Chiral and extended π-conjugated Bis(2-pyridyl)phospholes as assembling N,P,N pincers for coordination-driven synthesis of supramolecular [2,2]paracyclophane analogues

Article abstract of DOI:10.1002/chem.201001862

Chiral, π-conjugated 3,4-butano-1-phenyl-2,5-bis(2-pyridyl)phosphole derivatives 1 a^2,2′ and 1 a³ with chiral trans-1,2-diol moieties and fused pinene derivatives, respectively, were prepared from the corresponding chiral diynes by u

Full text of DOI:10.1002/chem.201001862

FULL PAPER
DOI: 10.1002/chem.201001862
Chiral and Extended p-Conjugated Bis(2-pyridyl)phospholes as Assembling
N,P,N Pincers for Coordination-Driven Synthesis of Supramolecular
[2,2]Paracyclophane Analogues
Ana Isabel Aranda Perez,[a] Thomas Biet,[a] Sꢀbastien Graule,[a] Tomohiro Agou,[a, b]
Christophe Lescop,[a] Neil R. Branda,[c] Jeanne Crassous,*[a] and Rꢀgis Rꢀau*[a]
Abstract: Chiral, p-conjugated 3,4-
butano-1-phenyl-2,5-bis(2-pyridyl)-
C2-symmetric rectangles that are
[2,2]paracyclophane analogues were
obtained, as demonstrated by X-ray
crystallography. During the course of
this study, the first stable water-soluble
phosphole derivative (1a2·2HCl) was
prepared. Furthermore, achiral 3,4-
butano-1-phenyl-2,5-bis-
jugation. A supramolecular rectangle
was obtained by coordination to CuI
and assembly with a dicyano stilbene.
This coordination-driven supramolec-
ular assembly contains a total of four
aza[4]helicene moieties and displays
two types of p–p stacking interactions
in the solid state, that is, between two
helicene moieties and between one hel-
icene and a bridging dicyano ligand.
All the supramolecular arrangements
are discussed by comparing them with
previous work on the parent 3,4-
butano-1-phenyl-2,5-bis(2-pyridyl)-
phosphole.
phosphole derivatives 1a2,2’ and 1a3
with chiral trans-1,2-diol moieties and
fused pinene derivatives, respectively,
were prepared from the corresponding
chiral diynes by using the Fagan–
Nugent method. Their UV/Vis absorp-
tion and chiroptical properties (optical
rotation and circular dichroism) were
studied. Their behavior as N,P,N che-
lates towards coordination of CuI and
formation of chiral supramolecular as-
semblies with p-conjugated ditopic di-
cyano ligands was investigated. Chiral
phosphole 1a4 was syn-
ACHUTNGRENU(NG aza[4]helicene)ACHUTNGTRENNUGN
thesized and displays extended p con-
Keywords: copper · N,P ligands ·
phospholes · pi interactions · supra-
molecular chemistry
Introduction
havior.[1] These group 15 heteroles exhibit limited aromatic
character due to the inherent properties of the P atom (pyr-
amidal geometry, inert s-pair effect),[2] which result in high
reactivity of both their dienic and heteroatom moieties. This
behavior, which is very different from that of their N or S
analogues, makes phospholes appealing for many purposes.
For example, they are versatile synthons for the preparation
of various P heterocycles, such as phosphanorbornadienes,
through Diels–Alder reactions[3] involving their dienic
moiety or according to a 1,5-shift[4] of the P substituent,[5] or
phosphaferrocenes and phosphinines through transforma-
tion into nucleophilic phospholide anions.[6] They also offer
useful ring systems for constructing designer p-conjugated
systems with tailored properties.[1e] In this field, a variety of
phosphole-based conjugated oligomers and polymers,[7] in-
cluding cyclic derivatives,[7d,e] have recently been synthesized
for use as semiconducting materials in devices such as or-
ganic light-emitting diodes and organic field-effect transis-
tors (OFETs).[7a,d]
Phospholes are the most studied P heterocycles due to their
easy accessibility, good stability, and versatile chemical be-
[a] Dr. A. I. Aranda Perez, T. Biet, Dr. S. Graule, Dr. T. Agou,
C. Lescop, Dr. J. Crassous, Prof. R. Rꢀau
Sciences Chimiques de Rennes, UMR 6226 CNRS
Universitꢀ de Rennes 1
Campus de Beaulieu, 35042 Rennes Cedex (France)
Fax : (+33)2-23-23-69-39
E-mail: jeanne.crassous@univ-rennes1.fr
regis.reau@univ-rennes1.fr
[b] Dr. T. Agou
Present address: Kyoto University Pioneering Research Unit for Next
Generation and Institute for Chemical Research
Kyoto University
Gokasho, Uji, 611-0011 Kyoto (Japan)
[c] N. R. Branda
4D LABS at Simon Fraser University, Burnaby, BC (Canada)
Another important application of phospholes is their use
as building blocks for tailoring ligands toward binding of
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.201001862.
Chem. Eur. J. 2011, 17, 1337 – 1351
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1337

transition metals because their P atoms behave as classical
two-electron donors.[8] A wide variety of mono- and biden-
tate phosphole-containing ligands, including heteroditopic
P,N donors, have been reported.[5] The most important appli-
cation of metal–phosphole complexes is in homogeneous
catalysis. For example, they have been used in diverse cata-
lytic processes such as olefin/CO copolymerization,[9] hydro-
formylation of olefins,[10] Suzuki–Myaura and Heck cou-
plings,[11] telomerization reactions,[12] allylic alkylation,[13]
and hydrogenation of ketones.[14] Given the versatility and
popularity of phospholes in coordination chemistry, it is sur-
prising that, despite their potential use in asymmetric cataly-
sis, very few chiral phosphole ligands have been described
to date.[13,15]
Figure 1. Multidipolar NLOphore A and metal–bisACTHNUGRTNEUNG(helicene) assembly B.
donor with a bridging P atom, a very rare coordination
mode for phosphine ligands.[22] This unique coordination be-
havior was used to assemble U-shaped CuI dimers 2a1 and
2b1, which are useful as molecular clips for the supramolec-
ular synthesis of p-stacked metallocyclophanes C when they
undergo self-assembly with ditopic cyano-capped p linkers
(Scheme 1). In these supramolecular rectangles (C), the aro-
matic ditopic ligands are forced to participate in face-to-face
p interactions (phenyl centroid–centroid distances: 3.4–
3.5 ꢂ) with small lateral offsets, as a consequence of the
A
recent development that combines coordination
chemistry and p-conjugated systems is the use of mixed pyr-
idine–phosphole derivatives for coordination-driven supra-
molecular synthesis of complex architectures. For example,
multidipolar NLOphore A[16] and metal–bis
ACHTNUTRGNE(NUG helicene) as-
sembly B[17] were obtained by stereoselective coordination
of predesigned p-conjugated P,N ligands to a Pd2+ center
(Figure 1). In this context, 2,5-bis(2-pyridyl)phosphole 1a1
(Scheme 1) plays a special role because it is an effective
N,P,N pincer ligand for the stabilization of a variety of metal
dimers, including PdI,[18] PtI,[19] AgI,[20] and CuI[21] ions. In
these complexes, 1a1 acts as a six-electron m-1kN:1,2kP:2kN
I
I
ꢀ
short Cu Cu intermetallic distance imposed by the bridg-
ing phosphane coordination mode. Therefore, supramolec-
ular assemblies C can be regarded as analogues of [2,2]para-
Scheme 1. Molecular clips 2a1 and 2b1, synthesis of supramolecular p-stacked rectangles C, and general structure of [2,2]paracyclophanes D.
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Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
cyclophanes D (Scheme 1). Furthermore, the discrete rec-
tangles of C stack into infinite columns due to intermolecu-
lar p–p interactions.[21] Note that this type of supramolecular
organization of p-conjugated systems is of great interest for
the development of advanced materials for devices such as
OFETs.[23]
zation of these new assemblies is discussed and compared
with those based on parent phosphole 1a1. Of particular in-
terest, it will be shown that the substitution pattern of the
N,P,N pincers has a dramatic influence on the p–p stacking
of these novel p-stacked metallocyclophanes in the solid
state. On the one hand, increasing the steric hindrance of
the N,P,N ligand (1a1!1a3) allowed the first isolated metal-
locyclophane C (i.e., without intermolecular p–p stacking)
to be obtained. On the other hand, using the two N,P,N li-
gands 1a2 and 1a4 generates unprecedented intermolecular
p–p interactions between the p walls and the p fragments of
the covalent bridges of two metallocyclophanes C, affording
discrete p stacks. These results illustrate the versatility of
ACHTUNGTRENNUNG[2,2]Paracyclophanes D are layered p-conjugated mole-
cules par excellence, and this unique three-dimensional aro-
matic skeleton has been used in many areas, such as materi-
als science, organometallic chemistry, supramolecular
chemistry, and nanochemistry.[24–27] However, creating struc-
tural diversity within this class of p-stacked compounds by
varying either their p walls or their covalent bridges remains
a challenge for organic chemists.[28,29] We recently started to
tackle this challenge by using the coordination-driven supra-
molecular synthetic strategy depicted in Scheme 1. Indeed,
varying the ditopic cyano-capped p linkers provides ready
access to [2,2]paracyclophane supramolecular analogues C
with p walls of different lengths, chemical p compositions,
and geometries (linear, bent; Scheme 1).[21c]
the transition-metal-assisted self-assembly of
p systems
based on CuI-dimers assembled by bis(2-pyridyl)phosphole
ligands to vary the p stacking in the solid state.
