Synthesis, spectroscopic characterization and structural investigation of a new symmetrically trisubstituted benzene derivative: 3,3′, 3′′-(Benzene-1,3,5-triyl)tripropiolic acid

Article abstract of DOI:10.1016/j.molstruc.2013.04.005

The new 1,3,5-trisubstituted benzene derivative 1 featuring three propiolic acid side arms symmetrically attached to a benzene core has been synthesized. Spectroscopic studies including ¹H and ¹³C NMR as well as FTIR measurements wer

Full text of DOI:10.1016/j.molstruc.2013.04.005

Journal of Molecular Structure 1043 (2013) 103–108
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Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Synthesis, spectroscopic characterization and structural investigation of a new
symmetrically trisubstituted benzene derivative: 3,30,300-(Benzene-1,3,5-triyl)
tripropiolic acid
a,
Alexander S. Münch a, Felix Katzsch b, Edwin Weber b, , Florian O.R.L. Mertens
⇑
⇑
a Institute of Physical Chemistry, Technical University Bergakademie Freiberg, Leipziger Straße 29, 09596 Freiberg, Germany
b Institute of Organic Chemistry, Technical University Bergakademie Freiberg, Leipziger Straße 29, 09596 Freiberg, Germany
g r a p h i c a l a b s t r a c t
h i g h l i g h t s
ꢀ
ꢀ
A new extended analogue of trimesic
acid has been prepared.
The structure of the compound is
determined by single crystal X-ray
diffraction.
ꢀ
A new hydrogen bond motif of graph
set R34(12) was obtained.
a r t i c l e i n f o
a b s t r a c t
Article history:
The new 1,3,5-trisubstituted benzene derivative 1 featuring three propiolic acid side arms symmetrically
attached to a benzene core has been synthesized. Spectroscopic studies including 1H and 13C NMR as well
as FTIR measurements were performed. The single crystal structure of 1 shows involvement of a water
molecule giving rise to formation of a new 12-membered hydrogen bonded ring motif of graph set
R34(12) while the packing is typically interspersed with channel-like voids of different dimension contain-
ing additional ethanol and water molecules which, however, could not be localized precisely.
Ó 2013 Elsevier B.V. All rights reserved.
Received 28 February 2013
Received in revised form 3 April 2013
Accepted 3 April 2013
Available online 13 April 2013
Keywords:
1,3,5-Substituted benzene
Tripropiolic acid
Cross coupling reaction
Single crystal X-ray structure
Hydrogen bond interaction
1. Introduction
and gels [4], or organic electronic and optoelectronic materials [5].
Moreover, with the development of supramolecular chemistry,
Owing to their structural behavior, symmetrically trisubstitued
benzenes have arisen interest for a long time [1] involving different
fields of application such as discotic mesogens [2], amphiphiles [3]
they have become particular relevant as construction elements
for the design of trigonal tectons and other trigonally controlled
framework components [6]. Aside from this, particular trisubsti-
tuted benzenes have also been used as chelating metal complex-
ants, which include molecular capsules and containers, or to
construct dendritic compounds as well as crystalline hosts and
spacer-type building blocks for the formation of various aggregate
structures [7]. Significant examples of these latter types of
⇑
Corresponding authors. Tel.: +49 (0)3731 39 2386; fax: +49 (0)3731 39 3170 (E.
Weber), tel.: +49 (0)3731 39 3192; fax: +49 (0)3731 39 3588 (F.O.R.L. Mertens).
E-mail addresses: edwin.weber@chemie.tu-freiberg.de (E. Weber), florian.mer
tens@chemie.tu-freiberg.de (F.O.R.L. Mertens).
