Cationic complexes of antimony(III) and bismuth(III) stabilized by intra- or intermolecular coordination

Article abstract of DOI:10.1021/om970322k

Three cationic aryl-ahtimony and -bismuth complexes stabilized by intra- or intermolecular coordination have been prepared. Treatment of either SbAr₂Cl or BiAr₂Cl (Ar = 2-[(dimethylamino)methyl]phenyl, 2-(Me₂NCH₂)C₆H₄) with TIPF₆ afforded [SbAr₂][PF₆] (1) or [BiAr₂][PF₆] (2), respectively. A related complex, [SbPh₂{OP(NMe₂)₃}₂][PF₆] (5), stabilized by intermolecular coordination, was prepared via the reaction of SbPhCl₂ with 2 equiv of TlPF₆ in the presence of an excess of OP(NMe₂)₃. The X-ray crystal structures of compounds 1, 2, and 5 are described; the coordination geometry at the group 15 element center in each new compound was found to be distorted trigonal bipyramidal.

Full text of DOI:10.1021/om970322k

Organometallics 1997, 16, 3597-3600
3597
Ca tion ic Com p lexes of An tim on y(III) a n d Bism u th (III)
Sta bilized by In tr a - or In ter m olecu la r Coor d in a tion
Claire J . Carmalt,† Denise Walsh,† Alan H. Cowley,*,† and
Nicholas C. Norman*,‡
Department of Chemistry & Biochemistry, The University of Texas at Austin, Austin, Texas
78712, and School of Chemistry, Cantock’s Close, University of Bristol, Bristol, BS8 1TS, U.K.
Received April 16, 1997X
Three cationic aryl-antimony and -bismuth complexes stabilized by intra- or intermo-
lecular coordination have been prepared. Treatment of either SbAr2Cl or BiAr2Cl (Ar )
2-[(dimethylamino)methyl]phenyl, 2-(Me2NCH2)C6H4) with TlPF6 afforded [SbAr2][PF6] (1)
or [BiAr2][PF6] (2), respectively. A related complex, [SbPh2{OP(NMe2)3}2][PF6] (5), stabilized
by intermolecular coordination, was prepared via the reaction of SbPhCl2 with 2 equiv of
TlPF6 in the presence of an excess of OP(NMe2)3. The X-ray crystal structures of compounds
1, 2, and 5 are described; the coordination geometry at the group 15 element center in each
new compound was found to be distorted trigonal bipyramidal.
In tr od u ction
(NMe2)3}4]+ 10 and [BiI2(py)3(dppmO2)]+ (py ) pyridine,
dppmO2 ) Ph2P(O)CH2(O)PPh2).2 Further pertinent
examples of bismuth or antimony monocations include
the dimeric species [Bi2(µ-Cl)2Cl2(tu)6]2+ (tu ) thio-
urea)11 and [Sb2Cl2(NPPh3)2(CH3CN)4]2+ 12 and the
octahedral catecholate cation [Sb(O2C6H4)(phen)2]+ (phen
) 1,10-phenanthroline).13 Each of the monocations
listed above involves some degree of base stabilization,
and it is only very recently that [Cp*2Sb]+ and [Cp′′′2Sb]+
(Cp* ) pentamethylcyclopentadienyl, Cp′′′ ) 1,2,4-tri-
tert-butylcyclopentadienyl), the first examples of base-
free stibocenium cations, have been reported.14
In a recent series of papers1-3 we have reported the
first examples of a range of cationic, 4-coordinate, 10-
electron diarylbismuth(III) and bis(organotransition
metal)bismuth(III) monocations. By means of X-ray
crystallography, it was established that the stereochem-
istry of cations of the general type [BiR2(L)2]+ (where R
) Ph, L ) OPPh3, OP(NMe2)3; R ) mesityl, L )
OP(NMe2)3)1,2 conforms to expectation in the sense that
the bismuth center adopts an equatorially vacant trigo-