Results
Herein we show that this coordination-driven synthesis
can be used with a variety of bridging molecular CuI2 clips
and allows easy and original structural variations of the
[2,2]paracyclophane framework. This molecular engineering
involves the use of novel functionalized bis(2-pyridyl)phosp-
hole N,P,N pincers that impart new properties (chirality or
extended p conjugation) to supramolecular [2,2]paracy-
clophane analogues C. These mixed N,P,N ligands feature
unprecedented structures in phosphole chemistry. For exam-
ple, ligands 1a2, 1a2’, and 1a3 (Figure 2) are the first report-
Synthesis and characterization of chiral bis(2-pyridyl)phosp-
holes 1a2,2’,3 and bis(naphthoquinolyl)phosphole 1a4: The
supramolecular synthetic approach described in Scheme 1
offers a straightforward way to introduce chirality into
[2,2]paracyclophane analogues C by means of optically pure
bis(2-pyridyl)phosphole N,P,N pincers. Therefore, we investi-
gated two different methods of endowing N,P,N ligand 1a1
with chiral functionality. The first method is to introduce
trans-dihydroxy or dioxolane groups onto the cyclohexane
ring of the fused phosphole system (derivatives 1a2 and 1a2’;
Figure 2). The second approach involves introduction of
chiral pyridine substituents at the 2,5-positions of the phos-
AHCTUNGTRENNUNG
based on the preparation of 2-pyridine-capped (ꢀ)-1,7-octa-
diyne-4R,5R-dioxolane 4a2 (Scheme 2). This compound was
obtained in moderate yield by Sonogashira coupling of
diyne (R,R)-3a2 with 2-bromopyridine under typical condi-
1
tions.[30] The H and 13C NMR spectroscopic data and the el-
Figure 2. Newly synthesized functionalized 2,5-bis(2-pyridyl)phosphole
derivatives.
ed chiral mixed phosphole–pyridine derivatives. Likewise,
compound 1a4, in which the phosphole ring is decorated
with naphthoquinolyl moieties, has a new type of extended
p-conjugated system based on two aza[4]helicene fragments.
The synthesis, structural characterization, and elucidation of
electronic (UV/Vis absorption) and chiroptical (molar rota-
tion (MR), circular dichroism (CD)) properties of the newly
synthesized phospholes (Figure 2) are detailed. The one-pot
Scheme 2. Synthesis of phospholes (R,R)-1a2’ and (R,R)-1a2·2HCl. Con-
ditions: i) 2-bromopyridine, [PdCl2ACHTNUGTRNEG(UN PPh3)2], CuI, Et3N, 65%;
ii) [Cp2ZrCl2], 2nBuLi, THF then PhPBr2, Ar, RT, overnight, 65%; iii)
conc. HCl, MeOH, quantitative.
synthesis of p-stacked metallocyclophanes of type
C
(Scheme 1) based on CuI2 clips with these functionalized
N,P,N pincers is also presented. The supramolecular organi-
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1339

J. Crassous, R. Rꢀau et al.
Table 1. Selected NMR data and yields of isolated product for 2-pyridyl-
capped diynes 4, 5, and 7 and phospholes 1a1–4
.
d
G
Yield
[%]
d(1H)py[a]
[ppm]
dG
Yield
[%]
[ppm]
–
–
–
1a1[c] 8.50, 7.45 (H6, +11.7
H3 py)
–
4a2 8.50, 7.35
(H6, H3)
65
57
55
1a2’ 8.50,7.45 (H6, +19.0
H3 py)
65
69
50
4a3 8.07, 7.19
(H6, H3)
1a3
8.13, 7.28 (H6, +11.4
H3 py)
4a4 9.32, 8.94
(H1, H12)
1a4
9.32, 8.98 (H1, +12.3
H12)
Figure 3. X-ray structure of 1a2·2H+ (Clꢀ ions omitted).
[a] At 300 MHz in CDCl3. [b] At 81 MHz in CDCl3. [c] From ref. [7j].
emental analysis support the proposed structure of 4a2
(Table 1). This diyne was engaged in oxidative coupling with
angles between the central P-containing ring and the pyri-
dine substituents (20–308) allow delocalization of the p
system over the entire molecule. The synthesis of 1a2·2HCl
illustrates that “classical” organic reactions, such as acid-cat-
alyzed acetal cleavage, can be conducted in the presence of
a s3,l3-phosphole moiety. It is indeed remarkable that the P
atom, which has a reactive lone pair,[1] is not protonated
under these acidic reaction conditions. To the best of our
knowledge, 1a2·2HCl is the first dicationic phosphole deriv-
ative reported to date. This unusual P heterole exhibits in-
teresting properties; due to its ionic nature, it is soluble in
water. In fact, 1a2·2HCl is the first water-soluble trivalent
phosphole derivative reported to date. Furthermore, no de-
composition of phosphole 1a2·2HCl was observed (by moni-
zirconocene
followed
by
[ZrCp2]/PPh
exchange
(Scheme 2).[31] This Fagan–Nugent reaction afforded phosp-
hole 1a2’ (Scheme 2), which was isolated in 65% yield as an
air-stable solid after purification by column chromatography.
Its structure was supported by high-resolution mass spec-
trometry and elemental analysis. Because phosphole 1a2’ is
C2-symmetric, its P atom is not a stereogenic element. Its
31P{1H} NMR spectrum, therefore, shows a single peak at
d=19.0 ppm. This value is shifted to lowfield compared with
that of 1a1 (d=11.7 ppm; Scheme 1), but is in the range of
those observed for other 1-phenyl phospholes.[7j,32] Most of
1
the H NMR signals are split into two sets of peaks due to
diastereotopicity arising from the symmetry of the molecule.
For example, the methyl groups of the dioxolane fragment
are anisochronous (see the Experimental Section). The cy-
Table 2. Selected bond lengths [ꢂ] and angles [8] of the Nm-PN moieties of
ligand 1a1,[7j,32] CuI molecular clip 2a1,[21b] chiral bis(2-pyridyl)phosphole
(R,R)-1a2·2HCl, and the supramolecular assemblies C2–4
.
1
clohexyl moiety displays six sets of signals in the H NMR
spectrum between d=2.6 and 4.4 ppm, and the typical sig-
nals for the pyridyl moieties are observed (Table 1). Similar-
ly, the 13C NMR spectrum of 1a2’ displays two sets of signals
that undergo short- and long-range coupling with the P
atom. The protective 1,3-dioxolane group of 1a2’ can subse-
quently be removed with concentrated HCl in MeOH to
give quantitatively dicationic phosphole hydrochloride
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
P C1
ꢀ
P C8
C1 C2
C2 C7
C7 C8
C1 CPy C1-P-C8
ꢀ
C8 CPy
1a1
1.806(6) 1.365(9) 1.478(9) 1.354(8) 1.466(9) 90.5(3)
1.806(6) 1.467(8)
1a2·2HCl[a] 1.792(7) 1.393(9) 1.473(10) 1.368(10) 1.448(10) 90.2(3)
1
1a2·2HCl (Scheme 2), which was characterized by H, 13C,
and 31P NMR spectroscopy and HRMS (the [MꢀH2O]+ ion
1
was observed). As expected, the H signals attributed to the
1.800(7)
–
1.485(10)
– –
pyridinium rings of 1a2·2HCl are shifted to lowfield (see the
Experimental Section) compared with those of the corre-
sponding pyridine fragments of neutral derivative 1a2’
(Scheme 2). The fact that the P atom is not protonated is
supported by the 31P NMR chemical shift of 1a2·2HCl (d=
+22.1 ppm), which is comparable to that of tricoordinate P-
phenyl phosphole 1a2’ (d=+19.0), and the absence of a
large JPH coupling constant. The proposed structure of
1a2·2HCl was confirmed by single-crystal X-ray diffraction
(Table 6, Figure 3). Compound 1a2·2HCl crystallizes in the
P21 space group of the monoclinic system. The asymmetric
unit contains two crystallographically independent 1a2·2H+
molecules, four Clꢀ anions, and one water molecule. The
metric data of this dicationic phosphole are essentially com-
parable to those of nonfunctionalized 2,5-bis(2-pyridyl)-
–
–
–
1.806(7) 1.358(9) 1.465(9) 1.397(9) 1.440(10) 89.5(3)
1.817(7) 1.484(9)
1.814(2) 1.362(3) 1.479(3) 1.367(3) 1.465(3) 90.45(10)
1.823(2) 1.465(3)
1.801(10) 1.359(12) 1.467(13) 1.373(14) 1.464(12) 91.7(4)
2a1
C2[b]
1.815(8)
–
1.489(13)
– –
–
–
–
1.823(9) 1.355(12) 1.481(12) 1.324(12) 1.474(11) 88.9(4)
1.825(7) 1.481(12)
1.812(4) 1.361(6) 1.463(7) 1.349(7) 1.465(7) 89.7(2)
1.812(5)
–
1.805(5) 1.374(7) 1.462(7) 1.356(7) 1.447(7) 91.0(2)
1.824(5) 1.452(7)
1.808(6) 1.362(8) 1.485(9) 1.338(8) 1.472(8) 89.9(3)
1.815(6) 1.482(9)
C3[b]
1.452(7)
–
–
–
–
–
C4[c]
[a] Two independent molecules in the unit cell. [b] Noncentrosymmetric
phosphole 1a1 (Table 2, Figure 3). Note that the small twist supramolecular assemblies. [c] Centrosymmetric supramolecular assembly.
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Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
toring by 31P NMR spectroscopy) after three days in concen-
trated acidic aqueous media (ca. pH 1). This result opens
new interesting perspectives for the synthesis of water-solu-
ble phosphole-based p-conjugated systems or ligands for
catalysis.
