Supramolecular networks of a H-shaped aromatic phenol host

Article abstract of DOI:10.1039/b9nj00234k

X-Ray crystal structures of 1,4-di[bis(hydroxyphenyl)methyl]benzene and its solvates and cocrystals were analyzed for the occurrence of network architectures. From the simplest 1D ladder in EtOAc, DMSO and i-PrOH solvates of 1 (R₁ = R₂

Full text of DOI:10.1039/b9nj00234k

View Article Online / Journal Homepage / Table of Contents for this issue
New Journal of Chemistry
An international journal of the chemical sciences
www.rsc.org/njc
Volume 34 | Number 4 | April 2010 | Pages 573–768
ISSN 1144-0546
PAPER
Ashwini Nangia et al.
Supramolecular networks of a
H-shaped aromatic phenol host
1144-0546(2010)34:4;1-O

View Article Online
PAPER
www.rsc.org/njc | New Journal of Chemistry
Supramolecular networks of a H-shaped aromatic phenol hostw
Ranjit Thakuria, Bipul Sarma and Ashwini Nangia*
Received (in Montpellier, France) 2nd June 2009, Accepted 5th October 2009
First published as an Advance Article on the web 23rd November 2009
DOI: 10.1039/b9nj00234k
X-Ray crystal structures of 1,4-di[bis(hydroxyphenyl)methyl]benzene and its solvates and
cocrystals were analyzed for the occurrence of network architectures. From the simplest 1D
ladder in EtOAc, DMSO and i-PrOH solvates of 1 (R1 = R2 = R4 = H, R3 = OH), doubly-
interpenetrated 1D ladders in its guest-free form and 1D/2D-interpenetrated ladder networks in a
cocrystal with phenazine were identified. The dioxane and DMSO solvates of 2 (R1 = R3 = OMe,
R2 = OH, R4 = H), and the DMSO and toluene solvates of 4 (R1 = H, R2 = R4 = Me,
R3 = OH) also adopt 1D ladder networks. Monomethyl phenol 3 (R1 = R2 = H, R3 = OH,
R4 = Me) makes 2D grids of ladders that include nitromethane solvent in the channels. The
hexagonal (6,3) net in the cocrystal of 1 with pyrazine-N,N0-dioxide is triply-interpenetrated in a
2D architecture. The DMF solvate of 3 is similar to 1ꢀ(PyzNO)2, except that the (6,3) nets are
doubly-interpenetrated via Hopf links. An orthorhombic nitromethane solvate of 1 is 2D - 3D
polycatenated with a degree of catenation (DOC) = 2/2, whereas the monoclinic polymorph
of 1ꢀ(CH3NO2)2, as well as the chloroform inclusion structure of 4, adopt the rare (5,34) pentagonal
net. Platonic (6,3) and Catalan (5,34) nets in the broader category of a uniform network topology
were realized from H-shaped molecules 1–4 in different solvent inclusion and cocrystal structures.
Finally, a cocrystal of 1 with quinoxaline forms a polyrotaxane 1D - 1D chain of Euclidean
entanglement. Polythreaded rotaxane, pentagonal Catalan and 1D/2D interpenetrated nets are,
as such, rare in organic molecular crystals. The role of the solvent/co-former in affording diverse
supramolecular networks and entanglement modes are rationalized in the crystal structures.
crystal structures can be topologically classified akin to
Introduction
inorganic and coordination network structures.1d,1e,1h,4 Recent
literature1,2,4 indicates that the number and diversity of net-
work topologies in organic structures is not as prolific com-
pared to those formed in metal–organic coordination
polymers. The classification of crystal structures as networks
is a first step to establishing topological similarities between
architectures built from organic, inorganic or metal–organic
building units, which is an important activity in crystal
engineering, with applications in materials science. Here, we
present new examples of rare network topologies and inter-
penetration/catenation modes of organic supramolecular
architectures built from a H-shaped tecton.
Network architectures are common in inorganic structures,
minerals, metal–organic compounds and coordination polymers.1
Robson, Batten, Ciani, Carlucci and Proserpio have reviewed2
recent examples of polycatenation, polythreading and poly-
knotting in coordination structures. Carlucci et al.3 distin-
guished interpenetration from catenation, in that the former
type of entanglement involves no change in the dimensionality
of the original 2D or 3D nets, whereas the latter entanglement
type increases the overall dimensionality of 1D or 2D compo-
nents to a higher level. In contrast, Batten and Robson1c,2c
refer to both situations as interpenetration, albeit of
different types.
In general, the classification of organic crystal structures as
nets is a recent and less common trend; the similarity of the
rhombohedral hydroquinone structure (b-polymorph) to b-
polonium being a classic example. The fact that hydrogen
bonds are weaker and less directional than metal–heteroatom
and metal–ligand bonds means that the geometry of organic
structures is not as clearly definable as that at the metal center
of coordination compounds and polymers. Even though
hydrogen bond directionality has an angular spread, organic
Results
1,4-Di[bis(40-hydroxyphenyl)methyl]benzene (1) and its methoxy
and methyl derivatives 2–4 were prepared by the acid-catalyzed
condensation of terephthaldehyde with the requisite phenol
(4 equiv.).5 All compounds were purified and characterized
by their NMR and IR spectra. These molecules may be viewed
as having a para-substituted phenyl linker that connects
bis(hydroxylphenyl)methyl groups on the two sides for dir-
ected self-assembly (Fig. 1(a)). The peripheral O atoms that
engage in hydrogen bonding and their connectivity to the
carbon core via tetrahedral C atoms are considered to define
the H-shape of prototype molecule 1. The fact that the
connecting carbon centers are sp2 or sp3 hybridized and have
angles that are far from the idealized 1801 and 901 is not
School of Chemistry, University of Hyderabad, Hyderabad 500 046,
India. E-mail: ashwini.nangia@gmail.com
w Electronic supplementary information (ESI) available: Crystal pack-
ing diagrams and DSC/TGA plots. CCDC reference numbers
717784–717798. For crystallographic data in CIF or other electronic
format see DOI: 10.1039/b9nj00234k
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 623