0022-2860/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.molstruc.2013.04.005

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A.S. Münch et al. / Journal of Molecular Structure 1043 (2013) 103–108
aggregate structures are the organic–inorganic hybrid compounds,
usually called metal–organic frameworks (MOFs) [8], the hydrogen
bond stabilized networks (HNBs) [9], or the covalently linked or-
ganic frameworks (COFs) [10] as the latest development along this
line of porous materials design. Within this frame, in particular
symmetric tricarboxylic acids derived from benzene have proven
very effective [11]. First and foremost, this is the case for the basic
compound trimesic acid [12]. But also extended analogues that
feature side arms with phenylene or ethynylene–phenylene spacer
units inserted between the central ring and the carboxyl groups
have been developed [13] though with the increasing length of
the side arms, network interpenetration is becoming an increasing
problem [14].
range from 25 to 500 °C using a temperature ramp of 5 K/min.
The powder X-ray pattern was collected on a Philips X0Pert
Diffractometer using Cu Ka radiation (k = 1.541 Å, 40 kV, 30 mA).
Scanning electron microscopy images were observed on a Jeol
JSM 7001F scanning electron microscope using gold as a thin
conducting layer.
2.2. Synthesis
2.2.1. 1,3,5-Tris(3-hydroxy-3-methyl-1-butynyl)benzene 3 [15]
1,3,5-Tribromobenzene (7.43 g, 23.59 mmol) was added to a
mixture
of
2-methylbut-3-yn-2-ol
(MEBYNOL)
(11.58 g,
Remarkably, however, it seems that a more simply modified
analogue of trimesic acid with only short alkyne moieties inserted
between the aromatic core and the carboxyl groups 1 (Fig. 1), hav-
ing the potential to reduce the tendency of network interpenetra-
tion, has neither been intended for MOF nor HBN formation.
Related to this possibility, in the present paper we describe the
synthesis of 1, report results of spectroscopic studies, and discuss
the single crystal structure of the new compound.
184.12 mmol) and dry triethylamine (100 mL) under argon atmo-
sphere. The stirred solution was degassed by heating for 1 h under
argon. After cooling down the solution to room temperature, CuI
(46 mg, 0.23 mmol) and Pd(PPh3)4 (400 mg, 0.6 mmol) were added.
The resulting mixture was stirred at 25 °C for 30 min, then at 50 °C
for 1 h and for 3.5 h under reflux. The solid was removed by filtra-
tion and washed with diethyl ether (2 ꢂ 30 mL). The combined or-
ganic solvents (filtrate and wash solution) were evaporated to give
a dark colored solid. Crystallization from ethanol/water (1:1)
yielded 3 as a pale gray powder (6.54 g, 86%). Mp = 169 °C. 1H
NMR (500.13 MHz, CDCl3): dH = 7.39 (s, ArAH), 1.59 (s, CH3). 13C
NMR (125.76 MHz, CDCl3): dC = 137.2, 123.3 (ArAC), 94.9
(ArAC„C), 80.5 (ArAC„C), 65.5(CA(CH3)2OH), 31.4 (CH3).
2. Experimental
2.1. General experimental and physical measurements
All denoted chemicals are commercially available and were
used without further purification. Solvents (triethylamine and tet-
rahydrofuran) were subjected to standard drying procedures.
The melting points were measured on a microscope heating
stage (Thermovar Reichert-Jung). 1H and 13C NMR spectra were re-
corded (25 °C) with a Bruker Avance III 500 NMR spectrometer at
500.13 MHz and 125.76 MHz, respectively, using CDCl3 (2, 3) and
DMSO-d6 (1) as solvent. Chemical shifts (d) are given in ppm refer-
ring to tetramethylsilane as internal standard. The mass spectrum
was measured on a Varian 3200Q-TRAP. The IR spectrum was ob-
tained from a Varian 3100 FT-IR spectrometer in the region of
3800–450 cmꢁ1 (KBr pellet). The TG–DSC analysis was performed
with a Setaram Sensys TGA DSC coupled with the Varian TGA/IR
interface under an argon flow of 20 mL/min in the temperature
2.2.2. 1,3,5-Triethynylbenzene 2 [15]
A solution of 3 (6.54 g, 19.62 mmol) in toluene (100 mL) was
heated up to boiling. Powdered potassium hydroxide (3.30 g,
58.86 mmol) was added and the mixture refluxed for 5 h. After
cooling down to room temperature, diethyl ether (50 mL) was
added. The organic phase was washed with water (2 ꢂ 100 mL),
dried (Na2SO4), and evaporated to give a dark brown solid which
was purified by sublimation at 80 °C under vacuum yielding color-
less needles of 2 (1.56 g, 52%). Mp = 104 °C. 1H NMR (500.13 MHz,
CDCl3): dH = 7.57 (s, ArAH), 3.15 (s, C„CAH). 13C NMR
(125.76 MHz, CDCl3): dC = 135.6, 122.9 (ArAC), 81.6 (ArAC„C),
78.7 (ArAC„C).
