Synthesis, structures, and UV-visible absorption spectra of tri(9 anthryl)bismuthine derivatives

Article abstract of DOI:10.1021/om020124f

Tri(9-anthryl)bismuthines 3 and their difluorobismuth derivatives 4 have been synthesized and their UV-visible absorption spectra have been determined. The change from the tricoordinate 3 to the pentacoordinate 4 causes a subtle blue-shift in the λ_0-0 of the anthryl moieties due to the decreased intramolecular through-space interaction between the anthryl moieties. Among the compounds, tri(9-anthryl)difluorobismuth, 4a, forms unique cocrystals with chloroform that have a porous honeycomb packing structure due to the π-stacking of the anthryl moieties.

Full text of DOI:10.1021/om020124f

Organometallics 2002, 21, 2555-2558
2555
Syn th esis, Str u ctu r es, a n d UV-Visible Absor p tion
Sp ectr a of Tr i(9-a n th r yl)bism u th in e Der iva tives
Shigehiro Yamaguchi,*,†,‡ Toshiaki Shirasaka,† and Kohei Tamao*,†
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, J apan, and PRESTO,
J apan Science and Technology Corporation (J ST), Uji, Kyoto 611-0011, J apan
Received February 14, 2002
Summary: Tri(9-anthryl)bismuthines 3 and their dif-
luorobismuth derivatives 4 have been synthesized and
their UV-visible absorption spectra have been deter-
mined. The change from the tricoordinate 3 to the
pentacoordinate 4 causes a subtle blue-shift in the λ0-0
of the anthryl moieties due to the decreased intramo-
lecular through-space interaction between the anthryl
moieties. Among the compounds, tri(9-anthryl)difluoro-
bismuth, 4a , forms unique cocrystals with chloroform
that have a porous honeycomb packing structure due to
the π-stacking of the anthryl moieties.
F igu r e 1. The change in the through-space interaction of
anthryl groups in the trianthrylsilicon and -bismuth com-
pounds.
Sch em e 1a
In the chemistry of the main group element-contain-
ing π-electron systems, the coordination number change
of the element represents a new strategy for the control
of their photophysical properties, giving rise to new
functions such as sensing.1-5 From this viewpoint, we
have so far investigated the coordination number-
photophysical property relationships for the tri(9-an-
thryl) derivatives of boron,2 silicon,3 and phosphorus,4
wherein the structural changes associated with the
changes in the coordination number perturb the through-
space interaction among the three anthryl groups
(Figure 1), leading to significant changes in their
photophysical properties. For example, the change from
trianthrylfluorosilane 1 to the corresponding difluoro-
silicate 2 results in about a 10 nm blue-shift of the
absorption maxima together with a remarkable en-
hancement of the fluorescence.3 In our continuing
studies, we have become interested in their bismuth
analogues, the trianthrylbismuthines 3 and their dif-
luorobismuth derivatives 4. We envisioned that the
a
Reagents and Conditions: (i) n-BuLi (1 mol amount),
Et2O, -78 ∼0 °C; (ii) BiCl3 (0.33 mol amount), rt; (iii) XeF2 (1
mol amount), CH2Cl2, rt.
studies of these ultimate trianthryl derivatives of the
heaviest main group element with the largest atomic
radii would provide decisive information about the
through-space interaction among the three anthryl
groups (Figure 1). In this contribution, we present the
synthesis, structures, and coordination number-pho-
tophysical property relationships of the trianthrylbis-
muth derivatives.6 The unique packing structure of a
cocrystal of tri(9-anthryl)difluorobismuth, 4a , with chlo-
roform will also be described.
Two series of the bismuth compounds, i.e., the tri(9-
anthryl)bismuth derivatives and tris(10-n-butyl-9-an-
thryl)bismuth derivatives, have been prepared, as shown
in Scheme 1. Thus, the reactions of the anthryllithiums
with BiCl3 in ether gave the trianthrylbismuthines 3a
and 3b, which were further transformed into the cor-
responding difluorobismuth derivatives 4a and 4b,
respectively, by treatment with XeF2. All these com-
pounds are air- and moisture-stable but gradually
decompose under ambient light in air.7 In an inert
atmosphere, however, these compounds are stable enough
to be handled. Although the unsubstituted derivatives
3a and 4a were hard to purify to the analytically pure
† Institute for Chemical Research, Kyoto University.
