Inorganic Chemistry
ARTICLE
and the structure demonstration of the corresponding Cu2+ and
Zn2+ complexes by single crystal XRD. In addition to this, the
phosphate binding of the in situ prepared zinc complex of L,
[ZnL], has also been demonstrated.
13C NMR (CDCl3, 100 MHz, δ ppm): 31.3, 37.8 (C(CH3)3), 34.0, 34.3
(C(CH3)3), 32.3 (ArÀCH2ÀAr), 42.7 (CH2N), 78.7 (OCH2), 125.6,
126.0, 127.8, 133.3, 142.2, 147.7, 149.3, 150.4 (ArÀC). ES MS: m/z =
735.26 (M+, 100%).
Synthesis and Characterization of L. A mixture of 2 (0.3 g,
0.43 mmol) and 1c (0.33 g, 0.85 mmol) were stirred in 50 mL of methanol
at room temperature for 12 h, and the yellow precipitate that formed was
filtered, washed, and dried under vacuum. Yield (0.33 g, 52%). Anal.
’ EXPERIMENTAL SECTION
General Information and Materials. 1H and 13C NMR spectra
were measured on a Varian Mercury NMR spectrometer working at
400 MHz. The mass spectra were recorded on Q-TOF micromass (YA-105)
using electrospray ionization method. Steady state fluorescence spectra
were measured on Perkin-Elmer LS55. The absorption spectra were
measured on Varian Cary 100 Bio. The elemental analyses were
performed on a ThermoQuest microanalysis instrument, and the FT
IR spectra were measured on Perkin-Elmer spectrometer using KBr
pellets. The diffraction data were collected on OXFORD DIFFRAC-
Calcd for C100H120N4O6 3CH3OH: C, 78.79; H, 8.47; N, 3.57. Found:
3
C, 78.76; H, 8.10; N, 3.54%. FTIR (KBr, cmÀ1): 3397 (νOH), 1633
(νCdN). 1H NMR (CDCl3, δ ppm): 0.85 (s, 18H, C(CH3)3), 1.16 (s,
18H, C(CH3)3), 1.19 (s, 18H, C(CH3)3), 3.17 (d, 4H, ArÀCH2ÀAr, J =
13.8 Hz), 3.49 (s, 8H, ArÀCH2), 3.56 (s, 4H, ArÀCH2), 4.00 (t, OCH2,
4H, J = 5.5 Hz), 4.16 (m, 8H, ArÀCH2ÀAr and NCH2), 6.67 (s, 4H,
ArÀH), 6.90 (s, 4H, ArÀH), 7.10À7.33 (m, 24H, ArÀH), 7.56 (s, 2H,
ArÀOH), 8.53 (s, 2H, CHdN), 13.12 (s, 2H, ArOH). 13C NMR
(CDCl3, 100 MHz, δ ppm): 31.2, 31.6, 31.8 (C(CH3)3), 31.4 (ArÀ
CH2ÀAr), 33.9, 34.0, 34.1 (C(CH3)3), 51.2 (PhÀCH2ÀN), 58.5
(NCH2), 59.0 (NCH2CH2), 75.5 (OCH2), 118.1, 125.2, 125.8, 126.3,
126.6, 126.9, 127.9, 128.3, 128.7, 129.0, 129.4, 130.6, 132.5, 140.2, 140.9,
141.5, 147.1, 149.9, 150.7, 157.3 (ArÀC), 168.0 (NCH). ES MS: m/z =
1474 (M+, 20%).