Fig. 1. Three step synthesis of compound 1.

A.S. Münch et al. / Journal of Molecular Structure 1043 (2013) 103–108
105
2.2.3. 3,30,300-(Benzene-1,3,5-triyl)tripropiolic acid 1
performed using PLATON [18] and molecular graphics were gener-
ated using SHELXTL [17].
To a mixture of Mg (0.608 g, 25 mmol) in dry THF (25 mL), ethyl
bromide (2.72 g, 25 mmol) in dry THF (10 mL) was added dropwise
under an argon atmosphere. The mixture was stirred at room tem-
perature until the formation of ethylmagnesium bromide was
complete (1.5 h). Then, compound 2 (1.00 g, 6.70 mmol) in dry
THF (10 mL) was added and the stirring was continued for
15 min. After that, CO2 gas (99.2%, Praxair) was bubbled through
the solution at room temperature for 5 h. During this time, a yellow
brown solid was formed which changed the color to pale yellow.
The reaction mixture was acidified with 5% aqueous hydrochloric
acid (25 mL) and diluted with diethyl ether (25 mL) and water
(25 mL). The organic phase was separated, washed with water
(2 ꢂ 50 mL), dried (Na2SO4), and evaporated under reduced pres-
sure. The residue was stirred in CHCl3 (30 mL) at room temperature
for 3 h, then collected, and dried in vacuum at 60 °C to yield 1 as a
yellow powder (1.28 g, 68%). Mp 160 °C (dec.). 1H NMR
(500.13 MHz, DMSO-d6): dH = 14.07 (s, COOAH), 8.01 (s, ArAH).
13C NMR (125.76 MHz, DMSO-d6): dC = 153.8 (CACOOH), 137.4
(ArAC), 121.0 (ArAC), 83.1 (ArAC„C), 81.0 (C„CACOOH). IR:
ꢀ
3. Results and discussion
3.1. Synthesis of compound 1
For the synthesis of compound 1,
a three-step reaction
sequence as specified in Fig. 1 was used. In the first step, this
involves reaction of 1,3,5-tribromobenzene with 2-methylbut-3-
yn-2-ol applying a Pd-catalyzed Sonogashira–Hagihara CAC cou-
pling protocol [19,20] to the protected trialkyne 3. In a second step,
the protecting groups at the alkyne side arms were removed by
treatment with potassium hydroxide to give 2. Following a related
procedure [21] in the closing step, 2 was converted to 1 via a Grig-
nard addition to carbon dioxide with the Grignard reagent being
derived from 2 and ethylmagnesium bromide (prepared from ethyl
bromide and magnesium). Considering the sequence of reactions, 1
has been obtained in an overall yield of 30%.
All synthesized compounds were confirmed by melting point
measurements and 1H and 13C NMR spectroscopy. In addition,
the target compound 1 was characterized by IR spectroscopy, mass
spectrometry, and TG–DSC measurement.
m
= 3550, 3247, 3082, 2964, 2582, 2526, 2231, 1836, 1730, 1679,
1656, 1584, 1443, 1381, 1283, 1230, 1198, 1167, 1381, 913, 890,
795, 755, 672, 644, 607, 591. MS(ESI): m/z calc. for C15H6O6:
282.02, found: 282.1 [M]+.
