Solid-state structural study of the charge-transfer complexes of 5,7,9-trimethyl- and 2,11,20-trithia[33](1,3,5)cyclophanes

Article abstract of DOI:10.1002/ejoc.200390190

5,7,9-Trimethyl[3₃](1,3,5)cyclophane (1), with two binding sites of different donating ability, adopts a C₃ conformation both in the solid state (-170 °C) and in CD₂Cl₂ solution at -90 °C. 5,7,9-Trimethyl[3₃](1,3,5)cyclophane-2,11,20-trione (9) has the same C₃ symmetry, while [3₃](1,3,5)cyclophane-2,11,20-trione (12) adopts the C_s structure in the solid state (-170 °C). The structures of 1 and 9 are the first examples of C₃ or C_3h symmetries in the [3₃](1,3,5)cyclophanes; their preferred conformers are C_s both in solution and in the solid state. The cyclophane 1 shows much stronger donating ability than the parent [3₃](1,3,5)cyclophane (2). In the TCNQ-F₄ (1:1) complex of 1, the donor (D) and the acceptor (A) are stacked alternately, with partial and complete D-A overlaps being observed in the solid state (-170 °C) in the forms of partial D-A overlap of the methyl-substituted benzene face and TCNQ-F₄ and of nearly complete D-A overlap of the methyl-unsubstituted benzene face and TCNQ-F₄. The former type of overlap is generally observed in the TCNQ-F₄ complexes of the [3_η]cyclophanes, and the transannular D-A distance (3.22 A) is much shorter than that in the latter (3.58 A). This supports the idea that the methyl-substituted benzene ring interacts more strongly than the methyl-unsubstituted benzene ring with the acceptor. Consistently with this, two types of acceptor columns are observed, and the transannular distances between acceptors are 3.45 A for the methyl-unsubstituted side and 3.26 A for the methyl-substituted side. In the 2,11,20-trithia[3₃](1,3,5)cyclophane (4)-TCNQ-F₄ (1:1) complex, an alternating D-A stacking similar to that in [3₃](1,3,5)cyclophane (2)-TCNQ-F₄ (1:1) is observed. The acceptors are stacked in a parallel fashion and form an infinite column, the A-A distance in the (4)-TCNQ-F₄ (1:1) complex being 3.10 A, and the acceptors in the unit cell are arranged parallel in a plane, the A-A distance being 3.12 A. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Full text of DOI:10.1002/ejoc.200390190

FULL PAPER
Solid-State Structural Study of the Charge-Transfer Complexes of 5,7,9-
Trimethyl- and 2,11,20-Trithia[33](1,3,5)cyclophanes[‡]
Mikio Yasutake,[a,b,c] Koji Araki,[d] Ming Zhou,[a,b] Rika Nogita,[a,b] and
Teruo Shinmyozu*[a]
Keywords: Charge transfer / Conformation analysis / Cyclophanes / NMR spectroscopy
5,7,9-Trimethyl[33](1,3,5)cyclophane (1), with two binding
sites of different donating ability, adopts a C3 conformation
both in the solid state (−170 °C) and in CD2Cl2 solution at
−90 °C. 5,7,9-Trimethyl[33](1,3,5)cyclophane-2,11,20-trione
(9) has the same C3 symmetry, while [33](1,3,5)cyclophane-
2,11,20-trione (12) adopts the Cs structure in the solid state
complexes of the [3n]cyclophanes, and the transannular D-A
˚
distance (3.22 A) is much shorter than that in the latter (3.58
˚
A). This supports the idea that the methyl-substituted ben-
zene ring interacts more strongly than the methyl-unsubsti-
tuted benzene ring with the acceptor. Consistently with this,
two types of acceptor columns are observed, and the transan-
˚
(−170 °C). The structures of 1 and 9 are the first examples nular distances between acceptors are 3.45 A for the methyl-
of C3 or C3h symmetries in the [33](1,3,5)cyclophanes; their
˚
unsubstituted side and 3.26 A for the methyl-substituted side.
preferred conformers are Cs both in solution and in the solid
In the 2,11,20-trithia[33](1,3,5)cyclophane (4)-TCNQ-F4 (1:1)
state. The cyclophane 1 shows much stronger donating abil- complex, an alternating D-A stacking similar to that in
ity than the parent [33](1,3,5)cyclophane (2). In the TCNQ-F4
(1:1) complex of 1, the donor (D) and the acceptor (A) are
[33](1,3,5)cyclophane (2)-TCNQ-F4 (1:1) is observed. The
acceptors are stacked in a parallel fashion and form an infinite
stacked alternately, with partial and complete D-A overlaps column, the A−A distance in the (4)-TCNQ-F4 (1:1) complex
˚
being observed in the solid state (−170 °C) in the forms of
partial D-A overlap of the methyl-substituted benzene face
and TCNQ-F4 and of nearly complete D-A overlap of the
being 3.10 A, and the acceptors in the unit cell are arranged
˚
parallel in a plane, the A-A distance being 3.12 A.