View Article Online
Y- and T-shaped organic tectons,1e,1i,1j,4,7 L-shaped8 molecules,
and V-shaped9 molecular tweezers. The significant literature on
metal–ligand building blocks for assembling supramolecular
networks of coordination compounds and infinite polymers,
which is somewhat outside the scope of this article, is reviewed
elsewhere.1e,1g,2,10 H-shaped organic pentiptycene functional
molecules11a and an Mo–Au phosphinidene complex11b are
known, but these structures are not in the host–guest or
cocrystal network category. H-shaped tetraphenol host 1 is,
as such, a new tecton in organic nets with only two short papers
having been published by our group.5,12 Here, we present
network diversity in the solvates and cocrystals of 1–4. When
the guest species is a typical solvent, the binary adduct is
referred to as a solvate, and if the second component is a solid
co-former then the product is generally called a cocrystal.
Although ‘‘solvate’’ and ‘‘cocrystal’’ have slightly different
meanings, both terms are used within the broader category of
multi-component crystal structures.13 Network structures are
described in the order of 1D ladders6a,14 to interpenetrated
ladders to 2D hexagonal sheets15 to polycatenated 3D frame-
works to Catalan (5,34)12 and polyrotaxane16 nets.
Crystallization of 1 from EtOAc gave solvated crystal
ꢀ
1ꢀ(EtOAc)2 in the space group P1 with half a molecule of 1
in the crystallographic unit due to the imposed inversion
symmetry. The host molecules form a 1D ladder network
through phenol O–Hꢀ ꢀ ꢀO hydrogen bonds (O1–H1ꢀ ꢀ ꢀO2
1.78 A, 1651; Table 1) and the EtOAc molecules are connected
on the sides (O2–H2Aꢀ ꢀ ꢀO4 1.75 A, 1731). Adjacent layers of
host and guest molecules are offset in such a way that the
ladder rung region (cavity dimensions are given in Table 2)
is sandwiched between guest molecules of adjacent layers. In
1ꢀ(DMSO)2 solvate (monoclinic space group P21/c, half
molecule of 1), the solvent molecule acts as a connector to
convergently direct OH groups of the host via O–Hꢀ ꢀ ꢀO
hydrogen bonds (O2–H2Aꢀ ꢀ ꢀO3, 1.74 A, 1711; O1–H1Aꢀ ꢀ ꢀO3,
1.69 A, 1721). The difference in the O–Hꢀ ꢀ ꢀO bonds between
the two structures (Fig. 2) is attributed to the stronger hydro-
gen bond acceptor basicity of DMSO compared to EtOAc
(pKHB scale: SQO 2.58, CQO 1.00).17 DMSO acts as a dual
acceptor of hydrogen bonds from two host molecules and
becomes part of the ladder network, whereas EtOAc is a single
hydrogen bond acceptor from the host ladder. The i-PrOH
solvate 1ꢀ(i-PrOH)4 (pKHB Osp3 0.82) is similar to the EtOAc
structure. However, a difference between the EtOAc and
i-PrOH solvent molecules is that the former behaves as a
terminal acceptor whereas the latter is a connector of host
ladder nets via helical O–Hꢀ ꢀ ꢀO trimers (Fig. S1, ESIw). There
is a half molecule of 1 and two i-PrOH molecules in the unit
cell of 1ꢀ(i-PrOH)4, of which one disordered guest molecule
was removed using the SQUEEZE program (see the Experi-
mental section). Small solvent molecules reside in the ladder
rung regions to give a close-packed crystal structure (see
Fig. S2 for more examples, ESIw).
Fig. 1 (a) Molecules 1–4 used for network construction in this paper.
The phenol OH groups are oriented outward to form hydrogen bond
networks. (b) The H-shape of the molecular core of 1 is realized by
connecting the phenol O atoms and the central para-phenyl linker C
atoms. (c) The # atoms that make up the H-shape are nearly coplanar,
deviating from the mean plane by 0.49, 0.58 and 0.86 A. Molecule 1 is
extracted from its MeOH solvate structure (ref. 5).
relevant. What is important is that the mean plane of the phenol
O and para-phenyl linker C atoms (marked # in Fig. 1(b))
are nearly coplanar (Fig. 1(c), deviation from the mean plane
o 1 A) and make an idealized H-shape. The importance of
tetraphenol hosts was emphasized by Aoyama’s group as a new
class of organic zeolites in the inclusion structures of 5 and its
derivatives.6 H-shaped organic molecular tectons are, as such,
rare to our knowledge, even though there are examples of
A half molecule of 1–4 is present in the unit cell of solvates,
cocrystals and guest-free forms that crystallize in space groups
with an inversion center, the only exception being the 1ꢀ(4,40-
BipyNO)2 cocrystal with the space group Pca21. Octamethoxy
derivative 2 gave crystalline solvate 2ꢀ(dioxane)2 with the space
ꢀ
group P1, whose 1D ladder network is structurally similar to
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
624 | New J. Chem., 2010, 34, 623–636