‡ PRESTO, J apan Science and Technology Corporation (J ST).
(1) A mini-review: Yamaguchi, S.; Akiyama, S.; Tamao, K. J .
Organomet. Chem., in press.
(2) (a) Yamaguchi, S.; Akiyama, S.; Tamao, K. J . Am. Chem. Soc.
2000, 122, 6335. (b) Yamaguchi, S.; Akiyama, S.; Tamao, K. J . Am.
Chem. Soc. 2001, 123, 11372.
(3) Yamaguchi, S.; Akiyama, S.; Tamao, K. J . Am. Chem. Soc. 2000,
122, 6793.
(4) Yamaguchi, S.; Akiyama, S.; Tamao, K. J . Organomet. Chem.
2002, 646, 277.
(5) Properties control based on the changes in the valence states of
the main group elements: (a) Barbarella, G.; Favaretto, L.; Zambian-
chi, M.; Pudova, O.; Arbizzani, C.; Bongini, A.; Mastragostino, M. Adv.
Mater. 1998, 10, 551. (b) Barbarella, G.; Favaretto, L.; Sotgiu, G.;
Zambianchi, M.; Bongini, A.; Arbizzani, C.; Mastragostino, M.; Anni,
M.; Gigli, G.; Cingolani, R. J . Am. Chem. Soc. 2000, 122, 11971. (c)
Barbarella, G.; Favaretto, L.; Sotgiu, G.; Zambianchi, M.; Antolini, L.;
Marseglia, E. A.; Tedesco, E.; Gigli, G.; Cingolani, R. Synth. Met. 2000,
115, 47. (d) J iang B.; Tilley, T. D. J . Am. Chem. Soc. 1999, 121, 9744.
(e) Suh, M. C.; J iang, B.; Tilley, T. D. Angew. Chem., Int. Ed. 2000,
39, 2870. (f) Hay, C.; Vilain, D. L.; Deborde, V.; Toupet, L.; Re´au, R.
Chem. Commun. 1999, 345. (g) Hay, C.; Fischmeister, C.; Hissler, M.;
Toupet, L.; Re´au, R. Angew. Chem., Int. Ed. 2000, 39, 2870. (h) Hay,
C.: Hissler, M.; Fischmeister, C.; Rault-Berthelot, J .; Toupet, L.;
Nyulaszi, L.; Reau, R. Chem. Eur. J . 2001, 7, 4222.
(6) Through this paper, the discussion is made from a viewpoint of
the changes in the coordination number rather than the changes in
the valence state in order to compare the present results to the previous
silicon case.
10.1021/om020124f CCC: $22.00 © 2002 American Chemical Society
Publication on Web 05/14/2002

2556 Organometallics, Vol. 21, No. 12, 2002
Notes
F igu r e 3. UV-visible absorption spectra of tris(9-butyl-
anthryl)bismuthine, 3b (solid line), and tris(9-butylan-
thryl)difluorobismuth, 4b (broken line), in THF.
Ta ble 1. UV-Visible Absor p tion Sp ectr a l Da ta for
An th r ylbism u th Der iva tivesa
F igu r e 2. ORTEP drawings of (a) 3b and (b) 4b (50%
probability for thermal ellipsoids). Selected bond lengths
(Å) and bond angles (deg): 3b: Bi1-C1 2.296(6), Bi1-C15
2.282(6), Bi1-C29 2.293(6), C1-Bi1-C15 101.1(2), C1-
Bi1-C29 105.3(2), C15-Bi1-C29 105.8(2); 4b : Bi1-C1
2.214(4), Bi1-C15 2.214(4), Bi1-C29 2.207(5), Bi1-F1
2.202(4), Bi1-F2 2.144(3), C1-Bi1-C15 120.2(2), C1-
Bi1-C29 124.5(2), C15-Bi1-C29 115.3(2), F1-Bi1-F2
176.5(1).
compound
λ0-0 (nm)
log ꢀ
3b
4b
3c
4c
412
407
392
392
4.55
4.47
3.98
3.71
a
In THF.
in Figure 3, and the data are summarized in Table 1
together with those for anthrylditolylbismuthine, 3c,11
and anthrylditolyldifluorobismuth, 4c, for comparison.