methyl-unsubstituted benzene face and TCNQ-F4. The for- ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
mer type of overlap is generally observed in the TCNQ-F4
Germany, 2003)
Introduction
In previous papers we have reported the strong electron-
donating abilities of [3n]cyclophanes (CPs) (n ϭ 3Ϫ6), their
solid-state structural properties, and structural and electri-
cal properties of their charge-transfer (CT) complexes with
acceptors such as TCNQ and TCNQ-F4.[2,3]
Among the [3n]CP-TCNQ-F4 complexes (n ϭ 3Ϫ6), the
[33](1,3,5)CP 2-TCNQ-F4 (1:1) complex showed the highest
conductivity in single crystals, and this was ascribed to the
formation of an infinite column of partially overlapped ac-
ceptors with a short acceptorϪacceptor distance and to the
close contact of the acceptors arranged parallel in a plane
of the unit cell, while no formation of such a column was
observed in the TCNQ-F4 (1:1) complex of the [36]CP 3,
irrespective of the strongest donating ability in the [3n]CPs
(n ϭ 2Ϫ6).[3a] In the crystal packing diagram of the [3n]CPs,
neighboring cyclophane molecules are arranged in an or-
thogonal fashion,[3] whereas the 5,7,9-trifluoro- and
5,7,9,14,16,18-hexafluoro[33](1,3,5)CPs are stacked with the
fluorinated benzene rings facing each other, with the re-
peated stacking forming a column in the solid state.[4] We
have modified the [33](1,3,5)CP skeleton in order to study
[‡]
Multibridged [3n]cyclophanes, 16. Part 15: Ref.[1]
[a]
Institute for Fundamental Research of Organic Chemistry
(IFOC), Kyushu University,
Hakozaki, Fukuoka 812-8581, Japan
Fax: (internat.) ϩ 81-92/642-27354
E-mail: shinmyo@ms.ifoc.kyushu-u.ac.jp
[b]
Department of Chemistry, Faculty of Science, Kyushu
University,
Hakozaki, Fukuoka 812-8581, Japan
[c]
Henkel Research Center of Advanced Technology, Molecular
Engineering Institute, Kinki University,
Kayanomori 11-6, Iizuka, Fukuoka 820-8555, Japan
[d]
Department of Applied Chemistry, Kyushu Institute of
Technology,
1-1 Sensui-cho, Tobata-ku, Kitakyushu 804-8550, Japan
Supporting information for this article is available on the
WWW under http://www.eurjoc.org or from the author.
1343
Eur. J. Org. Chem. 2003, 1343Ϫ1351  2003 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim 1434Ϫ193X/03/0407Ϫ1343 $ 20.00ϩ.50/0

M. Yasutake, K. Araki, M. Zhou, R. Nogita, T. Shinmyozu
FULL PAPER
the donor (D)Ϫacceptor (A) interaction in the solid state (1st HOMO Ϫ8.88 eV, PM3)-TCNE complex (λmax
ϭ
in more detail. We chose 5,7,9-trimethyl[33](1,3,5)CP 1 as a 594 nm).[13] This indicates that TCNE interacts more
donor with two binding sites of different donating ability, as strongly with the methyl-substituted benzene ring than with
well as 2,11,20-trithia[33](1,3,5)CP 4[5] and 1,3,10,12,19,21- the methyl-unsubstituted one, and the electron-donating
hexathia[33](1,3,5)CP 5[6] as donors with enhanced inter- ability of 1 is similar to that of [34](1,2,3,5)CP (CT band
molecular interactions in the crystal packing.
with TCNE, λmax ϭ 632 nm).[13b]
Compound 1 shows a reversible cyclic voltammogram,
the first half-wave oxidation potential (E1/2) being ϩ0.73 V
(Epa ϭ ϩ1.09 V vs. Fc/Fcϩ, Cl2CHCHCl2) (Figure 1), much
lower than that of [33](1,3,5)CP 2 (ϩ1.31 V) and similar to
that of [34](1,2,3,5)CP (ϩ0.69 V).[3a] Thus, both the E1/2
data and the magnitude of the CT interaction indicate that
the donating ability of 1 is similar to that of [34](1,2,3,5)CP.
S3[33](1,3,5)CP 4 (1st HOMO Ϫ9.06 eV, PM3) shows its CT
band with TCNE at λmax ϭ 530 nm (CHCl3), while
S6[33]CP 5 does not show any CT band with TCNE. This
is ascribed to the significantly low lying HOMO level of 5
(Ϫ9.16 eV, PM3). PM3 calculations indicate that introduc-
tion of sulfur atoms onto the bridges of the [33](1,3,5)CP
significantly lowers the LUMO level and moderately lowers
the HOMO level; the LUMO level of S3[33]CP 4 is
Ϫ0.51 eV and that of S6[33]CP 5 is Ϫ1.39 eV.[12] Compound
5 has the smallest HOMOϪLUMO gap and the lowest
LUMO level of the [33](1,3,5)CPs.
Results and Discussion
Synthesis
The Me3[33](1,3,5)CP 1 was synthesized by the p-tolylsul-
fonylmethyl isocyanide (TosMIC) coupling method.[7Ϫ9]
The TosMIC adduct 7 was obtained from 1,3,5-tris(bromo-
methyl)-2,4,6-trimethylbenzene (6) and TosMIC[10] under
phase-transfer conditions (NaOH, nBu4NI, CH2Cl2/H2O)
(76%). Coupling of the adduct 7 with 1,3,5-tris(bromome-
thyl)benzene (8) in the presence of NaH in DMF and sub-
sequent acid hydrolysis gave triketone 9 (14%). Reduction
of the ketone carbonyl groups afforded 1 (63%), along with
Me3[33]CP-one 10 (4%). The yield of the TosMIC coupling
was moderate, but this synthetic route provided a straight-
forward and short approach to 1 (Scheme 1). The use of
NaH and DMF[9] in place of NaOH in CH2Cl2/H2O under
phase-transfer conditions improved the coupling yield.
