts have been described in more detail in a recent
review, with numerous key references cited, by Whitmire whose
group has been one of the most active in this field.19
Only the first two of the above compounds are monomeric
in the solid state with the expected trigonal pyramidal co-
ordination geometry around the bismuth centre. In the other
examples, coordination numbers of four to six are observed
resulting from the Lewis acidity anticipated for bismuth()
when bonded to electronegative groups.20
All of the above compounds contain bismuth() although
some pentavalent species containing alkoxide groups, viz.
Ph3Bi(OR)2, Ph3BiBr(OR) and Ph4Bi(OR) (R = C6F5, C6Cl5)
have recently been described by Hoppe and Whitmire.21
As part of our interest in the chemistry of bismuth, we
undertook to prepare and characterise a range of alkoxy
halides of bismuth() the results of which are described herein.
This study was motivated in part because we were not aware of
any previously structurally characterised examples, although
† As discussed in ref. 20 and refs. therein, three-coordinate bismuth()
is trigonal pyramidal (as expected by VSEPR) and, with suitably elec-
tronegative groups (X), moderately Lewis acidic. In terms of the bond-
ing model whereby this Lewis acidity is associated with the Bi–X σ*-
orbitals, coordination of one, two or three ligands occurs trans to one
of the Bi–X bonds resulting in disphenoidal, square-based pyramidal
and octahedral structures respectively. There is no specific geometrical
requirement for the Bi() lone pair in this model although in the
four- and five-coordinate geometries, the lone pair would generally be
described as stereochemically active.
J. Chem. Soc., Dalton Trans., 1998, 4049–4054
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Table 1 Selected crystallographic details for the complexes 1, 2, 3 and 5a
1
2
3
5
Empirical formula
M
Crystal system
a/Å
b/Å
c/Å
C12H17BiCl2O2
473.14
C13H19BiCl2O2
487.16
C28H39BiClNO3
682.03
C66H62BiBr3O2P2
1397.81
Monoclinic
11.5964(5)
13.1136(6)
38.747(2)
95.77(1)
5862.5(4)
P21/n
Monoclinic
14.266(3)
14.629(3)
14.468(3)
99.90(3)
2974.4(10)
C2/c
Monoclinic
15.769(3)
13.743(3)
14.405(3)
95.58(3)
3107.0(11)
C2/c
Monoclinic
12.418(3)
13.841(3)
16.892(3)
91.77(3)
2902.1(10)
P21/n
β/Њ
U/Å3
Space group
Z
8
8
4
4
µ/mmϪ1
12.203
11.685
6.194
5.150
Extinction coefficient
Reflections measured
Independent reflections
Rint
0.00015(3)
9327
3396
0.0650
0.0395
0.00018(2)
9560
3549
0.0283
0.0241
0.00018(6)
17745
6572
0.0358
0.0282
0.00084(8)
36656
13388
0.1043
0.0659
Final R indices, [I > 2σ(I)]
a Data collected at 173(2) K.
Fig. 1 A view of the dimeric unit in 1 showing the atom numbering
scheme. Atoms are drawn as spheres of arbitrary radius. Selected bond
lengths: Bi(1)–Cl(1) 2.456(2), Bi(1)–Cl(2) 2.585(2), Bi(1)–Cl(2B)
3.297(2), Bi(1)–O(1) 2.211(5), Bi(1)–O(1A) 2.463(5), Bi(1)–O(2)
2.648(6) Å.
