Supporting Information
for
Sequential multiphoton absorption enhancement induced by zinc complexation in functionalized distyrylbenzene analogs
Graziano Fabbrini, Raffaele Riccò, Enzo Menna, Michele Maggini,* Vincenzo Amendola, Mattia Garbin, Massimo Villano, Moreno Meneghetti
Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo 1, 35131 Padova, Italy.
*To whom correspondence should be addressed Phone: +39-0498275662 /Fax: +39-0498275792 Email address:
[email protected]
Contents 1. Synthetic details and characterization for compounds 4, 5, 7, 9-14 (NMR and IR spectra for 2 and 3) 2. Titration for stoichiometry and binding constant determination Figure S1 Figure S2 Figure S3 Figure S4 Figure S5 Figure S6 Figure S7 Figure S8 Figure S9 Figure S10 Figure S11
1
H NMR of 2 C NMR of 2 1 H NMR of 3 13 C NMR of 3 IR spectrum of 2 IR spectrum of 3 ESI-MS of 2 ESI-MS of 3 ESI-MS of 2-Zn2+ complex ESI-MS of 3-Zn2+ complex Fluorescence spectral changes observed upon the addition of Zn2+ to 2 and 3 (stoichiometry and binding constant determination) 13
1
OCH3 3
O X
N O
N
H3CO
N 3 2, X = -CN 3, X = -N(CH3)2
N
OCH3 O
3
3
X
HO
O P OEt OEt
O
CHO O
H3CO
H3CO 3
3 4, X = -CN, 5, X = -N(CH3)2
7
OCH3
OCH3
O
3
NC
OH
OCH3
O
O
3
NC
3
EtOOC
Br
O
COOEt
O
H3CO 3
H3CO 3
O
H3CO
3
9
10
11
OCH3
O
3
HO
O OH
H3CO
OCH3
O
OCH3
3
Br Br
O 3
H3CO
O
H3CO 3
EtO O P EtO
O
O
OEt P O OEt OCH3 3
3 13
12
14
Phosphonate 4. Bromobenzyl derivative 10 (147 mg, 0.24 mmol) and triethylphosphite (213 mg, 1.28 mmol) were brought to 150 °C for 3 h. The crude product was purified by flash column chromatography (SiO2, eluent: ethyl acetate/petroleum ether 1:1, then ethyl acetate/ethanol 9:1). 2
139 mg (87%) of 10 were isolated as a yellow-green oil. 1H-NMR (250 MHz, CDCl3) δ 7.65-7.56 (m, 4H), 7.59-7.52 (d, 1H, Jtrans = 16.5 Hz), 7.31-7.7.06 (d, 1H, Jtrans = 16.5 Hz), 7.11 (s, 1H), 6.98 (s, 1H), 4.20-4.15 (m, 4H), 4.11-4.3.99 (m, 4H), 3.90.3.85 (m, 4H), 3.80-3.62 (m, 12H), 3.57-3.50 (m, 4H), 3.37 (s, 3H), 3.35 (s, 3H), 3.30-3.22 (d, 2H, J = 21.5 Hz), 1.29-1.23 (t, 6H, J = 7.2 Hz); 13
C-NMR (62.9 MHz, CDCl3) δ 151.22-151.10 (d, JCP = 7.4 Hz), 150.97, 143.76, 142.57, 132.54,
127.36-127.33 (d, JCP = 1.8 Hz), 127.33-126.96 (d, JCP = 6.9 Hz), 125.36-125.29 (d, JCP = 4.1 Hz), 122.75-122.59 (d, JCP = 9.7 Hz), 119.25, 116.54-116.45 (d, JCP = 5.5 Hz), 110.90-110.84 (d, JCP = 3.2 Hz), 110.31, 72.03-72.01 (d, JCP = 1.3 Hz), 70.92, 70.90, 70.78, 70.68, 69.99, 69.88, 69.09, 62.16-62.06 (d, JCP = 6.4 Hz), 59.12, 27.90-25.69 (d, JCP = 138.0 Hz), 16.58-16.49 (d, JCP = 6.0 Hz); IR (KBr) ν 2870 (ν C-H), 2222 (ν C≡N), 1409 (ν C=C-H), 1243 (ν O-P=O), 1199 (ν P-OC), 1058 (νs C-O-C) cm-1; ESI-MS: C34H50NO11P (m/z): 680 [M + H]+. Phosphonate 5. To a solution of bis-phosphonate 14 (430 mg, 0.61 mmol) and 4-(N,Ndimethylamino)benzaldehyde (91 mg, 0.61 mmol) in 15 ml of dry DMF at 0 °C, a suspension of tBuOK (68 mg, 0.61 mmol) in 5 ml of dry DMF was added dropwise over a period of 15 min under a nitrogen atmosphere. When the addition was complete, the mixture was stirred at room temperature for 12 h. The mixture was diluted with water (30 ml) and extracted with CH2Cl2 (3 x 30 ml). The combined organic layers were dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The crude product purified by flash column chromatography (SiO2, eluent: ethyl acetate/toluene/ethanol 6:4:1). 100 mg (24%) of 5 were isolated as an orange oil. 1H-NMR (250 MHz, CDCl3) δ 7.35-7.32 (d, 2H, J = 8.7 Hz), 7.08-7.03 (d, 1H, Jtrans = 16.6 Hz), 6.84-6.77 (d, 1H, Jtrans = 16.6 Hz), 6.96 (s, 1H), 6.85 (s, 1H), 6.68-6.64 (d, 2H, J = 8.5 Hz), 4.10-3.93 (m, 8H), 3.82-3.80 (m, 4H), 3.70-3.55 (m, 12H), 3.43-3.40 (m, 4H), 3.29 (s, 3H), 3.27 (s, 3H), 3.213.12 (d, 2H, J = 21.7 Hz), 2.91 (s, 6H), 1.20-1.15 (t, 6H, J = 7.0 Hz);
13
C-NMR (62.9 MHz,
CDCl3) δ 150.92, 150.04, 149.98, 129.82, 128.89, 127.49, 116.41-116.32 (d, JCP = 5.3 Hz), 115.90115.82 (d, JCP = 5.3 Hz), 114.16-114.11 (d, JCP = 2.9 Hz), 112.56, 111.94, 109.87-109.82 (d, JCP = 3 Hz), 71.82-71.80 (d, JCP = 1.9 Hz), 70.78, 70.70, 70.57, 70.50, 70.43, 70.42. 69.84, 69.77, 69.63, 69.11, 68.77, 61.91, 61.80, 40.52, 27.52-25.31 (d, JCP = 138 Hz), 16.36-16.27 (d, JCP = 5.6 Hz); IR (KBr) ν (cm-1): 2923 (ν C-H), 1415 (ν C=C-H), 1351 (ν C-N), 1249 (ν O-P=O), 1207 (ν P-O-C), 1053 (νs C-O-C), 959 (δ C=C-H) cm-1; ESI-MS C35H56NO11P (m/z) = 720 [M + Na]+. Aldehyde-alcohol 7. To a solution of bis-alcohol 12 (5.00 g, 10.8 mmol) in 500 ml of CH2Cl2 at 0 °C, a suspension of DDQ (2.45 g, 10.8 mmol) in 300 ml of CH2Cl2 was added dropwise over a period of 2 h. When the addition was complete, the mixture was stirred at room temperature for 12 3
h. The mixture was filtered and the filtrate was concentrated under reduced pressure and the residue purified by flash column chromatography (SiO2, eluent: ethyl acetate/ethanol 9:1). 4.47 g (90%) of 7 were isolated as a yellow oil. Elemental analysis calculated for C22H36O10: C = 57.38, H = 7.88; found: C = 57.37, H = 7.85. 1H-NMR (250 MHz, CDCl3) δ 10.43 (s, 1H), 7.27 (s, 1H), 7.08 (s, 1H), 4.69 (s, 2H), 4.25-4.15 (m, 4H), 3.89-3.80 (m, 4H), 3.71-3.61 (m, 12H), 3.56-3.52 (m, 4H), 3.37 (s, 6H);
13
C-NMR (62.9 MHz, CDCl3) δ 189.35, 156.53, 150.54, 139.63, 124.22, 113.73, 110.05,