Figure 1. Cyclic voltammograms of [3n]cyclophanes in
Cl2CHCHCl2 (scan rate 20 mV/s)
Scheme 1. Synthesis of 5,7,9-trimethyl[33](1,3,5)cyclophane (1); a)
TosMIC, NaOH, nBu4NI, CH2Cl2/H2O; b) NaH, DMF, room
temp.; c) concd. HCl, CH2Cl2; d) H2NNH2·H2O, KOH, diethyl-
ene glycol
Structural Study
In the parent [33](1,3,5)CP 2, two conformers with Cs and
The 2,11,20-trithia[33](1,3,5)CP 4 was prepared by litera- C3h symmetries are conceivable, the Cs isomer being more
ture procedures,[5] and 1,3,10,12,19,21-hexathia[33]-
(1,3,5)CP 5 was obtained by coupling of 1,3,5-trimer-
captobenzene and CH2Br2 in tBuOH under high-dilution
conditions.[6] General synthetic methods for thia[3n]CPs
(n ϭ 2Ϫ5) have already been reported by Vögtle et al.[11]
Electronic Properties
In Me3[33](1,3,5)CP 1 (1st HOMO Ϫ8.63 eV, PM3),[12]
the donating ability of the methyl-substituted benzene ring
would be expected to be much stronger than that of the
methyl-unsubstituted benzene ring. In CHCl3 solution, the
CT band of the 1-TCNE complex appears at 632 nm, a sig-
nificant bathochromic shift from that of the [33](1,3,5)CP 2 a bridge flipping process
Scheme 2. Conformational isomerism of [33](1,3,5)cyclophanes by
1344
Eur. J. Org. Chem. 2003, 1343Ϫ1351

Charge-Transfer Complexes of 5,7,9-Trimethyl- and 2,11,20-Trithia[33](1,3,5)cyclophanes
FULL PAPER
stable than the C3h isomer by 0.4 kcal/mol on the basis of
a variable temperature (VT) 1H NMR study in CD2Cl2. The
energy barrier for the bridge flipping process involving 2
(TS) as a transition state is 12.4 kcal/mol (Tc ϭ Ϫ70 °C,
Scheme 2).[14] The Cs isomer preferred in solution is also
observed in the solid state of 2.[3a] Density functional calcu-
lations (B3LYP) on 2 indicate almost the same stability for
the two conformers.[15]
X-ray
structural
analysis
shows
that
the
Me3[33](1,3,5)CP-trione 9 has a chiral C3 symmetry at Ϫ170
°C (Figure 2). This is the first example of C3 or C3h sym-
metry in the [33](1,3,5)CPs; the Cs conformer is generally
observed in the crystal structures of [33](1,3,5)CPs, as seen
in the methyl-unsubstituted trione 12 (Figure 3). Transan-
˚
nular distances between the bridged [3.079(2)Ϫ3.083(2) A]
˚
and unbridged carbon atoms [3.137(2)Ϫ3.142(2) A] in 9 are
shorter than the corresponding distances in 12
˚
[3.153(3)Ϫ3.163(2) A for the bridged carbon atoms and
˚
3.179(3)Ϫ3.231(3) A for unbridged carbon atoms].
Figure 3. ORTEP drawings (A, top view; B, side view) of
[33](1,3,5)cyclophanetrione 12 at Ϫ170 °C; selected transannular
˚
distances [A]: C(4)ϪC(17) 3.163(3), C(7)ϪC(14) 3.179(3),
C(5)ϪC(18) 3.231(3), C(8)ϪC(15) 3.153(3), C(6)ϪC(19) 3.156(3),
C(9)ϪC(16) 3.184(3)
The crystal structures (at Ϫ170 °C) of Me3[33](1,3,5)CP
1 and the monoketone 10 are shown in Figures 4 and 5.
Enantiomeric C3 structures, in which three bridges are di-
rected toward the counterclockwise or clockwise positions,
are observed in 1, as in the case of the trione 9. The ketone
10 also has a chiral structure with a C1 symmetry, similar
to that of 1.
Figure 2. ORTEP drawings (A, top view; B, side view) of trimethyl-
[33](1,3,5)cyclophane-trione (9) at Ϫ170 °C; selected transannular
˚
distances [A]: C(1)ϪC(15) 3.140(2), C(2)ϪC(10) 3.079(2),
We have performed conformational analyses[16] of
[3.3]meta-[17,18] and [3.3]para-cyclophanes,[19,20] and also of
C(3)ϪC(11) 3.137(2), C(4)ϪC(12) 3.079(2), C(5)ϪC(13) 3.142(2),
C(6)ϪC(14) 3.083(2)
Eur. J. Org. Chem. 2003, 1343Ϫ1351
1345

M. Yasutake, K. Araki, M. Zhou, R. Nogita, T. Shinmyozu
FULL PAPER
Figure 4. ORTEP drawings (A, top view; B, side view) of trimethyl[33](1,3,5)cyclophane (1) at Ϫ170 °C; selected transannular distances
˚
[A]: C(1)ϪC(10) 3.072(3), C(2)ϪC(11) 3.137(4), C(3)ϪC(12) 3.087(4), C(4)ϪC(13) 3.173(4), C(5)ϪC(14) 3.097(4), C(6)ϪC(15) 3.160(4),
C(25)ϪC(34) 3.090(3), C(26)ϪC(35) 3.145(3), C(27)ϪC(36) 3.081(3), C(28)ϪC(37) 3.158(3), C(29)ϪC(38) 3.096(3), C(30)ϪC(39) 3.157(3)
multibridged [3n]cyclophanes (n ϭ 3Ϫ6),[14,21,22] by the vari- 15.0 Hz)] at Ϫ90 °C (500 MHz, CD2Cl2, Figure S3, Sup-
1
able-temperature (VT) H and 13C NMR methods. A flip- porting Information]. This indicates that the bridge flipping
ping process of the bridges similar to that in [33](1,3,5)CP slows down as the temperature is lowered and the molecule
1
2 was observed in the H NMR spectrum of 1 in CD2Cl2. is frozen as the preferred C3 conformer at Ϫ90 °C. Simi-
The aromatic and methyl proton signals appear as singlets larly, only the C3 conformer is observed in the 13C NMR
at δ ϭ 6.78 and 2.24 ppm at 20 °C, while the benzylic pro- spectrum of 1 at Ϫ91 °C.[24] The energy barrier for this
ton signals show strongly temperature-dependent behavior process, based on the benzylic proton signals of 1, is esti-
[27]
(300 MHz, CD2Cl2, Figure S2, Supporting Information; see mated as 9.9 Ϯ 0.2[25,26] and 10.4 Ϯ 0.2
kcal/mol (Tc ϭ
also footnote on the first page of this article). The benzylic Ϫ48 °C). Compound 1 therefore exists as the C3 conformer
proton signals of 1-[D6][23] show two singlets at δ ϭ 2.68 both in solution and in the solid state, and this is in sharp
1
and 2.88 ppm at 20 °C, and each signal gradually broadens contrast with the parent 2. The H NMR spectrum of the
as the temperature is lowered, finally splitting into a pair of Me3[33]CP-trione 9 shows aromatic and methyl proton sig-
doublets [δ ϭ 2.35 ppm (d, J ϭ 13.7 Hz) and 2.91 (d, J ϭ nals as singlets at δ ϭ 7.00 and 2.33 ppm, while both
14.0 Hz); δ ϭ 2.73 ppm (d, J ϭ 14.7 Hz) and 2.89 (d, J ϭ benzylic proton signals also appear as singlets at δ ϭ 3.66
1346
Eur. J. Org. Chem. 2003, 1343Ϫ1351

Charge-Transfer Complexes of 5,7,9-Trimethyl- and 2,11,20-Trithia[33](1,3,5)cyclophanes
FULL PAPER
ficient HOMOϪLUMO orbital interactions. In contrast,
nearly complete D-A overlap is observed between the
methyl-unsubstituted benzene ring and TCNQ-F4. The for-
˚
mer transannular D-A distance (3.22 A) is much shorter
than that for the methyl-unsubstituted benzene ring and
˚
TCNQ-F4 (3.58 A), which clearly supports the idea that
the methyl-substituted benzene ring interacts more strongly
than the methyl-unsubstituted benzene ring with the ac-
ceptor. The donors and acceptors are stacked alternately as
usual.[2,3] Two types of acceptor columns are observed, and
˚
the transannular distances between acceptors are 3.45 A on
˚
the methyl-unsubstituted side and 3.26 A on the methyl-
substituted side (Figure 7).