3.2. FTIR spectroscopic study of 1
2.3. Single crystal X-ray analysis
The FTIR spectrum of 1 was recorded in the region from 450
to 3800 cmꢁ1 using a KBr pellet. Fig. 2 demonstrates the corre-
sponding IR spectrum of a crystalline sample dried in vacuum
at 60 °C for 3 h which does not indicate any typical bands of
the solvents mesitylene and ethanol that have been used for
crystallization. However, an intensive and broad band at
3247 cmꢁ1 denotes the inclusion of water molecules in the lat-
tice. This result points to the fact that strong hydrogen bonding
between the carboxyl groups and water molecules may have
formed.
The single crystal X-ray diffraction data of compound 1 were
collected at 100 K on a Bruker Kappa diffractometer equipped with
an APEX II CCD area detector and graphite-monochromatized Mo
Ka radiation (k = 0.71073 Å) employing u and x scan modes. The
data were corrected for Lorentz and polarization effects. Semiem-
pirical absorption correction was applied using the SADABS
program [16]. The SAINT program [16] was used for the integration
of the diffraction profiles. The crystal structure was solved by
direct methods using SHELXS-97 [17] and refined by full-matrix
least-squares refinement against F2 using SHELXL-97 [17]. All
non-hydrogen atoms were refined anisotropically. The hydrogen
atoms were generated at ideal geometrical positions and refined
with the appropriate riding model. Geometrical calculations were
Moreover, specific bands of the organic acid function can be
determined, such as OAH stretches at 2964 cmꢁ1, overtone and
combination bands in the range between 2526 and 2600 cmꢁ1
,
C@O stretch mode at 1730 cmꢁ1
, in plane OAH band at
Fig. 2. FTIR spectrum of 1 between 3800 and 450 cmꢁ1 (KBr pellet).

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A.S. Münch et al. / Journal of Molecular Structure 1043 (2013) 103–108
Fig. 3. TG–DSC analysis (a) of 1 combined with the IR spectrum of the gases released from the heated sample after 40 min (b). Curves in the upper diagram: black –
temperature ramp, gray – mass flow, and light gray – heat flow.
Table 1
1422 cmꢁ1, CAO vibration at 1283 cmꢁ1, and an out-of-plane OAH
Crystal data and refinement details of the structure determination.
band at 913 cmꢁ1. The intensive IR mode at 2231 cmꢁ1 indicates
Crystal data
1
C
the characteristic C„C stretch band of a disubstituted alkyne.
Beside these vibration bands, typical modes of the aromatic ring
are found, including CAH stretches between 3000 and
3100 cmꢁ1, summation bands at 1772 and 1836 cmꢁ1, ring modes
Empirical formula
Formula weight (g/mol)
Crystal description
Crystal system
Space group
Unit cell dimension (Å)
15H6O6ꢃH2O
300.21
Yellow needle
Monoclinic
P21/n
a = 13.9613(7)
b = 3.7082(2)
c = 30.6316(17)
b = 92.505(4)
1584.32(15)
4
at 1443 and 1584 cmꢁ1
, an in-of-plane CAH vibration at
1167 cmꢁ1, and an out-of-plane CAH band at 890 cmꢁ1. The vibra-
tion modes at 672, 890, and 1584 cmꢁ1 are bands characteristic of
the 1,3,5-substitution pattern of the aromatic ring [22].
V (Å3)
Z
Dx (g cmꢁ3
)
1.259
0.102
616
Absorption coefficient (mmꢁ1
F(000)
)
3.3. TG–DSC analysis of 1 coupled with IR spectroscopy
Crystal size (mm)
0.53 ꢂ 0.15 ꢂ 0.05
The thermogravimetry coupled with differential scanning calo-
rimetry of 5.35 mg of 1 were performed under an argon flow of
20 mL/min in the temperature range from 25 to 500 °C (Fig. 3a).
In order to investigate gases released by heating effects like decom-
position, the TG–DSC setup was coupled with an IR spectrometer.