Another strategy used to endow the N,P,N framework of
bis(2-pyridyl)phosphole 1a1 with chirality was to introduce a
fused pinene component into each of the pyridine rings (de-
rivative 1a3; Figure 2). A great variety of chiral pyridines
have been synthesized from optically active natural terpenes
by Krçnke-type reactions.[33] These pyridine derivatives are
versatile synthons for the design of chiral ligands for asym-
metric metal catalysis[34,35] and stereoselective coordination-
based supramolecular assembly with predetermined ligand
chirality.[36] Our approach to synthesizing target derivative
1a3 (Figure 2) relies on the preparation of enantiopure
diyne 4a3 by a Sonogashira coupling involving 1,7-octadiyne
and triflate 3a3 (Scheme 3). This diyne was subjected to a
Scheme 4. Conditions: i) hn, cat. I2, toluene, 58%; ii) NaI, Me3SiCl,
CH3CN, 80%; iii) Pyridine, Tf2O, 65%; iv) 1,7-octadiyne, [Pd2ACHTUNGTRENNUNG(dba)3],
PPh3, Et3N, 55%; v) [Cp2ZrCl2], 2nBuLi, THF then PhPBr2, Ar, RT, 4 h,
50%.
zation reaction, which is a common way to obtain helicene
derivatives,[39] in the presence of a catalytic amount of
iodine to give 3-methoxynaphtho
[1,2-f]quinoline 5a4 (58%
ACHTUNGTRENNUNG
yield). Demethylation of 5a4 in the presence of trimethyl-
chlorosilane and NaI[40] gave naphtho
ACTHNUTRGNE[UNG 1,2-f]quinolin-3(4H)-
one 6a4 (80% yield), and subsequent reaction with triflic an-
hydride[35a] afforded triflate derivative 7a4, which was isolat-
ed in 65% yield following column chromatography
(Scheme 4). A Sonogashira coupling with 1,7-octadiyne in
the presence of PPh3, Et3N, and [Pd2ACHTNUTRGNE(NUG dba)3] (dba=trans,
trans-dibenzylideneacetone) as the catalyst generated the
poorly soluble diyne 4a4 in 55% yield. Phosphole 1a4 was
obtained in 50% yield of isolated product by treating diyne
4a4 with zirconocene and dibromophenylphosphine. This
phosphole displayed a typical 31P{1H} NMR signal at d=
12.3 ppm (Table 1). The 1H NMR spectrum displayed two
downfield signals that are characteristic of the H1 and H12
protons of the aza[4]helicene moiety (Table 1).[17,41] The lack
of separate signals for stereoisomers supports the expecta-
tion that each of the aza[4]helicene “arms” rapidly inverts
at room temperature, as is typical for small helicenes of this
type.[42]
Scheme 3. Conditions: i) 1,7-octadiyne, [PdCl2ACHTUNRGTNEUNG(PPh3)2], CuI, HNiPr2,
57%; ii) [Cp2ZrCl2], 2nBuLi, THF then PhPBr2, Ar, RT, 3 h, 69%.
Fagan–Nugent reaction to give desired enantiopure phosp-
hole 1a3 (Scheme 3), which was purified by column chroma-
tography as an air-stable pale yellow powder (69% yield).
Once again, due to the C2 symmetry of the molecule, the
phosphorus atom is not a stereogenic center and only one
singlet, at d=11.4 ppm, was recorded in the 31P{1H} NMR
spectrum. Besides the signals that are characteristic of the
1
pinene and (CH2)4 bridge moieties, the H NMR spectrum
shows two characteristic signals for the H3 and H6 protons
1
of the pyridyl groups (Table 1). Here again, most of the H
and 13C signals are split into two sets of peaks due to diaster-
eotopicity.
Electronic and chiroptical properties of functionalized 2,5-
bis(2-pyridyl)phospholes 1a2–4: The presence of an extended
p-conjugated system in phospholes 1a2–4 (Figure 2) was
shown by absorptions in the visible regions of the spectra
that can be attributed to p–p* transitions.[7j] The influence
of introducing substituents onto the bis(2-pyridyl)phosphole
platform of 1a1 on the energy of these absorptions is quite
surprising. The presence of substituents on the two pyridine
rings has almost no influence on the absorptions (lmax values
for 1a1 and 1a3 differ by only 6 nm; Table 3). In contrast,
the presence of the dioxolane moiety on the P-fused carbo-
cyle has a much larger impact on the absorptions, and a
blueshift (Dlmax =34 nm) is observed on going from 1a1 to
1a2’ (Table 3). The optical structure–property relationship in
The final target phosphole is compound 1a4, which has
aza[4]helicene substituents (Figure 2) and, therefore, has a
new type of extended conjugated p system. Following the
Fagan–Nugent method, the preparation of 1a4 necessitated
the synthesis of aza[4]helicene-capped diyne 4a4
(Scheme 4). This diyne was obtained according to a Wittig
reaction/photocyclization sequence followed by a deprotec-
tion/trifluoromethylsulfonation/Sonogashira
sequence
(Scheme 4).[37] The Wittig reaction between 6-methoxy-2-
pyridine carboxaldehyde[38] and 2-methylnaphthyltriphenyl-
phosphonium bromide gave olefin 3a4 in 76% yield as a cis/
trans mixture. This olefin was then engaged in a photocycli-
Chem. Eur. J. 2011, 17, 1337 – 1351
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1341

J. Crassous, R. Rꢀau et al.
Table 3. UV/Vis absorption data for phospholes 1a1–1a4.[a]
1a1
1a2’
1a2·2HCl
1a3
1a4
l [nm]
e [nm]
390
10500
366
11800
361[b]
10800
384
28000
432
18000
[a] Recorded in CH2Cl2 unless otherwise noted. [b] MeOH.
this bis(2-pyridyl)phosphole series is quite difficult to ration-
alize because it is the pyridine rings and not the carbocycle
that are directly involved in the extended p conjugation (the
latter is fully saturated). Note that the dicationic bis(2-pyri-
dyl)phosphole 1a2·2HCl displays a lmax value (recorded in
MeOH) at high energy (Table 3). This tuning of the optical
property of phosphole-based p-conjugated systems by
remote substituents or protonation of pyridines is unprece-
dented in the emerging field of P materials. As expected, a
bathochromic shift was observed on replacing the 2-pyridyl
groups in 1a1 with two p-extended naphtoquinolyl moieties
in 1a4 (Dlmax =52 nm), which results in extension of the p-
conjugated pathway.
Molar optical rotations (MRs) and electronic circular di-
chroism (CD) of the enantiopure diynes and of the corre-
sponding phospholes were measured in CH2Cl2 or MeOH.
Although all phospholes displayed modest CD values (De<
5 molꢀ1 cmꢀ1), their specific and molar rotations were sub-
stantial (Table 4). Two features are worthy of note. First, the
Figure 4. a) UV/Vis and b) CD spectra of diyne (+)-4a2 (a) and
phosphole (ꢀ)-1a2’ (c).
Table 4. Experimental specific optical rotations of enantiopure diynes
(R,R)-4a2, 4a3 and phospholes (R,R)-1a2&#39;, (R,R)-1a2·2HCl, and 1a3
(see Schemes 2 and 3).[a,b]
Coordination-driven synthesis of [2,2]paracyclophane ana-
logues from functionalized 2,5-bis(2-pyridyl)phospholes
1a2–4: We have previously shown that bis(2-pyridyl)phosp-
hole 1a1 is an efficient N,P,N pincer for stabilizing U-shaped
CuI dimers 2a1 and 2b1 (Scheme 1).[21] These bimetallic spe-
cies are versatile molecular clips for guiding the organiza-
tion of a variety of ditopic p systems with different lengths,
geometries, and nature of the p system in p-stacked supra-
molecular rectangles C (Scheme 1).[21] Therefore, it was of
interest to illustrate the use of chiral or p-conjugated N,P,N
chelates 1a2–4 in a similar approach to endow supramolec-
ular assemblies of type C with functional bridges. The supra-
molecular synthetic strategy towards derivatives C that we
used involves a one-pot procedure for in situ synthesis of bi-
A
(R,R)-
N
4a3
1a3
4a2
1a2’
a2D3
ꢀ71.5 ꢀ87
ꢀ320 ꢀ484
[degcm2 dmolꢀ1
]
]
ꢀ2D3
[degcm2 dmolꢀ1
[a] All spectra were recorded in CH2Cl2 unless otherwise noted.
[b] Within an error of ꢁ2%. [c] MeOH.
substitution pattern of the phosphole ring has an impact on
the MR values, as shown by the comparison of phospholes
1a2’ (ꢀ299) and 1a2·2HCl (+75), which have the same basic
skeleton (Figure 2). Second, the phosphole derivatives ex-
hibit higher MRs than their diyne precursors (Table 4). This
effect is particularly pronounced for phosphole 1a2’ bearing
a chiral dioxolane ring (1a2’ versus 4a2, Table 4). Moreover,
the CD of phosphole 1a2’ displays two bands at l=273 and
345 nm, whereas the CD of the corresponding diyne 4a2 is
almost silent in this region (Figure 4). At first glance, this
phenomenon is rather surprising because the chiral fragment
is rather remote from the bis(2-pyridyl)-1-phenylphosphole
moiety. However, because these CD bands are due to p–p*
transitions, the bis(2-pyridyl)-1-phenylphosphole moiety is a
chromophoric probe that senses the chirality of the mole-
cule. Therefore, it is very likely that this effect arises from
preferential conformations of the bis(2-pyridyl)phosphole p-
conjugated fragment resulting in atropoisomerism.
metallic CuI2 clips.[21] Indeed, reaction of [Cu
ACHTUNGRTNEUN(G CH3CN)4]BF4,
bis(diphenylphosphino)methane (dppm), and one of the
newly prepared functionalized bis(2-pyridine)phospholes
1a2’, 1a3, or 1a4 (2:1:1 molar ratio) in CH2Cl2 at room tem-
perature, followed by self-assembly with homoditopic dicya-
1
2
no p linkers Lp or Lp , afforded supramolecular rectangles
C2·4BF4, C3·4BF4, and C4·4BF4 in high yields (> 81%;
Scheme 5).