The cyclophane moiety in the S3[33](1,3,5)CP 4-TCNQ-
F4 (1:1) complex shows a Cs structure in the crystals at
Ϫ170 °C, as in the case of the free cyclophane 4.[29] The
˚
transannular D-A distance is 3.29 A and the average trans-
˚
annular distance between two benzene rings is 3.23 A. The
overlapping mode of the donor and acceptor is similar to
that in [33]CP 2-TCNQ-F4 (Figure 8).[3] An alternating D-
A stacking similar to that of 2-TCNQ-F4 is observed in the
crystal packing diagram. The partially overlapped acceptors
˚
form an infinite column with distances of 3.10 A between
acceptors [Figure 9 (A)], a distance longer than that in the
˚
[33]CP 2-TCNQ-F4 (1:1) complex (2.93 A), probably be-
cause of the weaker donating ability of 4 than of 2. Close
˚
contact between the acceptors (3.12 A) arranged parallel in
a plane of the unit cell is also observed [Figure 9 (B)], as in
the case of the crystal packing of [33](1,3,5)CP 2-TCNQ-F4
(1:1) complex.[3a]
Conclusion
Me3[33](1,3,5)CP 1 adopts the C3 conformation both in
the solid state (Ϫ170 °C) and in solution (CD2Cl2, Ϫ90 °C).
The same conformation is observed in the triketone 9 in the
solid state, and the result is in sharp contrast with the pre-
ferred Cs conformers of the parents 2 and 12. The electron-
donating ability of 1, from the magnitude of the CT interac-
tion and the oxidation potential (E1/2), is similar to that of
[34](1,2,3,5)CP. In the Me3[33]CP 1-TCNQ-F4 (1:1) com-
plex, the methyl-substituted benzene ring interacts more
strongly than the methyl-unsubstituted one with the ac-
ceptor. The D-A stacking mode in the S3[33](1,3,5)CP 4-
TCNQ-F4 (1:1) complex is similar to that in the [33]CP 2-
TCNQ-F4 (1:1) complex, and the fact that the AϪA dis-
tances in an acceptor column are longer in the former than
in the latter reflect the weaker donating ability of 4 relative
to 2. The expected intermolecular interaction of the sulfur
atoms in the solid state is not observed in the
S3[33](1,3,5)CP 4-TCNQ-F4 (1:1) complex. Thus, modest
Figure 5. ORTEP drawings (A, top view; B, side view) of trimethyl-
[33](1,3,5)cyclophane-2-one (10) at Ϫ170 °C; selected transannular
˚
distances [A]: C(1)ϪC(10) 3.099(8), C(2)ϪC(11) 3.154(8),
C(3)ϪC(12) 3.084(8), C(4)ϪC(13) 3.170(8), C(5)ϪC(14) 3.093(7),
C(6)ϪC(15) 3.170(8)
and 3.88 ppm in CDCl3. This compound, and also the tri-
ketone 12, show no temperature-dependent phenomena
down to Ϫ90 °C in their 1H NMR spectra, suggesting much
lower energy barriers to the CH2COCH2 bridge flipping
process than to the CH2CH2CH2 bridge flipping process.
Solid-State Structures of the CT Complexes[3,28]
Two types of D-A overlap are observed in the crystals of modification of the skeleton of the donor effects changes in
1-TCNQ-F4 (1:1) complex at Ϫ170 °C (Figure 6). One is the D-A overlapping mode and the crystal packing mode.
partial D-A overlap of the methyl-substituted benzene ring Single-crystal conductivity data for the 1- and 4-TCNQ-F4
and TCNQ-F4, generally observed in TCNQ-F4 complexes (1:1) complexes have not yet been obtained because of in-
of [33](1,3,5)CP 2[3a] and [36]CP 3,[2][3a] and ascribed to ef- sufficient amounts of the single crystals.
Eur. J. Org. Chem. 2003, 1343Ϫ1351
1347

M. Yasutake, K. Araki, M. Zhou, R. Nogita, T. Shinmyozu
FULL PAPER
Figure 6. The crystal structure of the trimethyl[33](1,3,5)cyclophane (1)-TCNQ-F4 (1:1) complex at ؊170 °C: side views (A and B) and
top view (C)
by the procedures reported by Van der Made et al.[31] Cyclic vol-
tammograms were recorded with a BAS-100 B/W electrochemical
Experimental Section
analyzer. A Pt wire counter-electrode and an Ag/0.01  AgNO3
General: Melting points: Yanako micro melting point apparatus
reference electrode were used. The measurements were carried out
MP-S3. NMR: JEOL JNM-GX 270, AL-300, and A500. Chemical
in a 0.1  1,1,2,2-tetrachloroethane solution of a substrate with
shifts are reported as δ values (ppm) relative to internal tetrameth-
Bu4NPF6 as supporting electrolyte, and the oxidation potential val-
ues were calibrated with ferrocene. 1,1,2,2-Tetrachloroethane was
dried with CaCl2 and distilled just before use.
