Synthesis and characterization of monomeric and dimeric structures of calix[4]arenes containing amidoferrocene

Article abstract of DOI:10.1007/s10870-007-9301-y

The reaction of 1,1′-bis(chlorocarbonyl)ferrocene with bis-aminobenzylcalix[4]arene gave amidoferrocene calix[4]arene monomer 1. Compound 1 crystallized in the monoclinic system P21/c with a = 11.196(6) A, b = 14.971(11) A, c = 32.007(2) A, β = 96.413(4)°

Full text of DOI:10.1007/s10870-007-9301-y

J Chem Crystallogr (2008) 38:363–368
DOI 10.1007/s10870-007-9301-y
ORIGINAL PAPER
Synthesis and Characterization of Monomeric and Dimeric
Structures of Calix[4]arenes Containing Amidoferrocene
Chomchai Suksai Æ Pannee Leeladee Æ
Colin Jennings Æ Thawatchai Tuntulani Æ
Palangpon Kongsaeree
Received: 4 July 2007 / Accepted: 5 November 2007 / Published online: 17 November 2007
Ó Springer Science+Business Media, LLC 2007
Abstract The reaction of 1,10-bis(chlorocarbonyl)
ferrocene with bis-aminobenzylcalix[4]arene gave amido-
ferrocene calix[4]arene monomer 1. Compound 1 crystal-
Introduction
Calixarenesaresyntheticmacrocyclesusedas buildingblocksin
nanotechnology and supramolecular chemistry [1]. They were
also used as molecular scaffolds for the preparation of novel
selective receptors for ions and neutral molecules [2]. Moreover,
calix[4]arene bearing a sensory unit have been attracted much
chemist’s attention in recent years owing to possible applica-
tions as chemical sensors [3–5]. For example, calixarenes
functionalized with the amidoferrocene group have been shown
to be very effective electrochemical sensors for cations [6–8]
anions [9–12] and neutral molecules [13–14]. Herein, we report
the synthesis and characterization of calix[4]arenes containing
amidoferrocene units 1–3 including the crystal structure of 1
determined by X-ray diffraction analysis.
˚
lized in the monoclinic system P21/c with a = 11.196(6) A,
˚
˚
b = 14.971(11) A, c = 32.007(2) A, b = 96.413(4)° and
3
V = 5330.9(6) A . X-ray diffraction analyses of 1 showed
˚
that the calix[4]arene scaffold was in cone conformation in
which the intramolecular hydrogen bonding were formed
through OH groups at the lower rim to stabilize the structure.
Moreover, the intramolecular hydrogen bond between the
amide groups of the amidoferrocene unit also presented
in the crystal structure. On the other hand, the condensation
of 1,10-bis(chlorocarbonyl)ferrocene with p-tert-bis-amin-
obenzylcalix[4]arene resulted in the monomeric 2 and
1
[2 + 2] dimeric compounds 3. H-NMR studies signified
that the calix[4]arene building block in compounds 2 and 3
adopted the cone conformation.
Fe
O
O
Fe
NH
HO
HN
OH
Keywords Metallocene ꢀ Amidoferrocene ꢀ
O
O
Calix[4]arene
NH
HN
O
O
O
O
OH
HO
C. Suksai (&)
Department of Chemistry, Faculty of Science, Burapha
University, Chonburi 20131, Thailand
e-mail: jomjai@buu.ac.th
(1)
(2)
O
O
O
O
P. Leeladee ꢀ C. Jennings ꢀ T. Tuntulani (&)
Department of Chemistry, Faculty of Science, Chulalongkorn
University, Bangkok 10330, Thailand
Fe
O
O
N
H
N
H
OH
OH
HO
HO
H
N
H
N
e-mail: tthawatc@chula.ac.th
O
O
Fe
P. Kongsaeree
Department of Chemistry, Faculty of Science, Mahidol
University, Bangkok 10400, Thailand
(3)
123

364
J Chem Crystallogr (2008) 38:363–368
Experimental
presence of triethylamine (0.26 mL, 1.50 mol) in dried
CH2Cl2 and the solution was stirred at room temperature
for 4 h under N2. The organic layer was washed with water
(3 9 100 mL), dried with anhydrous MgSO4 and filtered.
The solvent was removed under reduced pressure. The
residue was purified by SiO2 column chromatography
using CH2Cl2:EtOAc (2:1) as eluant to obtain compound 1
as an orange powder in 0.135 g (25% yield). Orange
crystals of 1 suitable for X-ray structural investigations
were obtained by slow evaporation of the solution of 1 in
All reagents were of reagent grade and were used without
1
further purification unless stated otherwise. H-NMR, 13C-
NMR and 2D-NMR spectra were record in DMSO-d6 on a
BRUKER AVANCE 400 NMR spectrometer. Elemental
analyses were performed on a Perkin-Elmer 2400 CHN
elemental analyzer.