At first, a sample of single crystals was intensively dried in vacuum
at 100 °C for 5 h removing all solvent molecules, like water, ethanol,
or mesitylene. The obtained TG curve possesses only one step
beginning at 160 °C. After 40 min, the corresponding IR spectrum
shows a flat broad band at 3250 cmꢁ1 typical of the OAH stretch
vibrations of water, two high bands at 2320 and 2355 cmꢁ1 corre-
lating with an asymmetric C@O valence vibration of carbon dioxide,
and a band at 667 cmꢁ1 belonging to the deformation vibration of
CO2. In addition, an exothermic effect was observed which is unu-
sual for melting processes (Fig. 3a). Thus, it can be reasoned that
the synthesized tricarboxylic acid decomposes at a temperature
higher than 160 °C. The evaluation of the peak area results in a va-
lue of ꢁ233 kJ/mol for the decomposition enthalpy.
Data collection
Temperature (K)
Radiation, wavelength (Å)
Collected reflections
h Range (°)
100(2)
Mo Ka, 0.71073
20,949
1.33–25
Index ranges
Unique data, Rint
R1, wR2 [l > 2 (l)]
h
k
l
ꢁ16/16, ꢁ4/4, ꢁ36/36
2808, 0.0595
r
0.0507, 0.1318
0.0753, 0.1451
R1, wR2 (all data)
Refinement
Nref, Npar
2808, 209
1.06
0.000, 0.000
ꢁ0.218, 0.419
Goodness of fit on F2
Max. and av. shift/error
Min. and max. resid. dens. (e Å3)
3.4. X-ray single crystal analysis of 1
Slow evaporation of the solvent from a solution of 1 in mesity-
lene/ethanol/water (10:1:1) yielded transparent yellow needles

A.S. Münch et al. / Journal of Molecular Structure 1043 (2013) 103–108
107
Table 2
Selected intermolecular hydrogen bonds of the studied structure.
Atoms involved
Symmetry
Distance (Å)
Angle (°)
Dꢃ ꢃ ꢃA
Hꢃ ꢃ ꢃA
D–Hꢃ ꢃ ꢃA
O1–H1ꢃ ꢃ ꢃO6
2 ꢁ x, 3 ꢁ y, ꢁz
2.617(2)
2.676(2)
2.490(2)
2.922(3)
2.870(3)
1.78
1.84
1.66
1.99
2.00
171
172
172
162
148
O3–H3ꢃ ꢃ ꢃO2
1 ꢁ x, 1 ꢁ y, ꢁz
O5–H5ꢃ ꢃ ꢃO1G
O1G–H1Gꢃ ꢃ ꢃO6
O1G–H2Gꢃ ꢃ ꢃO4
1 + x, 1 + y, z
3/2 ꢁ x, ꢁ3/2 + y, 1/2 ꢁ z
1/2 ꢁ x, 1/2 + y, 1/2 ꢁ z
Fig. 4. Molecular structure of 1, showing the atom labeling scheme with displace-
ment ellipsoids drawn at the 50% probability level.
Fig. 5. Hydrogen bond motif R34(12) including numbering of the involved oxygen
donor and acceptor atoms.
Fig. 6. Packing structure of 1 (a) and van-der-Waals model including illustration of
the channel framework (b).
suitable for single crystal X-ray investigation. Crystal data and
details of the structure determination are given in Table 1. The
compound crystallizes in the monoclinic space group P21/n, with
the unit cell containing 1, water and ethanol. While the water mol-
ecules are integrated in the crystal lattice by connecting the car-
boxyl functions, the other solvent molecules are only included in
the porous host lattice. Although the measurement took place at
100 K, it was not possible to precisely localize and refine the only
weakly bonded or disordered guest molecules. Therefore, the high
residual electron density was removed by the SQUEEZE method of
the PLATON program [18] and corresponds to approximate two
ethanol and two water molecules per unit cell. The further refine-
ment was executed with the solvent free host structure.