On diffusion of pentane vapor into a solution of C2·4BF4
in CH2Cl2/MeOH, single crystals suitable for X-ray diffrac-
tion were obtained (Table 6). No polymorphism was re-
vealed by careful examination of the crystal batch. Com-
pound C2·4BF4 crystallizes in the P21 space group of the
monoclinic system. This compound is a noncentrosymmetric
1342
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Chem. Eur. J. 2011, 17, 1337 – 1351

Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
Scheme 5. Coordination-driven synthesis of supramolecular rectangles C2–4 from functionalized phospholes 1a2–4
.
metallacycle of type C (Scheme 1) in which the four CuI
centers lie in the same plane defining a rectangle (Figure 5a,
droxyl groups. In other words, the CuI2 clips are assembled
by N,P,N pincer 1a2 (Figure 2). Interestingly, in the solid
state, intermolecular p–p stacking interactions (intermolecu-
ꢀ
torsion angle Cu1-Cu2-Cu3-Cu4 0.128; short Cu Cu dis-
ꢀ
tance 2.7 ꢂ; long Cu Cu dis-
tance 11.7 ꢂ). All counterions
are located outside the self-as-
sembled structure. The metric
parameters of the dicationic
(CuI) (1a2)
2ACHTUNGTRENNUNG ACHTUNGTRENNUNG(dppm) cores of
metallacycle C2, including the
metal–metal and metal–mP dis-
ꢀ ꢂ
tances and the directing ( C
ꢂ ꢀ
N)-Cu-Cu-(N C ) angles, com-
pare well with those of corre-
sponding molecular clip 2a1
(Table 5).[21] The aromatic di-
topic 1,4-dicyanobenzene li-
gands are parallel with a small
lateral offset of 0.2 ꢂ (Fig-
ure 5b), and they participate in
p–p interactions (p–p distan-
ces: 3.5–3.6 ꢂ). Overall the rec-
tangle is C2 symmetric, with the
dppm and phosphole moieties
having an anti position with re-
spect to the rectangle defined
by the four Cu atoms (Fig-
ure 5a). During the course of
the supramolecular synthesis of
C2·4BF4, the dioxolane groups
were cleaved and the fused car-
bocycles of the P-containing
Figure 5. a) X-ray crystal structures of supramolecular assemblies C2–4 (H atoms, counterions, and solvent mol-
2
ecules omitted for clarity). In the case of C3, the conformational disorder of the double bond of connector Lp
ring have chiral trans-1,2-dihy- is not shown). b) View along the long sides of the Cu4 quadrangle.
Chem. Eur. J. 2011, 17, 1337 – 1351
ꢁ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
1343

J. Crassous, R. Rꢀau et al.
Table 5. Selected bond lengths [ꢂ], angles [8], and torsion angles [8] for the Cu2ACTHNUTRGNE(UNG Nm-PN) moieties of molecu-
the compound in CH2Cl2. This
compound crystallizes in the
P21 space group of the mono-
clinic system and is a noncen-
trosymmetric rectangle of type
lar clip 2a1[21b] and supramolecular assemblies C2–4
.
ꢀ
ꢀ
Cu mP
Cu N
Cu···Cu
N-Cu-mP
Cu-mP-Cu mP-Cu-Cu
Cu-NC- CN-Cu-Cu-NC
2.018(2) 5.7
2a1
2.2898(8)
2.5221(8)
2.057(2) 2.6696(7)
2.061(2)
2.037(8) 2.7650(16) 82.5(2)
2.027(8)
–
85.80(7)
82.78(7)
67.19(2)
60.56(2)
52.248(19) 2.014(3)
C2[a] 2.400(3)
2.432(3)
–
69.81(8)
54.54(7)
55.65(6)
–
169.8(8) 0.9
C
(Figure 5a, torsion angle
83.7(2)
–
173.6(8)
–
Cu1-Cu2-Cu3-Cu4, 2.018; short
–
–
ꢀ
Cu Cu distance, 2.9351(10),
2.368(3)
2.454(3)
2.074(7) 2.7251(16) 81.8(2)
68.79(7)
54.10(6)
57.10(6)
51.93(3)
52.83(4)
–
171.7(8) 3.3
172.7(8)
168.4(4) 13.2
175.3(4)
2.085(8)
83.1(2)
81.63(11) 75.23(4)
82.39(12)
ꢀ
3.0060(9) ꢂ; long Cu Cu dis-
C3[a] 2.4474(13) 2.083(4) 3.0060(9)
tance, 18.4 ꢂ). The intermetal-
lic distances within the Cu2
2.4772(15) 2.099(4)
–
–
–
–
–
–
–
fragments
(2.9351(10)–
2.4210(14) 2.082(4) 2.9351(10) 82.49(12) 72.90(4)
2.5177(17) 2.101(4) 85.28(13)
C4[b] 2.3902(18) 2.075(5) 2.7656(11) 83.18(15) 70.42(5)
2.4061(18) 2.092(5) 86.78(16)
52.03(3)
55.07(4)
54.52(4)
55.06(4)
168.4(5) 9.5
172.5(5)
164.3(5) 18.9
168.1(6)
3.0060(9) ꢂ) are among the
longest observed to date for an
MI dimer (M=CuI, AgI, PdI,
PtI) assembled by a bis(2-pyri-
[a] Noncentrosymmetric supramolecular assemblies. [b] Centrosymmetric supramolecular assembly.
dyl)phosphole ligand with
a
bridging phosphane (the previ-
lar distances ꢃ3.5 ꢂ) exist between the phenyl ring of link-
ous longest distance was 2.9501(6) ꢂ).[20] Nevertheless, the
1
ers Lp of metallacycle C2 and the phenyl groups of the
two mP Cu distances are almost the same and in the range
ꢀ
dppm ligands, affording a discrete p stack of six phenyl units
(Figure 6). Remarkably, this type of stacking is not observed
in the solid-state structure of the analogous metallocyclo-
of those classically observed for bridging phosphole donors
(Table 5). Despite these rather long intermetallic distances
within the molecular clips, the p walls of rectangle C3·4BF4
display a parallel-displaced organization (Figure 5b, lateral
offset 1.1 ꢂ) and are involved in intramolecular p interac-
tions (p–p distances: 3.4–3.5 ꢂ). Therefore, introduction of
the fused pinene moieties on the pyridine donors does not
prevent the formation of p-stacked metallocyclophanes C.
However, in contrast to what is observed with the corre-
sponding metallocyclophane incorporating clip 2a1, supra-
molecular assembly C3·4BF4 does not stack (Figure 7) in the
solid state to form infinite p-stacked columns.[21] It is likely
that the steric hindrance associated with the pinene moieties
prevents supramolecular organization of metallocyclophanes
C3·4BF4 in columns but instead allows the characterization
of isolated p-stacked metallocyclophane. Hence, modifica-
tion of the steric hindrance of the assembling bis(2-pyridyl)-
phosphole ligand does not prevent the formation of the
target [2,2]paracyclophane analogues C but allows for a con-
trol of their supramolecular organization. This result is of
great interest because it demonstrates that the driving force
for the formation of metallocyclophanes of type C is not the
establishment of intermolecular p–p interactions within col-
umns. The preparation of assemblies C2,3 (Scheme 5,
Figure 5) illustrates that chirality can be readily introduced
in [2,2]paracyclophane framework by coordination-driven
supramolecular synthesis. Although these supramolecular
rectangles display moderate specific and molar rotations
(C3·4BF4: [f]2D3 =+180 (C=0.13, CH2Cl2)), this novel ap-
proach opens very interesting perspectives for diversifying
the structures of [2,2]paracyclophanes, which are an impor-
tant family of layered p-conjugated systems.
1
phane featuring nonchiral clip 2a1 with spacer Lp , for which
no such intermolecular p stacks were observed.[21c] In fact,
this is the first time that intermolecular p–p interactions in-
volving the clip and the p walls are observed for assemblies
of type C. Therefore, the coordination-driven synthesis of
supramolecular p-stacked metallacyclophane C2 with the
novel bis(2-pyridine)phosphole 1a2’ reveals interesting and
new features in [2,2]paracyclophane chemistry. It shows that
1) chirality can easily be incorporated within the covalent
bridges by using optically active bis(2-pyridine)phosphole li-
gands, 2) reactive OH groups can be introduced at the pe-
riphery of the molecule, and 3) novel types of supramolec-
ular organization of p-stacked metallacyclophanes involving
the ligands of the CuI bridges can be observed.
Single crystals of the supramolecular assembly C3·4BF4
were grown by diffusion of pentane vapor into a solution of
Single crystals of C4·4BF4 were obtained by diffusion of
pentane vapor into a CH2Cl2/MeOH solution. This com-
pound crystallizes in the centrosymmetric I41/a space group
of the tetragonal system (Table 6). Compound C4 is a cen-
trosymmetric tetracationic supramolecular rectangle of type
Figure 6. Discrete p stack of six phenyl units observed in the solid-state
structure of supramolecular assembly C2 (phenyl groups of dppm ligands
in light gray and phenyl groups of the Lp1 ligand in dark gray).
1344
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Chem. Eur. J. 2011, 17, 1337 – 1351

Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
helicenephosphole ligands of
two other metallocyclophanes
(I1: intermolecular p–p distan-
ces ꢃ3.5 ꢂ, Figure 9b). In other
words, the p walls of C4·4BF4
are “sandwiched” between the
two aza[4]helicene moieties to
give a unique example of a
fourfold
p-stacked
mixed
system involving aza[4]helicene
and stilbene p-conjugated moi-
eties (Figure 9b). This result
nicely confirms that the intro-
Figure 7. View of the stacking pattern of p-stacked metallocyclophane C3.
duction of functionalities on the
molecular clip does not perturb
ꢀ
C (Figure 5a; Cu1-Cu2-Cu1’-Cu2’ 08; short Cu Cu distance
the formation of p-stacked metallacycles C, but influences
their self-assembly processes (Figure 10). Moreover, it
shows that the organization in the solid state of different p-
conjugated systems could be monitored by tailoring the as-
sembling N,P,N ligands of (CuI)2 molecular clips.