View Article Online
Table 1 Hydrogen bonds in the crystal structures of 1–4
Compound
Interaction
Hꢀ ꢀ ꢀA/A
Dꢀ ꢀ ꢀA/A
D-Hꢀ ꢀ ꢀA (1)
Symmetry code
1
O1–H1Aꢀ ꢀ ꢀO3
O2–H2Aꢀ ꢀ ꢀO1
O3–H3Aꢀ ꢀ ꢀO4
C16–H16ꢀ ꢀ ꢀO2
C22–H22ꢀ ꢀ ꢀO2
O1–H1Aꢀ ꢀ ꢀO3
O2–H2Aꢀ ꢀ ꢀO3
C18–H18Aꢀ ꢀ ꢀO2
O1–H1ꢀ ꢀ ꢀO2
1.76
1.82
1.72
2.45
2.46
1.69
1.74
2.32
1.78
1.75
2.36
1.66
1.61
1.74
1.64
1.64
1.71
1.84
2.43
2.41
1.81
1.78
1.99
1.92
2.33
1.72
1.78
2.30
2.23
1.86
1.84
2.40
1.94
2.06
2.49
2.49
1.96
1.72
2.36
2.43
1.77
2.40
1.75
1.87
2.33
1.80
1.96
2.40
2.47
2.44
2.06
2.729(4)
2.789(4)
2.683(5)
3.512(5)
3.389(5)
2.663(3)
2.711(3)
3.400(6)
2.742(1)
2.725(1)
3.426(2)
2.629(3)
2.588(3)
2.715(3)
2.611(8)
2.423(11)
2.682(8)
2.641(8)
3.513(11)
3.478(11)
2.791(3)
2.739(3)
2.950(4)
2.848(3)
3.353(7)
2.669(2)
2.757(3)
3.328(3)
3.283(3)
2.826(4)
2.816(4)
3.477(5)
2.880(5)
2.867(5)
3.404(6)
3.350(6)
2.744(3)
2.653(4)
3.387(4)
3.355(5)
2.750(3)
3.365(3)
2.724(3)
2.789(3)
3.267(3)
2.723(5)
2.875(6)
3.280(7)
3.233(7)
3.476(7)
2.935(3)
168
167
165
167
143
172
171
173
165
173
166
167
171
170
169
133
168
136
179
168
179
166
165
156
157
161
170
157
164
169
173
172
159
138
142
135
135
156
157
142
176
148
171
155
158
155
155
137
126
159
147
1 ꢂ x, 2 ꢂ y, 1 ꢂ z
x, ꢂ1 + y, z
x, 1 + y, z
1 ꢂ x, 1 ꢂ y, ꢂz
ꢂ1 + x, y, z
1ꢀ(DMSO)2
1 + x, ꢂ1 + y, z
x, ꢂ1 + y, z
1
1
2
ꢂx, + y, ꢂ z
2
x, y, 1 + z
1ꢀ(EtOAc)2
O2–H2Aꢀ ꢀ ꢀO4
C16–H16ꢀ ꢀ ꢀO3
O1–H1ꢀ ꢀ ꢀO2
1 ꢂ x, 1 ꢂ y, ꢂz
a
—
x, ꢂy, ꢂ + z
1
1ꢀ(i-PrOH)4
2
1
O2–H2Aꢀ ꢀ ꢀO3
O3–H3Aꢀ ꢀ ꢀO1
O1–H1Aꢀ ꢀ ꢀO5
O2–H2Aꢀ ꢀ ꢀO6
O3–H3Aꢀ ꢀ ꢀO8
O4–H4Aꢀ ꢀ ꢀO7
C37–H37ꢀ ꢀ ꢀO6
C52–H52ꢀ ꢀ ꢀO7
O1–H1Aꢀ ꢀ ꢀO2
O2–H2Aꢀ ꢀ ꢀN2
O3–H3Aꢀ ꢀ ꢀN1
O4–H4ꢀ ꢀ ꢀO3
x, 1 ꢂ y, + z
2
a
—
x, ꢂ1 + y, z
1ꢀ(4,40-BipyNO)2
1
ꢂx, ꢂy, ꢂ + z
2
1
1
2
ꢂ x, 1 + y, ꢂ + z
2
x, 1 + y, z
1
+ x, 1 ꢂ y, z
2
1
+ x, ꢂy, z
2
1ꢀ(Phez)1.5
x, ꢂ1 + y, z
1 + x, 1 + y, z
—
a
x, ꢂ1 + y, z
C43–H43ꢀ ꢀ ꢀO4
O1–H1Aꢀ ꢀ ꢀO4
O2–H2Aꢀ ꢀ ꢀO3
C19–H19ꢀ ꢀ ꢀO2
C20–H20ꢀ ꢀ ꢀO1
O1–H1Aꢀ ꢀ ꢀN1
O2–H2Aꢀ ꢀ ꢀN2
C22–H22ꢀ ꢀ ꢀO2
O2–H2ꢀ ꢀ ꢀO5
1 ꢂ x, ꢂy, 1 ꢂz
1 + x, 1 + y, z
1ꢀ(PyzNO)2
3
2
1
2
x, ꢂ y, ꢂ + z
1
2
1
2
ꢂx, ꢂ + y, ꢂ z
3
1
ꢂ1 + x, ꢂ y, + z
2
2
1ꢀ(Quinox)2
2ꢀ(dioxane)2
1 + x, y, ꢂ1 + z
1 ꢂ x, ꢂy, ꢂz
1
2
1
2
x, ꢂ y, + z
x, ꢂ1 + y, z
a
O5–H5ꢀ ꢀ ꢀO7
—
C19–H19Bꢀ ꢀ ꢀO1
C20–H20Bꢀ ꢀ ꢀO6
O2–H2ꢀ ꢀ ꢀO5
1 ꢂ x, 1 ꢂ y, ꢂz
1 ꢂ x, 2 ꢂ y, 1 ꢂ z
1 + x, y, z
2ꢀ(DMSO)2
O5–H3ꢀ ꢀ ꢀO7
ꢂ1 + x, y, ꢂ1 + z
3
1
2
C6–H6ꢀ ꢀ ꢀO4
1 + x, ꢂ y, + z
2
x, y, 1 + z
C21–H21Cꢀ ꢀ ꢀO3
O1–H1Aꢀ ꢀ ꢀO2
C13–H13ꢀ ꢀ ꢀO1
O1–H1Aꢀ ꢀ ꢀO2
O2–H2Aꢀ ꢀ ꢀO1
O1–H1ꢀ ꢀ ꢀO1
1
3
2
1
2
3ꢀ(DMF)2
+ x, ꢂ y, + z
2
1
1 3
2
ꢂ x, + y, ꢂ z
2
2
3ꢀ(CH3NO2)2
1 ꢂ x, ꢂy, ꢂz
x, ꢂ1 + y, z
1
1
4
ꢂx, ꢂ + y, ꢂ z
2
2
4ꢀ(DMSO)2
O1–H1ꢀ ꢀ ꢀO3
ꢂ1 + x, 1 + y, z
O2–H2ꢀ ꢀ ꢀO1
1 + x, y, z
C17–H17Aꢀ ꢀ ꢀO2
C18–H18Cꢀ ꢀ ꢀO3
C22–H22Aꢀ ꢀ ꢀO3
O2–H2ꢀ ꢀ ꢀO1
ꢂ1 + x, y, z
ꢂ1 + x, 1 + y, z
2 ꢂ x, ꢂy, ꢂz
x, 1 + y, ꢂ1 + z
4ꢀ(toluene)
a
Hostꢀ ꢀ ꢀguest interaction.
1ꢀ(EtOAc)2. Adjacent ladders are connected via dioxane
(O5–H5ꢀ ꢀ ꢀO7 2.06 A, 1381) to give a 2D sheet structure. A
second guest molecule (O8 dioxane) fills the space in the
channel framework (Fig. 3(a)). There are two crystallographi-
cally distinct solvent molecules, both residing on inversion
centers: O7 and O8 dioxane molecules are disordered over two
positions, with disorder being modelled in both cases. Com-
pound 3, on crystallization from nitromethane, afforded a host
ladder network structure (Fig. 3(b)) similar to the 4ꢀ
(CH3NO2)2 solvate, which extends into a 2D sheet through
O–Hꢀ ꢀ ꢀO hydrogen bonds. A guest-free form of 4 was crystal-
lized from dichloromethane, but this crystal structure (Fig. S3,
ESIw) cannot be classified as a net.
A guest-free form of 1 was obtained upon crystallization
ꢀ
from CH3NO2 in the space group P1 with two half molecules in
the asymmetric unit (Z0 = 2), a situation that arises in crystal
structures where the molecule has a packing problem.7a,18
1D ladder networks sustained by O–Hꢀ ꢀ ꢀO hydrogen bonds
(O1–H1Aꢀ ꢀ ꢀO3, 1.76 A, 1681; O2–H2Aꢀ ꢀ ꢀO1, 1.82 A, 1671;
O3–H3Aꢀ ꢀ ꢀO4, 1.72 A, 1651) run along [010]. Two such
networks are inclined at an angle of 73.61 and interpenetrate
such that the para-phenyl connectors of the second ladder
weave through the rectangular rungs of the first (Fig. 4).
Compound 1 and phenazine (Phez) afforded cocrystal
1ꢀ(Phez)1.5, with one full and one half molecule of phenazine
ꢀ
and two half molecules of 1 in the unit cell (P1). One of the
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 625

View Article Online
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
626 | New J. Chem., 2010, 34, 623–636

View Article Online
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 627

View Article Online
Fig. 3 (a) The host ladder network of 2 is connected by dioxane (O7,
blue) and filled with a second dioxane molecule in the channels (O8,
green) of the 2ꢀ(dioxane)2 solvate. Methoxy groups self-include in the
rung region. (b) The crystal structure of 3ꢀ(CH3NO2)2 showing the
cooperative O–Hꢀ ꢀ ꢀO hydrogen bond tetramer that assembles and
connects 1D ladder networks and nitromethane C–Hꢀ ꢀ ꢀO dimers in
the rectangular rungs.
Fig. 2 (a) The host ladder network of 1 along [001]. EtOAc molecules
are hydrogen-bonded on the sides and lie above/below the rung region
of adjacent layer ladders. (b) The DMSO solvate of 1. Solvent
molecules connect H-shaped phenols via O–Hꢀ ꢀ ꢀO hydrogen bonds
in a host–guest ladder network along [100].
host molecules (blue in Fig. 5) together with a half Phez
(green) molecule form a 2D sheet sustained by O–Hꢀ ꢀ ꢀO and
O–Hꢀ ꢀ ꢀN hydrogen bonds (O4–H4ꢀ ꢀ ꢀO3 1.92 A, 1561;
O3–H3Aꢀ ꢀ ꢀN1 1.99 A, 1651). The second ladder (red) weaves
through the rectangular rung regions of the first ladder, which
is part of the 2D sheet, at an inclination of 731 to give a rare
example of a 1D/2D interpenetrated network. The second
Phez (light blue) molecule dangles from the (red) second
ladder (O1–H1Aꢀ ꢀ ꢀO2 1.81 A, 1791; O2–H2Aꢀ ꢀ ꢀN1 1.78 A,
1661) and does not act as a connector.
Fig. 4 Double interpenetration of inclined ladders in the guest-free
form of 1. Symmetry-independent molecules are colored differently.
pyridine to pyridine-N-oxide, the corresponding cocrystal
structures are very different. The latter structure is topo-
logically a (6,3) net, where 4,40-BipyNO expands the ring size
and is filled, in part, by self-inclusion of the H-shaped molecule.
With DMF solvent, 3 produced a structure having dis-
ordered solvent molecules that were removed using the
SQUEEZE program (see Experimental section). 3ꢀ(DMF)2 is
an example of a 2D - 2D interpenetration of (6,3) honey-
comb nets. Here, the hexagonal net is expanded in 2D and
another (6,3) net is intertwined in a parallel fashion (Fig. 7(a)),
illustrating a clear case of interpenetration through Hopf links
The crystal structure of 1 with 4,40-bipyridine,5 1ꢀ(4,40-
Bipy)2, forms a perfect 1D ladder network (Fig. 6(a)). This
structure is comparable with the 4,40-bipyridine-N,N0-dioxide
(4,40-BipyNO) cocrystal of 1 (Fig. 6(b)). Whereas geometri-
cally the co-former is a linear extension upon going from
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
628 | New J. Chem., 2010, 34, 623–636