71.93, 70.90, 70.70, 70.62, 70.58, 70.54, 69.71, 69.51, 68.98, 68.52, 61.13, 59.04, 59.01; IR (KBr) 3447 (ν O-H), 2874 (ν C-H), 1676 (ν C=O), 1206 (δ C-H, δ O-H), 1057 (ν C-O-C) cm-1. Stylbene 9. To a solution of 4-cyanobenzyl-diethylphosphonate 8 (275 mg, 1.08 mmol) in 20 ml of dry THF at 0 °C, NaH (105 mg, 2.62 mmol) was added under a nitrogen atmosphere, and the resulting solution was stirred for 15 min. Then, a solution of tris(pyridyl)amino aldehyde-alcohol 7 (500 mg, 1.08 mmol) in 10 ml of dry THF was added and the mixture was stirred at room temperature for 3 h. The solvent was removed under reduced pressure and the crude product purified by flash column chromatography (SiO2, eluent: toluene/ethyl acetate/ethanol 4:5:1). 449 mg (74%) of 9 were isolated as a yellow oil. 1H-NMR (250 MHz, CDCl3) δ 7.59-7.52 (d, 1H, Jtrans = 16.2 Hz), 7.59-7.57 (m, 4H), 7.10-7.04 (d, 1H, Jtrans = 16.2 Hz), 7.07 (s, 1H), 6.97 (s, 1H), 4.65 (s, 2H), 4.17-4.14 (t, 4H, J = 8.7 Hz), 3.86-3.82 (t, 4H, J = 8.6 Hz), 3.72-3.61 (m, 12H), 3.52-3.50 (m, 4H), 3.34 (s, 3H), 3.32 (s, 3H);
13
C-NMR (62.9 MHz, CDCl3) δ 150.98, 150.59, 142.25, 132.37,
132.10, 126.94, 126.57, 126.44, 124.91, 118.82, 113.80, 110.37, 109.80, 71.62, 70.47, 70.41, 70.31, 70.24, 70.21, 69.59, 69.44, 68.84, 68.49, 60.57, 58.60; IR (KBr) 3456 (ν O-H), 2875 (ν C-H), 2222 (ν C≡N), 1418 (ν C=C-H), 1199 (δ O-H), 1060 (νs C-O-C), 967 (δ C=C-H) cm-1; ESI-MS: C30H41NO9 (m/z) = 582 [M + Na]+. Bromobenzyl stylbene 10. To a solution of trans-stylbene 9 (420 mg, 0.75 mmol) in 20 ml of dry THF at 0 °C under a nitrogen atmosphere, a solution of PBr3 (244 mg, 0.90 mmol) in 10 ml of dry THF was added dropwise over a period of 10 min. The resulting solution was stirred for 1 h at 0 °C. The solvent was removed under reduced pressure and the crude product purified by flash column chromatography (SiO2, eluent: ethyl acetate). 390 mg (84%) of 10 were isolated as a yellow-green oil. 1H-NMR (250 MHz, CDCl3) δ 7.65-7.58 (m, 4H), 7.58-7.51 (d, 1H, Jtrans = 16.7 Hz), 7.14-7.08 (d, 1H, Jtrans = 16.7 Hz), 7.11 (s, 1H), 6.94 (s, 1H), 4.57 (s, 2H), 4.25-4.15 (m, 4H), 3.93-3.87 (m, 4H), 3.78-3.62 (m, 12H), 3.57-3.50 (m, 4H), 3.37 (s, 3H), 3.35 (s, 3H); 13C-NMR (62.9 MHz, CDCl3) δ 151.29, 151.07, 142.34, 132.56, 128.08, 127.92, 127.43, 127.09, 127.01, 119.20, 116.17, 111.11, 110.57, 72.05, 72.01, 71.04, 70.93, 70.82, 70.80, 70.70, 70.68, 69.91, 69.29, 69.15, 59.13, 28.87; IR 4
(KBr) 2922 (ν C-H), 2222 (ν C≡N), 1414 (ν C=C-H), 1321 (δ CH2-Br), 1060 (νs C-O-C), 953 (δ C=C-H) cm-1; ESI-MS: C30H40NO8Br (m/z) = 542 [M - Br]+. Bis-ester
11.