nal-bipyramidal coordination geometry with the L ligands
and aryl groups in axial and equatorial sites, respec-
tively. Most of the other known structurally character-
ized bismuth or antimony monocations feature the
coordination of a dihalide unit, [EX2]+ (E ) Sb, Bi; X )
halide), by a polydentate oxygen or nitrogen donor
ligand. Examples include the crown ether complexes
[SbCl2(18-crown-6)]+,4 [BiCl2(18-crown-6)]+,5 [BiBr2(18-
crown-6)]+,6 and [BiCl2(MeCN)(18-crown-6)]+,7 the poly-
ether complexes [BiBr2(hexa(ethylene glycol))]+ and
[BiBr2(penta(ethylene glycol))]+,6 and a cation stabilized
by an aza macrocyclic ligand, [SbCl2(Me3[9]aneN3)]+.8
Each of the foregoing examples features a bent [EX2]+
moiety, as is also found in the arene complex
[BiCl2(C6Me6)][AlCl4].9 Linear [EX2]+ coordination is
possible, however, as exemplified by [BiI2{OP-
Information on dications of the heavier group 15
elements is somewhat sparse. Of the three structurally
authenticated dications, two of them, [SbCl(15-crown-
5)]2+ 7 and [BiCl(MeCN)2(18-crown-6)]2+,7 involve coor-
dination by a crown ether. The third example, [BiPh-
{OP(NMe2)3}4]2+,2 features stabilization of the highly
electrophilic [BiPh]2+ moiety by coordination of four
OP(NMe2)3 ligands. Interestingly, some structurally
characterized bismuth and antimony trications have
been previously reported, including the octahedral spe-
cies [Bi(dmpu)6]3+ (dmpu ) N,N′-dimethylpropylene
urea),15 [Bi(tu)6]3+ 16 and [Bi(aptu)6]3+ (aptu ) 1-allyl-
,
3-(2-pyridyl)thiourea-S)17 and the crown ether com-
plexes [M(12-crown-4)2(MeCN)]3+ (M ) Sb, Bi).18
In the present contribution, we describe the synthesis
and X-ray structures of three cationic aryl-bismuth
† The University of Texas at Austin.
‡ University of Bristol.
X Abstract published in Advance ACS Abstracts, J uly 1, 1997.
(1) Carmalt, C. J .; Norman, N. C.; Orpen, A. G.; Stratford, S. E. J .
Organomet. Chem. 1993, 460, C22.
(10) Clegg, W.; Farrugia, L. J .; McCamley, A.; Norman, N. C.; Orpen,
A. G.; Pickett, N. L.; Stratford, S. E. J . Chem. Soc., Dalton Trans. 1993,
2579.
(2) Carmalt, C. J .; Farrugia, L. J .; Norman, N. C. J . Chem. Soc.,
Dalton Trans. 1996, 443.
(3) Carmalt, C. J .; Farrugia, L. J .; Norman, N. C. J . Chem. Soc.,
Dalton Trans. 1996, 455.
(4) Neuhaus, A.; Frenzen, G.; Pebler, J .; Dehnicke, K. Z. Anorg. Allg.
Chem. 1992, 618, 93.
(11) Battaglia, L. P.; Bonamartini Corradi, A.; Pelizzi, G.; Vidoni
Tani, M. E. Cryst. Struct. Commun. 1975, 4, 399.
(12) Garbe, R.; Pebler, J .; Dehnicke, K.; Fenske, D.; Goesman, H.;
Baum, G. Z. Anorg. Allg. Chem. 1994, 620, 592.
(13) Huber, F.; Preut, H.; Alonzo, G.; Betazzi, N. Inorg. Chim. Acta
1955, 102, 181.
(5) Alcock, N. W.; Ravindran, M.; Willey, G. R. J . Chem. Soc.,
Chem.Commun. 1959, 1063.
(6) Rogers, R. D.; Bond, A. H.; Aguinaga, S.; Reyes, A. J . Am. Chem.
Soc. 1992, 114, 2967.
(14) Sitzmann, H.; Ehleiter, Y.; Wolmersha¨user, G.; Ecker, A.;
U¨ ffing, C.; Schno¨ckel, H. J . Organomet. Chem. 1997, 527, 209.
(15) Carmalt, C. J .; Farrugia, L. J .; Norman, N. C. Z. Anorg. Allg.
Chem. 1995, 621, 47.
(7) Scha¨fer, M.; Frenzen, G.; Neumu¨ller, B.; Dehnicke, K. Angew.