Fig. 2 A view of the dimeric unit in 2 showing the atom numbering
scheme. Atoms are drawn as spheres of arbitrary radius. Selected bond
lengths: Bi(1)–Cl(1) 2.4563(13), Bi(1)–Cl(2) 2.5695(13), Bi(1)–Cl(2B)
3.3317(14), Bi(1)–O(1) 2.187(3), Bi(1)–O(1A) 2.497(3), Bi(1)–O(2)
2.680(3) Å.
trans to the chlorine Cl(2). trans to the shorter Bi–O bond is the
thf ligand for which the Bi–O distance [1, Bi(1)–O(2) 2.648(6);
2, Bi(1)–O(2) 2.680(3) Å] is significantly longer than both the
Bi(1)–O(1) distances as expected for a dative bond involving a
relatively weakly bound ligand. All of these Bi–O distances are
comparable to previously established values. For alkoxide
groups bound to bismuth, a wide range is observed between
about 2.1 and 2.9 Å as noted by Whitmire19 (see also refs. 7–18),
the shorter distances generally being found for terminal OR
groups or in situations where the coordination numbers and/or
steric congestion is low. Bi–O bond lengths to coordinated
thf ligands are usually longer as stated above, typical values
ranging from 2.6 to 2.8 Å.26
26(b), (c), (e)], but weak interactions involving Cl(2) are present
as shown for 1 in Fig. 3. Thus an interaction exists between the
chlorine atom Cl(2) of one dimer and the adjacent bismuth
atom of a neighbouring dimer unit (the dimer units as shown in
Fig. 3 are related by the crystallographic c glide), this longer
interaction [1, Bi(1) ؒ ؒ ؒ Cl(2B) 3.297(2); 2, Bi(1) ؒ ؒ ؒ Cl(2B)
3.3317(14) Å] being approximately trans to Cl(1). The over-
all structure may therefore be described as a loosely bound
polymer of more strongly bound dimers, somewhat similar
to the situation found in the structure of [BiI3(hmpa)]
[hmpa = OP(NMe2)3] although the dimer units in that case
have Ci rather than C2 symmetry.27 This results in bismuth co-
ordination environments in 1 and 2 which are close to octa-
hedral if the longer Bi ؒ ؒ ؒ Cl interactions are included.
It is interesting to note that it is the aryloxide groups which
form the stronger bridging interactions rather than the chlorine
atoms [chlorine bridges are well established in oligomeric
chlorobismuth() structures; for some examples see refs. 20,
There are no examples of which we are aware of neutral
bismuth alkoxy halides with which to compare 1 and 2, but
the structure of the antimony compound [Sb2Cl4(NHMe2)2-
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J. Chem. Soc., Dalton Trans., 1998, 4049–4054

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Fig. 4 A view of the dimeric dianion in 3 showing the atom numbering
scheme. Atoms are drawn as spheres of arbitrary radius. Selected bond
lengths: Bi(1)–Cl(1) 3.0020(12), Bi(1)–Cl(1A) 2.9325(13), Bi(1)–O(1)
2.154(3), Bi(1)–O(2) 2.152(3), Bi(1)–O(3) 2.113(3) Å.
SbCl2(OC6H2But3-2,4,6), the synthesis of which is described
in the Experimental section. Attempted crystal structure
analysis revealed that the crystals obtained contain a mono-
meric species hydrogen bonded to a molecule of the free alcohol
HOC6H2But3-2,4,6 as shown below, i.e. [SbCl2(OC6H2But3-
2,4,6)(HOC6H2But3-2,4,6)]. However, the structure was of poor
quality and is not suitable for publication or much further
discussion, although the data and subsequent refinement were
sufficient to unambiguosly locate the heavy atom positions; unit
cell data is provided in the Experimental section.
But
Cl
Sb
But
O
Cl
But
H
Fig. 3 A view of the polymeric structure of 1.