The molecular structure of the compound in the crystal is pre-
sented in Fig. 4 showing that the ethynyl substituents deviate from
the ideal linear geometry, which is obvious considering the alkyne
bond angles [171.97° (C1–C2–C3) and 177.21° (C2–C3–C10);
176.77° (C4–C5–C6) and 179.64° (C5–C6–C12); 170.93°
(C7–C8–C9) and 176.31° (C8–C9–C14)]. This deviation is probably
a consequence of the molecular arrangement in the solid state and
the intermolecular interactions being effective [23]. Furthermore,
the carboxyl groups are slight twisted with respect to the aromatic
ring plane as indicated by the interplanar angles of 9.08°
(O1–C1–O2), 6.66° (O3–C4–O4) and 13.66° (O5–C7–O6). In contrast
to the hydrogen bonded ‘‘chicken-wire’’ network typical for trimesic
acid [24], the structure of 1 shows a distinct difference in so far that a
water molecule is involved giving rise to a particular network pat-
tern. More strictly speaking, a water molecule as hydrogen bond do-
nor connects two carbonyl functions of two different molecules of 1
by strong OAHꢃ ꢃ ꢃO bonds [d(O1Gꢃ ꢃ ꢃO4) = 2.870(3) and d(O1G
ꢃ ꢃ ꢃO6) = 2.922(3) Å] [25,26]. A carboxyl group of another molecule
of 1 is included via hydrogen bonding [d(O3ꢃ ꢃ ꢃO2) = 2.676(2) and
d(O1ꢃ ꢃ ꢃO6) = 2.617(2) Å] to yield a new ring motif which follows
the graphset R34(12) (Fig. 5). Parameter details of thehydrogen bond-
ing interactions are specified in Table 2.
In the crystal packing, the molecules form a tape structure with
superimposed tapes held together by
the aromatic rings [27] and the alkyne units [28]. Tapes which lie
p–p interactions between

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A.S. Münch et al. / Journal of Molecular Structure 1043 (2013) 103–108
side by side are twisted against each other (interplanar angle:
60.63°) and are stabilized by strong OAHꢃ ꢃ ꢃO bonds
[d(O5ꢃ ꢃ ꢃO1G) = 2.490(2) Å] between the acid hydroxyl group
O5–H5 and the water oxygen O1G. Three different types of chan-
nel-like voids (A, B and C) exist in the lattice having different
dimensions (Fig. 6). Ethanol is probably included in the biggest
channel (A, ca. 4.0 ꢂ 6.1 Å2), whereas water should be included in
the smaller channel (B, ca. 2.3 ꢂ 3.1 Å2). The third channel (C,
1.7 ꢂ 2.4 Å2) is most probably unfilled because it is too small for
inclusion of any solvent molecules. With the PLATON program
[18], a packing index of the unit cell of 60.5% and a solvent acces-
sible void of 321.3 Å3, which equates to 20% of the unit cell volume,
was calculated.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.molstruc.2013
.04.005.
References
[1] D.B. Clapp, A.A. Morton, J. Am. Chem. Soc. 58 (1936) 2172.
[2] (a) S. Chandrasekhar, G.A. Ranganath, Rep. Prog. Phys. 53 (1990) 57;
(b) S. Sergeyev, W. Pisula, Y.H. Geerts, Chem. Soc. Rev. 36 (2007) 1902;
(c) R.J. Bushby, K. Kawata, Liq. Cryst. 38 (2011) 1415.
[3] (a) P. Besenius, K.P. van den Hout, H.M.H.G. Albers, T.F.A. de Greef, L.L.C. Olijve,
T.M. Hermans, B.F.M. de Waal, P.H.H. Bomans, N.A.J.M. Sommerdijk, G. Portale,
A.R.A. Palmans, M.H.P. van Genderen, J.A.J.M. Vekemans, E.W. Meijer, Chem.
Eur. J. 17 (2011) 5193;
(b) E. Weber, Angew. Chem. Int. Ed. 22 (1983) 616.
[4] D.K. Smith, in: J.L. Atwood, J.W. Steed (Eds.), Organic Nanostructures, Wiley-
VCH, Weinheim, 2008, pp. 111–154.
[5] (a) K. Nøgaard, M.B. Nielsen, T. Bjørnholm, in: T.J.J. Müller, U.H.F. Bunz (Eds.),
Functional Organic Materials, Wiley-VCH, Weinheim, 2007, pp. 353–392;
(b)B. Pignataro (Ed.), Molecules at Work, Wiley-VCH, Weinheim, 2012.