ꢀ
2.8 ꢂ; long Cu Cu distance 18.8 ꢂ). The metric parameters
of the dicationic (CuI)
2A
(dppm) cores are classical
(Table 5) and the p walls of the linkers exhibit a parallel-dis-
placed p-stacking arrangement (lateral offset 1.6 ꢂ; p–p dis-
tances ꢃ3.5 ꢂ; Figure 5b). Interestingly, the twist angles be-
tween the phosphole ring and the aza[4]helicene moieties
are quite small (29–368), and allow the presence of extended
p-conjugated systems within the N,P,N ligand and CuI–CuI
dimer (Figure 8). This result sheds light on the potential of
Conclusions
We have shown that the Fagan–Nugent route is an efficient
method to prepare new classes of chiral p-conjugated phosp-
holes and phospholes with aza[4]helicene (naphtoquinolyl)
moieties. Even though their structures have been greatly
modified (especially on the periphery of the molecular back-
bone), these novel derivatives retain their ability to act as
N,P,N chelators and afford CuI dimers that can be used as
molecular clips in the coordination-driven synthesis of
supramolecular analogues of [2,2]paracyclophane. This plug-
and-play method offers structural diversity by introducing
functional groups (e.g., OH) or steric properties (e.g., chiral-
ity) on the bridge of the resulting [2,2]paracyclophane ana-
logues. These results illustrate the versatility of our supra-
molecular approach in assembling p-conjugated systems be-
cause the nature of the N,P,N ligands also impacts the supra-
molecular organization of the p-stacked rectangles through
the existence of various types of p–p interactions. Indeed,
varying their steric and electronic properties results in un-
precedented supramolecular organizations of metalloparacy-
clophanes. Discrete or infinite p stacks can be generated in
the solid state by specific molecular engineering of the
bis(2-pyridyl)phosphole skeleton. These results extend the
scope of our coordination-driven approach towards the con-
trolled organization of p systems in the solid state because
they show that the N,P,N pincer is not only a “spectator” as-
sembling ligand in metalloparacyclophanes C but can influ-
ence the supramolecular organization as well.
Figure 8. Local view of rectangle C4 in the crystal showing the extended
p-conjugated backbone of the N,P,N pincer.
coordination chemistry to rigidify ligands (Figure 8). In fact,
a rigid extended p-conjugated system is constructed by clip-
ping the two aza[4]helicenes and the central phosphole with
CuI ions.
The synthesis and solid-state characterization of supra-
molecular rectangle C4·4BF4 show that it is possible to use
sophisticated bis(2-pyridyl)phosphole pincers featuring an
extended p-conjugated system in this supramolecular syn-
thetic approach. The presence of the extended p system on
the N,P,N ligand provides the rectangle C4·4BF4 with re-
markable supramolecular organization. First, an aza[4]heli-
cene moiety shares p–p interactions with the symmetrically
related aza[4]helicene moiety of a neighboring supramolec-
ular rectangle (I2: intermolecular p–p distances ꢃ3.5 ꢂ; Fig-
ure 9a). Second, additional p–p interactions take place be-
tween the p walls of one metallocyclophane and the aza[4]-
Experimental Section
General information: All experiments were performed under an atmos-
phere of dry argon by using standard Schlenk techniques. Commercially
Chem. Eur. J. 2011, 17, 1337 – 1351
ꢁ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
1345

J. Crassous, R. Rꢀau et al.
(R,R)-4a2 as a brown oil (yield 0.24 g,
65%). [a]2D3 =+26.5, [f]2D3 =+52 (C=
0.08, CH2Cl2); 1H NMR (300 MHz,
CD2Cl2): d=8.50 (brs, 2H; H6 py),
7.61 (m, 2H; H4 py), 7.35 (m, 2H; H3
py), 7.17 (m, 2H; H5 py), 4.15 (m, 2H;
CH), 4.15 (m, 4H; CH2), 1.41 ppm (s,
6H; CH3); 13C{1H} NMR (75.46 MHz,
CD2Cl2): d=149.8 (CH py), 143.1
ꢂ
ꢂ
(C ), 136.1 (CH py), 132.0 (C ), 127.0
(CH py), 122.7 (CH py), 109.4 (C-
AHCTNUTGERG(NNNU CH3)2), 85.6 (CHCH2), 82.0, 77.8, 27.2
(CH2), 23.7 ppm (CH3); UV/Vis
(CH2Cl2, 1.28ꢃ10ꢀ3 m): l (e)=288 nm
(1600 nm); CD (CH2Cl2, 5.3ꢃ10ꢀ4 m):
l=388 (ꢀ0.2), 294 (ꢀ0.4), 275 (ꢀ0.1),
242 nm (2.8); elemental analysis calcd
(%) for C21H20N2O2: C 75.88, H 6.06,
N 8.43; found: C 75.85, H 6.05, N 8.40.
Phosphole (R,R)-(ꢀ)-1a2’: A solution
of nBuLi (1.6m) in hexane (0.6355 mL,
1.048 mmol) was slowly added drop-
wise to
a solution of [Cp2ZrCl2]
(127 mg, 0.44 mmol) in THF (10 mL)
at ꢀ788C. The reaction mixture was
stirred at ꢀ308C for 1 h. Then a solu-
tion of (+)-4a2 (145 mg, 0.44 mmol) in
THF (10 mL) was slowly added at
ꢀ788C. The solution was warmed to
RT and stirred for 1 d. Freshly distilled
PhPBr2 (99 mL, 0.47 mmol) was added
to this solution at ꢀ508C. The solution
was then filtered over basic alumina
under inert conditions and the volatile
materials removed under vacuum. Pu-
rification by column chromatography
(silica gel, pentane/diethyl ether 3:2)
gave phosphole 1a2’ as a yellow solid
(yield 126 mg, 65%). M.p. 1508C;
[a]2D3 =ꢀ67.9, [f]2D3 =ꢀ299 (C=0.35,
Figure 9. Packing pattern observed in the solid-state structure of assembly C4. The isolated supramolecular rec-
tangle is in black, and the neighboring supramolecular rectangles in gray; see text for details. a) Intermolecular
p–p interactions I1 and I2. b) Fourfold discrete mixed p-stacked system.
CH2Cl2);
1H NMR
(300 MHz,
available reagents were used as received without further purification. Sol-
CD2Cl2): d=8.57 (brs, 2H; H6 Py), 7.52–7.60 (m, 2H; o-H Ph), 7.42–7.47
(m, 2H; H3 Py), 7.33 (m, 2H; m-H Ph), 7.25–7.30 (m, 1H; p-H Ph), 7.1–
7.18 (m, 2H; H4 Py), 7–7.05 (m, 2H; H5 Py), 4.39 (m, 1H), 4.09 (m, 1H),
3.81 (m, 1H), 3.48 (m, 1H), 3.13 (m, 1H), 2.70 (m, 1H), 1.55 (s, 3H;
CH3), 1.50 ppm (s, 3H; CH3); 13C{1H} NMR (75.46 MHz, CD2Cl2, cou-
pling constants not assigned): d=155.4, 154.5, 149.54, 149.3, 145.4, 145.3,
145.1, 143.8, 143.7, 136.5, 136.1, 136.0, 134.0, 133.7, 131.9, 131.7, 131.1,
131.0, 129.4, 128.7, 128.6, 128.5, 128.4, 127.8, 127.7, 127.6, 123.8, 123.7,
123.4, 123.3, 123.2, 121.3, 121.1, 121.0, 111.5, 78.3, 32.9, 31.8, 27.3 ppm;
31P{1H} NMR (81 MHz, CDCl3): d=19.0 ppm; UV/Vis (CH2Cl2, 3.7ꢃ
10ꢀ5 m): l (e)=366 nm (11800 nm); CD (CH2Cl2, 5.3 10ꢀ4 m): l=399
(0.25), 345 (ꢀ0.6), 273 nm (3.5); HRMS (EI): m/z calcd for C27H25O2P:
440.1654; found: 440.1655; elemental analysis calcd (%) for
C27H25N2O2P: C 73.62, H 5.72, N 6.36; found: C 73.60, H 5.75, N 6.34.
Phosphole hydrochloride (R,R)-(+)-1a2·2HCl: Conc. HCl (50 mL) was
added to a solution of 1a2’ (5 mg, 0.011 mmol) in MeOH (0.5 mL). The
reaction mixture was stirred at RT for 1 h. The solvents were removed
under vacuum to give 1a2·2HCl as a yellow solid (total conversion).
[a]2D3 =+15.9, [f]2D3 =+75 (C=0.35, MeOH); 1H NMR (300 MHz,
MeOD): d=8.83 (s, 2H), 8.61 (t, J=7.7 Hz, 2H), 8.18 (t, J=7.5 Hz, 2H),
7.97 (t, J=6.6 Hz, 2H), 7.27–7.38 (m, 5H), 4.20 (m, 1H), 4.07 (m, 1H),
3.75–3.52 (m, 1H), 3.28 (m, 1H), 3.10 (m, 1H), 2.84–2.64 ppm (m, 1H);
13C{1H} NMR (75.46 MHz, MeOD, coupling constants not assigned): d=
146.7, 146.7, 142.5, 142.4, 140.4, 134.2, 133.9, 131.6, 131.6, 129.4, 129.3,
128.2, 128.1, 125.3, 125.2, 67.8, 67.7, 31.0, 30.9 ppm; 31P{1H} NMR
(81 MHz, MeOD): d=22.1 ppm; UV/Vis (MeOH, 3.6ꢃ10ꢀ5 m): l (e)=
361 nm (10800 nm); low CD values; HRMS (EI): m/z calcd for
C24H19OP: 382.1235 [MꢀH2O]+; found: 382.1237.
vents were freshly distilled under argon from sodium/benzophenone (tet-
rahydrofuran, diethyl ether) or from phosphorus pentoxide (pentane, di-
chloromethane). PPhBr2 was prepared as described in the literature.[47] Ir-
radiation reactions were conducted by using a Heraeus TQ 150 mercury
vapor lamp. Preparative separations were performed by gravity column
chromatography on basic alumina (Aldrich, Type 5016A, 150 mesh,
58 ꢂ) or silica gel (Merck Geduran 60, 0.063–0.200 mm) in 3.5–20 cm col-
umns. 1H, 13C, 31P, and 19F NMR spectra were recorded by using Bruker
1
AM300 and DPX200 spectrometers. H and 13C NMR chemical shifts are
reported in parts per million (ppm) relative to Me4Si as an external stan-
dard. 31P NMR downfield chemical shifts are expressed with a positive
sign relative to external 85% H3PO4 and are proton-decoupled. High-res-
olution mass spectra were obtained by using a Varian MAT 311 or a Zab-
Spec TOF Micromass instrument at CRMPO, University of Rennes 1.