But
O
(µ-OEt)2] has been reported by Wright and co-workers.24 The
structure of [Sb2Cl4(NHMe2)2(µ-OEt)2] is dimeric with OEt
groups which bridge slightly more asymmetrically than do the
bridging aryloxy groups in 1 and 2 [Sb–O 2.005(4) and 2.478(4)
Å]. The coordination sphere of each antimony is completed by
two chlorine atoms and one NHMe2 ligand such that the overall
geometry is square-based pyramidal. Unlike in 1 and 2,
however, the two square-based pyramids share an edge between
the apex of the pyramid and a basal vertex resulting in a dimer
with Ci symmetry (in 1 and 2 the square pyramids share a basal
edge). Some degree of intermolecular interaction involving
bridging chlorine atoms is present but the distances are long
and structurally not as well defined as in 1 and 2. The structure
of the unligated compound SbCl2(OEt) is also known.22
This compound also contains a dimeric diantimony unit with
slightly asymmetric bridging OEt groups [the four Sb–O dis-
tances are 1.961(9), 1.998(9), 2.359(6) and 2.507(6) Å] and
chlorine atoms which may be described as terminal [Sb–Cl
2.463(2), 2.416(3), 2.400(2) and 2.411(3) Å]. As in the structures
of 1 and 2, the monomer units share a basal edge but in such a
way that the apices are anti rather than syn (i.e. the dimer units
have Ci rather than C2 symmetry). Two of the chlorine atoms,
one for each antimony, bridge very asymmetrically between
dimer units [Sb ؒ ؒ ؒ Cl 3.439(4) and 3.394(4) Å] consistent with a
description of the structure similar to 1 and 2 as a loosely
bound polymer of dimers. The other two chlorine atoms form
weak links between these dimer chains [Sb ؒ ؒ ؒ Cl 3.311(3) and
3.215(3) Å] resulting in a more two-dimensional structure.
We were also able to prepare an antimony complex con-
taining two chlorine atoms and one alkoxy group, namely
But
But
In addition to the preparation and characterisation of
neutral alkoxy bismuth halides, we were also interested in
looking at anionic species. The Lewis acidity of bismuth()
when coordinated to electronegative substituents means that
the addition of, for example, a halide anion source provides
a ready mechanism of preparing anionic bismuthate com-
pounds.26a,b Thus addition of [NMe4]Cl to the neutral, tris-
7
(aryloxide) Bi(OC6H3Me2-2,6)3 in CH2Cl2 solution afforded,
after work-up, crystals of the ionic compound [NMe4]2-
[Bi2(OC6H3Me2-2,6)6(µ-Cl)2] 3, the structure of which was
established by X-ray crystallography (Fig. 4). Compound 3
exists as discrete ions in the solid state with no short interionic
contacts. The bismuth part comprises crystallographically
centrosymmetric, dianionic units (Fig. 4) of formula
[Bi2(OC6H3Me2-2,6)6(µ-Cl)2]2Ϫ in which each bismuth centre
resides in a square-based pyramidal coordination environment
being bonded to three terminal aryloxide groups and two
bridging chlorine atoms. The two chlorines are both in basal
sites and bridge almost symmetrically although with quite long
Bi–Cl bonds (see below) [Bi(1)–Cl(1) 3.0020(12), Bi(1)–Cl(1A)
2.9325(13) Å]. The two remaining basal sites are occupied by
aryloxide groups for which the Bi–O distances are identical
[Bi(1)–O(1) 2.154(3), Bi(1)–O(2) 2.152(3) Å] as expected in view
of the similarity of the trans Bi–Cl bond lengths. The remaining
aryloxide resides in the apical site and has the shortest Bi–O
bond [Bi(1)–O(3) 2.113(3) Å] consistent with the absence of any
J. Chem. Soc., Dalton Trans., 1998, 4049–4054
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trans ligand or group; this latter distance is close to the short
end of the range of Bi–O distances mentioned above19 and to
the Bi–O lengths in the neutral compound Bi(OC6H3Me2-2,6)3.7
The angles around the bismuth centre are unexceptional and do
not deviate significantly from idealised values. It is interesting
to note that it is the chlorine atoms which bridge in the
structure of 3 unlike in 1 and 2, where it is the aryloxide groups
which are bridging, but the nature of the bridging interaction
is somewhat unusual. In most bridging halide bismuth
compounds, the bridges are either symmetric with Bi–X bonds
only slightly longer than terminally bonded halides, or are
asymmetric with one short and one long bond [see refs. 20,
26(a), (b), (c), (e) and 27 for examples]. In the case of 3 however,
as mentioned above, all Bi–Cl bonds are close to 3 Å and there-
fore quite long (a terminal Bi–Cl bond distance is typically
about 2.6 Å20). An overall description of 3 as comprising two
neutral Bi(OC6H3Me2-2,6)3 units loosely associated with two
chloride anions might therefore be appropriate as illustrated
below.