ylsilane (TMS) in CDCl3 unless otherwise noted. FAB-MS: JEOL
JMS-SX/SX 102A mass spectrometer (m-nitrobenzyl alcohol). IR:
Hitachi Nicolet I-5040 FT-IR. Elemental analysis: The Service
Center for the Elementary Analysis of Organic Compounds, affili-
X-ray Crystallographic Study: All measurements were made with a
ated to the Faculty of Science, Kyushu University. Analytical thin Rigaku RAXIS-RAPID-S imaging plate area detector with graph-
˚
layer chromatography (TLC) and column chromatography were
ite-monochromated Mo-Kα (λ ϭ 0.71069 A) and Cu-Kα (λ ϭ
˚
performed on 60 F254 silica gel (Merck) and silica gel 60 (40Ϫ63
1.54178 A) radiation and a rotating anode generator. The crystal
µm), respectively. DMF was dried with molecular sieves (4 A). structures were solved by direct methods [SIR92[32] (1, 9, 10, 4-
˚
2,11,20-Trithia[33](1,3,5)cyclophane (4) was obtained by treatment
of 1,3,5-tris(bromomethyl)benzene with Na2S/Al2O3 in CH2Cl2/
TCNQ-F4, 1-TCNQ-F4), MULTAN88[33] (12) and expanded by use
of Fourier techniques (DIRDIF94[34]). The non-hydrogen atoms
EtOH.[5b] 1,3,10,12,19,21-Hexathia[33](1,3,5)cyclophane (5) was were refined anisotropically (1, 9, 10, 12, 4-TCNQ-F4) and refined
prepared by means of the coupling reaction between 1,3,5-trimer-
by full-matrix least squares (1-TCNQ-F4),[35] while hydrogen atoms
captobenzene[30] and CH2Br2 in tBuOH under high-dilution con- were refined isotropically. All the computations were performed by
ditions (10%).[6] 2,4,6-Tris(bromomethyl)-1,3,5-trimethylbenzene
(6) was prepared by bromomethylation of 1,3,5-trimethylbenzene
use of teXsan.[36] CCDC-184791 (1), -184794 (9), -184793 (10),
-184790 (12), -184792 (1-TCNQ-F4), and -184795 (4-TCNQ-F4)
1348
Eur. J. Org. Chem. 2003, 1343Ϫ1351

Charge-Transfer Complexes of 5,7,9-Trimethyl- and 2,11,20-Trithia[33](1,3,5)cyclophanes
FULL PAPER
Figure 9. ORTEP drawings (CPK model) of the crystal packing
diagram of trithia[33](1,3,5)cyclophane 4-TCNQ-F4 (1:1) complex
at Ϫ170 °C
1,3,5-Tris[2-isocyano-2-(tolylsulfonyl)ethyl]-2,4,6-trimethylbenzene
(7): TosMIC (15.0 g, 76.8 mmol) in CH2Cl2 (60 mL) was added
dropwise at 0Ϫ10 °C over a period of 1 h to a stirred mixture of
NaOH (15.0 g, 375 mmol) and nBu4NI (1.0 g) in water (25 mL) and
CH2Cl2 (50 mL). After the addition, 2,4,6-tris(bromomethyl)-1,3,5-
trimethylbenzene (6, 6.81 g, 17.1 mmol) in CH2Cl2 (70 mL) was ad-
ded to the mixture at 0Ϫ10 °C over 10 min. After the addition, the
mixture was stirred overnight. The reaction mixture was poured
into water and extracted with CH2Cl2. The combined extracts were
washed with brine, dried with Na2SO4, and filtered. The filtrate
was concentrated under reduced pressure, and the concentrate was
diluted with CH2Cl2/MeOH (1:5). The resulting precipitate was
collected by filtration to give the TosMIC adduct 7 (9.62 g, 76%).
Orange powder reprecipitated from CH2Cl2/MeOH (1:5), m.p.
Figure 7. The crystal packing diagram of the trimethyl[33](1,3,5)-
cyclophane (1)-TCNQ-F4 (1:1) complex at Ϫ170 °C
1
178Ϫ179 °C (dec.). H NMR: δ ϭ 2.21 (s, 3 H, ϪCH3), 2.31 (s, 3
H, CH3), 2.32 (s, 3 H, CH3), 2.50 (s, 9 H, CH3), 3.50 (m, 6 H,
CH2CH), 4.52 (m, 3 H, CH2CH), 7.43Ϫ7.45 (m, 6 H, ArH),
7.88Ϫ7.91 (m, 6 H, ArH) ppm. IR (KBr): ν˜ ϭ 2135 (NC) cmϪ1
.
FABMS: m/z ϭ 742 [Mϩ ϩ 1]. C39H39N3O6S3 (742): calcd. C 63.13,
H 5.30, N 5.66; found C 63.21, H 5.45, N 5.84.
5,7,9-Trimethyl[33](1,3,5)cyclophane-2,11,20-trione (9): A mixture
of 1,3,5-tris(bromomethyl)benzene (8, 3.85 g, 10.8 mmol) and 7
(8.00 g, 10.8 mmol) in DMF (1.0 L) was added dropwise at room
temperature over a period of 10 h to a stirred suspension of NaH
(60%, 1.55 g, 38.8 mmol) in DMF (1500 mL). After completion of
addition, the mixture was stirred overnight. The DMF was re-
moved under reduced pressure and water was added to the residue.
The mixture was extracted with CH2Cl2. HCl (concd., 200 mL) was
added to the combined extracts, and the mixture was stirred over-
night at room temperature. The organic layer was separated, and
the aqueous layer was extracted with CH2Cl2. The organic portion
and CH2Cl2 extracts were combined, and the combined CH2Cl2
solutions were washed with brine, dried with Na2SO4, and filtered.
The filtrate was concentrated under reduced pressure, and the con-
centrate was diluted with MeOH to give the triketone 9 (550 mg,
Figure 8. The crystal structure of the trithia[33](1,3,5)cyclophane
4-TCNQ-F4 (1:1) complex at Ϫ170 °C (A, top view; B, side view)
1
14%). Colorless prisms [CH2Cl2/hexane (3:1)], m.p. Ͼ 300 °C. H
NMR: δ ϭ 2.33 (s, 9 H, CH3), 3.66 (s, 6 H, CH2COCH2), 3.88 (s,
6 H, CH2COCH), 7.00 (s, 3 H, ArH) ppm. IR (KBr): ν˜ ϭ 1687
(CϭO) cmϪ1. FABMS: m/z ϭ 360 [Mϩ]. C24H24O3 (360): calcd. C
79.97, H 6.71; found C 79.93, H 6.71.
contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge at www.ccdc.cam.ac.uk/
conts/retrieving.html [or from the Cambridge Crystallographic
Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK; Fax: 5,7,9-Trimethyl[33](1,3,5)cyclophane (1): A mixture of 9 (246 mg,
(internat.) ϩ 44-1223/336-033; E-mail: deposit@ccdc.cam.ac.uk].