CD specific rotations (in degcm2 gꢀ1) were measured in a 1 dm thermo-
stated quartz cell by using a Jasco-P1010 polarimeter. Circular dichroism
(in mꢀ1 cmꢀ1) was measured by using a Jasco J-815 circular dichroism
spectrometer. (R,R)-3a2 and triflate (R,R)-(ꢀ)-3a3 were prepared accord-
ing to the literature procedures.[30b,35a]
ACHTUNGTRENNUNG
CTHUNGTRENNUNG
10%), CuI (8 mg, 0.047 mmol, 10%), and Et3N (10 mL) were added to a
stirred solution of 2-bromopyridine (188 mL, 1.97 mmol) in anhydrous
THF (10 mL) at RT under argon. After 5 min, diyne (R,R)-3a2 (200 mg,
1.12 mmol) was added, and the resulting mixture was stirred overnight.
Evaporation of the solvents under vacuum and purification by column
chromatography on silica gel (eluent: heptane/EtOAc 3:2) afforded
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Chem. Eur. J. 2011, 17, 1337 – 1351

Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
2.91 (s, 4H), 2.77 (m, 2H), 2.66 (m,
2H), 2.26 (m, 2H), 1.86 (m, 2H), 1.71
(m, 2H), 1.39 (s, 6H), 1.21 (d, J=
5.6 Hz, 2H), 1.18 (d, J=5.6 Hz, 2H),
0.88 (m, 2H), 0.61 (s, 3H), 0.60 ppm
(s, 3H); 13C{1H} NMR (75.46 MHz,
CDCl3, coupling constants not as-
signed): d=154.1, 147.1, 146.7, 146.6,
145.6, 145.6, 144.0, 139.5, 133.6, 133.3,
128.4, 128.1, 128.0, 123.4, 123.2, 123.0,
122.9, 44.3, 40.09, 39.4, 32.8, 32.7, 31.8,
29.0, 28.8, 26.0, 23.2, 21.4 ppm;
31P{1H} NMR (122 MHz, CDCl3): d=
11.4 ppm; UV/Vis (CH2Cl2, 5.5ꢃ
10ꢀ5 m):
l (e)=384 nm (28000 nm);
CD (CH2Cl2, 5.6ꢃ10ꢀ4 m): l=417
(0.26), 326 (0.44), 298 (ꢀ0.6), 272
(0.66), 259 (1.35), 242 (ꢀ0.2), 223 nm
(4.3); elemental analysis calcd (%) for
C38H41N2P: C 81.98, H 7.42, N 5.03;
found: C 81.94, H 7.46, N 4.98.
2-Methoxy-6-[2-(naphthalen-2-yl)vi-
nyl]pyridine (3a4): nBuLi (1.6m,
1 equiv) in hexane (2.3 mL) was added
to a suspension of 2-methylnaphthyl-
triphenylphosphinium bromide (1.76 g,
3.64 mmol) in dry THF (30 mL) under
argon at ꢀ788C. Then the mixture was
warmed to room temperature and
stirred for 45 min. After cooling to
ꢀ788C, 2-methoxy-6-pyridinecarboxal-
dehyde (500 mg, 1 equiv) was added
dropwise. After addition was complet-
Figure 10. View of the stacking pattern of p-stacked metallocyclophane C4 in the crystal.
ed, the reaction mixture was warmed
to RT and stirred for 3 h. The reaction
mixture was filtered through Celite
Synthesis of bisACHTUNGTRENNUNG[(6R,8R)-5,6,7,8-tetrahydro-7,7-dimethyl-6,8-methanoiso-
quinolin-3-yl]-1,7-octadiyne ((ꢀ)-4a3):
A
mixture of triflate (ꢀ)-3a3
with CH2Cl2 and the solvent was removed under vacuum. The resulting
oily mixture was purified by column chromatography (silica gel, eluent:
heptane) to give 3a4 as a yellow oil (cis/trans mixture; yield 1.9 g, 76%).
1H NMR (200 MHz, CDCl3): d=7.97–7.70 (m, 6H), 7.58–7.38 (m, 5H),
7.28–7.20 (m, 1.3H), 6.95 (d, J=12.4 Hz, 1H), 6.83 (d, J=7.3 Hz, 1.3H),
6.70 (d, J=12.4 Hz, 1H), 6.60 (d, J=8.2 Hz, 1H), 4.09 (s, 1H; OCH3,
cis), 3.69 ppm (s, 3H; OCH3, trans); 13C{1H} NMR (50 MHz, CDCl3): d=
163.5 (C), 153.4 (C), 138.9 (CH), 138.4 (CH), 134.9 (C), 133.3 (C), 133,0
(CH), 132.6 (C), 132.3 (CH), 130.2 (CH), 128.3 (CH), 128.1 (CH), 128.0
(CH), 127.9 (CH), 127.7 (CH), 127.6 (2CH), 127.3 (CH), 127.1 (CH),
126.3 (C), 126.1 (CH), 125.9 (2CH), 123.7 (CH), 117.2 (CH), 115.8 (CH),
109.7 (CH), 109.3(C), 53.2 (CH3), 53.1 ppm (CH3); HRMS (EI): m/z
calcd for C18H15NO: 261.11536; found: 261.1150; elemental analysis calcd
(%) for C18H15NO: C 82.73, H 5.79, N 5.36; found: C 82.71, H 5.80, N
5.36.
(1.35 g, 4.2 mmol), 1,7-octadiyne (0.25 mL, 1.9 mmol), [PdCl2ACTHNUTRGEN(UNG PPh3)2]
(0.13 g, 0.19 mmol), CuI (22 mg, 0.12 mmol), and HNiPr2 (20 mL) was
stirred at RT for 3 d. HNiPr2 was removed under reduced pressure, and
the resulting solids were extracted with Et2O. The solvent was stripped
off, and the crude brown oil was subjected to chromatography (SiO2, hep-
tane/Et2O 1/1 to Et2O only) to give diyne (ꢀ)-4a3 as pale yellow solid
(yield 482.3 mg, 57%). M.p. 1358C: [a]2D3 =ꢀ71.5, [f]D23 =ꢀ320 (C=0.40,
CH2Cl2); 1H NMR (300 MHz, CDCl3): d=8.07 (s, 2H; H6 pyr), 7.19 (s,
2H; H3 pyr), 2.93 (d, J=2.6 Hz, 4H), 2.80 (t, J=5.5 Hz, 2H), 2.68 (dt,
J=9.5 Hz, 4.8 Hz, 2H), 2.50 (m, 4H), 2.28 (sept, J=2.9 Hz, 2H), 1.82
(quint, J=3.3 Hz, 4H), 1.40 (s, 6H), 1.18 (d, J=9.5 Hz, 2H), 0.62 ppm (s,
6H); 13C{1H} NMR (75 MHz, CDCl3): d=146.15 (CH), 144.59 (C),
141.68 (C),141.62 (C),126.14 (CH),88.87 (C), 81.02 (C),44.45 (CH), 39.93
(CH), 39.18 (C), 32.49 (CH2), 31.70 (CH2), 27.56 (CH2), 25.96 (CH3),
21.32 (CH3), 18.90 ppm (CH2); UV/Vis (CH2Cl2, 1.38ꢃ10ꢀ4 m): l (e)=293
(11100), 284 nm (12100 nm); CD (CH2Cl2, 1.38ꢃ10ꢀ4 m): l=308 (ꢀ0.8),
296 (3.5), 286 (3.1), 268 (5.6), 245 nm (ꢀ40.3); HRMS (EI): m/z calcd for
C32H36N2: 448.2878; found: 448.2885; elemental analysis calcd (%) for
C32H36N2: C 85.67, H 8.09, N 6.24; found: C 85.65, H 8.10, N 6.22.
3-MethoxynaphthoACTHNUTRGNEUNG
[1,2-f]quinoline (5a4): A mixture of cis- and trans-3a4
(350 mg, 1.34 mmol) in toluene (700 mL) and in the presence of catalytic
quantities of iodine was irradiated overnight with a 150 W mercury vapor
lamp. Then the solvent was removed under vaccum and the crude prod-
uct was purified over silica gel (eluent: heptane) to give 5a4 as a yellow
solid (yield 200 mg, 58%). 1H NMR (CDCl3, 200 MHz): d=9.26 (d, J=
9 Hz, 1H), 8.88 (d, J=8.3 Hz, 1H), 8.05–8.00 (m, 2H), 7.88–7.85 (m,
2H), 7.68 (t, J=7.1 Hz, 2H), 7.28 (s, 1H), 7.05 (d, J=9.2 Hz, 1H),
4.19 ppm (s, 3H; OCH3); 13C{1H} NMR (50 MHz, CDCl3): d=161.8 (C),
147.4 (C), 138.4 (CH), 133.5 (C), 130.51 (CH), 129.8 (C), 129.5 (C), 128.7
(CH), 127.6 (CH), 127.4 (C), 127.3 (CH), 126.8 (CH), 126.2 (CH), 126.1
(CH), 121.4 (C), 111.0 (CH), 53.5 ppm (CH3); HRMS (EI): m/z calcd for
C18H13NO: 259.09971; found: 259.0978; elemental analysis calcd (%) for
C18H13NO: C 83.37, H 5.05, N 5.40; found: C 83.38, H 5.04, N 5.42.