Fig. 5 A view of the monomeric bismuth dianion in 5 showing the
atom numbering scheme. Atoms are drawn as spheres of arbitrary
radius. Selected bond lengths: Bi(1)–O(1) 2.193(7), Bi(1)–O(2) 2.119(7),
Bi(1)–Br(1) 2.8218(13), Bi(1)–Br(2) 2.793(2), Bi(1)–Br(3) 3.1107(12) Å.
2–
RO
RO
RO
Cl
Cl
OR
OR
Bi
Bi
discussion of the structure; unit cell data are given in the
Experimental section. An interesting structure for comparison
with 5 and 6 is [Na2(thf)4][Bi(SC6F5)5]29 which contains a
monomeric bismuth pentathiolate dianion.
OR
A compound similar to 3 was also isolated from the reaction
28
between the tris(aryloxide) Bi(OC6H2Me3-2,4,6)3 and the
The structures presented and described herein show that a
range of neutral and anionic mixed aryloxy–halide bismuth()
complexes can be readily prepared and there is every reason to
expect a rich structural chemistry for this class of compound.
This structural variety is further enhanced by the ability of both
the halide and aryloxide groups to engage in bridging inter-
actions which, in the case of the halides, may range from
symmetric to very asymmetric; such variety is a common
feature of systems where secondary bonding interactions are
important aspects of the solid state structure.20 The extent to
which the species reported here retain any integrity in solution
is unclear and halide and aryloxide exchange is likely, especially
in coordinating solvents as we have observed many times before
in related aryl bismuth halide chemistry.26a,b,30 This state of
affairs often leads to compounds being isolated which are not
consistent with the reaction stoichiometry and it is therefore
sometimes difficult to design rational syntheses to specific
compounds. However, this is to be expected in systems which
rapidly exchange in solution; the products which crystallise are
often the least soluble and not necessarily the major species
present in solution.
bromide source [PPh4]Br. The structure was established by
X-ray crystallography to be [PPh4]2[Bi2Br2(OC6H2Me3-2,4,6)4-
(µ-Br)2] 4 containing a centrosymmetric dianionic dimeric
unit analogous to that found in 3 except that it contained one
terminal bromine and two terminal aryloxide groups rather
than three terminal aryloxides. The bridging bromines (note
that as with 3, it is the halides which bridge rather than the
aryloxide groups) were notably asymmetric but problems with
poor data prevented a satisfactory refinement and no further
details will be described here. The basic structure is represented,
however, in the diagram below and unit cell data are given in the
Experimental section.
2–
RO
Br
RO
Bi
Br
Bi
Br
Br
OR
OR
Another crystalline compound isolated from the reaction
system which afforded 4 was shown by X-ray crystallography to
be the species [PPh4]2[BiBr3(OC6H2Me3-2,4,6)2] 5 which con-
tains the monomeric bismuth dianion [BiBr3(OC6H2Me3-
2,4,6)2]2Ϫ (Fig. 5); there are no short interionic contacts. The
coordination geometry about the bismuth centre is square-
based pyramidal with all three bromines in the basal plane and
one of the aryloxide groups in the apical site. The Bi–O dis-
tances differ from each other in much the same way as is found
in the structure of 3 in that the apical Bi–O length [Bi(1)–O(2)
2.119(7) Å] is significantly shorter than the basal Bi–O distance
[Bi(1)–O(1) 2.193(7) Å] which lies trans to a bromine. Of the
three Bi–Br bond lengths, those of the two bromines which lie
trans to each other are similar [Bi(1)–Br(1) 2.8218(13), Bi(1)–
Br(2) 2.793(2) Å] but significantly shorter than the unique
bromine trans to the basal aryloxide group [Bi(1)–Br(3)
3.1107(12) Å].