Eur. J. Org. Chem. 2003, 1343Ϫ1351
0.682 mmol), KOH (3.0 g), triethylene glycol (70 mL), and
1349

M. Yasutake, K. Araki, M. Zhou, R. Nogita, T. Shinmyozu
FULL PAPER
Table 1. Summary of crystallographic data and refinement details
9
12
1
10
1-TCNQ-F4
4-TCNQ-F4
Empirical formula
Formula mass
C24H24O3
360.45
C21H18O3
318.37
C24H30
318.5
C24H28
332.48
O
C36H30F4N4
594.65
C30H18F4N4S3
606.67
Crystal color and habit
Crystal size [mm]
Crystal system
yellow prism
colorless prism
colorless prism
colorless prism
black prism
black prism
0.50 ϫ 0.15 ϫ 0.50 0.30 ϫ 0.20 ϫ 0.10 0.50 ϫ 0.20 ϫ 0.10 0.30 ϫ 0.10 ϫ 0.50 0.25 ϫ 0.05 ϫ 0.30 0.40 ϫ 0.05 ϫ 0.35
monoclinic
P21/c (no.14)
Ϫ170
9.2787(2)
9.8357(3)
19.6689(5)
monoclinic
P21/c (no.14)
Ϫ170
13.689(1)
8.3921(7)
14.933(1)
orthorhombic
Pbca (no.61)
Ϫ170
27.9768(5)
26.3687(6)
9.5405(2)
tetragonal
P42bc (no.106)
Ϫ170
19.7229(8)
19.7229(8)
8.9812(3)
triclinic
monoclinic
C2/c (no.15)
Ϫ170
25.7978(8)
8.4535(4)
14.5992(5)
¯
Space group
P1 (no.2)
Temperature [°C]
Ϫ150
˚
a [A]
9.2797(3)
9.8998(3)
17.6269(4)
82.786(1)
100.1819(9)
117.553(9)
1411.28(7)
2.0
1.399
620.00
8.42 (Cu-Kα)
136.5 (I Ͼ 2.0σ)
4834
˚
b [A]
˚
c [A]
α [°]
β [°]
γ [°]
100.7094(5)
115.820(2)
123.7236(8)
3
˚
V [A ]
1763.78(7)
4.0
1.357
768.00
0.88 (Mo-Kα)
55.0 (I Ͼ 3.0σ)
16276
1544.2(2)
4.0
1.369
672.00
0.91 (Mo-Kα)
55.0 (I Ͼ 3.0σ)
9917
7038.1(4)
16.0
1.202
2784.00
0.67 (Mo-Kα)
55.0 (I Ͼ 3.0σ)
54897
3493.6(2)
8.0
1.264
1440.00
0.75 (Mo-Kα)
55.0 (I Ͼ 3.0σ)
27642
2648.1(2)
4.0
1.522
1240.00
3.38 (Mo-Kα)
55.0 (I Ͼ 3.0σ)
11718
Z
ρcalcd. [g/cm3]
F(000)
µ [cmϪ1
]
2θmax [°]
No. of reflections
Measured reflections
Rint
4033
0.030
3425
0.081
8036
0.052
2139
0.072
4834
0.050
3014
0.032
Observed reflections
No. of parameters
3169
341
2246
290
4585
434
1582
227
3763
419
1911
191
Reflection/parameter ratio 9.29
7.74
10.56
6.97
8.98
10.01
R
Rw
GOF
0.046
0.076
1.27
0.055
0.081
1.30
0.052
0.075
1.22
0.070
0.105
1.30
0.056
0.157
1.09
0.039
0.052
1.21
NH2NH2·H2O (15 mL) was heated at 130 °C for 3.5 h while stirring
and then at 200 °C for 2 h. The reaction mixture was poured into
a mixture of ice/water and concd. HCl, and the mixture was ex-
tracted with tert-butyl methyl ether. The combined extracts were
washed with water, dried with Na2SO4, and filtered. After removal
of the solvent under reduced pressure, the residue was purified by
column chromatography on silica gel with CH2Cl2/hexane (1:3) to
give 1 (137 mg, 63%, Rf ϭ 0.50), along with 5,7,9-trimethyl[33](1,3,-
5)cyclophane-2-one (10, 8 mg, 4%). 1: Colorless prisms (hexane),
Acknowledgments
We gratefully acknowledge financial support by a Grant-in-Aid for
Scientific Research (B) (No. 14340200) from the Ministry of Edu-
cation, Culture, Sports, Science and Technology, Japan. T. S. sin-
cerely thanks for the financial support by the Shorai Foundation
for Science and Technology, Japan.
m.p. 225Ϫ226 °C. 1H NMR:
δ ϭ 2.07Ϫ2.15 (m, 6 H,
[1]
W. Matsuda-Sentou, T. Shinmyozu, Tetrahedron: Asymmetry
CH2CH2CH2), 2.24 (s, 9 H, CH3), 2.68 (t, J ϭ 6.1 Hz, 4 H,
CH2CH2CH2), 2.88 (t, J ϭ 6.2 Hz, 4 H, CH2CH2CH2), 6.84 (s, 3
H, ArH) ppm. FABMS: m/z ϭ 318 [Mϩ]. C24H30 (318): calcd. C
90.51, H 9.49; found C 90.29, H 9.40. 10: Colorless prisms
2001, 12, 839Ϫ842.
[2]
M. Yasutake, Y. Sakamoto, S. Onaka, K. Sako, H. Tatemitsu,
T. Shinmyozu, Tetrahedron Lett. 2000, 41, 7933Ϫ7938.
[3a] M. Yasutake, T. Koga, Y. Sakamoto, S. Komatsu, M. Zhou,
[3]
K. Sako, H. Tatemitsu, S. Onaka, Y. Aso, S. Inoue, T. Shin-
myozu, J. Am. Chem. Soc. 2002, 124, 10136Ϫ10145.