View Article Online
Fig. 5 Interpenetrated ladders in the 1ꢀ(Phez)1.5 cocrystal. (a) Phez and host molecules (green and blue) form a 2D sheet that is interpenetrated by
a host ladder (red) with dangling Phez molecules (light blue). (b) The 1D/2D interpenetrated ladder network in the same color scheme as (a).
Fig. 6 (a) Hydrogen-bonded ladders in 1ꢀ(4,40-Bipy)2 with rectangular rung dimensions of 16.7 ꢃ 6.9 A. No solvent is included in the crystal
lattice. Close packing is achieved by the offset stacking of ladders (ref. 5). (b) 1ꢀ(4,40-BipyNO)2 is topologically a (6,3) net of host molecule self-
inclusion. The arrangement of the pendant groups is inside the supramolecular ring for one of the H-shaped molecules, leading to partial self-
inclusion. This structure is not easily classified as a net. Molecular rings overlay as shown.
(Fig. 7(b)). These can be defined as two-component links of
two unknots that no isotopy can separate, such that there are
two non-intersecting spheres that can isolate each component,
or simply two interlocked rings that can be separated only by
cutting open one ring.
N-oxide O acceptor in a (6,3) network. Due to the tetrahedral
angle at the OH donor group and the bent hydrogen bond to
the PyzNO spacer (O1–H1Aꢀ ꢀ ꢀO4 1.72 A, 1611;
O2–H2Aꢀ ꢀ ꢀO3 1.78 A, 1701), the ring size of the (6,3) topo-
logical net is actually an expanded 6-membered ring. A single
ring of 22.2 ꢃ 14.1 ꢃ 8.4 A (dimensions in Table 2 give the
available space inside) is occupied by two identical rings to
In the cocrystal of
1
with pyrazine-N,N0-dioxide, 1ꢀ
(PyzNO)2, the host molecule is hydrogen-bonded to the
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 629

View Article Online
Fig. 7 (a) Parallel 2D - 2D 2-fold interpenetration in the crystal
structure of 3ꢀ(DMF)2. Disordered solvent molecules are omitted. (b)
A Hopf link.
give a 2D - 2D 3-fold interpenetrated network19 structure
(Fig. 8) connected by a Hopf link, which is nothing but a
[2]-catenane.2,20
Crystallization of 1 from CH3NO2 with a trace amount of
added CF3CH2OH (CH3NO2 : CF3CH2OH B 50 : 1) afforded
the 1ꢀ(CH3NO2)2 solvate as plate-shaped crystals with the
space group Pbca. Four molecules of 1 are connected via
solvent molecules to form an idealized (6,3) net of 18.6 ꢃ
13.3 ꢃ 10.3 A cavities. The polycatenation of 2D hexagonal
sheets completes the 3D crystal structure (Fig. 9). The network
in this structure is different from that of the PyzNO cocrystal.
This structure is an example of 2D - 3D polycatenation with
a degree of catenation (DOC)2 = 2/2, which means that two
layers are catenated with one hexagonal ring and vice versa.
The CH3NO2 solvate of 1 is identical to its MeOH and EtOH
solvates5 in terms of stoichiometry, space group, lattice para-
meters, catenation mode and the role of the solvent as bridges
between the host molecules.
Fig. 8 (a) The O–Hꢀ ꢀ ꢀO hydrogen-bonded (6,3) network of expanded
hexagonal rings (green lines show ring sides 1–6) in 1ꢀ(PyzNO)2. (b)
The triply interpenetrated network connected by a Hopf link.
centers are 3-connected nodes and the 4-connected hydrogen
bond tetramer is auto-generated (Fig. 10(d)). A tetrahedral
center can function as a pseudo-trigonal or pseudo-square
node (Fig. S5, ESIw).21a A difference between Catalan and
the previously described hexagonal and ladder nets is that
the present case is a uniform network topology (only one type
n-gon) under the subclass of Catalan net (two nodes having
different 3- and 4-connectivities), whereas the earlier examples
were Platonic nets (all nodes are 3-connected).1a
The use of CH3NO2 as a minor component in the solvent
mixture (CH3NO2 : CF3CH2OH B 1 : 6) gave a solvated poly-
morph of 1ꢀ(CH3NO2)2 with the space group P21/c. The
asymmetric unit contains 0.5 host molecules and 1 guest
molecule in both crystal structures. The network in this latter
monoclinic form is best understood by analyzing the octa-
methyl derivative 4ꢀ(CHCl3)2 solvate.12 Two host molecules
hydrogen bond via an O–Hꢀ ꢀ ꢀO tetramer to form pentagons of
5.4 ꢃ 5.4 A that are occupied by the guest species (Fig. 10(a)).
The 2D sheet of pentagonal (5,34) nets in the (100) plane has
four- and three-connected nodes in a 1 : 2 ratio.21 This struc-
ture and the related 1ꢀ(CH3NO2)2 solvate (Fig. 10(b)) are early
examples of all-organic pentagonal nets. A side-on approach
of two H-shaped molecules (Fig. S4, ESIw) gives a pentagonal
tiling of (5,34) nets (Fig. 10(c)), such that the sp3 tetrahedral
Cocrystallization of 1 with quinoxaline afforded single
crystals of 1ꢀ(Quinox)2, which were solved into the monoclinic
space group P21/c. The network structure is of the 1D poly-
rotaxane or polythreading type.16 Distinct motifs can be
entangled via rotaxane-like mechanical links, and this implies
the presence of closed loops, as well as connectors that thread
through the loops. However, in contrast to bimolecular rotaxanes,
in which the loop and thread are made up from different
molecules, here the loop and thread belong to the same binary
molecular system (Fig. 11). The OH groups at the V-nodes of
different H-shaped molecules orient convergently to form a
closed loop (ring) with the co-former spacer, while the para-
substituted benzene ring connects the loops (thread), as shown
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
630 | New J. Chem., 2010, 34, 623–636