1
Synthesis of compound 1
CHCl3. H-NMR (400 MHz, CDCl3, ppm): d 8.49 (s, 2H,
NH), 8.19 (s, 2H, OH), 8.10 (s, 2H, ArH), 7.75 (d, 2H,
ArH), 7.32 (t, 2H, ArH), 7.18 (d, 2H, ArH), 7.08 (d,
4H, ArH), 6.95 (d, 4H, ArH), 6.82 (t, 2H, ArH), 6.65 (t, 2H,
ArH), 5.01 (s, 4H, –OCH2–), 4.86 (s, 4H, CpH), 4.55
(s, 4H, CpH), 4.32 (d, J = 12 Hz, AB system, Ar–CH2–
Ar), 3.95 (d, J = 12 Hz, AB system, Ar–CH2–Ar). ESI-MS
(positive mode) m/z: 873.34 [M + H]+. Analysis calculated
for C54H44FeN2O6: C 74.31, H 5.08, N 3.21%; found: C
74.35, H 5.10, N 3.25%.
bis-Nitrobenzylcalix[4]arene (a)
Calix[4]arene (0.50 g, 1.20 mmol), K2CO3 (0.162 g,
1.20 mmol) and a catalytic amount of KI in 50 mL of dry
acetonitrile were stirred at room temperature for 30 min
under N2. The solution of 3-nitrobenzylchloride (0.50 g,
2.90 mmol) in 30 mL of dried acetonitrile was then added
dropwise and the solution mixture was refluxed for 24 h.
After cooling to room temperature, the solvent was evap-
orated in vacuo and the residue was dissolved in CH2Cl2
(100 mL). The organic layer was washed with 3 M HCl
(2 9 100 mL) and water (2 9 100 mL). The organic layer
was dried with anhydrous MgSO4 and filtered. The solvent
was removed under a reduced pressure to obtain a residue.
Purification by SiO2 column chromatography using a
mixture of CH2Cl2/hexane (1:1) as eluent gave bis-nitro-
benzylcalix[4]arene (a) as a white powder (0.52 g, 63%).
Synthesis of Compounds 2 and 3
p-tert-Butyl-bis-nitrobenzylcalix[4]arene (c)
A mixture of p-tert-butyl-calix[4]arene (2.00 g, 3.13 mmol),
K2CO3 (0.435 g, 3.13 mmol) and a catalytic amount of KI
in 50 mL of dried acetonitrile was stirred at room tem-
perature under N2 for 30 min. The solution of
3-nitrobenzylchloride (1.31 g, 7.63 mmol) in 30 mL of
dried acetonitrile was added dropwise and the solution
mixture was refluxed for 24 h. The solvent was evaporated
in vacuo and CH2Cl2 (100 mL) was added. The organic
phase was washed with 3 M HCl (2 9 100 mL) and water
(2 9 100 mL). The organic layer was dried with anhy-
drous MgSO4 and filtered. The solvent was removed to
give crude c. The crude product was placed on a silica gel
column using 30% Hexane:CH2Cl2 as eluant to obtain
compound c as a white powder (1.982 g, 69%).
bis-Aminobenzylcalix[4]arene (b)
Reduction of the bis-nitrobenzylcalix[4]arene (a) to bis-
aminobenzylcalix[4]arene was carried out using Raney
Nickel and hydrazine. Hydrazine (2.28 mL, 46 mmol) was
added to the solution mixture of bis-nitrobenzylca-
lix[4]arene (0.50 g, 0.72 mmol) and Raney Nickel
(0.376 g, 6.5 mmol) in the mixture of ethyl acetate:meth-
anol (15:11 mL) under N2 atmosphere. The solution was
heated at 60 °C for 1 h. After cooling to room temperature,
the solution was filtered and the solvent was evaporated.