Yasutake, T. Koga, C. Lim, M. Zhou, W. Matsuda-Sentou, T.
Shinmyozu, in Cyclophane Chemistry for the 21st Century (Ed.:
H. Takemura), Research Signpost, Kerana, India, 2002, p.
265Ϫ300.
1
(CH2Cl2/hexane), m.p. 232Ϫ233 °C. H NMR: δ ϭ 2.12Ϫ2.16 (m,
[3b]
M.
4 H, CH2CH2CH2), 2.27 (s, 9 H, CH3), 2.67Ϫ2.72 (m, 4 H,
CH2CH2CH2), 2.91 (t, J ϭ 6.3 Hz, 4 H, CH2CH2CH2), 3.62 (s, 2
H, CH2COCH2), 3.80 (s, 2 H, CH2COCH2), 6.84 (s, 3 H, ArH)
ppm. IR (KBr): ν˜ ϭ 1688 (CϭO) cmϪ1. FABMS: m/z ϭ 332 [Mϩ].
C24H28O (332): calcd. C 86.70, H 8.49; found C 86.35, H 8.38.
[4]
T. Koga, M. Yasutake, T. Shinmyozu, Org. Lett. 2001, 3,
1419Ϫ1422.
[5] [5a]
[5b]
F. Vögtle, Justus Liebigs Ann. Chem. 1970, 735, 193Ϫ195.
R. G. Lichtenthaler, F. Vögtle, Chem. Ber. 1973, 106,
CT Complexes: TCNQ-F4 (12.4 mg, 0.045 mmol) was dissolved in
CHCl3 (13 mL) in a 100-mL glass vial at room temperature, and
this solution was mixed with Me3[33]CP 1 (14.3 mg, 0.045 mmol)
in CHCl3 (10 mL). The mixture was allowed to stand until blue
crystals of the Me3[33]CP 1-TCNQ-F4 (1:1) complex were formed.
IR (KBr): ν˜ ϭ 2223 (CN) cmϪ1. Similarly, the S3[33]CP 4-TCNQ-
F4 (1:1) complex was obtained as dark-red prisms by recrystalliza-
tion from a mixture of CHCl3 and CH3CN (1:1). IR (KBr): ν˜ ϭ
1319Ϫ1327.
[6]
F. Vögtle, R. G. Lichtenthaler, Tetrahedron Lett. 1972,
1905Ϫ1906.
[7] [7a]
K. Kurosawa, M. Suenaga, T. Inazu, T. Yoshino, Tetra-
[7b]
hedron Lett. 1982, 23, 5335Ϫ5338.
T. Shinmyozu, Y. Hirai,
T. Inazu, J. Org. Chem. 1986, 51, 1551Ϫ1555.
H. Sasaki, T. Kitagawa, Chem. Pharm. Bull. 1983, 31,
2868Ϫ2878.
[8]
2217 (CN) cmϪ1
.
1350
Eur. J. Org. Chem. 2003, 1343Ϫ1351

Charge-Transfer Complexes of 5,7,9-Trimethyl- and 2,11,20-Trithia[33](1,3,5)cyclophanes
FULL PAPER
[9]
[22]
[23]
J. Breitenbach, F. Vögtle, Synthesis 1992, 41Ϫ42.
H. F. Bettinger, P. v. R. Schleyer, H. F. Schaefer, III, J. Am.
Chem. Soc. 1998, 120, 1074Ϫ1075.
[10] [10a]
B. E. Hoogenboom, O. H. Oldenziel, A. M. van Leusen,
[10b]
Hexadeuterated Me3[33](1,3,5)CP 1-[D6] was prepared from the
triketone 9 via the thioacetal, followed by nBu3SnD reduction
in refluxing xylene.[17b]
Org. Synth. 1977, 57, 102Ϫ106.
A. M. van Leusen, R. J.
Bouma, O. Possel, Tetrahedron Lett. 1975, 16, 3487Ϫ3488.
F. Vögtle, Chem.-Ztg. 1971, 95, 668Ϫ669.
The semiempirical MO calculations were performed with the
aid of the MOPAC2000 programs, graphically facilitated by use
of WINMOPAC ver. 3 (Fujitsu Limited).
[11]
[12]
[24]
The 13C NMR spectroscopic data of the Me3[33]CP 1 at Ϫ91
°C (CD2Cl2, 75 MHz) support the C3 symmetry of the con-
former because four aliphatic carbon atoms (δ ϭ 19.3, 25.3,
29.4, and 35.5 ppm) and four aromatic carbon signals (δ ϭ
124.8, 133.4, 135.8, 141.4 ppm) are observed.
[13] [13a]
Y. Sakamoto, N. Miyoshi, T. Shinmyozu, Angew. Chem.
[13b]
Int. Ed. Engl. 1996, 35, 549Ϫ550.
Y. Sakamoto, N. Mi-
[25] [25a]
A. Mannschreck, G. Rissmann, F. Vögtle, D. Wild, Chem.
yoshi, M. Hirakida, S. Kusumoto, H. Kawase, J. M. Rudzinski,
[25b]
Ber. 1967, 100, 335Ϫ346.
I. C. Calder, P. J. Garratt, J.
T. Shinmyozu, J. Am. Chem. Soc. 1996, 118, 12267Ϫ12275. [13c]
Chem. Soc. B 1967, 660Ϫ662. ∆G‡ [cal/mol] ϭ 2.303 ϫ 1.987
T. Shinmyozu, M. Hirakida, S. Kusumoto, M. Tomonou, T.
Tc (10.319 Ϫ log10κc ϩ log10Τc) where κc ϭ π 21/2[(νΑ Ϫ νΒ)2
[13d]
Inazu, J. M. Rudzinski, Chem. Lett. 1994, 669Ϫ672.
Sakamoto, T. Shinmyozu, Recent Res. Dev. Pure Appl. Chem.
1998, 2, 371Ϫ399.