TION XCALIBUR-S. All the perchlorate salts, viz., Mn(ClO4)2 6H2O,
3
Fe(ClO4)2 xH2O, Co(ClO4)2 6H2O, Ni(ClO4)2 6H2O, Cu(ClO4)2
3
3
3
3
6H2O, Zn(ClO4)2 6H2O, Cd(ClO4)2 H2O, NaClO4 H2O, KClO4,
Ca(ClO4)2 4H2O, and Mg(ClO4)2 6H2O, were procured from Sigma
3
3
3
3
3
Aldrich Chemical Co. Salts possessing different anions, viz., Bu4NF,
Me4NCl, Bu4NBr, Bu4NI, Bu4NClO4, Bu4NH2PO4, Na2HPO4,
Na4P2O7, NaSCN, NaOAc, Na2SO4, Na2CO3, NaNO3, and NaBF4,
were purchased from Sisco Research Laboratories Pvt Ltd., India. Bulk
solutions of L and the metal salts were made in CHCl3 and MeOH,
respectively, at 6 Â 10À4 M. All the fluorescence titrations were carried
out in 1 cm quartz cells by using 50 μL of L, and the total volume in each
measurement was made to 3 mL to give a final concentration of the
ligand as 10 μM (i.e., the 3 mL solution contains 2.950 mL of CH3OH
and 0.050 mL of CHCl3). During the titration, the concentration of
metal perchlorate was varied accordingly to result in requisite mole
ratios of metal ion to L, and the total volume of the solution was
maintained at 3 mL in each case by addition of CH3OH. For absorption
studies, the final concentration of [L] was kept constant at 20 μM, and
the procedure used for the titrations was the same as that used for
fluorescence titrations.
Synthesis and Characterization of Zinc Complex of L, 3. To
a solution of L (0.08 g, 0.05 mmol) in CH2Cl2 (5 mL) was added
zinc(II) acetate (0.013 g, 0.06 mmol) in methanol dropwise. After
stirring for one day, the reaction mixture was heated for 5 h at 40 °C. The
solvent was evaporated, and the complex was recrystallized from
methanolÀdichloromethane mixture. Yield (0.063 g, 75%). FTIR
(KBr, cmÀ1): 1616 (νCdN), 3388 (νOH). Anal. Calcd for C200H236
-
N8O12Zn2: C, 78.12; H, 7.74; N, 3.64. Found: C, 78.58; H, 7.50; N, 3.61%.
1H NMR (CDCl3, 400 MHz): 1.12 (s, 18H, SalÀ(CH3)3), 1.14 (s, 18H,
(CH3)3), 1.16 (s, 18H, (CH3)3), 3.53À3.60 (m, 4H, OCH2), 3.64 (s,
8H, ArÀCH2), 3.67 (s, 4H, ArÀCH2), 4.04, 4.01 (bs, 2H, ÀNCH2),
4.17, 3.78, 3.46, 2.95 (d, J = 12.8 Hz, 8H, ArÀCH2ÀAr), 4.77 (t, J =
10.80, 10.52 Hz, 2H, NCH2), 6.74 (d, J = 2.64 Hz, 2H, ArÀH), 6.85 (s,
4H, ArÀH), 6.90À6.96 (dd, 4H, ArÀH), 7.14 (t, J = 7.36, 7.36 Hz, 4H,
ArÀH), 7.28 (t, J = 7.44, 8.76 Hz, 8H, ArÀH), 7.46 (d, J = 7.12 Hz, 8H,
ArÀH), 7.81 (d, J = 2.64 Hz, 2H, ArÀH), 8.40 (s, 2H, ArÀOH), 8.44 (s,
2H, imine-H). m/z (MALDI-TOF) 3074.84 ([3]+). Single crystals were
grown by slow evaporation of 3 in a mixture of chloroform and
methanol.
Synthesis and Characterization of Copper Complex of L, 4.
The copper complex has been synthesized by following the procedure
used for the synthesis of zinc complex, viz., by adding copper(II) actetate
(0.014 g, 0.07 mmol) to L (0.10 g, 0.07 mmol). The complex formed was
recrystallized from a mixture of methanol and dichloromethane. Yield
(0.07 g, 67%). FTIR (KBr, cmÀ1): 1620 (νCdN), 3438 (νOH). Anal.