The residue was dissolved in 50 mL of CH2Cl2 and washed
with water (2 9 50 mL). The organic layer was then dried
with anhydrous MgSO4, filtered and the solvent was
evaporated to give bis-aminobenzylcalix[4]arene (b) in a
quantitative yield.
p-tert-Butyl-bis-aminobenzylcalix[4]arene (d)
Compound c (0.67 g, 0.73 mmol) and Raney Ni (0.42 g,
7.30 mmol) were suspended in a mixture of ethylacetate
15 mL and MeOH 11 mL under N2. Subsequently,
hydrazine (2.3 mL, 47 mmol) was added and the mixture
was heated at reflux for 2 h. The unreacted Raney Ni was
removed while the solution was still warm and the filtrate
was removed under reduce pressure. The crude product
was then dissolved in CH2Cl2 50 mL and washed with
water (3 9 50 mL). The organic layer was separated and
Compound (1)
Compound b (0.40 g, 0.60 mmol) was reacted with 1,10-
bis(chlorocarbonyl)ferrocene (0.19 g, 0.60 mmol) in the
123

J Chem Crystallogr (2008) 38:363–368
365
X-ray Crystal Structure Determination
dried over anhydrous MgSO4. The solvent was removed in
vacuo to obtain compound d as a white solid in a quanti-
tative yield.
X-ray diffraction measurement for 1 was performed on a
Bruker–Nonius Kappa CCD diffractometer with graphite-
˚
monochromated Mo-Ka radiation (k = 0.7107 A). The
data collection was performed on COLLECT program [15].
Crystal cell refinement and data reduction were carried out
using HKL DENZO and SCALEPACK [16]. The struc-
tures were solved by direct method and were refined on F2
by full-matrix least-squares technique using the SHELXL-
97 [17] program on WinGX package [18]. Crystal data,
data collection parameters and structure refinement details
are given in Table 1. During the last stage of the refine-
ment, disorder on chlorine atoms of chloroform in the
structure of 1 was found. The disorder was modeled with
two equally weighted sets of chlorine atoms. The non-H
atoms were refined with anisotropic displacement thermal
Compounds (2) and (3)
To a stirred solution of compound d (0.67 g, 0.73 mmol)
and triethylamine (0.26 mL, 1.83 mmol) in 150 mL of
CH2Cl2 was added a solution of 1,10-bis(chlorocar-
bonyl)ferrocene (0.23 g, 0.73 mmol) in dichloromethane
(20 mL). The solution was stirred at room temperature for
4 h. The solution was subsequently washed with water
(2 9 100 mL) and the organic layer was dried over
anhydrous Na2SO4. The solvent was removed by a rotary
evaporator to give a red oily residue which was purified by
column chromatography (SiO2) using 20% EtOAc:CH2Cl2
as eluent. The orange solid of monomeric compound 2
(Rf = 0.65) (0.16 g, 22%) and dimeric compound 3
(Rf = 0.78) (0.24 g, 5%) were obtained.
Table 1 Crystallographic data and final refinement parameters for
(1)
(1)
Chemical formula
Molecular weight
Color
C56H46Cl6N2FeO6
1111.49
Compound (2)
Orange
1H-NMR (400 MHz, CDCl3, ppm): d 8.60 (s, 2H, NH),
8.08 (s, 2H, OH), 7.76 (s, 2H, ArH), 7.67 (d, 2H,
J = 6.4 Hz, ArH), 7.28 (t, 2H, J = 7.2 Hz, ArH), 7.17 (d,
2H, J = 7.6 Hz, ArH), 7.03 (s, 4H, ArH), 6.90 (s, 4H,
ArH), 4.95 (s, 4H, –OCH2–), 4.87 (s, 4H, CpH), 4.50 (s,
4H, CpH), 4.27 (d, J = 13.2 Hz, AB system, Ar–CH2–Ar),
3.31 (d, J = 12.8 Hz, AB system, Ar–CH2–Ar), 1.26 (s,
18H, Ar–CH3), 1.05 (s, 18H, Ar–CCH3). ESI-MS (positive
mode) m/z: 1154.24 [M + H2O + K]+. Analysis calculated
for C70H76FeN2O6: C 76.63, H 6.98, N 2.55%; found: C
76.65, H 7.01, N 2.53%.