While 3b has the λ0-0 band of the anthryl moieties at
412 nm, the λ0-0 of 4b appeared at 407 nm with an
extinction coefficient comparable with that of 3b. Thus,
the change from tricoordinate to pentacoordinate causes
a blue-shift of the λ0-0 by 5 nm.6 A similar solvent effect
on the λ0-0 was also observed in benzene: 3b, 414 nm;
4b, 409 nm. Considering the identical λ0-0 values
between the monoanthryl derivatives 3c and 4c, the
blue-shift observed for the trianthryl series is attributed
not to the change in the electronic effect of the bismuth
moiety,9 but to the decreased through-space interaction
among the three anthryl groups.12
form due to their limited solubility and high photore-
activity, the butyl derivatives 3b and 4b have good
solubilities to the common solvents such as THF and
benzene and the purification by recrystallization readily
afforded the analytically pure products.
The structures of the butyl derivatives 3b and 4b
have been determined by X-ray crystallography, as
shown in Figure 2. The tricoordinate 3b has a trigonal
pyramidal structure with the sum of the Cipso-Bi-Cipso
angles being 312.2°. This is a rather large value relative
to those of the other triarylbismuthanes,8 probably due
to the steric repulsion among the anthryl groups. The
pentacoordinate 4b has a nearly ideal trigonal bipyra-
midal structure; the sum of the Cipso-Bi-Cipso angle is
360° and the F-Bi-F angle is 176.5(1)°. As an index to
estimate the distance between the anthryl groups in 3b
and 4b,3 their nonbonded Cipso- - -Cipso distances are
compared to each other, revealing that the change from
the tricoordinate 3b (av 3.61 Å) to the pentacoordinate
4b (av 3.83 Å) elongates the distance by about 0.2 Å.6
In addition, the arrangement of the three anthracene
rings around the central Bi atom is changed from
trigonal pyramidal in 3b to trigonal planar in 4b.
The UV-visible absorption spectra of the butyl de-
rivatives 3b and 4b have been determined to elucidate
the effect of the coordination number on their absorption
properties.9,10 The measurements were carried out using
the THF solutions of their analytically pure samples
under an argon atmosphere. Their spectra are shown
The comparison of the present results with the
previously reported observations for the trianthrylsilane
series 1 and 23 provides notable insights into the
through-space interaction. Thus, the tricoordinate 3b
(9) UV-visible absorption spectra of triarylbismuthines: (a) Rao,
C. N. R.; Ramachandran, J .; Balasubramanian, A. Can. J . Chem. 1961,
39, 171. (b) Zohn, H.; Schindlbauer, H.; Hammer, D. Monatsh. Chem.
1967, 98, 731. (c) Matano, Y.; Kurata, H.; Murafuji, T.; Azuma, N.;
Suzuki, H. Organometallics 1998, 17, 4049.
(7) For example, 3b completely decomposed into 9-butylanthracene,
10,10′-dibutyl-9,9′-bianthryl, and other unidentified compounds upon
standing in a benzene solution under an oxygen atmosphere for 6 h
under ambient light. The photoreactivity of triarylbismuthines, see:
(a) Matano, Y.; Ikegami, T. Organobismuth Chemistry; Matano, Y.,
Suzuki, H., Eds.; Elsevier Science: Amsterdam, 2001; pp 21-246. (b)
Alberti, A.; Hudson, A. J . Organomet. Chem. 1979, 182, C49.