Phosphole (ꢀ)-1a3: A solution of nBuLi (2.5m) in hexane (1.0 mL,
2.5 mmol) was slowly added dropwise to a solution of [Cp2ZrCl2] (0.34 g,
1.2 mmol) in THF (25 mL) at ꢀ788C. The reaction mixture was stirred at
ꢀ308C for 1 h. Then, a solution of (ꢀ)-4a3 (0.50 g, 1.1 mmol) in 25 mL of
THF was slowly added at ꢀ788C. The solution was warmed to RT and
stirred for 1 d. Freshly distilled PhPBr2 (0.25 mL, 1.2 mmol) was added to
this solution at ꢀ508C, and the mixture was stirred for 3 h at RT. The so-
lution was then filtered through basic alumina under inert conditions and
the solvents removed under vacuum. Purification by column chromatog-
raphy (silica gel, eluent: pentane/diethyl ether 3:2) afforded phosphole
(ꢀ)-1a3 as a yellow solid (yield 422 mg, 69%). M.p. 1568C; [a]2D3 =ꢀ87,
NaphthoACHTUNGTRNEUNG
[1,2-f]quinolin-3(4H)-one (6a4): Compound 5a4 (650 mg,
2.5 mmol) was dissolved in acetonitrile (20 mL). Sodium iodide
(1.6 equiv, 600 mg) was then added to the solution followed by slow addi-
1
[f]2D3 =ꢀ484 (C 0.22, CH2Cl2); H NMR (300 MHz, CDCl3): d=8.13 (2H;
d, J=1.9 Hz), 7.34–7.39 (m, 2H), 7.05–7.11 (m, 3H), 3.21–3.43 (m, 2H),
Chem. Eur. J. 2011, 17, 1337 – 1351
ꢁ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
1347

J. Crassous, R. Rꢀau et al.
tion of trimethylsilyl chloride (1.6 equiv, 435 mg) and dropwise addition
of water (5 drops). The thick slurry was heated to 658C for 3 h, then the
reaction mixture was cooled to RT and water (10 mL) was added. The so-
lution was cooled to 08C and held for 1 h followed by vacuum filtration
to give 6a4 as a yellow solid, which was washed with cold ethyl acetate
and dried under vacuum (yield 500 mg, 80%). 1H NMR (DMSO,
200 MHz): d=12.23 (s, 1H), 8.97 (d, J=9.3 Hz, 1H), 8.71 (d, J=9.3 Hz,
1H), 8.12–8.08 (m, 2H), 7.87 (s, 2H), 7.73–7.70 (m, 2H), 7.63 (d, J=
8.6 Hz, 1H), 6.70 ppm (d, J=9.9 Hz, 1H); HRMS (EI): m/z calcd for
C17H11NO: 245.08406; found: 245.0842.
diffusion of pentane into a solution of the title compound in CH2Cl2/
MeOH, and were collected by suction and characterized by X-ray crystal-
lography (yield 94 mg, 81%). [a]2D3 =ꢀ19.0, [f]D23 =ꢀ460 (C=0.08,
CH2Cl2); UV/Vis (CH2Cl2, 4.45ꢃ10ꢀ5 m): l (e)=389 (15000), 289 nm
(38000 nm).
ꢀ
Supramolecular
rectangle
C3·4BF4
:
Cu
(CH3CN)4 BF4
(22 mg,
0.07 mmol) was added to a solution of chiral phosphole 1a3 (20 mg,
0.035 mmol) and dppm (14 mg, 0.035 mmol) in dry CH2Cl2 (10 mL).
After stirring for 1 h, 4,4’-dicyano-(E)-stilbene (8.2 mg, 0.035 mmol) was
added and the solution was stirred overnight. Yellow single crystals of
NaphthoACHTUNGTRENNUNG
[1,2-f]quinolin-3-yl trifluoromethanesulfonate (7a4): Quinoli-
ꢀ
C3·4BF4 were grown by vapor diffusion of pentane, collected by suction,
none 6a4 (250 mg, 1 mmol) was placed in a Schlenk tube under argon.
Dry CH2Cl2 and pyridine (246 mL, 3 equiv) were added and the reaction
mixture was cooled to 08C. Triflic anhydride (171 mL, 1.5 equiv) was
added slowly and the reaction was warmed to RT overnight. The solution
was washed with a saturated solution of NaHCO3 and then brine, dried
over MgSO4, and concentrated in vacuo to give 7a4 as a pale yellow oil
(yield 260 mg, 65%). The crude product was used without purification in
and characterized by X-ray crystallography (yield 44 mg, 84%). [a]D23
=
+6.1, [f]2D3 =+180 (C=0.13, CH2Cl2); UV/Vis (CH2Cl2, 5.5ꢃ10ꢀ5 m): l
(e)=390 (40000), 273 nm (150000 nm).
ꢀ
Supramolecular rectangle C4·4BF4
:
CuACHTNGUTERN(NUG CH3CN)4 BF4 (15.5 mg,
0.04 mmol) was added to a solution of 1a4 (15 mg, 0.02 mmol) and dppm
(8.6 mg, 0.04 mmol) in dry CH2Cl2 (5 mL) and the reaction mixture
stirred for 1 h. 4,4’-Dicyano-(E)-stilbene (9.2 mg, 0.04 mmol) was then
added and the solution was stirred overnight. A few drops of methanol
1
the following Sonogashira coupling. H NMR (200 MHz, CDCl3): d=9.35
ꢀ
were added to the solution; red single crystals of C4·4BF4 were obtained
(d, J=9 Hz, 1H), 8.67–8.64 (m, 1H), 8.05–7.97 (m, 3H), 7.92 (d, J=
8.5 Hz, 1H), 7.75 (d, J=8.3 Hz, 1H), 7.70–7.65 (m, 2H), 7.33 ppm (d, J=
9 Hz, 1H); 13C{1H} NMR (75.43 MHz, CDCl3): d=152.9 (C), 147.0 (C),
140.9 (CH), 133.5 (C), 132.5 (CH), 131.1 (C), 129.5 (C), 129.0 (CH),
128.9 (CH), 127.5 (CH), 126.9 (C), 126.3 (C), 126.0 (C), 125.0 (C),
111.7 ppm (CH); 19F NMR (188 MHz, CDCl3): d=ꢀ73.5 ppm.
by slow vapor diffusion of pentane, collected by suction, and character-
ized by X-ray crystallography (yield 58 mg, 92%). UV/Vis (CH2Cl2, 2.8ꢃ
10ꢀ5 m): l (e)=383 (5900), 537 (8800), 471 (15000), 402 (24900), 301 nm
(79000 nm).
X-ray crystallography: Single crystals suitable for X-ray crystal analysis
were obtained by slow diffusion of pentane vapor into solutions of supra-
molecular assemblies C2, C3, and C4 in CH2Cl2 or CH2Cl2/MeOH at RT.
Single crystals of phosphole 1a2·2HCl suitable for X-ray crystal analysis
were obtained by slow evaporation of 1a2·2HCl in water. Single-crystal
data were collected at 100 K by using an APEX II Bruker-AXS (Centre
de Diffractomꢀtrie, Universitꢀ de Rennes 1, France) with MoKa radiation
(l=0.71073 ꢂ). Reflections were indexed, subjected to Lorentzian/polar-
ization corrections, and integrated by using the DENZO program of the
KappaCCD software package. The data-merging process was performed
by using the SCALEPACK program.[43] Structure determinations were
performed by using direct methods with SIR97,[44] which revealed all
non-hydrogen atoms. The SHELXL program[45] was used to refine the
structures by full-matrix least-squares methods based on F2. All non-hy-
drogen atoms were refined with anisotropic displacement parameters.
Hydrogen atoms were included in idealized positions and refined with
isotropic displacement parameters. Table 6 lists the crystallographic data
for 1a2·2HCl. In the crystal lattices of the supramolecular rectangles
C2·4BF4ꢀ, C3·4BF4ꢀ, and C4·4BF4ꢀ, CH2Cl2 solvent molecules were found
in addition to the cationic supramolecular assemblies and their counter-
ions. These solvent molecules in most cases have a strong tendency to
leave the bulk crystal by evaporation once the crystals are removed from
the mother liquor, a process that induces rapid degradation of the single-
crystal integrity of the investigated crystals. To slow down this process,
single crystals of all these compounds were always coated with Paratone
oil once removed from the mother liquor and mounted at low tempera-
ture (100 K) as quickly as possible on the diffractometer goniometer, and
X-ray data were collected at low temperature (100 K). In most cases, X-
ray crystal structure resolution revealed that these solvent molecules
occupy an important volume of the crystal cell and are highly disordered.
Modeling of these disorders was not possible and we applied a squeeze
treatment to remove the scattering contribution of these molecules that
cannot be satisfactorily modeled. In these cases, anisotropic displacement
parameters associated with the atoms of the cationic coordination com-
1,8-Di
3 equiv) and then 1,7-octadiyne (140 mg, 1.1 equiv) were added to a solu-
tion of 7a4 (380 mg, 1.01 mmol), [Pd
2A(dba)3] (46 mg, 5 mol%), and PPh3
ACHTUNGTRENNUNG(naphthoACHTUNGTRENNUNG
[1,2-f]quinolin-3-yl)octa-1,7-diyne (4a4): HNiPr2 (430 mL,
CTHUNGTRENNUNG
(53 mg, 20 mol%) in THF (15 mL) under argon. The reaction mixture
was stirred for 3 d at 308C under argon, then the solution was washed
with water and brine. Organic phases were collected and precipitated
with Et2O. After filtration, 4a4 was obtained as a yellow solid (yield
310 mg, 55%). M.p. 1708C; 1H NMR (300 MHz, CDCl3): d=9.32 (d, J=
8.7 Hz, 2H), 8.94 (d, J=8.3 Hz, 2H), 8.16 (d, J=9 Hz, 2H), 8.09–8.05 (m,
4H), 7.96 (d, J=8.3 Hz, 2H), 7.87 (d, J=8.7 Hz, 2H), 7.75–7.62 (m, 6H),
2.72–2.66 (m, 4H), 2.03–1.97 ppm (m, 4H); 13C{1H} NMR (50 MHz,
CDCl3): d=148.2 (C), 142.6 (C), 137.5 (C), 135.5 (CH), 133.5 (C), 131.1
(CH), 131.0 (C), 130.0 (C), 128.8 (C), 128.4 (CH), 128.3 (CH), 127.3
(CH), 126.7 (CH), 126.6 (CH), 126.4 (CH), 124.7 (C), 124.2 (C), 123.5
ꢂ
ꢂ
ꢂ
ꢂ
(CH), 91.6 (C CCH2), 81.2 (C CCH2), 27.6 (C CCH2), 19.1 ppm (C
CCH2CH2); HRMS (EI): m/z calcd for C42H28N2Na: 583.21502; found:
583.2155; elemental analysis calcd (%) for C42H28N2: C 89.97, H 5.03, N
5.00; found: C 89.95, H 5.06, N 4.97.