Chem., Int. Ed. Engl. 1992, 31, 334.
(8) Willey, G. R.; Spry, M. P.; Drew, M. G. Polyhedron 1996, 15,
4497.
(16) Battaglia, L. P.; Bonamartini Corradi, A.; Pelizzi, G.; Vidoni
Tani, M. E. J . Chem. Soc., Dalton Trans. 1977, 1141.
(17) Battaglia, L. P.; Bonamartini Corradi, A. J . Chem. Soc., Dalton
Trans. 1981, 23.
(9) Frank, W.; Weber, J .; Fuchs, E. Angew. Chem., Int. Ed. Engl.
1957, 26, 74.
(18) Garbe, R.; Vollmer, B.; Neumu¨ller, B.; Pebler, J .; Dehnicke, K.
Z. Anorg. Allg. Chem. 1993, 619, 271.
S0276-7333(97)00322-1 CCC: $14.00 © 1997 American Chemical Society

3598 Organometallics, Vol. 16, No. 16, 1997
Carmalt et al.
Sch em e 1
and -antimony complexes stabilized by intra- or inter-
molecular coordination. Our motivation for the prepa-
ration and structural characterization of these cationic
complexes of the heavier group 15 elements stemmed
from two main considerations. First, we were interested
in investigating the differences resulting from the
presence of intra- versus intermolecular stabilization of
the cations, and second, we wished to attempt the
preparation of further examples of cationic compounds
of the heavier group 15 elements with low coordination
numbers.
F igu r e 1. View of the structure of 1+ showing the atom-
numbering scheme. Ellipsoids are drawn at the 30% level.
Hydrogen atoms are omitted.
Resu lts a n d Discu ssion
The colorless crystalline compounds 1 and 2 were
prepared via the reaction between TlPF6 and the
appropriate diarylelement monochloride in thf solution
at room temperature (Scheme 1). Elemental analytical
1
data, together with H and 13C NMR spectroscopic data
for both 1 and 2, were consistent with the anticipated
formulas. However, in order to reveal the extent to
which the NMe2 groups were coordinated to the group
15 element centers, it was necessary to determine the
structures of these compounds by X-ray crystallography.
Although they are not isomorphous, both 1 and 2
crystallize in the monoclinic space group P21/c or P21/n
with Z ) 4. The solid-state structures of both com-
pounds comprise [EAr2]+ (Ar ) 2-[(dimethylamino)m-
ethyl]phenyl, 2-(Me2NCH2)C6H4) cations (1+, E ) Sb;
2+, E ) Bi) and hexafluorophosphate anions (the [PF6]-
anion is disordered in the structure of 2). In the case
of 1, the ion pairs are well-separated, as evidenced by
the observation that the closest Sb‚‚‚F contact is 4.806
Å. Interestingly, the closest interionic contact in 2 is
much shorter (Bi‚‚‚F ) 3.49 Å). Examination of the
structure of cation 1+ (Figure 1) reveals that both amine
arms are coordinated strongly to the Sb center, the two
Sb-N bond lengths being identical within experimental
error (2.414(3) Å). Overall, the coordination geometry
of 1+ is that of an equatorially vacant trigonal bipyramid
in which the axial and equatorial sites are occupied by
amine nitrogen atoms and the ipso carbon atoms of the
aryl ligands, respectively, although all the bond angles
are less than ideal trigonal-bipyramidal values (Table
1). Thus, the N(1)-Sb-N(2) bond angle is 163.72(1)°
rather than 180° and the C(1)-Sb-C(10) bond angle of
95.7(1)° is considerably less than 120°. The former
angular diminution results primarily from the con-
straints imposed by the bidentate ligands, whereas the
latter is typical for heavier element complexes with this
geometry and reflects the stereochemical activity of the
equatorially disposed antimony lone pair. It is of
interest to compare the structure of 1+ with that of the
F igu r e 2. View of the molecular structure of the cation
2+ showing the atom-numbering scheme. Ellipsoids are
drawn at the 30% level. Hydrogen atoms are omitted.
precursor chloride, SbAr2Cl (3).19 The most conspicuous
difference is that only one of the amine arms is
coordinated in the case of 3. However, both species
adopt equatorially vacant trigonal-bipyramidal struc-
tures, the interrelationship between them being that
one of the amine arms in 1+ is replaced by a chloride
ligand in 3. As expected, the Sb-N bond lengths in 1+
(average 2.414(4) Å) are slightly shorter than those in
3 (2.463(2) Å) due to the more electrophilic nature of
the antimony center in the cation.