T. Meno, K. Sako, M. Suenaga, M. Mouri, T. Shinmyozu, T.
Inazu, H. Takemura, Can. J. Chem. 1990, 68, 440Ϫ445.
K. Hori, W. Sentou, T. Shinmyozu, Tetrahedron Lett. 1997,
38, 8955Ϫ8958.
For a very recent review on conformational study of cyclo-
phanes, see: L. Ernst, Prog. Nucl. Magn. Reson. Spectrosc.
2000, 37, 47Ϫ190.
Y.
1/2
ϩ 6 J2AB
) .
[26]
[27]
∆G‡ ϭ 9.9 kcal/mol: ∆ν ϭ νΑ Ϫ νΒ ϭ 280, JAB ϭ 13.8 Hz,
Tc ϭ Ϫ48 °C.
[14]
[15]
[16]
∆G‡ ϭ 10.4 kcal/mol: ∆ν ϭ νΑ Ϫ νΒ ϭ 80, JAB ϭ 14.8 Hz,
Tc ϭ Ϫ48 °C.
[28] [28a]
C. Cohen-Addad, M. Lebars, A. Renault, P. Baret, Acta
[28b]
Crystallogr., Sect. C 1984, 40, 1927Ϫ1931.
A. Renault, C.
Cohen-Addad, Acta Crystallogr., Sect. C 1986, 42, 1529Ϫ1533.
[28c]
A. Renault, C. Cohen-Addad, J. Lajzerowicz-Bonneteau,
J-P. Dutasta, M. J. Crisp, Acta Crystallogr., Sect. B 1987, 43,
[17] [17a]
[28d]
K. Sako, T. Hirakawa, N. Fujimoto, T. Shinmyozu, T. In-
480Ϫ488.
A. Renault, C. Cohen-Addad, P. Baret, Stud.
azu, H. Horimoto, Tetrahedron Lett. 1988, 29, 6275Ϫ6278. [17b]
Phys. Theor. Chem. 1987, 46, 611Ϫ612. [28e] A. Renault, C. Co-
hen-Addad, J. Lajzerowicz, E. Canadell, O. Eisenstein, Mol.
Cryst. Liq. Cryst. 1988, 164, 179Ϫ195.
K. Sako, T. Shinmyozu, H. Takemura, M. Suenaga, T. Inazu,
[17c]
J. Org. Chem. 1992, 57, 6536Ϫ6541.
T. Shinmyozu, T. Hi-
[29]
A. W. Hanson, E. W. Macaulay, Acta Crystallogr., Sect. B
1972, 28, 1255Ϫ1260.
rakawa, G. Wen, S. Osada, H. Takemura, K. Sako, J. M. Rud-
zinski, Liebigs Ann. 1996, 205Ϫ210. [17d] H. Takemura, H. Ka-
[30] [30a]
R. Adams, A. Ferretti, J. Am. Chem. Soc. 1959, 81,
riyazono, M. Yasutake, N. Kon, K. Tani, K. Sako, T. Shin-
myozu, T. Inazu, J. Org. Chem. 1999, 64, 9077Ϫ9079.
Wen, W. Matsuda-Sentou, K. Sameshima, M. Yasutake, D.
Noda, C. Lim, T. Satou, H. Takemura, K. Sako, H. Tatemitsu,
T. Inazu, T. Shinmyozu, J. Am. Chem. Soc., in press. [17f]T. Sa-
tou, T. Shinmyozu, J. Chem. Soc., Perkin Trans. 2. 2002,
393Ϫ397.
[30b]
[17e]
4927Ϫ4931.
R. Adams, A. Ferretti, J. Am. Chem. Soc.
G.
1959, 81, 4939Ϫ4940.
A. W. Van der Made, R. H. Van der Made, J. Org. Chem. 1993,
58, 1262Ϫ1263.
SIR92: A. Altomare, M. C. Burla, M. Camalli, M. Cascarano,
C. Giacovazzo, A. Guagliardi, G. Polidori, J. Appl. Crystallogr.
1994, 27, 435.
MULTAN88: T. Debaerdemaeker, G. Germain, P. Main, L. S.
Refaat, C. Tate, M. M. Woolfson, Computer programs for the
automatic solution of crystal structures from X-ray diffraction
data, University of York, U.K., 1988.
DIRDIF94: P. T. Beurskens, G. Admiraal, G. Beurskens, W. P.
Bosman, R. de Gelder, R. Israel, J. M. M. Smits, The DIRDIF-
94 program system, Technical Report of the Crystallography
Laboratory, University of Nijmegen, The Netherlands, 1994.
SHELXL-97: G. M. Sheldrick, Program for the Refinement of
Crystal Structures, University of Göttingen, Germany, 1997.
teXsan: Crystal Structure Analysis Package, Molecular Struc-
ture Corporation, 1985, 1999.
[31]
[32]
[18]
[19]
[20]
´
M. F. Semmelhack, J. J. Harrison, D. C. Young, A. Gutierrez,
[33]
[34]
S. Rafii, J. J. Clardy, J. Am. Chem. Soc. 1985, 107, 7508Ϫ7514.
F. A. L. Anet, M. A. Brown, J. Am. Chem. Soc. 1969, 91,
2389Ϫ2391.
K. Sako, T. Meno, H. Takemura, T. Shinmyozu, T. Inazu,
Chem. Ber. 1990, 123, 639Ϫ642.
[21] [21a]
T. Shinmyozu, M. Hirakida, S. Kusumoto, M. Tomonou,
T. Inazu, J. M. Rudzinski, Chem. Lett. 1994, 669Ϫ672. [21b] K.
[35]
[36]
Hori, W. Sentou, T. Shinmyozu, Tetrahedron Lett. 1997, 38,
[21c]
8955Ϫ8958.
Y. Sakamoto, N. Miyoshi, M. Hirakida, S.
Kusumoto, H. Kawase, J. M. Rudzinski, T. Shinmyozu, J. Am.
[21d]
Chem. Soc. 1996, 118, 12267Ϫ12275.
Y. Sakamoto, T.
Shinmyozu, Recent Res. Dev. Pure Appl. Chem. 1998, 2,
Received March 21, 2002
371Ϫ399.
[O02260]
Eur. J. Org. Chem. 2003, 1343Ϫ1351
1351