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Supporting Information Title: Authors: Content:
Novel C3v-Symetrical of N7-hexahomotriazacalix[3]-cryptand: A highly efficient receptor for halide anions. Chatthai Kaewtong,1 Saowarux Fuangswasdi,1 Nongnuj Muangsin,1 Narongsak Chaichit,2 Jacques Vicens,3 and Buncha Pulpoka*,1 Experimental procedure and characterization data…………………P.1 Table S1. Relative Affinities of the Halide Salts toward Host 1 ... ..P.3 and 1NMR Chemical Induced Upfield Shifts (CIS) Observed through Their Endo-Complexation in CDCl3 Complexation studies of ligand 1 by using UV-vis titrations………P.3 Figure S1. Absorption spectra of ligand 1 upon addition NBu4+Br-..P.4 Figure S2. Absorption spectra of ligand 1.Zn2+ upon addition……..P.4 NBu4+BrFigure S3. Percentage of free anions by each ligand studied as a ... P.5 function as a function of ligand concentration (CA = 1Χ 10-3 M). Figure S4. 1H NMR spectrum of N-benzylhexahomotriaza-.............P.6 p-chloro-calix[3]-tri(methyl acetate) (2a, cone) Figure S5. 1H NMR spectrum of N-benzylhexahomotriaza-.............P.7 p-chloro-calix[3]-tri(methyl acetate) (2b, partial cone) NMR spectra of compound 1………………………………………P.8 X-ray crystal structure of compound 1…………………………....P.13
Experimental Section NMR spectra were recorded on a Varian 400 MHz spectrometer in deuterated chloroform. MALDI-TOF mass spectra were recorded on a Biflex Bruker Mass spectrometer with 2-Cyano-4-hydroxycinnamic acid (CCA) or 2,5-Dihydroxybenzoic acid (DHB) as matrix. Elemental analyses were carried out on a CHNS/O analyzer (Perkin Elmer PE2400 series II). UV-Vis absorption measurements were performed on a Hewlett Packard 8452A Diode Array Spectrometry. Infrared spectra were obtained on a Nicolet Impact 410 using KBr pellet. Column chromatography was carried out using silica gel (Kieselgel 60, 0.063 – 0.200 mm, Merck). All reagents were standard analytical grade and used without further purification. THF was distilled over sodium and benzophenone under nitrogen. Commercial grade solvents such as acetone, hexane, dichloromethane, methanol and ethyl acetate were distilled before used. Toluene and DMF were dried over CaH2 and freshly distilled under nitrogen atmosphere prior to use. Synthesis: 1. Synthesis of N-benzylhexahomotriaza-p-chloro-calix[3]arene N-benzylhexahomotriaza-p-chlorocalix[3]arene was prepared according to the literature.2b 1H NMR (400 MHz, CD2Cl2) δ 11.2 (br s, 3H, OH), δ 7.29 (br s, 15H, ArH), 7.01 (s, 6H, ArH) 3.69 (s, 6H, NCH2Ar), 3.64 (s, 12H, NCH2Ar); 13C NMR (400 MHZ, CDCl3) δ 155.5, 136.4, 129.6, 129.4, 128.1, 127.3, 125.0, 122.7, 58.0, 56.7; IR (KBr) ν 3054, 3023, 2832, 2805, 1738, 1602, 1470, 1372, 1240, 1116, 863, 738, 699, 485 cm-1; MS (MALDI-TOF) Calcd for [C45H42Cl3N3O3]+: m/z 777.23. Found: m/z 778.69 [M + H]+. Anal. Calcd. for C45H42Cl3N3O3: C, 69.36; H, 5.43; N, 5.39. Found: C, 69.44; H, 5.49; N, 5.28. 2. Synthesis of N-benzylhexahomotriaza-p-chloro-calix[3]-tri(methyl acetate) (2)