Size (mm3)
0.284 9 0.203 9 0.113
293(2) K
Monoclinic
P21/c
Temperature (K)
Crystal system
Space group
˚
a (A)
11.1960 (6)
14.9700 (11)
32.007 (2)
90
˚
b (A)
˚
c (A)
a (°)
b (°)
c (°)
96.413 (4)
90
3
˚
V (A)
5330.9 (6)
4
Z
F(000)
Dcalc (g cm-3
l (mm-1
2284
Compound (3)
)
1.384
1H-NMR (400 MHz, CDCl3, ppm): d 8.85 (br, s, 2H, NH),
8.16 (br, s, 2H, ArH), 8.03 (br, s, 2H, ArH), 7.70 (br, s, 2H,
OH), 7.43 (br, s, 2H, ArH), 7.28 (br, s, 2H, ArH), 7.13 (s,
4H, ArH), 6.88 (s, 4H, ArH), 5.05 (s, 4H, –OCH2–), 4.56
(s, 4H, CpH), 4.40 (s, 4H, CpH), 4.39 (d, J = 12.0 Hz, AB
system, Ar–CH2–Ar), 3.39 (d, J = 11.6 Hz, AB system,
Ar–CH2–Ar). 13C-NMR (400 MHz, CDCl3, ppm): d
168.98, 150.64, 149.52, 147.33, 141.87, 139.08, 137.89,
132.62, 129.89, 127.83, 125.66, 125.19, 121.71, 118.98,
117.34, 71.39, 71.03, 31.73, 31.01. ESI-MS (positive
mode) m/z: 2212.03 [M + H2O + H]+. Analysis calcu-
lated for C140H152Fe2N4O12: C 76.63, H 6.98, N 2.55%;
found: C 76.66, H 6.96, N 2.57%.
)
0.635
h range for data collection
2.11–21.920
-10 B h B 11
-15 B k B 14
-33 B l B 31
Index ranges
Reflections collected/observed
15388/5976
[R(int) = 0.0783]
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I [ 2 r(I)]
R indices (all data)
5976/0/704
1.006
R1 = 0.0740, wR2 = 0.1711
R1 = 0.1326, wR2 = 0.2084
0.358, -0.234
Largest diff. peak
and hole (e - A
-3
)
˚
123

366
J Chem Crystallogr (2008) 38:363–368
parameters at the latter stages of refinement. All hydrogen
atoms (except H22, H27 and H45) are placed in geomet-
rically idealized positions and refined using general
isotropic temperature factors. The H atom bonded to C56
of the CHCl3 solvent molecule in (1) is not found in the
Fourier maps, but is accounted for in the formula sum and
formula weight calculations.
of 3 are closer to each other than that of compound 2. The
dimeric structure of compound 3 was substantiated by ESI-
MS revealing the [M + H2O + H]+ at m/z = 2212.03. The
transannular 1,3-hydroxyl groups distance of p-tert-butyl-
calix[4]arene is probably small to allow only 1 + 1 or
2 + 2 bridged ferrocene-calixarene species to occur
whereas the 3 + 3 oligomers can be produced from the
wider transannular of unsubstituent para-calix[4]arene
[19]. However, in our system the 2 + 2 and 3 + 3 bridge
Results and Discussion
ferrocene-calix[4]arenes of compound
observed.
1
were not
Synthesis and Characterization
The synthetic methods of calix[4]arenes containing
amidoferrocene 1, 2 and 3 are summarized in Scheme 1.
The structures of all compounds were characterized by
ESI-MS, NMR and elemental analyses.
Molecular Structure of Compound 1
Molecular structure of compound 1 is shown in Fig. 2. The
conformation of 1 exists as a cone conformation. The two
strong intramolecular O–HꢀꢀꢀO hydrogen bonding between
the phenolic oxygens and the proximal ethereal oxygens,
The cone conformation of the synthesized compounds
was confirmed by 1H-NMR spectrum. A typical AB pattern
of the methylene bridge (ArCH2Ar) protons was observed
at 4.37 and 3.13 ppm (J = 12.0 Hz), 4.37 and 3.13 ppm
(J = 12.0 Hz), 4.37 and 3.13 ppm (J = 12.0 Hz) for com-
pounds 1, 2 and 3, respectively. The NH amide protons
were found at downfield positions around 8.50–8.85 ppm
due to the formation of an intramolecular hydrogen bond-
ing of the amidoferrocene unit, in agreement with the
crystal structure, vide infra. The positive ion electrospray
mass spectrometry of 1 and 2 show the peak corresponding
to the monomer species at m/z = 1321.63 [M + Na]+ and
1154.24 [M + H2O + K]+, respectively.
CpH
Monomer (2)
NH
1
Interestingly, the H-NMR spectra of compounds 2 and
CpH
Dimer (3)
3 (Fig. 1) show that the integration of all peaks in the
spectrum of 3 is equal to that of 2. However, the feature of
the peaks of compounds 2 and 3 are totally different. The
NH
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
1
dimeric molecule 3 shows broader peaks in the H-NMR
spectrum. Moreover, the two singlet protons of the Cp ring
Fig. 1 1H-NMR spectra of monomer 2 and dimer 3 in CDCl3
Scheme 1 Strategy for the
synthesis of calix[4]arene
NO2O2N
NH2 H2N
HO
HO
OH
OH
(iii)
amidoferrocene derivatives
(1)–(3); (i) CH3CN, KI, reflux
24 h, (ii) Raney/Ni, hydrazine,
EtOAc:MeOH 15:11, reflux
60 °C 1 h and (iii) 1,10-
bis(chlorocarbonyl)ferrocene,
CH2Cl2, rt, 3 h
(ii)
(i)
(1)
O
O
O
O
HO
OH
HO
OH
(b)
(a)
NO2O2N
NH2H2N
HO
HO
OH
OH
(ii)
(i)
O
O
O
O
(iii)
HO
HO
OH
OH
(2) and (3)
(d)
(c)
123

J Chem Crystallogr (2008) 38:363–368
367
˚
Table 2 (a) Selected bond lengths (A) and angles (°) of compound 1.