Synthesis and Characterization of 1. A mixture of p-tert-
butylcalix[4]arene (1.0 g, 1.55 mmol), K2CO3 (0.85 g, 6.20 mmol),
NaI (0.92 g, 6.13 mmol), and chloroacetonitrile (0.4 mL, 5.33 mmol) in
50 mL of acetone was refluxed under nitrogen atmosphere for 7 h. The
reaction mixture was allowed to cool down to room temperature and
filtered through Celite. The Celite was washed with dichloromethane to
obtain light brown clear solution. This was concentrated to give brown
solid, which was recrystallized from chloroform/methanol to give white
crystalline solid. Yield (900 mg) 80%. Anal. Calcd for C48H58N2O4: C,
79.30; H, 8.04; N, 3.85. Found: C, 79.49; H, 8.30; N, 3.92%. FTIR
1
(KBr, cmÀ1): 1482 (νCN), 3515 (νOH). H NMR (CDCl3, δ ppm):
Calcd for C100H118N4O6Cu CH3CN: C, 77.70; H, 7.74; N, 4.44%.
0.88, (s, 18H, C(CH3)3), 1.32 (s, 18H, C(CH3)3), 3.45 (d, J = 13.55 Hz,
4H, ArÀCH2ÀAr), 4.22 (d, J = 13.55 Hz, 4H, ArÀCH2ÀAr), 4.81 (s,
4H, OCH2), 6.73 (s, 4H, ArÀH), 7.12 (s, 4H, ArÀH).
3
Found: C, 77.50; H, 8.07; N, 4.04. ESI MS: m/z = 1535.68 ([4]+). Single
crystals were grown by slow evaporation of 4 taken in acetonitrile.
Synthesis and Characterization of Iron Complex of L, 5.
The procedure used for the synthesis of iron complex is same as that
used for the zinc and copper complex but by adding iron(II) perchlorate
(0.017 g, 0.07 mmol) to L (0.10 g, 0.07 mmol). The complex formed has
been crystallized from a mixture of dichloromethane and methanol;
however, no single crystals could be obtained. Yield (0.06 g, 60%). FTIR
Synthesis and Characterization of 2. To a vigorously stirred
solution of 1 (0.58 g, 0.81 mmol) in 32 mL of diethyl ether was added
LiAlH4 (0.25 g, 7.13 mmol), and the reaction mixture was refluxed for
5 h. After that, the reaction flask was immersed into an iceÀwater bath,
and excess LiAlH4 was destroyed by the addition of wet benzene into the
reaction mixture. The clear organic layer was decanted, and the inorganic
salts were rinsed with benzene. The combined organic layers were
evaporated to dryness to yield diamine, as a light yellow solid. Yield
(470 mg) 85%. Anal. Calcd for C48H66N2O4: C, 78.43; H, 9.05; N, 3.81.
Found: C, 78.29; H, 8.87; N, 3.97%. FTIR (KBr, cmÀ1): 3362 (νOH/NH).
1H NMR (CDCl3, δ ppm): 1.10 (s, 18H, C(CH3)3), 1.24 (s, 18H,
C(CH3)3), 3.29 (t, J = 4.76, 4.76 Hz, 4H, NCH2), 3.37 (d, J = 12.82 Hz,
4H, ArÀCH2ÀAr), 4.07 (t, J = 4.76, 4.76 Hz, 4H, OCH2), 4.32 (d, J = 12.82
Hz, 4H, ArÀCH2ÀAr), 6.97 (s, 4H, ArÀH), 7.04 (s, 4H, ArÀH).
(KBr, cmÀ1): 1617 (νCdN). Anal. Calcd for C100H118N4O6Fe CH2Cl2:
3
C, 75.22; H, 7.50; N, 3.47. Found: C, 74.84; H, 7.50; N, 3.44. ESI MS:
m/z = 1527.73 ([5]+).
’ RESULTS AND DISCUSSION
The receptor molecule, L, has been synthesized by three
steps23 (Scheme 1) starting from p-tert-butylcalix[4]arene followed
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dx.doi.org/10.1021/ic200544a |Inorg. Chem. 2011, 50, 7050–7058