View Article Online
hydrogen bonds, perhaps for steric reasons. DMSO behaves
as a single acceptor, similar to EtOAc, in these structures
(Fig. S2, ESIw). Dioxane connects host ladders via hydrogen
bonds. Solvents devoid of donor or acceptor groups generally
occupy the channel or rung region of the host ladder by space
filling, e.g. as in 4ꢀ(toluene). The pentagonal Catalan net in
4ꢀ(CHCl3)2 and 1ꢀ(CH3NO2)2 came as an unexpected bonus.12
This result was rationalized as the self-assembly of two
H-shaped molecules in a side-on manner, which is a novel
way of building a pentagonal (5,34) net and is unprecedented
compared to the two previous literature reports.21 The larger
volume of CHCl3 compared to CH3NO2 means that the latter
is present as a dimer in ladders, whereas the former solvent has
one molecule in the cavity of 4. Small sized solvent molecules,
such as MeOH and EtOH, generally form hexagonal sheet
structures through hydrogen bonding with the solvent. The
large supramolecular hexagon ring achieves close packing
through catenation or interpenetration.
In the case of heteroaromatic cocrystal formers, p-stacking
plays an important role. Aromatic stacking is facilitated in the
larger surface area rings of phenazine and quinoxaline, but not
for 4,40-bipyridine or its N-oxide, as seen in the crystal
structures of 1ꢀ(Phez)1.5 and 1ꢀ(Quinox)2. The ability of
extended p-stacking to direct phenol OH groups towards
convergent hydrogen bonding with aza heterocycles has been
noted in cocrystal systems.22 The p-stacking of quinoxaline is
with a longer interplanar separation than phenazine, which
results in a new kind of polytheading or polyrotaxane net-
work. Co-formers with two hydrogen bond acceptor groups,
such as 4,40-bipyridine, usually act as connectors to give
expanded ladders, e.g. 1ꢀ(4,40-Bipy)2. However, 4,40-bipyridine-
N,N0-dioxide behaves differently to give a distorted 2D net
because hydrogen bond donors can approach the stronger
N–O acceptor from many directions (in-plane and out-of-
plane), whereas donor groups lie mostly in the aromatic plane
of the pyridyl N acceptor, i.e. co-former functionality directs
network variability.
Fig. 9 (a) CH3NO2 molecules act as bridges in the supramolecular
hexagon of four H-shaped molecules in 1ꢀ(CH3NO2)2 (Pbca form).
(b) 2D - 3D polycatenation with a DOC = 2/2 of the 18.6 ꢃ 13.3 ꢃ
10.3 A cavity completing the molecular packing by space filling. The
three sides of the pseudohexagon have different dimensions.
Aoyama’s group6 illustrated organic zeolites constructed
from tetraphenol 5. Zeolites are a class of porous materials
capable of sorbing guest molecules in pores or cavities. The
guest molecules reside in internal cavities, which may be
constructed by using intermolecular interactions such as
hydrogen bonds and metal coordination bonds. Pentagonal
and hexagonal channels and cavities can easily include a
variety of solvent molecules. TGA showed that solvent mole-
cules were released at their boiling point or at a slightly higher
temperature in host–guest solvates of 1 and 4. The host is
stable up to B260 1C.
The different molecular networks analyzed in the 23 crystal
structures of H-shaped tectons (13 new examples and 10
previously reported5,12) are summarized in Table 2 and shown
in Fig. 12. Whereas such a large number of diverse network
architectures are not unprecedented in metal–organic struc-
tures and coordination polymers,23 organic networks are not
as widespread. We reason that differences in hydrogen bond-
ing and p-stacking due to the guest and co-former species are
responsible for network diversity in conformationally-flexible
H-shaped molecules. The molecular conformations of parent
molecule 1 and octamethyl derivative 4, both of which
in Fig. 11(b) and (c). This polyrotaxane type of 1D - 1D
polythreaded network of alternating rings and rods can be
considered as ‘‘Euclidean entanglement’’2, i.e. there is no
increase in the dimensionality of the network.
The thermal behavior of the solvates is summarized in
Table 3 and DSC/TGA plots are shown in Fig. S6 (ESIw).
Discussion
Solvents having only hydrogen bond acceptor groups, such as
EtOAc, DMSO, dioxane and CH3CN, generally result in a
ladder network in their inclusion complexes with 1. The
phenol OH groups hydrogen bond to form 1D ladders and
unused OH groups of the host molecule are hydrogen-bonded
to the solvent acceptor, except in DMSO solvates. Because of
its better acceptor strength, DMSO behaves as a double
hydrogen bond acceptor and is part of the 1D ladder network.
These small solvent molecules reside above and below the
rectangular rung regions of host ladders. When bulky methyl
or methoxy groups are present (as in 2 and 4), even DMSO
cannot come sufficiently close to the host to accept two
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 631

View Article Online
Fig. 10 Pentagons of self-assembled 4 are filled with (a) disordered CHCl3 and (b) CH3NO2 molecules in the monoclinic form of 1ꢀ(CH3NO2)2.
(c) The 2D Catalan (5,34) net of H-shaped molecule 4 creates channels by the perfect stacking of sheets. (d) The side-on hydrogen bonding of
H-shaped molecules via an O–Hꢀ ꢀ ꢀO tetramer. Connection of the trigonal carbon centers auto-generates the 4-connected node.
crystallized in many solvates and guest-free forms, are shown
in Fig. 13. Even though the phenol hydroxyl groups and para-
phenyl ring adopt numerous orientations and conformations,
the H-shape of these tetraphenol molecules and their copla-
narity with respect to the mean plane defined in Fig. 1 is a
persistent structural element. The phenol O and tetrahedral C
atoms deviate by no more than 1 A from the mean plane
(Table S1, ESIw). It is clear that conformational flexibility, the
orientation of the OH groups and solvent hydrogen bonding
promote network diversity in H-shaped tectons. The relation-
ship between the composition of the host network and the pKa
of co-former was recently discussed.24 In general, however,
predicting the topology and entanglement in organic 2D and
3D network structures is difficult,25 and the most one can do is
to rationalize the results after crystal structure determination
and analysis.
and diverse networks from the same starting tecton. Among
1D ladders and polyrotaxanes, 2D honeycomb and Catalan
nets, as well as their interpenetrated/catenated structures, the
most novel and remarkable results are the Catalan (5,34) nets
in 4ꢀ(CHCl3)2 and 1ꢀ(CH3NO2)2, the two-component poly-
rotaxane of 1ꢀ(Quinox)2, and the interpenetrated ladders in
the 1ꢀ(Phez)1.5 cocrystal and its guest-free form. We have also
shown novel examples of interpenetrated ladders, DOC 2/2
catenation, 2- and 3-fold interpenetrated (6,3) nets, and
polythreaded rotaxanes. This structural diversity is a result
of changes in guest hydrogen bonding, p-stacking and host
molecular conformation. A reason for guest- or co-former-
induced supramolecular diversity is that the H-shaped mole-
cule is flexible in three ways—by the phenol OH group
orientation, at the tetrahedral V-shaped bis(phenol) and
at the para-phenyl connector. The presence of a second
aromatic component gives interplay between hydrogen
bonding and p-stacking motifs. The rational construction
of novel network architectures from H-shaped molecules
should be possible based on a better understanding of the
network diversity of these structures.
Conclusions
H-shaped host molecules 1–4 are quite remarkable in their guest
inclusion and cocrystal-forming behavior, giving numerous
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
632 | New J. Chem., 2010, 34, 623–636

View Article Online
Table 3 Thermal analysis (TGA and DSC) of the inclusion com-
pounds
Calculated Guest
weight loss from release
host guest ratio Ton/1C
Observed
weight loss
from TGA
(%)
Boiling
point of
the
Inclusion
complexa
in X-ray
structure (%)
(from
DSC)
guest/1C
1ꢀ(DMSO)2 28.9
1ꢀ(CH3NO2)2 20.3
(Pbca form)
24.8
20.5
153.7
96.8
189
100–103
1ꢀ(EtOAc)2
26.2
4ꢀ(DMSO)2 28.1
27.1
21.0
17.2
13.6
28.9
90.0
153.1
60.4
125.0
94.3
77
189
100–103
110.6
61.2
4ꢀ(CH3NO2)2 14.0
4ꢀ(toluene)
4ꢀ(CHCl3)2
16.1
23.1
a
The P21/c form of the 1ꢀ(CH3NO2)2 and 1ꢀ(i-PrOH)4 samples could
not be generated in sufficient quantity to undertake TGA. They
exhibited Ton values in DSC at 108 and 78/113 1C, respectively.
Fig. 11 (a) Chair cyclohexane rings in the 1ꢀ(Quinox)2 cocrystal
structure sustained by O–Hꢀ ꢀ ꢀN hydrogen bonds. (b) The V-shaped
phenol OH groups are inwardly oriented by aromatic co-former p-
stacking to form a ring, while the para-phenyl connector of 1 is the
thread in the (c) 1D polyrotaxane network. (d) An idealized poly-
rotaxane.
Experimental section
Synthesis of host molecules
A mixture of terephthaldehyde (500 mg, 3.7 mmol) and phenol
(1.8 mL, 14.9 mmol, 4 equiv.) in glacial acetic acid (10 mL) was
treated dropwise with concentrated HCl (10 mL). The reaction
mixture was stirred at room temperature for 24 h, poured onto
Fig. 12 Supramolecular networks in host–guest compounds and
cocrystals of H-shaped molecules: (a) 1D ladder, (b) interpenetrated
ladders, (c) Catalan or (5,34) net, (d) common (6,3) hexagonal or 2D
brick wall motif, and (e) polyrotaxane or polythreading.
Fig. 13 The conformation of the H-shaped molecules in the crystal structures. (a) 1 in guest-free form having molecule A (red) and B (green),
CH3NO2 solvate (Pbca form) (blue), CH3NO2 solvate (P21/c form) (magenta), DMSO solvate (yellow), EtOAc solvate (brown), and i-PrOH
solvate (black). (b) 4 in guest-free form (green), CHCl3 solvate (red), CH3NO2 solvate (blue), DMSO solvate (yellow) and toluene solvate
(magenta). The H-shaped molecules adopt different conformations at the Y junction, as well as different para-phenyl connector and OH donor
orientations, in each crystal structure. Only the H atoms of the phenol OH group are shown; the CH hydrogens are excluded for clarity.
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 633