Even though 1 and the bismuth analogue, 2, are not
isomorphous, the structures of the cations are very
similar (Figure 2 and Table 1) and the comments that
were made concerning the pattern of bond angles in 1+
are pertinent to 2+ also. The structural interrelation-
ships between 2+ and the precursor chloride, BiAr2Cl
(4),19 are also similar to those of the analogous antimony
species. As anticipated, the Bi-N bond lengths in 2+
(average 2.500(1) Å) are slightly shorter than those in
419 (2.570(5) Å). Interestingly, the Bi-N bond length
19
in 2+ is identical with that in the dihalide BiArI2
(2.503(4) Å) within experimental error.
In general, the geometries of 1+ and 2+ are similar to
those of the type [BiR2(L)2]+ which feature monodentate
aryl ligands (R) and two-electron donors (L)1,2 in the
sense that they all possess an equatorially vacant
(19) Carmalt, C. J .; Cowley, A. H.; Culp, R. D.; J ones, R. A.;
Kamepalli, S.; Norman, N. C. Inorg. Chem., in press.

Cationic Complexes of Sb(III) and Bi(III)
Organometallics, Vol. 16, No. 16, 1997 3599
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for Com p ou n d s 1, 2, a n d 5
1
2
5
Sb(1)-C(1)
Sb(1)-C(10)
Sb(1)-N(1)
Sb(1)-N(2)
2.164(4)
2.165(4)
2.412(3)
2.416(4)
Bi(1)-C(1)
Bi(1)-C(10)
Bi(1)-N(1)
Bi(1)-N(2)
2.259(4)
2.253(2)
2.509(1)
2.491(1)
Sb(1)-C(1)
Sb(1)-C(7)
Sb(1)-O(1)
Sb(1)-O(2)
2.140(8)
2.138(1)
2.236(7)
2.231(7)
C(1)-Sb(1)-C(10)
C(1)-Sb(1)-N(1)
C(10)-Sb(1)-N(1)
C(1)-Sb(1)-N(2)
C(10)-Sb(1)-N(2)
N(1)-Sb(1)-N(2)
95.7(1)
74.4(1)
94.2(1)
94.5(1)
74.8(1)
163.72(1)
C(1)-Bi(1)-C(10)
C(1)-Bi(1)-N(1)
C(10)-Bi(1)-N(1)
C(1)-Bi(1)-N(2)
C(10)-Bi(1)-N(2)
N(1)-Bi(1)-N(2)
91.6(5)
73.0(5)
95.8(4)
95.4(5)
74.3(4)
164.8(4)
C(1)-Sb(1)-C(7)
C(1)-Sb(1)-O(1)
C(7)-Sb(1)-O(1)
C(1)-Sb(1)-O(2)
C(7)-Sb(1)-O(2)
O(1)-Sb(1)-O(2)
95.6(4)
84.5(5)
88.8(3)
87.9(5)
84.1(3)
169.1(3)
Sch em e 2
trigonal-bipyramidal geometry. In the cases of 1+ and
2+, the angular distortions are more pronounced because
of the constraints of bidentate ligation.
Since it had proved possible2 to isolate a bismuth
dication by treatment of BiPhBr2 with TlPF6 in the
presence of an excess of OP(NMe2)3, a similar approach
seemed appropriate in our quest for a comparable
antimony dication. However, as shown in Scheme 2,
20
the reaction of SbPhCl2 with TlPF6 and OP(NMe2)3
F igu r e 3. View of the molecular structure of the cation
5+ showing the atom-numbering scheme. Ellipsoids are
drawn at the 30% level. Hydrogen atoms are omitted.
For example, in the case of 5+ these angles differ by
over 5° (140.1(5) and 134.0(4)° for Sb(1)-O(1)-P(1) and
Sb(1)-O(2)-P(2), respectively). As pointed out previ-
ously,2 such differences reflect a relatively soft E-O-P
angular deformation potential and a consequent sensi-
tivity to crystal-packing forces.