Experimental
General procedures
All reactions were carried out under an atmosphere of dry
dinitrogen using standard Schlenk or dry-box techniques
using oven-dried or flame-dried glassware. All solvents used
were distilled under nitrogen and dried over appropriate drying
agents (CaH2 for CH2Cl2, Na for hexanes and sodium–
benzophenone for thf and Et2O). BiCl3 (99.99%) and all other
starting materials were procured from Aldrich and generally
used without further purification although in the case of the
phenols, it was sometimes necessary for these to be dried.
Preparations
A compound related to 5 was obtained from the reaction
7
between [PPh4]Br and Bi(OC6H3Me2-2,6)3 and shown by
[Bi2Cl4(thf)2(ì-OC6H3Me2-2,6)2] 1. A solution of BiCl3 (1.000
g, 1.59 mmol) in thf (20 cm3) was added to a stirred solution
of Na[OC6H3Me2-2,6], prepared from dried HOC6H3Me2-2,6
(0.387 g, 3.17 mmol) and sodium metal (0.073 g, 3.17 mmol), in
thf (10 cm3) at room temperature resulting in an immediate
colour change to bright orange and the formation of a white
X-ray crystallography to have the formula [PPh4]2[BiBr2-
(OC6H3Me2-2,6)3] 6. A monomeric bismuth dianion is present
as in 5 although in this case there are two bromines and three
aryloxide groups. Problems with the crystal structure refine-
ment, however, preclude a more detailed description and
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J. Chem. Soc., Dalton Trans., 1998, 4049–4054

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precipitate. After stirring for a further 20 min, this solution was
cooled to Ϫ20ЊC and the solid allowed to settle out. The
remaining orange solution was then transferred to another
Schlenk tube via cannula and the solvent volume was reduced
to about 2 cm3 under vacuum. Addition of an overlayer of n-
hexane (8 cm3) and subsequent solvent diffusion at room
temperature over a period of 1 h afforded orange, needle-like
crystals of 1 (20% isolated yield). Completely satisfactory
elemental analytical data were difficult to obtain due to the
lability of the coordinated thf ligands which result in low
carbon and high chlorine values. C12H17BiCl2O2 requires C,
30.45; H, 3.60; Cl, 15.00. Found: C, 28.60; H, 3.60; Cl, 15.75%.
over a period of several days afforded a crop of yellow
block-like crystals comprising both compounds 4 and 5. Only
variable analytical data could be obtained due to the isolated
solid comprising a mixture of two compounds and the difficulty
1
encountered in separating the two materials. H NMR data,
however, showed the presence of only one species in solution.
1H NMR (CDCl3): δ 7.7 (m, PPh4), 7.21 (m, 2H, 2,4,6-
Me3C6H2), 2.16 (s, 6H, 2,4,6-Me3C6H2), 2.12 (s, 3H, 2,6-
Me3C6H2).
[PPh4]2[BiBr2(OC6H3Me2-2,6)3] 6. A solution of Bi(OC6H3-
Me2-2,6)3 (0.100 g, 0.175 mmol), prepared according to ref. 7,
in CH2Cl2 (2 cm3) was added to a stirred solution of dried
[PPh4]Br (0.073 g, 0.174 mmol) in CH2Cl2 (1.5 cm3), afford-
ing a clear golden yellow solution. After 30 min the solvent
volume was reduced by vacuum and n-hexane (5 cm3) was
added as an overlayer. Subsequent solvent diffusion over-
night at room temperature afforded golden yellow, needle-like
crystals of 6. C72H67BiBr2O3P2 requires C, 61.30; H, 4.80; Br,
11.35; P, 4.40. Found: C, 60.25; H, 4.90; Br, 10.33; P, 3.54%. 1H
NMR (CDCl3): δ 7.7 (m, 40H, PPh4), 6.90 (m, 9H, 2,6-
Me2C6H3), 2.32 (s, 18H, 2,6-Me2C6H3).