To
a
solution
of
2,5-bis(ethoxymethyl)benzene-1,4-diol
diethyl
2,5-
dihydroxyterephthalate (10.17 g, 40 mmol) in 70 ml of dry DMF, anhydrous K2CO3 (18.20 g, 132 mmol) was added under a nitrogen atmosphere, and the resulting mixture was stirred at 60°C for 15 min. Then, 2-(2-(2-methoxy)-ethoxy)ethyl-p-toluensulphonate (28.06 g, 88 mmol) was added under a nitrogen atmosphere and the mixture was stirred at 60°C for 48 h. The solvent was removed under reduced pressure and the residue dissolved in CH2Cl2 (150 ml) and washed with 1 M NaOH solution (3 x 150 ml), 1 M HCl solution (3 x 150 ml) and then with water (3 x 150 ml). The solution was dried over anhydrous MgSO4 and the solvent was removed under reduced pressure. 21.0 g (96%) of 11 were isolated as a colorless oil. A.E. calculated for C26H42O12 (546.6) C = 57.14, H = 7.74; found C = 57.27, H = 7.54. 1H-NMR: (250 MHz, CDCl3) δ 7.40 (s, 2H), 4.40-4.31 (q, 4H, J = 7.2 Hz), 4.20-4.16 (t, 4H, J = 5.2 Hz), 3.88-3.85 (t, 4H, J = 5.2), 3.76-3.72 (m, 4H), 3.68-3.54 (m, 8H), 3.53-3.35 (m, 4H), 3.07 (s, 6H), 1.41-1.35 (t, 6H, J = 7.2 Hz); 13C-NMR (62.9 MHz, CDCl3) δ 165.34, 151.76, 125.04, 117.34, 71.77, 70.76, 70.51, 70.38, 69.73, 69.52, 61.10, 58.81, 14.13; IR (KBr) 2875 (ν C-H), 1728 (ν C=O), 1105 (νs C-O-C) cm-1. Bis-alcohol 12. To a solution of bis-ester 11 (5.02 g, 9.2 mmol) in 30 ml of dry THF at 0 °C, a 1 M solution of LiAlH4 (95 ml, 95 mmol) was added dropwise over a period of 1 h under a nitrogen atmosphere. The solution was heated to reflux for 30 min and then cooled to 0 °C. The excess of LiAlH4 was quenched with ethyl acetate and water. The mixture was concentrated under reduced pressure and then diluted with water (50 ml). The product was extracted with CH2Cl2 (3 x 50 ml) and dried over anhydrous MgSO4. The solvent was removed under reduced pressure. 3.96 g (93%) of 12 were isolated as a colorless oil. 1H-NMR (250 MHz, CDCl3) δ 6.85 (s, 2H), 4.62 (s, 4H), 4.16-4.13 (m, 4H), 3.83-3.80 (m, 4H), 3.68-3.62 (m, 12H), 3.55-3.53 (m, 4H), 3.36 (s, 6H);
13
C-
NMR (62.9 MHz, CDCl3) δ 151.32, 130.94, 114.57, 72.12, 70.85, 70.81, 70.76, 69.90, 69.09, 62.02, 59.20; IR (KBr) 3434 (ν O-H), 2874 (ν C-H), 1502 (ν C=C), 1200 (δ C-H, δ O-H), 1061 (ν C-O-C) cm-1; ESI-MS: C22H38O10 (m/z) = 485 [M + Na]+. Dibromobenzyl derivative 13. To a solution of bis-alcohol 12 (2.0 g, 4.3 mmol) in 30 ml of dry THF at 0 °C under a nitrogen atmosphere, a solution of PBr3 (2.91 g, 10.8 mmol) in 5 ml of dry THF was added dropwise over a period of 20 min. The resulting solution was stirred for 1 h at 0 °C and then heated to reflux for 4 h. The solvent was removed under reduced pressure and the crude 5
product purified by flash column chromatography (SiO2, eluent: ethyl acetate/petroleum ether 6:4). 1.80 g (71%) of 13 were isolated as a yellow oil. A.E. calculated for C22H36O8Br2 (588.3) C = 44.91, H = 6.16; found C = 45.07, H = 6.12. 1H-NMR (250 MHz, CDCl3) δ 6.89 (s, 2H), 4.52 (s, 4H), 4.18-4.15 (t, 4H, J = 4.7 Hz), 3.89-3.85 (t, 4H, J = 4.7 Hz), 3.76-3.74 (m, 4H), 3.70-3.65 (m, 8H), 3.56-3.54 (m, 4H), 3.38 (s, 6H);