View Article Online
crushed ice, and the precipitate filtered and washed with cold
water. Dried compound 1 was purified by column chromato-
graphy using EtOAc–n-hexane (1 : 4) to yield 884 mg (50%) of
the pure product.
Ph-CH), 6.85 (8H, d, J = 8 Hz, Ph-CH), 6.97 (4H, s, Ar-CH)
and 9.22 (4H, s, OH). mp 275–278 1C. Yield 50%.
1,4-Di[bis(30-hydroxy-20,40-dimethoxyphenyl)methyl]benzene
(2). IR (KBr/cmꢂ1): 3420, 2937, 1616, 1242, 1089, 783 and 694;
1H NMR (d, CDCl3): 3.59 (12H, s, OCH3), 3.84 (12H, s,
OCH3), 5.46 (4H, s, OH), 6.06 (2H, s, methine-CH), 6.31
(4H, d, J = 8 Hz, Ph-CH), 6.50 (4H, d, J = 8 Hz, Ph-CH)
and 6.99 (4H, br s, Ar-CH). mp 249–251 1C. Yield 60%.
Octamethoxy, tetramethyl and octamethyl derivatives 2, 3
and 4 were prepared by a similar method using appropriate
starting materials.
All compounds were synthesized, purified and characterized
by IR and NMR spectroscopy. FT-IR spectra were recorded
on a Jasco 5300 spectrophotometer. NMR spectra were
recorded on a Bruker Avance spectrometer at 400 MHz.
NMR chemical shifts on the d scale (ppm) and J couplings
(Hz) are reported. Melting points were recorded on a Fisher-
Johns apparatus and confirmed by endotherm peaks by DSC
(Fig. S6, ESIw).
1,4-Di[bis(40-hydroxy-30-methylphenyl)methyl]benzene (3).
IR (KBr/cmꢂ1): 3468, 2922, 1608, 1454, 1271, 775 and 609;
1H NMR (CDCl3, DMSO-d6): 2.50 (12H, s, CH3), 5.60 (2H, s,
methine-CH), 7.05 (4H, s, Ar-CH), 7.07 (4H, s, Ph-CH), 7.18
(4H, s, Ph-CH), 7.33 (4H, s, Ph-CH) and 8.79 (4H, s, OH). mp
254–257 1C. Yield 55%.
1,4-Di[bis(40-hydroxyphenyl)methyl]benzene (1). IR (KBr/
1,4-Di[bis(40-hydroxy-30,50-dimethylphenyl)methyl]benzene (4).
IR (KBr/cmꢂ1): 3586, 2918, 1670, 1302, 1147, 760 and 694; 1H
NMR (CDCl3): 2.17 (24H, s, CH3), 4.48 (4H, s, OH), 5.25
1
cmꢂ1): 3366, 1599, 1446, 1371, 1224, 760 and 636; H NMR
(d, DMSO-d6): 5.28 (2H, s, methine-CH), 6.64 (8H, d, J = 8 Hz,
Table 4 Crystallographic data
1 (guest-free) 1ꢀ(EtOAc)2
1ꢀ(DMSO)2 1ꢀ(i-PrOH)4
C36H38O6S2 C44H58O8
630.78 714.90
Monoclinic Monoclinic
1ꢀ(Phez)1.5
1ꢀ(Quinox)2 1ꢀ(PyzNO)2 1ꢀ(4,40-BipyNO)2
C50H38N3O4 C48H38N4O4 C40H34N4O8 C52H42N4O8
Chemical formula
C32H26O4
474.53
Triclinic
C40H42O8
650.74
Triclinic
Formula weight
Crystal system
Space group
T/K
744.83
Triclinic
ꢀ
P1
298
734.82
698.71
850.90
Monoclinic Monoclinic Orthorhombic
ꢀ
ꢀ
P1
100
P1
100
P21/c
100
C2/c
100
P21/c
298
P21/c
298
Pca21
298
a/A
b/A
c/A
a (1)
b (1)
g (1)
10.1926(10)
11.0478(10)
13.0960(14)
101.849(2)
102.082(2)
115.675(2)
2
1224.1(2)
1.287
0.084
7.3791(5)
10.4359(8)
11.3692(8)
93.3570(10) 90
95.2410(10) 96.343(2)
100.8240(10) 90
11.0387(11) 33.506(3)
7.4017(7) 5.8797(4)
19.4980(19) 22.036(2)
10.2976(8)
11.2084(9)
18.4225(15)
96.0410(10)
103.7210(10) 93.044(7)
102.7000(10) 90
14.472(6)
16.115(6)
8.057(3)
90
13.064(2)
7.6296(11)
16.929(3)
90
99.722(2)
90
20.631(4)
7.1465(14)
28.309(5)
90
90
90
90
115.061(2)
90
Z
1
2
4
2
2
2
4
V/A3
853.77(11)
1.266
0.087
7902
3008
3323
0.0401
0.1049
1.048
1583.3(3)
1.323
0.214
15752
2273
3932.5(6)
1.207
0.082
19346
2668
1987.1(3)
1.245
0.079
20835
4071
1876.3(13)
1.301
0.084
11675
2287
1663.1(4)
1.395
0.099
16408
2750
3273
0.0599
0.1334
1.141
4173.9(14)
1.354
0.092
40681
5879
Dc/g cmꢂ3
m/mmꢂ1
Reflections collected 12394
Observed reflections 2595
Total reflections
R1(I 4 2s(I))
wR2 (all)
4633
3127
3880
7790
3678
8317
0.0786
0.1032
0.991
0.0603
0.1273
1.062
0.0759
0.2116
1.042
0.0651
0.1538
1.016
0.0829
0.1429
1.118
0.1249
0.2726
1.112
Goodness-of-fit
2ꢀ(DMSO)2
C44H54O14S2 C48H58O16
2ꢀ(dioxane)2 3ꢀ(DMF)2
3ꢀ(CH3NO2)2 4 (guest-free) 4ꢀ(toluene)
4ꢀ(DMSO)2
C44H54O6S2
742.99
Monoclinic
P21/n
298
Chemical formula
C42H48N2O6 C38H40N2O8 C40H42O4
676.82
Monoclinic Triclinic
C2/c
100
C47H50O4
678.87
Triclinic
Formula weight
Crystal system
Space group
T/K
870.99
890.94
Triclinic
652.72
586.74
Monoclinic
P21/c
Monoclinic
P21/c
100
ꢀ
P1
298
ꢀ
P1
298
ꢀ
P1
100
100
a/A
b/A
c/A
a (1)
b (1)
g (1)
10.8550(7)
14.2040(9)
14.8984(9)
90
111.1700(10) 98.428(8)
90
9.039(4)
10.605(4)
13.461(6)
101.940(7)
23.799(2)
8.0974(8)
5.5173(5)
12.0094(12)
18.3595(15) 12.9806(13)
15.0090(17)
5.5072(6)
18.887(2)
90
104.850(2)
90
8.7313(7)
10.2761(9)
11.4745(10) 21.892(4)
64.9820(10) 90
75.9800(10) 102.049(4)
86.5800(10) 90
1
904.07(13)
1.247
0.078
9481
2754
3553
0.0764
0.1760
1.074
11.340(2)
8.2249(15)
90
113.226(5)
90
91.144(2)
96.446(2)
91.410(2)
1
854.17(14)
1.269
0.089
8866
2165
3331
0.0594
0.1388
1.023
112.198(7)
1
1132.4(8)
1.307
0.098
11616
2046
4379
0.0751
0.1797
0.990
Z
2
4
2
2
V/A3
2142.1(2)
1.350
0.192
3251.3(5)
1.383
0.092
11912
1923
1509.0(3)
1.291
0.082
14825
2260
2970
0.0604
0.1338
1.042
1996.9(6)
1.236
0.180
19868
2287
Dc/g cmꢂ3
m/mmꢂ1
Reflections collected 21901
Observed reflections 3017
Total reflections
R1(I 4 2s(I))
wR2 (all)
4227
3202
3891
0.0641
0.1565
1.000
0.0670
0.1694
0.978
0.1189
0.1888
1.181
Goodness-of-fit
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
634 | New J. Chem., 2010, 34, 623–636