[6] (a) J.W Steed, D.R Turner, K.J Wallace, Core Concepts in Supramolecular
Chemistry and Nanochemistry, Wiley, Chichester, 2007;
(b) J.W. Steed, A.L. Atwood, Supramolecular Chemistry, second ed., Wiley,
Chichester, 2009.
4. Conclusion
A new trigonal compound 1 featuring three propiolic acid side
arms symmetrically attached to a benzene core, being expected
to be a useful building block in the design and construction of
metal–organic or hydrogen bond stabilized networks, has been
synthesized via a three step reaction sequence involving metal
assisted coupling procedures. 1H and 13C NMR as well as FTIR spec-
troscopic data show characteristic properties of the compound
constitution. TG–DSC analysis combined with IR measurements
demonstrate instability of 1 exposed to a temperature higher than
160 °C by the escape of carbon dioxide. In the crystalline state, 1 is
involved in hydrogen bonding to water molecules, giving rise to a
new hydrogen-bonded ring motif following the graph set R34(12).
The packing structure is typically interspersed with channel-like
voids (A, B and C) of different dimensions containing proportional
to their sizes additional solvent molecules, i.e. ethanol (A) or water
(B). These interstitially included solvent molecules obviously con-
tribute to the stability of the crystal lattice since a distinct change
or decay of the crystal structure is indicated upon their removal.
Nevertheless, the presented linker- or tecton-type molecule 1
could be useful for the formation of porous metal–organic frame-
works helping to suppress interpenetration because of its moder-
ate length and rigidity of the side arms. Aside, the ethynylic
[7] (a) F. Vögtle, G. Richard, N. Werner, Dendrimer Chemistry, Wiley-VCH,
Weinheim, 2009;
(b) D.D. MacNicol, G.A. Downing, in: D.D. MacNicol, F. Toda, R. Bishop (Eds.),
Comprehensive Supramolecular Chemistry, vol. 6, Elsevier, Oxford, 1996, pp.
421–464;
(c) F. Vögtle, E. Weber, Angew. Chem. Int. Ed. 18 (1979) 753.
[8] (a)K. Rurack, R. Martínez-Máu˜ez (Eds.), The Supramolecular Chemistry of
Organic–Inorganic Hybrid Materials, Wiley, Hoboken, 2010;
(b)L.R. MacGillivary (Ed.), Metal-Organic Frameworks, Wiley, Hoboken, 2010;
(c) A.S. Münch, J. Seidel, A. Obst, E. Weber, F.O.R.L. Mertens, Chem. Eur. J. 17
(2011) 10958.
[9] (a) J.A.A.W. Elemans, S. Lei, S. De Feyter, Angew. Chem. Int. Ed. 48 (2009) 7298;
(b) D. Bonifazi, S. Mohnani, A. Llanes-Pallas, Chem. Eur. J. 15 (2009) 7004.
[10] (a) J.-X. Jiang, F. Su, A. Trewin, C.D. Wood, N.L. Campbell, H. Niu, C. Dickinson,
A.J. Ganin, M.J. Rosseinsky, Y.Z. Khimyak, A.I. Cooper, Angew. Chem. Int. Ed. 46
(2007) 8574;
(b) E. Sheepwash, V. Krampe, R. Scopelliti, O. Sereda, A. Neels, K. Severin,
Angew. Chem. Int. Ed. 50 (2011) 3034.
[11] (a) D. Kim, X. Song, J.H. Yoon, M.S. Lah, Cryst. Growth Des. 12 (2012) 4186;
(b) J. Li, Z. Ma, K. Deng, S. Lei, Q. Zeng, X. Fan, S. De Feyter, W. Huang, C. Wang,
Chem. Eur. J. 15 (2009) 5418;
(c) S. Förster, W. Seichter, E. Weber, Z. Naturforsch. 66b (2011) 939.