BisACHTUNGTRENNUNG{2,5-ACHTUNGTRENNUNG(naphthoACHTUNGTRENNUNG
[1,2-f]quinolin-3-yl)}phosphole (1a4): Diyne 4a4 (100 mg,
0.18 mmol) and [Cp2ZrCl2] (53 mg, 1 equiv) were placed in a Schlenk
tube and rigorously dried under vacuum before argon was added. THF
(10 mL) was added and the solution cooled to ꢀ788C. Then nBuLi (1.6m
in hexane, 276 mL, 2.4 equiv) was added dropwise and the resulting solu-
tion was stirred at ꢀ788C for 10 min, heated at 408C overnight, and then
recooled to ꢀ788C. PhPBr2 (41 mL, 1.1 equiv) was added dropwise, and
the resulting solution was stirred at RT for 6 h. The reaction mixture was
filtered over aluminum oxide and washed with THF. After evaporation
of the solvent, the product was filtered again over aluminum oxide with
CH2Cl2 as eluent (Rf =0.8). After evaporation of the solvent, 1a4 was ob-
tained as a light yellow solid (yield 60 mg, 50%). M.p. 1588C; 1H NMR
(300 MHz, CD2Cl2): d=9.32 (d, J=8.7 Hz, 2H), 8.98 (d, J=8.3 Hz, 2H),
8.20–8.1 (m, 6H), 8.00–7.90 (m, 6H), 7.80–7.60 (m, 6H), 7.40–7.30 (m,
1H), 7.20–7.10 (m, 3H), 3.80–3.60 (m, 2H), 3.30–3.10 (m, 2H), 2.20–
1.80 ppm (m, 4H); 31P{1H} NMR (81 MHz, CDCl3): d=12.3 ppm; UV/
Vis (CH2Cl2, 5.2ꢃ10ꢀ5 m): l (e)=288 (45000), 432 nm (18000 nm); ele-
mental analysis calcd (%) for C48H33N2P: C 86.21, H 4.97, N 4.19; found:
ꢀ
plexes are always satisfactory. In addition, in the case of C3·4BF4 the
2
central double bond of the ditopic connector Lp is disordered over two
statistically equal positions. Modeling of the resulting disorder was not
possible for the atoms of the neighboring phenyl rings. As a consequence,
some of these atoms have rather high anisotropic displacement parame-
ters. Table 6 gives the crystallographic data for C2·4BF4ꢀ, C3·4BF4ꢀ, and
C 86.20, H 5.04, N 4.13.
ꢀ
Supramolecular rectangle C2·4BF4
:
CuACHTNGUTERN(NUG CH3CN)4 BF4 (60.6 mg,
0.17 mmol) was added to a solution of 1a2 (38.8 mg, 0.09 mmol) and bis-
(diphenylphosphino)methane (dppm, 33.8 mg, 0.09 mmol) in dry CH2Cl2
ꢀ
A
C4·4BF4 after squeeze treatment. Table S1 (Supporting Information)
ꢀ
(20 mL) and the reaction mixture stirred for 1 h at RT. Then 1,4-dicyano-
benzene (57 mg, 0.44 mmol) was added and the reaction mixture was
gives the crystallographic data for C2·4BF4ꢀ, C3·4BF4ꢀ, and C4·4BF4
before squeeze treatment. Atomic scattering factors for all atoms were
ꢀ
stirred overnight. Yellow single crystals of C2·4BF4 were grown by slow
taken from International Tables for X-ray Crystallography.[46]
1348
www.chemeurj.org
ꢁ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2011, 17, 1337 – 1351

Supramolecular [2,2]Paracyclophane Analogues
FULL PAPER
Table 6. Crystal data and structure refinement for chiral bis(2-pyridyl)phospholes (R,R)-1a2·2HCl and supra-
[3] P.-H. Leung, Acc. Chem. Res.
2004, 37, 169–177.
molecular assemblies C2–4
.
[4] F. Mathey, Acc. Chem. Res. 2004,
37, 954–960.
G
C2·4BF4
C3·4BF4
C4·4BF4
[5] See: R. Rꢀau, P. Dyer, in Com-
prehensive Heterocyclic Chemistry
III, Vol. 3 (Eds.: A. R. Katritzky,
C. A. Ramsden, E. F. V. Scriven,
R. J. K. Taylor), Elsevier, Oxford,
2008, pp. 1029–1148, and referen-
ces therein.
[6] a) C. Mꢆller, D. Vogt, Dalton
Trans. 2007, 47, 5505–5523; b) P.
Le Floch, Coord. Chem. Rev.
2006, 250, 627–681.
[7] a) H.-C. Su, O. Fadhel, C.-J.
Yang, T.-Y. Cho, C. Fave, M.
Hissler, C.-C. Wu, R. Rꢀau, J.
Am. Chem. Soc. 2006, 128, 983–
995; b) M. Sebastian, M. Hissler,
C. Fave, J. Rault-Berthelot, C.
Odin, R. Rꢀau, Angew. Chem.
2006, 118, 6298–6301; Angew.
Chem. Int. Ed. 2006, 45, 6152–
6155; c) V. Lemau de Talancꢀ, M.
Hissler, L.-Z. Zhang, T. Kꢅrpꢅti,
L. Nyulꢅszi, D. Caras-Quintero, P.
formula
Mr
crystal system
space group
crystal size [mm]
a [ꢂ]
b [ꢂ]
c [ꢂ]
a [8]
b [8]
C48H46Cl4N4O5P2 C114H94B4Cu4F16N8O4P6 C158H146B4Cu4F16N8P6 C178H130B4Cu4F16N8P6
962.63
monoclinic
P21
2427.19
monoclinic
P21
2944.05
monoclinic
P21
3168.12
tetragonal
I41/a
0.30ꢃ0.24ꢃ0.16 0.2ꢃ0.1ꢃ0.05
0.2ꢃ0.1ꢃ0.03
13.502(1)
44.019(4)
14.354(2)
90
0.3ꢃ0.2ꢃ0.1
30.4676(12)
30.4676
38.5691(18)
90
8.138(1)
13.290(2)
21.647(2)
90
11.571(1)
36.691(3)
14.087(1)
90
98.044(5)
90
111.587(4)
90
108.585(3)
90
90
90
g [8]
V [ꢂ3]
Z
2318.2(5)
2
5561(1)
2
3556(2)
2
35803.2(21)
8
1calcd [Mgmꢀ3
T [K]
]
1.628
1.449
1.209
1.176
100(2)
100(2)
100(2)
100(2)
l
A
0.71069
0.376
0.71069
0.924
0.71069
0.645
0.71073
0.588
m
A
]
F
A
1000
2472
3040
12992
q limit [8]
index ranges
0.95–26.48
ꢀ10ꢄhꢄ8
ꢀ16ꢄkꢄ16
ꢀ20ꢄlꢄ27
11647
1.55–26.44
ꢀ14ꢄhꢄ14
ꢀ45ꢄkꢄ37
ꢀ16ꢄlꢄ17
37280
0.93–27.53
ꢀ16ꢄhꢄ17
ꢀ54ꢄkꢄ57
ꢀ18ꢄlꢄ18
60122
2.99–26.36
ꢀ38ꢄhꢄ23
ꢀ38ꢄkꢄ38
ꢀ48ꢄlꢄ28
166846
18212
reflns collected
independent reflns
reflns [I>2s(I)]
data/restraints/
parameters
Bꢇuerle,
R.
Rꢀau,
Chem.
7845
21174
35725
Commun. 2008, 19, 2200–2202;
d) Y. Matano, T. Miyajima, T. Fu-
kushima, H. Kaji, Y. Kimura, H.
Imahori, Chem. Eur. J. 2008, 14,
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14080
12509
24866
6741
7845/1/569
21174/0/1391
35725/1/1798
18212/0/973
GOF on F2
final R indices
[I>2s(I)]
1.114
0.978
0.937
0.894
R1 =0.0728
wR2 =0.1641
R1 =0.0937
wR2 =0.1898
0.00
R1 =0.0708
wR2 =0.1665
R1 =0.1256
wR2 =0.1868
0.079(15)
R1 =0.0584
wR2 =0.1350
R1 =0.0871
wR2 =0.1463
0.00
R1 =0.0831
wR2 =0.2047
R1 =0.1978
wR2 =0.2491
–
Miyajima,
H.
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R indices (all data)
absolute structure
parameter
largest diff. peak,
1.216, ꢀ0.488
0.845, ꢀ0.694
0.518, ꢀ0.585
0.724, ꢀ0.527
hole [eꢂꢀ3
]
CCDC 779867 (1a2·2HCl), 779868 (C2·4BF4ꢀ), 779869 (C3·4BF4ꢀ), and
779870 (C4·4BF4ꢀ) contain the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
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Acknowledgements
This work is supported by theMinistꢄre de l’Education Nationale, de la
Recherche et de la Technologie, the Centre National de la Recherche
Scientifique (CNRS), the Rꢀgion Bretagne, and the Agence Nationale de
la Recherche (ANR) (project PHOSHELIX-137104).
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Supramolecular [2,2]Paracyclophane Analogues
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Received: September 10, 2010
Published online: December 7, 2010
Chem. Eur. J. 2011, 17, 1337 – 1351
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www.chemeurj.org
1351