View Article Online
(2H, s, methine-CH), 6.70 (8H, s, Ph-CH) and 6.99 (4H, s,
CrystEngComm, 2003, 5, 269; (c) S. R. Batten, CrystEngComm,
2001, 3, 67.
3 (a) L. Carlucci, G. Ciani and D. M. Proserpio, Chem. Commun.,
2004, 380; (b) L. Carlucci, G. Ciani, S. Maggini and
D. M. Proserpio, Cryst. Growth Des., 2008, 8, 162.
Ar-CH). 261–264 1C. Yield 60%.
X-Ray crystallography
4 (a) I. A. Baburin, V. A. Blatov, L. Carlucci, G. Ciani and
D. M. Proserpio, Cryst. Growth Des., 2008, 8, 519;
(b) I. A. Baburin and V. A. Blatov, Acta Crystallogr., Sect. B:
Struct. Sci., 2007, 63, 791.
Reflections were collected on a Bruker SMART CCD diffracto-
meter. Mo-Ka (l = 0.71073 A) radiation was used to collect
the X-ray reflections of all the crystals (1–4). Data reduction
was performed using Bruker SAINT software.26 Structures
were solved and refined using SHELXL-9727 with anisotropic
displacement parameters for non-H atoms. Hydrogen atoms
on O were experimentally located in all of the crystal struc-
tures. All C–H atoms were fixed geometrically. A check of the
final CIF file using PLATON28 did not show any missed
symmetry. Disordered solvent molecules in 1ꢀ(i-PrOH)4 (one
out of two) and 3ꢀ(DMF)2 were removed by SQUEEZE within
PLATON. The crystal structures of 1ꢀ(Phez)1.5 and 1ꢀ(4,40-
BipyNO)2 could only be solved satisfactorily after fixing the
hydroxyl H atoms in refinement cycles (HFIX 83 command).
Friedel pairs were averaged in case of the non-centrosymmetric
space group Pca21 for 1ꢀ(4,40-BipyNO)2 (MERG 4 command).
All hydrogen atoms were fixed (HFIX command) and
toluene disorder was modelled with isotropic refinement for
1ꢀ(toluene). CIF files of all the crystal structures contain
refinement details under _refine_special_details. The crystallo-
graphic parameters for the 1–4 structures are summarized in
Table 4. Hydrogen bond distances listed in Table 1 are
neutron-normalized to fix the donor–H distance to its accurate
neutron value in the X-ray crystal structures (O–H 0.983 A,
N–H 1.009 A, C–H 1.083 A). The Tmin and Tmax values were
derived from SHELX based on the crystal size, since the
absorption correction is minimal in these light atom-containing
crystal structures. Packing diagrams were prepared using
X-Seed.29w
5 S. Aitipamula and A. Nangia, Supramol. Chem., 2005, 17, 17.
6 (a) K. Endo, T. Sawaki, M. Koyanagi, K. Kobayashi, H. Masuda
and Y. Aoyama, J. Am. Chem. Soc., 1995, 117, 8341;
(b) T. Tanaka, T. Tasaki and Y. Aoyama, J. Am. Chem. Soc.,
2002, 124, 12453; (c) K. Endo, T. Koike, T. Sawaki, O. Hayashida,
H. Masuda and Y. Aoyama, J. Am. Chem. Soc., 1997, 119, 4117;
(d) Y. Aoyama, K. Endo, T. Anzai, Y. Yamaguchi, T. Sawaki,
K. Kobayashi, N. Kanehisa, H. Hashimoto, Y. Kai and
H. Masuda, J. Am. Chem. Soc., 1996, 118, 5562; (e) K. Tanaka,
K. Endo and Y. Aoyama, Chem. Lett., 1999, 887; (f) Y. Aoyama,
K. Endo, K. Kobayashi and H. Masuda, Supramol. Chem., 1994,
4, 229.
7 (a) S. Aitipamula and A. Nangia, Chem.–Eur. J., 2005, 11, 6727;
(b) V. S. Senthil Kumar, A. Nangia, M. T. Kirchner and R. Boese,
New J. Chem., 2003, 27, 224.
8 G. R. Swiegers and T. J. Malefetse, Chem. Rev., 2000, 100, 3483.
9 (a) P. Grosshans, A. Jouaiti, N. Kardouh, M. W. Hosseini and
N. Kyritsakas, New J. Chem., 2003, 27, 1806; (b) F. G. Klarner and
¨
B. Kahlert, Acc. Chem. Res., 2003, 36, 919; (c) M. Harmata, Acc.
Chem. Res., 2004, 37, 862; (d) A. Sygula, F. R. Fronczek,
R. Sygula, P. W. Rabideau and M. M. Olmstead, J. Am. Chem.
Soc., 2007, 129, 3842.
10 (a) S. L. James, Chem. Soc. Rev., 2003, 32, 276; (b) K. Biradha,
CrystEngComm, 2003, 5, 374; (c) S. A. Barnett and
N. R. Champness, Coord. Chem. Rev., 2003, 246, 145;
(d) S. Kitagawa, R. Kitaura and S. Noro, Angew. Chem., Int.
Ed., 2004, 43, 2334; (e) N. W. Ockwig, O. Delgado-Friedrichs,
M. O’Keeffe and O. M. Yaghi, Acc. Chem. Res., 2005, 38, 176;
(f) S. Kitagawa and K. Uemura, Chem. Soc. Rev., 2005, 34, 109.
11 (a) J.-S. Yang and J.-L. Yan, Chem. Commun., 2008, 1501;
´
(b) M. A. Alvarez, I. Amor, M. E. Garcıa and M. A. Ruiz, Inorg.
Chem., 2008, 47, 7963.
12 R. Thakuria, B. Sarma and A. Nangia, Cryst. Growth Des., 2008,
8, 1471.
13 A. D. Bond, CrystEngComm, 2007, 9, 833.
14 (a) V. T. Nguyen, P. D. Ahn, R. Bishop, M. L. Scudder and
Acknowledgements
D. C. Craig, Eur. J. Org. Chem., 2001, 4489; (b) X.-Q. Lu, M. Pan,
¨
J.-R. He, Y.-P. Cai, B.-S. Kang and C.-Y. Su, CrystEngComm,
2006, 8, 827; (c) V. S. Senthil Kumar, F. C. Pigge and N. P. Rath,
New J. Chem., 2003, 27, 1554; (d) A. D. Bond, Chem.–Eur. J., 2004,
10, 1885.
We thank the CSIR (01(2079)/06/EMR-II) and DST (SR/S1/
RFOC-01/2007 Ramanna Fellowship) for research funding.
R. T. and B. S. thank the UGC and CSIR for fellowships.
DST (IRPHA) funded the CCD X-ray diffractometer and the
UGC is thanked for the UPE program. We thank a crystallo-
graphic reviewer for hints regarding an improved structure
solution for the disordered guest species and a chemical referee
for valuable insight into interpenetrated network modes.
15 (a) B. K. Saha, R. K. R. Jetti, L. S. Reddy, S. Aitipamula and
A. Nangia, Cryst. Growth Des., 2005, 5, 887; (b) B. R. Bhogala and
A. Nangia, New J. Chem., 2008, 32, 800.
16 (a) D. Whang and K. Kim, J. Am. Chem. Soc., 1997, 119, 451;
(b) C. S. A. Fraser, M. C. Jennings and R. J. Puddephatt, Chem.
Commun., 2001, 1310; (c) L. Carlucci, G. Ciani and
D. M. Proserpio, Cryst. Growth Des., 2005, 5, 37;
(d) K. K. Arora and V. R. Pedireddi, Cryst. Growth Des., 2005,
5, 1309; (e) A. A. Salaudeen, C. A. Kilner and M. A. Halcrow,
Chem. Commun., 2008, 5200; (f) X.-Y. Cao, Q.-P. Lin, Y. Y. Qin,
J. Zhang, Z.-J. Li, J.-K. Cheng and Y.-G. Yao, Cryst. Growth Des.,
2009, 9, 20.
References
1 (a) A. F. Wells, Three-Dimensional Nets and Polyhedra, Wiley,
New York, 1977; (b) M. O’Keeffe and B. G. Hyde, Philos. Trans.
R. Soc. London, Ser. A, 1980, 295, 553; (c) S. R. Batten and
R. Robson, Angew. Chem., Int. Ed., 1998, 37, 1460;
(d) G. R. Desiraju, Chem. Commun., 1997, 1475; (e) B. Moulton
and M. J. Zaworotko, Chem. Rev., 2001, 101, 1629;
(f) G. R. Desiraju, J. Mol. Struct., 2003, 656, 5; (g) K. Biradha,
17 C. Laurence and M. Berthelot, Perspect. Drug Discovery Des.,
2000, 18, 39.
18 (a) B. Sarma, S. Roy and A. Nangia, Chem. Commun., 2006, 4918;
(b) S. Aitipamula, G. R. Desiraju, M. Jaskolski, A. Nangia and
´
R. Thaimattam, CrystEngComm, 2003, 5, 447; (c) H.-J. Lehmler,
L. W. Robertson, S. Parkin and C. P. Brock, Acta Crystallogr.,
Sect. B: Struct. Sci., 2001, 58, 140; (d) C. P. Brock, Acta Crystallogr.,
Sect. B: Struct. Sci., 2002, 58, 1025.
M. Sarkar and L. Rajput, Chem. Commun., 2006, 4169;
¨
(h) L. Ohrstrom and K. Larsson, Molecule-Based Materials,
¨
19 (a) B. R. Bhogala, P. Vishweshwar and A. Nangia, Cryst. Growth
Des., 2002, 2, 325; (b) T. R. Shattock, P. Vishweshwar, Z. Wang
and M. J. Zaworotko, Cryst. Growth Des., 2005, 5, 2046;
(c) Q.-Y. Yang, S.-R. Zheng, R. Yang, M. Pan, R. Cao and
C.-Y. Su, CrystEngComm, 2009, 11, 680.
Elsevier, Amsterdam, 2005; (i) N. Malek, T. Maris, M.-E. Perron
and J. D. Wuest, Angew. Chem., Int. Ed., 2005, 44, 4021;
(j) R. Bishop, Acc. Chem. Res., 2009, 42, 67.
2 (a) L. Carlucci, G. Ciani and D. M. Proserpio, Coord. Chem. Rev.,
2003, 246, 247; (b) L. Carlucci, G. Ciani and D. M. Proserpio,
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
New J. Chem., 2010, 34, 623–636 | 635