(8) Ogawa, T. Organobismuth Chemistry; Matano, Y., Suzuki, H.
Eds.; Elsevier Science: Amsterdam, 2001; pp 441-546.
(10) Although we have attempted to evaluate the fluorescence
properties, the present trianthrylbismuth compounds gradually de-
composed under the fluorescence measurement condition.
(11) Rahman, M. M.; Matano, Y.; Suzuki, H. Organometallics 1997,
16, 3565.
(12) The difference between 4b and 4c (∆λ0-0, 15 nm) is comparable
to that between 9-butylanthracene (λ0-0, 389 nm) and anthracene (λ0-0
,
376 nm), suggesting that the longer λ0-0 of 4b relative to that of 4c is
attributed to the electronic effect of the butyl groups.

Notes
Organometallics, Vol. 21, No. 12, 2002 2557
longer Bi-C bond distance may allow the hexagonal
channels to form, which can accommodate chloroform
as the guest molecules.
Exp er im en ta l Section
1
Gen er a l P r oced u r es. H, 13C, and 19F NMR spectra were
1
measured with a Varian Mercury 300 spectrometer for H (300
MHz) and with a J EOL EX-270 spectrometer for 13C (67.8
MHz) and 19F (254 MHz), respectively. UV-visible absorption
spectra were measured with a Shimadzu UV-3100PC spec-
trometer using a degassed spectral grade THF. Compound 3c
was prepared according to the method reported by Suzuki and
co-workers.11
Tr is(10-bu tyl-9-a n th r yl)bism u th in e (3b). To a Et2O (50
mL) solution of 9-bromo-10-butylanthracene (1.45 g, 4.21
mmol) was added a hexane solution of n-BuLi (1.6 M, 2.6 mL,
4.21 mmol) at -78 °C. The reaction mixture was warmed to 0
°C and stirred for 1 h. The resulting solution was added to a
Et2O (20 mL) solution of BiCl3 (441 mg, 1.40 mmol) at -78
°C. The mixture was allowed to warm to room temperature
and stirred for 14 h. After usual aqueous workup, recrystal-
lization from a benzene-MeOH mixed solvent afforded ana-
lytically pure 3b (440 mg, 0.484 mmol) in 34% yield as yellow
1
crystals: mp 208 °C (dec). H NMR (C6D6): δ 0.87 (t, J ) 7.5
Hz, 9H), 1.38 (sex, J ) 7.5 Hz, 6H), 1.65 (m, 6H), 3.40 (m,
6H), 6.87 (m, 6H), 7.12 (m, 6H), 8.22 (d, J ) 8.4 Hz, 6H), 9.04
(d, J ) 8.1 Hz, 6H). 13C NMR (C6D6): δ 14.15, 23.58, 28.41,
33.59, 125.31, 125.54, 125.86, 131.58, 135.42, 137.29, 139.07,
163.11. Anal. Calcd for C54H51Bi: C, 71.35; H, 5.66. Found:
C, 70.96; H, 5.58.
Tr is(10-bu tyl-9-a n th r yl)d iflu or obism u th (4b). To a CH2-
Cl2 (20 mL) solution of 3b (430 mg, 0.47 mmol) was added a
CH2Cl2 (4 mL) solution of XeF2 (82 mg, 0.47 mmol) at room
temperature. After stirring for 10 min, the reaction mixture
was concentrated under reduced pressure. The resulting
mixture was recrystallized from a benzene-MeOH mixed
solvent to afford 4b (469 mg, 0.495 mmol) in 82% yield as red
crystals: mp 198 °C (dec). 1H NMR (CDCl3): δ 0.99 (t, J ) 7.5
Hz, 9H), 1.49 (sex, J ) 7.5 Hz, 6H), 1.78 (m, 6H), 3.54 (t, J )
8.1 Hz, 6H), 6.81 (m, 6H), 7.10 (m, 6H), 8.29 (d, J ) 8.7 Hz,
6H), 9.59 (d, J ) 8.7 Hz, 6H). 13C NMR (CDCl3): δ 14.17, 23.64,
28.95, 33.66, 125.00, 125.46, 127.12, 128.67, 131.19, 134.40,
141.85, 142.38. 19F NMR (CDCl3): δ -84.2. Anal. Calcd for
F igu r e 4. Crystal packing structure of 4a : (a) a view down
the c-axis and (b) a view of the bc-plane. Chloroform
molecules inside of the channels are omitted for clarity.