˚
(b) Hydrogen-bonding geometry (A, °) for compound 1
(a)
Bond lengths
C(20)–O(3)
C(26)–O(2)
C(29)–O(2)
C(47)–O(6)
C(4)–O(1)
C(13)–O(4)
1.370(7)
1.409(7)
1.452(6)
1.212(10)
1.368(8)
1.403(7)
C(54)–O(4)
C(36)–O(5)
C(47)–N(1)
C(48)–N(1)
C(35)–N(2)
C(36)–N(2)
1.457(7)
1.231(7)
1.344(10)
1.434(8)
1.423(9)
1.352(9)
Bond angles
O(1)–C(4)–C(5)
O(1)–C(4)–C(3)
C(8)–C(13)–O(4)
116.9(7) N(2)–C(36)–C(37) 115.8(6)
121.4(6) N(1)–C(47)–C(46) 116.0(8)
118.8(6) C(53)–C(48)–N(1) 118.7(6)
C(12)–C(13)–O(4) 117.6(7) C(49)–C(48)–N(1) 121.9(8)
O(3)–C(20)–C(15) 121.8(6) O(4)–C(54)–C(52) 109.6(6)
O(3)–C(20)–C(19) 116.0(6) C(26)–O(2)–C(29) 111.6(4)
O(2)–C(29)–C(30) 110.1(5) C(13)–O(4)–C(54) 117.0(4)
C(33)–C(35)–N(2) 119.2(6) O(6)–C(47)–N(1)
C(34)–C(35)–N(2) 121.7(6) O(6)–C(47)–C(46) 119.7(9)
O(5)–C(36)–N(2) 121.7(7) C(47)–N(1)–C(48) 129.0(7)
124.4(8)
Fig. 2 A view of the asymmetric unit of 1, displacement ellipsoids
are drawn at 30% probability level and intramolecular hydrogen
bonds are shown as dashed lines. H atoms have been omitted for
clarity, except for those involved in hydrogen bonding
O(5)–C(36)–C(37) 122.6(7) C(36)–N(2)–C(35) 125.5(6)
(b)
˚
˚
O(1)–O(2) 2.815 A and O(3)–O(4) 2.754(6) A, are jointly
responsible for such a cone conformation. This result is in
¨
agreement with the reports by Brunink [20] and Bohmer
D–HꢀꢀꢀA
D–H
HꢀꢀꢀA
DꢀꢀꢀA
D–HꢀꢀꢀA
O1–H21ꢀꢀꢀO2
O3–H22ꢀꢀꢀO4
N1–H29ꢀꢀꢀO5
0.82
2.05
2.815(5)
2.754(6)
2.925(7)
155.9
173(8)
135.6
0.81(7)
0.96
1.95(8)
2.16
[21] which presented that the presence of two vicinal or
two opposite phenolic groups is sufficient to stabilize the
cone conformation, with a preference for OH-depleted or
substituted calix[4]arenes to adopt the 1,3-alternate for-
mation. It should be mentioned that the distance of
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (Fax:
+44-1233-336033; e-mail: deposit@ccdc.cam.ac.uk).
˚
separation of the transannular 1,3-hydroxyl groups 3.169 A
which is larger than the distance of the original calix[4]-
˚
arene (ca. 2 A) [22]. However, this distance is less than the
˚
cyclopentadienyl–cyclopentadienyl distance of 3.25 A
Acknowledgements The financial support from The Thailand
Research Fund and the Center of Innovation in Chemistry: Post-
graduate Education and Research Program in Chemistry (PERCH-
CIC) are gratefully acknowledged. CJ is supported by the NSF-REU
Thailand program.
˚
[23]. The average Fe–Cp(centroid) distance is 1.620 A
which is identical to other ferrocenyl derivatives [24–25],
and the angle of Cp–Fe–Cp is 178.81°.
The more intriguing feature of this molecule is the
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˚
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