View Article Online
20 (a) J.-P. Sauvage, Acc. Chem. Res., 1998, 31, 611; (b) S. S.-Y. Chui,
R. Chen and C.-M. Che, Angew. Chem., Int. Ed., 2006, 45, 1621;
(c) S. T. Caldwell, G. Cooke, B. Fitzpatrick, D.-L. Long,
G. Rabania and V. M. Rotello, Chem. Commun., 2008, 5912;
(d) J.-Q. Liu, Y.-Y. Wang, L.-F. Ma, G.-L. Wen, Q.-Z. Shi,
S. R. Batten and D. M. Proserpio, CrystEngComm, 2008, 10, 1123.
21 (a) B. Moulton, J. Lu and M. J. Zaworotko, J. Am. Chem. Soc.,
2001, 123, 9224; (b) S. W. Keller and S. Lopez, J. Am. Chem. Soc.,
1999, 121, 6306.
(d) M. R. Montney, S. M. Krishnan, N. M. Patel,
R. M. Supkowski and R. L. LaDuca, Cryst. Growth Des., 2007,
7, 1145; (e) X.-Q. Liang, X.-H. Zhou, C. Chen, H.-P. Xiao,
Y.-Z. Li, J.-L. Zuo and X.-Z. You, Cryst. Growth Des., 2009, 9,
1041; (f) Z. Su, J. Xu, J. Fan, D.-J. Liu, Q. Chu, M.-S. Chen,
S.-S. Chen, G.-X. Liu, X.-F. Wang and W.-Y. Sun, Cryst. Growth
Des., 2009, 9, 2801.
24 A. Delori, E. Suresh and V. R. Pedireddi, Chem.–Eur. J., 2008, 14,
6967.
22 (a) B. Sarma, L. S. Reddy and A. Nangia, Cryst. Growth Des.,
2008, 8, 4546; (b) L. R. MacGillivray, J. L. Reid and
J. A. Ripmeester, J. Am. Chem. Soc., 2000, 122, 7817;
25 Y.-B. Men, J. Sun, Z.-T. Huang and Q.-Y. Zheng, Angew. Chem.,
Int. Ed., 2009, 48, 2873.
26 G. M. Sheldrick, SADABS, Program for area detector adsorption
(c) T. Friscic
´
and L. R. MacGillivray, Chem. Commun., 2005,
correction, Institute for Inorganic Chemistry, University of Gottingen,
¨
5748; (d) G. S. Papaefstathiou, Z. Zhong, L. Geng and
L. R. MacGillivray, J. Am. Chem. Soc., 2004, 126, 9158;
(e) L. R. MacGillivray, G. S. Papaefstathiou, T. Frisicic,
T. D. Hamilton, D.-K. Bucar, Q. Chu, D. B. Varshney and
I. G. Georgiev, Acc. Chem. Res., 2008, 41, 280.
Germany, 1996.
27 (a) G. M. Sheldrick, SHELXS-97, Program for the solution of
crystal structures, University of Gottingen, Germany, 1997;
¨
(b) G. M. Sheldrick, SHELXL-97, Program for the refinement of
crystal structures, University of Gottingen, Germany, 1997.
¨
23 (a) A. J. Blake, N. R. Champness, P. Hubberstey, W.-S. Li,
M. A. Withersby and M. Schroder, Coord. Chem. Rev., 1999,
28 (a) A. L. Spek, PLATON, A Multipurpose Crystallographic Tool,
Utrecht University, Utrecht, The Netherlands, 2002;
(b) A. L. Spek, J. Appl. Crystallogr., 2003, 36, 7.
29 L. J. Barbour, X-Seed: Graphical Interface to SHELX-97 and
POVRay, University of Missouri-Columbia, Columbia, MO, 1999.
¨
183, 117; (b) L. Carlucci, G. Ciani, D. M. Proserpio and S. Rizzato,
J. Solid State Chem., 2000, 152, 211; (c) D. K. Kumar, D. A. Jose,
A. Das and P. Dastidar, Inorg. Chem., 2005, 44, 6933;
ꢁc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010
636 | New J. Chem., 2010, 34, 623–636