The Bi atoms are purple and the F atoms are green.
has longer nonbonded Cipso- - -Cipso distances (av 3.61
Å) than those in the pentacoordinate 2 (3.28-3.45 Å),
which has no significant through-space interaction.
Nevertheless, in compound 3b the through-space inter-
action among the anthryl groups indeed occurs, sug-
gesting that not the distance but the arrangement of
the three anthryl groups is crucial to producing the
through-space interaction. However, it is also true that
the distance between the anthryl groups affects the
degree of the through-space interaction, in light of the
fact that the blue-shift observed for the present bismuth
series is smaller than that for the silicon series.
C
54H51BiF2: C, 68.49; H, 5.43. Found: C, 68.41; H, 5.50.
Tr i(9-a n th r yl)bism u th in e (3a ). This compound was pre-
pared essentially in the same manner described for 3b and
was characterized by means of 1H NMR spectroscopy and mass
spectrometry: mp >300 °C. 1H NMR (CDCl3): δ 6.94 (m, 6H),
7.26 (m, 6H), 7.98 (d, J ) 8.1 Hz, 6H), 8.42 (s, 3H), 8.49 (d, J
) 8.7 Hz, 6H). MS (FAB) m/e (relative intensity): 740 (M+,
10), 562 (100).
Tr i(9-a n th r yl)d iflu or obism u th (4a ). This compound was
prepared essentially in the same manner described for 4b and
was characterized by means of 1H and 19F NMR spectroscopy
and X-ray crystallography: mp 165 °C (dec). 1H NMR
(CDCl3): δ 7.01-7.12 (m, 6H), 7.37-7.44 (m, 6H), 8.16 (d, J
) 8.4 Hz, 6H), 8.53-8.84 (m, 9H). 19F NMR (CDCl3): δ -60.0
(br). For compounds 3a and 4a , the 13C NMR spectra could
not be measured due to their low solubility to organic solvents,
and the elemental analyses failed even using their crystals
obtained by the recrystallization.
(9-An th r yl)d i(p-tolyl)d iflu or obism u th (4c). This com-
pound was prepared essentially in the same manner desribed
for 4b: mp 225 °C (dec). 1H NMR (CDCl3): δ 2.45 (s, 6H),
7.42-7.49 (m, 4H), 7.53 (d, J ) 8.4 Hz, 4H), 8.04-8.10 (m,
2H), 8.31 (d, J ) 8.4 Hz, 4H), 8.46-8.52 (m, 2H), 8.62 (s, 1H).
13C NMR (CDCl3): δ 21.48, 125.43, 126.88, 128.03, 129.15,
131.91, 132.14, 132.88, 133.47, 133.54, 135.05, 142.10, 153.85.
19F NMR (CDCl3): δ -141.0. Anal. Calcd for C28H23BiF2: C,
55.45; H, 3.82. Found: C, 55.47; H, 3.83.