[Bi2Cl4(thf)2(ì-OC6H2Me3-2,4,6)2] 2. A solution of BiCl3
(0.500 g, 1.59 mmol) in thf (20 cm3) was added to a stirred
solution of Na[OC6H2Me3-2,4,6], prepared from dried
HOC6H2Me3-2,4,6 (0.220 g, 1.62 mmol) and sodium metal
(0.037 g, 1.61 mmol), in thf (10 cm3) at room temperature
resulting in an immediate colour change to bright orange-
yellow and formation of a white precipitate. After stirring for
a further 20 min, the solution was cooled to Ϫ20ЊC and the
solid allowed to settle out. The remaining yellow-orange
solution was transferred to another Schlenk tube via cannula
and the solvent volume was reduced to about 2 cm3 by vacuum.
Addition of an overlayer of n-hexane (8 cm3) and subsequent
solvent diffusion at room temperature over a period of 1 h
afforded yellow-orange, needle-like crystals of 2 (19 % isolated
yield). Completely satisfactory elemental analytical data were
difficult to obtain due to the lability of the coordinated thf
ligands which result in low carbon and high chlorine values.
C13H19BiCl2O2 requires C, 32.05; H, 3.95; Cl, 14.55. Found: C,
27.55; H, 3.40; Cl, 16.35%.
X-Ray crystallography
All crystals were mounted under argon on glass fibres using
grease. Data collections were performed on a Siemens (Bruker)
SMART area detector diffractometer using graphite mono-
chromated Mo-Kα radiation, at Ϫ100ЊC. In each case a full
hemisphere of reciprocal space was scanned by 0.3Њ ω steps.
Structures were solved and refined by standard methods.
Absorption corrections were applied using SADABS31 and
extinction coefficients were refined.
Unit cell data for [SbCl2(OC6H2But3-2,4,6)(HOC6H2But3-
SbCl2(OC6H2But3-2,4,6). A solution of SbCl3 (0.500 g, 2.19
mmol) in thf (20 cm3) was added to a stirred solution of
Li[OC6H2But3-2,4,6], prepared from dried HOC6H3But3-2,4,6
(0.576 g, 2.19 mmol) and LiBun (1.4 cm3 of a 1.6 M solution in
hexanes), in thf (10 cm3), giving a pale yellow coloured solution
which overnight became greenish-yellow. After this time, the
solvent volume was reduced to about 2 cm3 by vacuum and n-
hexane (8 cm3) was added as an overlayer resulting in colourless
block-like crystals after several weeks at room temperature.
C36H59Cl2O2Sb requires C, 60.35; H, 8.30; Cl, 9.90. Found: C,
60.70; H, 8.90; Cl, 9.10%.
¯
2,4,6)]: triclinic, P1, a = 9.375(5), b = 9.880(4), c = 22.975(8) Å,
α = 92.75(3), β = 95.83(2), γ = 117.38(4)Њ.
¯
Unit cell data for 4: triclinic, P1, a = 12.501(3), b = 13.698(3),
c = 14.287(3) Å, α = 101.34(3), β = 106.84(3), γ = 105.16(3)Њ.
¯
Unit cell data for 6: triclinic, P1, a = 13.040(3), b = 13.548(3),
c = 20.361(4) Å, α = 70.77(3), β = 74.01(3), γ = 65.60(3)Њ.
CCDC reference number 186/1192.
See http://www.rsc.org/suppdata/dt/1998/4049/ for crystallo-
graphic files in .cif format.
Acknowledgements
We thank the EPSRC for support and N. C. N. thanks Laporte
plc and The Royal Society for additional supporting funds.