[12] (a) G. Féréy, C. Serre, C. Mellot-Draznieks, F. Millange, S. Surblé, J. Dutour, I.
Margiolaki, Angew. Chem. Int. Ed. 43 (2004) 6296;
(b) C. Mellot-Draznieks, J. Dutour, G. Férey, Angew. Chem. Int. Ed. 43 (2004)
6290;
(c) S. Griessl, M. Lackinger, M. Edelwirth, M. Hietschold, W.M. Heckl, Single
Mol. 3 (2002) 25;
p-electrons could interact with small molecules in ways that can
be exploited for the practical use of the respective compounds.
(d) A. Dimitriev, N. Lin, J. Weckesser, J.V. Barth, K. Kern, J. Phys. Chem. B 106
(2002) 6907;
Acknowledgments
(e) S.V. Kolotuchin, E.E. Fenlon, S.R. Wilson, C.J. Loweth, S.C. Zimmerman,
Angew. Chem. Int. Ed. 34 (1995) 2654.
[13] L. Kampschulte, M. Lackinger, A.-K. Maier, R.S.K. Kishore, S. Griessl, M.
Schnittel, W.M. Heckl, J. Phys. Chem. B 110 (2006) 10829.
[14] (a) P. Vishweshwar, D.A. Beauchamp, M.J. Zaworotko, Cryst. Growth Des. 6
(2006) 2429;
(b) B.R. Bhogala, P. Vishweshwar, A. Nangia, Cryst. Growth Des. 2 (2002) 325.
[15] W. Shu, C. Guan, W. Guo, C. Wang, Y. Shen, J. Mater. Chem. 22 (2012) 3075.
[16] S.A.I.N.T. Bruker, SADABS, Bruker AXS Inc., Madison, Wisconsin, USA, 2007.
[17] G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
Financial support by the European Union (European regional
development fund) and by the Ministry of Science and Art of Sax-
ony (Cluster of Excellence ‘‘Structure Design of Novel High-Perfor-
mance Materials via Atomic Design and Defect Engineering
[ADDE]’’) is gratefully acknowledged by F.K. A.M. thanks the Deut-
sche Forschungsgemeinschaft (Priority Program 1362 ‘‘Porous Me-
tal-Organic Frameworks’’) for financial support. We thank Anja
Obst for conducting the SEM measurements, Jürgen Seidel and Jut-
ta Lange for carrying out the TG–DSC–IR measurements.
[18] A.L. Spek, Acta Crystallogr. D65 (2009) 148.
[19] K. Sonogashira, Y. Tohda, N. Hagihara, Tetrahedron Lett. 16 (1975) 4467.
[20] S. Takahashi, Y. Kuroyama, K. Sonogashira, N. Hagihara, Synthesis 8 (1980)
627.
[21] R. Saravanakumar, B. Varghese, S. Sankararaman, CrystEngComm 11 (2009)
337.
Appendix A. Supplementary material
[22] B. Smith, Infrared Spectral Interpretation, CRC Press, New York, 1999.
[23] F. Katzsch, D. Eißmann, E. Weber, Struct. Chem. 23 (2012) 245.
[24] F.H. Herbstein, M. Kapon, G.M. Reisner, J. Inclusion Phenom. 5 (1987) 211.
[25] C. Fischer, G. Lin, W. Seichter, E. Weber, Tetrahedron 67 (2011) 5656.
[26] D. Eißmann, F. Katzsch, E. Weber, Struct. Chem. 23 (2012) 1131.
[27] C.A. Hunter, J.K.M. Sanders, J. Am. Chem. Soc. 112 (1990) 5525.
[28] P.R. Schreiner, M. Prall, V. Lutz, Angew. Chem. Int. Ed. 42 (2003) 5757.
The crystallographic information file has been deposited by
using the Cambridge structure database (CCDC 912744). These
data can be obtained free of charge via www.ccdc.cam.ac.uk/data-
request/cif, by e-mailing data-request@ccdc.com.ac.uk or by con-
tacting the Cambridge CB21 EZ, UK; fax: +44 1223 336033.