In conclusion, it has been demonstrated that antimo-
ny(III) and bismuth(III) monocations can be synthesized
when stabilized by either intra- or intermolecular
coordination by Lewis basic moieties. However, the
attempt to prepare a dicationic complex of antimony(III)
was unsuccessful due to complications that arose on
account of a facile redistribution reaction.
afforded an antimony monocation salt of formula
[SbPh2{OP(NMe2)3}2][PF6] (5) rather than the targeted
dication salt [SbPh{OP(NMe2)3}x][PF6]2. Clearly, an
aryl-halide redistribution reaction is involved in the
formation of 5. Such reactions are, in fact, commonly
encountered in the solution chemistry of arylantimony
and arylbismuth halides.21 Preliminary characteriza-
tion of 5 was provided both by a satisfactory elemental
analysis and by integration of the phenyl and OP-
(NMe2)3 1H NMR resonances, but in order to confirm
the structural assignment, an X-ray crystallographic
study was carried out. Compound 5 crystallizes in the
orthorhombic space group Pna21 with Z ) 4 and consists
of [SbPh2{OP(NMe2)3}2]+ (5+) and hexafluorophosphate
anions; there are no unusually short interionic contacts.
While they are not isomorphous, the structure of 5 bears
a close resemblance to those of [BiPh2{OP(NMe2)3}2][PF6]
(6)2 and [BiPh2{OP(NMe2)3}2][BF4] (7).2 Like those of
Exp er im en ta l Section
1
+ and 2+, the geometry of 5+ at the group 15 center is
Gen er a l P r oced u r es. All manipulations were performed
under a dry, oxygen-free dinitrogen or argon atmosphere using
standard Schlenk techniques or an Innovative Technology
System One-M drybox. Unless otherwise stated, all solvents
were dried over sodium and distilled from sodium benzophe-
none ketyl under argon prior to use. The reagents SbAr2Cl,19
BiAr2Cl,19 and SbPhCl220 were prepared according to literature
methods. All other reagents were procured commercially and
used without further purification. Elemental analyses were
performed by Atlantic Microlab, Inc., Norcross, GA.
P h ysica l Mea su r em en ts. Mass spectra (CIMS) were run
on a MAT 4023 instrument, and NMR spectra were recorded
on a GE QE-300 spectrometer (1H, 300.19 MHz; 13C, 75.48
MHz). NMR spectra are referenced to C6D6, which was dried
over sodium-potassium alloy and distilled prior to use; 1H and
13C chemical shifts are reported relative to Si(CH3)4 (0.00 ppm).
Melting points were obtained in sealed glass capillaries under
argon and are uncorrected.
equatorially vacant trigonal bipyramidal (Figure 3 and
Table 1), the equatorial and axial sites being occupied
by phenyl groups and OP(NMe2)3 ligands, respectively.
Interestingly, the C-Sb-C bond angle (95.6(4)°) and the
average Sb-C bond length (2.139(8) Å) in 5+ are very
similar to those in 1+ (95.7(1)° and 2.164(4) Å), even
though the aryl groups are bidentate in the latter.
However, as expected, the axial bond angle in 5+
(169(3)°) is somewhat closer to 180° than that in 1+
(163.72(1)°). Finally, in comparing the structure of 5+
with those of the related bismuth cations 6+ and 7+, one
finds considerable variation in the E-O-P bond angles.
(20) Nunn, M.; Sowerby, D. B.; Wesolek, D. M. J . Organomet. Chem.
1953, 251, C45.
(21) Carmalt, C. J .; Cowley, A. H.; Decken, A.; Norman, N. C. J .
Organomet. Chem. 1995, 469, 59 and references therein.

3600 Organometallics, Vol. 16, No. 16, 1997
Carmalt et al.