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To a solution of N-benzylhexahomotriaza-p-chlorocalix[3]arene (1.171 g, 1.50 mmol) and NaH (0.25 g, 10.5 mmol) in THF (40 mL) and DMF (30 mL) was added with a solution of methyl bromoacetate (0.902 g, 5.85 mmol) in THF (10 mL). After stirring for 2 days at 80 oC, The reaction mixture was evaporated, extracted with CH2Cl2, and washed with diluted HCl 3M. The organic layer was dried over anhydrous Na2SO4, filtered, and evaporated. Column chromatography on siliga gel (hexane/EtOAc = 3:2, v/v) afforded 2a (0.242 g, 0.236 mmol) in 16 % yield as a deep yellow oil. 1H NMR (400 MHz, CDCl3) δ 7.46-7.38 (m, 9H, ArH), 7.32-7.29 (m, 6H, ArH), 7.01 (s, 6H, ArH), 4.42 (s, 6H, OCH2CO), 3.90 (s, 9H, OCH3), 3.72 (s, 6H, NCH2Ar), 3.54 (br s, 12H, NCH2Ar); 13C NMR (400 MHZ, CDCl3) δ 169.1, 152.3, 139.2, 133.9, 130.1, 129.0, 128.9, 128.9, 128.6, 127.3, 71.0, 62.4, 52.5, 52.1; IR (KBr) ν 3427, 2949, 2918, 2844, 2357, 1762, 1435, 1365, 1182, 1123, 1057, 878, 750, 691 cm-1; MS (MALDI-TOF) Calcd for [C54H54Cl3N3O9]+: m/z 993.29. Found: m/z 994.69 [M + H]+. Anal. Calcd. for C54H54Cl3N3O9: C, 65.61; H, 5.47; N, 4.22. Found: C, 65.12; H, 6.17; N, 4.08.and 2b (pale yellow solid, 33 %); 1H NMR (400 MHz, CDCl3) δ 7.55 (d, J = 7.6 Hz, 2H, ArH), 7.45 (t, J = 7.6 Hz, 2H, ArH), 7.38-7.30 (m, 11H, ArH), 7.16 (s, 2H, ArH), 7.14 (s, 2H, ArH), 7.09 (s, 2H, ArH), 4.32 (s, 4H, OCH2CO), 3.93-3.68 (m, 19H, OCH2CO, NCH2Ar and OCH3), 3.72 (s, 6H, NCH2Ar), 3.59 (s, 2H, NCH2Ar), 3.56 (s, 2H, NCH2Ar), 3.46-3.35 (m, 6H, NCH2Ar); IR (KBr) ν 3427, 2949, 2918, 2844, 2357, 1762, 1435, 1365, 1182, 1123, 1057, 878, 750, 691 cm-1; MS (MALDI-TOF) Calcd for [C54H54Cl3N3O9]+: m/z 993.29. Found: m/z 994.69 [M + H]+. 3. Synthesis of N7- hexahomotriaza-p-chlorocalix[3]-cryptand (1). To a solution of 2a (0.485 g, 0.472 mmol) was charged with a solution of tris(2-aminoethyl)amine (0.069 g, 0.472 mmol) in 1:1 methanol : toluene mixture (10 mL). The solution was reflux for 38 h. and, then, a second crop of tris(2aminoethyl)amine (0.0345 g, 0.236 mmol) was added. The mixture was refluxed for additional 72 h. After removing the solvents, the crude mixture was precipitated with methanol. Column chromatography of the precipitate on silica gel (acetone/CH2Cl2 = 3 : 7, v/v) gave 1 (0.256 g, 0.245 mmol, 52 %) as a white solid; 1H NMR (400 MHz, CD3Cl2) δ 7.33-7.30 (m, 9H, ArH), 7.27-7.20(m, 6H, ArH), 6.94 (s, 6H, ArH), 4.01 (s, 6H, OCH2CO), 3.54 (s, 6H, ArCH2N), 3.38 (br s, 6H, NCH2CH2NH), 3.30 (s, 12H, NCH2Ar), 2.70 (br s, 6H, NCH2CH2NH); 13C NMR (400 MHZ, CDCl3) δ 167.8, 151.2, 138.2, 133.3, 131.2, 129.4, 129.0, 128.7, 127.7, 73.0, 62.0, 56.0, 52.1, 38.0; IR (KBr) ν 3443, 3388, 2925, 2844, 2361, 1668, 1513, 1439, 1353, 1182, 1120, 1038, 849, 867, 746, 695 cm-1; MS (MALDI-TOF) Calcd for [C57H60Cl3N7O6]+: m/z 1043.37. Found: m/z 1044.11 [M + H]+. Anal. Calcd. for C57H60Cl.3N7O6: C, 65.48; H, 5.78; N, 9.38. Found: C, 65.13; H, 5.91; N, 9.36.