During the course of the study on the crystal struc-
tures, we also found that the unsubstituted trian-
thryldifluorobismuth, 4a , forms unique cocrystals with
chloroform in a 1:1 ratio, which crystallizes in trigonal
space group P3h1c with a porous honeycomb packing
structure, as shown in Figure 4. The intermolecular
offset face-to-face π-stacking of the anthryl moieties of
the present C3v symmetry molecule (intermolecular
anthracene-anthracene distance, ∼3.4 Å) results in the
formation of large hexagonal linear channels extending
along the c-axis with the mean diameter of about 6 Å,
which are filled with disordered chloroforms. Notably,
this honeycomb motif is unique for the present bismuth
case. Other C3v symmetry trianthryl analogues, trian-
thrylborane,2 trianthryldifluorosilicate,3 and trian-
thryldifluorophosphorane,4 which we have already pre-
pared, never form this type of packing structure. The

2558 Organometallics, Vol. 21, No. 12, 2002
Ta ble 2. Cr ysta llogr a p h ic Da ta for Com p ou n d s 3b, 4a , a n d 4b
Notes
3b
4a ‚CHCl3
4b‚0.5C6H6
C57H54BiF2
formula
mol wt
C54H51Bi
C43H28BiF2Cl3
898.03
908.98
986.03
cryst color, habit
cryst dimens, mm
cryst syst
space group
cell const
a, Å
colorless, prismatic
0.20 × 0.20 × 0.10
triclinic
red, prismatic
0.20 × 0.20 × 0.20
trigonal
orange, prismatic
0.20 × 0.20 × 0.10
triclinic
P1h (No. 2)
P3h1c (No. 163)
P1h (No. 2)
9.8404(5)
22.298(2)
9.7168(7)
95.712(2)
104.838(5)
93.981(4)
2040.7(2)
2
15.5590(4)
8.5586(3)
13.7108(4)
17.1509(6)
9.5357(3)
94.909(2)
90.606(2)
103.523(2)
2171.1(1)
2
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
1794.31(8)
2
1.662
Z
D
calcd, g cm-3
1.479
1.508
temp, °C
-100
-120
-100
µ(Mo KR), cm-1
2θmax, deg
43.49
51.68
41.01
55.2
7289 (I > 3σ(I))
14.67
0.057
0.080
55.0
1176 (I > 3σ(I))
15.47
0.048
0.062
55.1
8035 (I > 3σ(I))
14.82
0.037
0.056
no. of unique reflns
reflns/param ratio
Ra
b
Rw
GOF
1.25
1.18
1.02
a
b
2 1/2
R ) ∑|Fo| - |Fc|/∑|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑wFo
] .
X-r a y Cr ysta l Str u ctu r e An a lysis. Single crystals of 3b,
4a , and 4b suitable for the X-ray crystallography were
obtained by recrystallization from a CHCl3-hexane mixed
solvent for 4a and a benzene-MeOH mixed solvent for 3b and
4b, respectively. Intensity data were collected on a Rigaku
RAXIS-IV imaging plate area detector with graphite-mono-
chromated Mo KR radiation to a maximum 2θ value of 55°.
The data were corrected for Lorentz and polarization effects
and secondary extinction. The crystal structures were solved
by direct methods in SIR9213 for 3b and 4a and by the heavy-
atom Patterson methods14 for 4b, and full-matrix least squares
refinements were carried out for all non-hydrogen atoms.
Hydrogen atoms were included except for those of solvent
molecules in the crystals of 4a and 4b, but not refined. All
the calculations were performed using the teXsan crystal-
lographic package from Molecular Structure Corp. The crystal-
lographic data for these compounds are summarized in Table
2.
Ack n ow led gm en t. We acknowledge the financial
support from the Ministry of Education, Culture, Sports,
Science and Technology, J apan, for the Grant-in-Aids
for the COE Research on Elements Science, No.
12CE2005, and S.Y. thanks PRESTO, J apan Science
and Technology Corporation (J ST).
Su p p or tin g In for m a tion Ava ila ble: Crystal structure
data for 3b, 4a , and 4b, including tables of atomic coordinates,
anisotropic displacement parameters, bond distances, and
bond angles. This material is available free of charge via
Internet at http://pubs.acs.org.
(13) Altomore, A.; Burla, M. C.; Camalli, M.; Cascarano, M. Giaco-
vazzo, C.; Guagliardi, A.; Polidori, G. J . Appl. Crystallogr. 1994, 27,
435.
(14) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.;
Garcia-Granda, S.; Gould, R. O.; Smits, J . M. M.; Smykalla, C. The
DIRDIF program system; Techincal Report of the Crystallography
Laboratory; University of Nijimegen: The Netherlands, 1992.
OM020124F