Ta ble 2. Cr ysta l Da ta a n d Deta ils of In ten sity, Mea su r em en t, a n d Str u ctu r e Refin em en t for 1, 2, a n d 5
1
2
5
formula
fw
C18H24F6N2PSb
535.11
C18H24F6N2PBi
622.34
C28H54F6N6O3P3Sb
851.43
temp, K
153(2)
298(2)
153(2)
λ, Å
0.710 73
monoclinic
P21/n
11.926(5)
14.094(4)
12.787(4)
103.39(3)
2091.0(12)
4
0.710 73
monoclinic
P21/c
7.5114(7)
27.224(3)
10.519(1)
92.033(9)
2149.7(4)
4
0.710 73
orthorhombic
Pna21
16.6783(1)
14.9964(1)
15.5319(1)
90°
cryst syst
space group
a, Å
b, Å
c, Å
â, deg
V, Å3
3884.8(5)
4
Z
d(calcd), g/cm3
abs coeff, cm-1
cryst size, mm
θ range, deg
total no. of rflns
no. of obsd rflns
no. of ref params
1.700
14.54
0.14 × 0.14 × 0.11
2.10-27.51
9565
4797
261
0.994
0.0716/0.0382
1.923
83.32
0.59 × 0.31 × 0.19
2.45-24.96
4901
3749
261
1.074
0.1475/0.0500
1.456
8.99
0.51 × 0.39 × 0.26
2.25-27.50
8291
4954
441
1.016
0.1268/0.0574
2
GOF on F
wR2/R1 [I > 2σ(I)]a
a
2
R1 ) ∑||Fo| - |Fc||/∑|Fo|; wR2 ) [∑[w(Fo - Fc2)2]/∑[w(Fo2)2]]1/2, w ) 1/[σ2(Fo2) + (aP)2 + bP], where P ) [Max(0,Fo2)/3 + 2Fc2/3].
P r ep a r a tion s. Com p ou n d 1. A sample of SbAr2Cl (2.145
g, 5.04 mmol) was dissolved in 30 mL of thf to give a pale
yellow solution. A solution of TlPF6 (1.76 g, 5.04 mmol) in thf
(25 mL) was added dropwise at room temperature, which led
to the immediate formation of a white precipitate. The
reaction mixture was stirred for 30 min and then filtered
through Celite, resulting in a colorless solution which was
reduced in vacuo to a volume of approximately 10 mL. Cooling
of this solution to -20 °C overnight afforded a 79% yield of
colorless, crystalline 1 (mp 220-222 °C). Anal. Calcd for
C24H46SbF6N6O2P3: C, 36.99; H, 5.95; N, 10.78. Found: C,
36.24; H, 5.67; N, 10.60. HRMS: calcd for [SbPh2{OP-
(NMe2)3}2]+ m/ z 633.219 576, found 633.220 628. 1H NMR
(CD2Cl2): δ 2.32 (d, 36H, OP(NMe2)3), 7.54 (t, 2H, C6H5), 7.68
(t, 2H, C6H5), 8.22 (d, 2H, C6H5). 13C{1H} NMR (C6D6): δ 36.4
(s, OP(NMe2)3), 130.0 (s, C, C6H5), 133.0 (s, CH, C6H5), 134.1
(s, CH, C6H5), 150.0 (s, C, C6H5).
X-r a y Cr ysta llogr a p h y. Crystallographic data and details
of the data collection procedures and structure refinement for
1, 2, and 5 are presented in Table 2. Crystals of 2 were grown
by solvent diffusion of CH2Cl2 and hexanes at -20 °C, whereas
1 and 5 were grown from thf solutions stored at -20 °C. Data
sets for 1 and 5 were collected on a Siemens P4 diffractometer
at -100 °C, whereas an Enraf-Nonius CAD4 diffractometer
was used for the collection of data for 2 at 25 °C. Graphite-
monochromated Mo KR radiation (λ ) 0.710 73 Å) was used
for all structures. Accurate unit cell parameters were deter-
mined by recentering 25 optimal high-angle reflections. Three
standard reflections were measured every 1800 s during data
collection, and no decreases in intensities were noted. Cor-
rections were applied for Lorentz-polarization and absorption
(SHELXA22 for 2 and 5, face-indexed for 1) effects. The
structures were solved for the heavy atoms by direct methods.
The [PF6]- anion is disordered in compound 2 (and to some
extent in compound 5); however, this disorder in the anions
does not constitute a major problem in the characterization of
the cations, which represent the focal point of this work.