[NMe4]2[Bi2(OC6H3Me2-2,6)6(ì-Cl)2] 3. A solution of Bi-
(OC6H3Me2-2,6)3 (0.100 g, 0.175 mmol), prepared according to
ref. 7, in CH2Cl2 (2 cm3) was added to a stirred solution of dried
[NMe4]Cl (0.019 g, 0.175 mmol) in CH2Cl2 (1.5 cm3), resulting
in a cloudy yellow solution. After stirring for 30 min, the
solvent volume was reduced slightly by vacuum and n-hexane
(5 cm3) was added as an overlayer resulting in yellow, needle-
like crystals of 3 after standing overnight at room temperature
although unreacted [NMe4]Cl also crystallises as well. Satis-
factory analytical data could not be obtained in this case due
to co-crystallisation of 3 with unreacted [NMe4]Cl and the
difficulty encountered in separating the two materials. 1H NMR
(CDCl3): δ 6.99, (m, 9H, 2,6-Me2C6H3), 3.50, (s, 12H, NMe4),
2.27 (s, 18H, 2,6-Me2C6H3).
References
1 M. Maeda, Y. Tanaka, M. Fukukumi and Q. T. Asaro, Jpn. J. Appl.
Phys., 1988, 27, L209.
2 S. M. Kazakov, C. Chaillout, P. Bordet, J. J. Capponi, M. Nunez-
Regueiro, A. Rysak, J. L. Tholence, P. G. Radaelli, S. N. Putilin
and E. V. Antipov, Nature (London), 1997, 390, 148.
3 J. F. Scott, F. M. Ross, C. A. Paz de Araujo, M. C. Scott and
M. Huffman, MRS Bull., 1996, 21, 33.
4 K. R. Kendall, C. Navas, J. K. Thomas and H.-C. zur Loye, Chem.
Mater., 1996, 8, 642.
5 R. K. Grasselli and J. D. Burrington, Adv. Catal., 1981, 30, 133;
R. K. Grasselli, J. Chem. Educ., 1986, 63, 216.
6 W. Ueda, T. Isozaki, F. Sakyu, S. Nishiyama and Y. Morikawa, Bull.
Chem. Soc. Jpn., 1996, 69, 485; S. Lin and W. Ueda, Chem. Lett.,
1997, 901.
7 W. J. Evans, J. H. Hain and J. W. Ziller, J. Chem. Soc., Chem.
Commun., 1989, 1628.
8 A. Haaland, H.-P. Verne, H.-V. Volden, R. Papiernik and
L. Hubert-Pfalzgraf, Acta Chem. Scand., 1993, 47, 1043.
9 C. M. Jones, M. D. Burkart and K. H. Whitmire, Angew. Chem.,
Int. Ed. Engl., 1992, 31, 451; C. M. Jones, M. D. Burkart,
R. E. Bachman, D. L. Serra, S.-J. Hwu and K. H. Whitmire, Inorg.
Chem., 1993, 32, 5136.
[PPh4]2[Bi2Br2(OC6H2Me3-2,4,6)4(ì-Br)2]
4 and [PPh4]2-
[BiBr3(OC6H2Me3-2,4,6)2] 5. A solution of Bi(OC6H2Me3-
2,4,6)3 (0.050 g, 0.0814 mmol), prepared from reaction of BiCl3
with Na[OC6H2Me3-2,4,6] as described for 2 in the appropriate
ratios, in CH2Cl2 (3 cm3) was added to dried [PPh4]Br (0.034 g,
0.0811 mmol) and stirred for 30 min affording a clear yellow
solution. After this time, the solvent volume was reduced by
vacuum to about 2 cm3 and n-hexane (5 cm3) was added as an
overlayer. Subsequent solvent diffusion at room temperature
J. Chem. Soc., Dalton Trans., 1998, 4049–4054
4053

View Article Online
10 M.-C. Massiani, R. Papiernik, L. G. Hubert-Pfalzgraf and
J.-C. Daran, Polyhedron, 1991, 10, 437.
11 M.-C. Massiani, R. Papiernik, L. G. Hubert-Pfalzgraf and
J.-C. Daran, J. Chem. Soc., Chem. Commun., 1990, 301.