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Table S1. Relative Affinities of the Halide Salts toward Host 1 and 1NMR Chemical Induced Upfield Shifts (CIS) Observed through Their Endo-Complexation in CDCl3. CIS (ppm)a Entry tetrabutylammonium halide 1 2 3 4
TBA+FTBA+ClTBA+BrTBA+I-
a -0.066 -0.025 -0.060 -0.069
e
c
b
-0.066 -0.036 -0.058 -0.066
-0.066 -0.036 -0.056 -0.064
-0.063 -0.030 -0.053 -0.063
CIS defined as ∆δ = δ (complexed halide) - δ (free host). a, e, c, b refer to the relative position of the protons to charge when host encapsulation halide anion. b Not determined due to overlapping of the host and guest signals. a
Complexation studies of ligand 1 by using UV-vis titrations The complexation abilities of ligand 1 with zinc and anions of various sizes, geometries, and basicity such as chloride, nitrate, benzoate, dihydrogen phosphate, etc. were investigated by using spectrophotometric titration in DMSO at 25°C. When necessary, Bu4NPF6 was employed to keep the ionic strength at 0.01 M. Typically, the solution of ion of interest was added directly and successively into the cuvette containing ligand 1 and the spectral variation was recorded after each addition. The final guest-to-host ratios were varied case by case to obtain the optimal condition for complexation. The apparent stability constants were refined from spectrophotometric data using SIRKO program.8 To investigate the effect of cation on the binding ability of 1 toward anions, the ligand solution was added 600 equivalences of Zn(CF3SO4)2 before being titrated with anion of interest.
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Figure S1. Spectral change in the UV absorption of 1 (CL = 6×10-5 M) upon addition of NBu4+Br- (CA = 8×10-4 M) in DMSO (0 ≤ CA/CL ≤ 10.3).
Figure S2. Spectral change in the UV absorption of 1.Zn2+ (CL = 3.429×10-5 M) upon addition of NBu4+Br- (CA = 8×10-4 M) in DMSO (0 ≤ CA/CL ≤ 18).
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120
L+FL+ClL+Br-
% free of anions
100
L+IL+NO3L+AcCOOL+PhCOO-
80
LZn 2++F LZn 2++ClLZn 2++BrLZn 2++I-
60 40 20 0 0.0
0.5
1.0
1.5
2.0
2.5
3.0
Concentration of Ligand 1 (10-3)
Figure S3. Percentage of free anions by each ligand studied as a function as a function of ligand concentration (CL = 1 × 10-3 M).
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Figure S4. 1H NMR spectrum of N-benzylhexahomotriaza-p-chloro-calix[3]tri(methyl acetate) (2a, cone) in CDCl3 at 25 °C.
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Figure S5. 1H NMR spectrum of N-benzylhexahomotriaza-p-chloro-calix[3]tri(methyl acetate) (2b, partial cone) in CDCl3 at 25 °C.
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Figure S6. 1H NMR spectrum of N7-hexahomotriazacalix[3]-cryptand (1) in CDCl3 at 25 °C.
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Figure S7. 13C NMR spectrum of N7-hexahomotriazacalix[3]-cryptand (1) in CDCl3 at 25 °C.
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Figure S8. COSY spectrum of N7-hexahomotriazacalix[3]-cryptand (1) in CDCl3 at 25 °C.
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Figure S9. gHSQC spectrum of N7-hexahomotriazacalix[3]-cryptand (1) in CDCl3 at 25 °C.
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Figure S10. gHMBC spectrum of N7-hexahomotriazacalix[3]-cryptand (1) in CDCl3 at 25 °C.
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Figure S11. Crystal structure of N7-hexahomotriazacalix[3]-cryptand (1)