Subsequent difference syntheses gave all other non-hydrogen
atomic positions and these were refined by full-matrix least
squares on F2 using the Siemens SHELXL PLUS 5.0 (PC)
software package.22 All non-hydrogen atoms were allowed
anisotropic thermal motion. Hydrogen atoms were included
at calculated positions (C-H ) 0.96 Å) and were refined using
a riding model and a general isotropic thermal parameter.
C
18H24N2SbF6P: C, 40.40; H, 4.52; N, 5.23. Found: C, 40.20;
H, 4.50; N, 5.14. 1H NMR (C6D6): δ 2.76 (s, 12H, NMe2), 4.10
(s, 4H, CH2), 7.11-7.68 (m, 8H, C6H4). 13C{1H} NMR (C6D6):
δ 46.3 (s, CH3), 68.9 (s, CH2), 130.0 (s, CH, C6H4), 137.3 (s,
CH, C6H4), 144.5 (s, CH, C6H4), 147.6 (s, CH, C6H4); ipso
carbons not detected.
Com p ou n d 2. A sample of BiAr2Cl (0.193 g, 0.376 mmol)
was dissolved in thf (15 mL) to give a pale yellow solution. A
solution of TlPF6 (0.131 g, 0.376 mmol) in thf (10 mL) was
added dropwise at room temperature, which led to the im-
mediate formation of a white precipitate. The reaction mixture
was stirred overnight and then filtered through Celite, result-
ing in a colorless solution which was reduced in vacuo to a
volume of approximately 5 mL. Hexanes (20 mL) were then
added as an overlayer, and solvent diffusion over a period of
days at -20 °C resulted in the formation of a white crystalline
solid. This solid was redissolved in CH2Cl2 (5 mL) and hexanes
(15 mL) was added as an overlayer. Solvent diffusion over a
period of days at -20 °C afforded a 65% yield of colorless,
crystalline
2
(mp 232-234 °C).
Anal.
Calcd for
C
18H24N2BiF6P: C, 34.74; H, 3.90; N, 4.50. Found: C, 34.65;
H, 3.60; N, 4.00. HRMS: calcd for [BiAr2]+ m/ z 477.174 337,
found 477.172 686. 1H NMR (C6D6): δ 2.83 (s, 12H, NMe2),
4.25 (s, 4H, CH2), 7.45 (t, 2H, C6H4), 7.62 (t, 2H, C6H4), 7.72
(m, 2H, C6H4), 8.05 (m, 2H, C6H4). 13C{1H} NMR (C6D6): δ
46.3 (s, CH3), 68.9 (s, CH2), 130.0 (s, CH, C6H4), 137.3 (s, CH,
C6H4), 144.5 (s, CH, C6H4), 147.6 (s, CH, C6H4); ipso carbons
not detected.
Ack n ow led gm en t. We are grateful to the National
Science Foundation (Grant No. CHE-9629088) and the
Robert A. Welch Foundation for generous financial
support. N.C.N. and A.H.C. thank NATO for an inter-
national collaborative grant.
Com p ou n d 5. A sample of hmpa (0.1 mL, 0.575 mmol) was
added dropwise to a stirred solution of SbPhCl2 (0.127 g, 0.287
mmol) in thf (5 cm3) at room temperature, which resulted in
a colorless reaction mixture. A solution of TlPF6 (0.113 g, 0.287
mmol) in thf (6 mL) was then added, which resulted in the
immediate formation of a white precipitate. The reaction
mixture was stirred for 30 min and then filtered through
Celite, resulting in a pale yellow solution, which was reduced
in vacuo to a volume of approximately 5 mL. Cooling of the
resulting solution to -20 °C overnight afforded a 50% yield of
colorless, crystalline 5 (mp 172-176 °C). Anal. Calcd for
Su p p or tin g In for m a tion Ava ila ble: Listings of bond
distances, bond angles, atomic coordinates, and thermal
parameters for 1, 2, and 5 (25 pages). Ordering information
is given on any current masthead page.
OM970322K
(22) Sheldrick, G. M. SHELXTL PC Version 5.0; Siemens Analytical
X-ray Instruments, Inc., Madison, WI, 1994.