12 M. A. Matchett, M. Y. Chiang and W. E. Buhro, Inorg. Chem., 1990,
29, 358.
13 M. Veith, E.-C. Yu and V. Huch, Chem. Eur. J., 1995, 1, 26.
14 J. L. Jolas, S. Hoppe and K. H. Whitmire, Inorg. Chem., 1997,
36, 3335.
15 C. M. Jones, M. D. Burkart and K. H. Whitmire, J. Chem. Soc.,
Chem. Commun., 1992, 1638.
16 K. H. Whitmire, C. M. Jones, M. D. Burkart, J. C. Hutchison and
A. L. McKnight, Mater. Res. Soc. Symp. Proc., 1992, 271, 149.
17 N. N. Sauer, E. Garcia and R. R. Ryan, Mater. Res. Soc. Symp.
Proc., 1990, 180, 921.
18 S. C. James, N. C. Norman, A. G. Orpen, M. J. Quayle and
U. Weckenmann, J. Chem. Soc., Dalton Trans., 1996, 4159.
19 K. H. Whitmire, Chemtracts: Inorg. Chem., 1995, 7, 167.
20 N. C. Norman, Phosphorus, Sulfur Silicon Relat. Elem., 1994, 87,
167; C. J. Carmalt and N. C. Norman, in Chemistry of Arsenic,
Antimony and Bismuth, ed. N. C. Norman, Blackie Academic &
Professional, London, ch. 1, 1998.
25 J. W. Pell, W. C. Davis and H.-C. zur Loye, Inorg. Chem., 1996,
35, 5754.
26 (a) W. Clegg, R. J. Errington, G. A. Fisher, D. C. R. Hockless,
N. C. Norman, A. G. Orpen and S. E. Stratford, J. Chem.
Soc., Dalton Trans., 1992, 1967; (b) W. Clegg, R. J. Errington,
G. A. Fisher, R. J. Flynn and N. C. Norman, J. Chem. Soc., Dalton
Trans., 1993, 637; (c) C. J. Carmalt, W. Clegg, M. R. J. Elsegood,
R. J. Errington, J. Havelock, P. Lightfoot, N. C. Norman and
A. J. Scott, Inorg. Chem., 1996, 35, 3709; (d) J. R. Eveland and
K. H. Whitmire, Inorg. Chim. Acta, 1996, 249, 41; (e) S. C. James,
N. C. Norman, A. G. Orpen and M. J. Quayle, Acta Crystallogr.,
Sect. C, 1997, 53, 1024; ( f ) V. H. Krautscheid, Z. Anorg. Allg.
Chem., 1994, 620, 1559.
27 W. Clegg, L. J. Farrugia, A. McCamley, N. C. Norman, A. G.
Orpen, N. L. Pickett and S. E. Stratford, J. Chem. Soc., Dalton
Trans., 1993, 2579.
28 N. A. Compton, PhD Thesis, University of Newcastle upon Tyne,
1989.
29 L. J. Farrugia, F. J. Lawlor and N. C. Norman, Polyhedron, 1995,
14, 311.
30 C. J. Carmalt, A. H. Cowley, A. Decken and N. C. Norman,
J. Organomet. Chem., 1995, 496, 59.
21 S. Hoppe and K. H. Whitmire, Organometallics, 1998, 17, 1347.
22 G. E. Binder, W. Schwarz, W. Rozdzinski and A. Schmidt, Z. Anorg.
Allg. Chem., 1980, 471, 121.
31 G. M. Sheldrick, SADABS, A program for absorption correction
with the Siemens SMART system, University of Göttingen, 1996.
23 B. Detampel and A. Schmidt, Z. Anorg. Allg. Chem., 1992, 609,
35.
24 A. J. Edwards, N. E. Leadbeater, M. A. Paver, P. R. Raithby.
C. A. Russell and D. S. Wright, J. Chem. Soc., Dalton Trans., 1994,
1479.
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J. Chem. Soc., Dalton Trans., 1998, 4049–4054