13
C-NMR (62.9 MHz, CDCl3) δ 150.68, 127.94, 115.36, 71.87,
70.84, 70.64, 70.51, 69.67, 68.95, 58.97, 28.41; IR (KBr) 2872 (ν C-H), 1506 (ν C=C), 1225 (δ C-H), 1105 (δ C-Br), 1058 (ν C-O-C) cm-1. Bis-phosphonate 14. Dibromobenzyl derivative 13 (1.60 g, 2.72 mmol) and triethylphosphite (1.13 g, 6.80 mmol) were brought to 150 °C for 3 h. The crude product was purified by flash column chromatography (SiO2, eluent: ethyl acetate/petroleum ether 1:1, then ethyl acetate/ethanol 9:1). 1.60 g (84%) of 14 were isolated as a colorless oil. A.E. calculated for C30H56O14P2 (702.7) C = 51.28, H = 8.03; found C = 50.96, H = 7.89. 1H-NMR (250 MHz, CDCl3) δ 6.87 (s, 2H), 4.07-3.93 (m, 12H), 3.79-3.75 (m, 4H), 3.69-3.58 (m, 12H), 3.52-3.48 (m, 4H), 3.35 (s, 6H), 3.22-3.12 (d, 4H, J = 25.0 Hz), 1.20-1.15 (t, 12H, J = 6.8 Hz); 13C-NMR (62.9 MHz, CDCl3) δ 150.32, 119.93-119.84 (d, JCP = 5.0 Hz), 115.36, 71.72, 70.56, 70.54, 70.35, 69.63, 68.58, 61.80-61.70 (d, JCP = 6.4 Hz), 58.81, 27.27-25.05 (d, JCP = 139.0 Hz), 16.25-16.19 (d, JCP = 6.3 Hz); IR (KBr) 2874 (ν C-H), 1249 (ν O-P=O), 1213 (ν P-O-C), 1053 (νs C-O-C) cm-1
6
ppm
ppm 7.80
9.0 7.70 7.60 7.50
8.0 7.40 7.30
7.0 7.20 7.10 7.00
6.0
7 ppm 3.80
5.0
3.70 3.60
4.0
3.50
3.0 3.40
3.362
3.374
3.382
3.397
3.512 3.492 3.475 3.456
3.528
3.566 3.556 3.545
3.647 3.635 3.625
3.749
3.837 3.817 3.799 3.788
7.038
7.058 7.045
7.065
7.086 7.073
7.094
7.129
7.161
7.167
7.174
7.259 7.231
7.359
7.388
7.541 7.503
7.557
7.564
7.586 7.571
3.456 3.397 3.382 3.374 3.362 3.210 3.197
3.475
3.492
3.512
3.528
3.749 3.647 3.635 3.625 3.566 3.556 3.545
3.799 3.788
3.817
3.837
4.138
4.157
4.175
7.094 7.086 7.073 7.065 7.058 7.045 7.038
7.129
7.231 7.174 7.167 7.161
7.359 7.259
7.388
7.503
7.541
7.624 7.617 7.603 7.593 7.586 7.571 7.564 7.557 7.593
7.793
7.617 7.603
8.439 8.435 8.432 8.428 8.419 8.413 8.409 7.858
7.624
7.793
7.858
FIGURE S1
3.30
ppm 150 150.0 145.0
140 140.0
130 135.0
120 130.0
110 125.0
100
8
120.0 115.0
90 80
71.0 70.0
70 69.0
110.0
60
68.058
68.204
68.830
69.829 69.673 69.517
70.866
110.626 109.292
110.814
119.019 118.134
120.225
123.135 122.206 121.312
125.208
126.006 125.925 125.809
126.432
126.614
128.717
131.448
135.836 135.758
136.103
136.290
136.966
141.395
147.274
147.986 147.545
150.448 150.384
154.461
58.841 57.977
68.204 68.058 61.726
68.830
69.829 69.673 69.517
70.866
109.292
110.814 110.626
119.019 118.134
120.225
121.312
122.206
125.208 123.135
126.006 125.925 125.809
128.717 126.614 126.432
135.836 135.758 131.448
136.290 136.103
136.966
141.395
147.274
147.545
147.986
150.448 150.384
154.461
FIGURE S2
68.0
ppm 7.90
ppm 8.50 7.80 7.70
8.00 7.60 7.50 7.40
7.50 7.30 7.20
7.00 7.10 7.00 6.90
6.50 6.80
6.00
ppm
9 5.50 4.20
5.00
4.10 4.00
4.50 3.90
4.00
3.80
4.026 3.953 3.941 3.816
3.70
3.50
3.60
6.70
3.00
3.489
3.545
3.608
4.054 3.903
2.995
3.338
3.354
3.489
3.545
3.903 3.816 3.608
3.920
4.187 3.920
4.208
4.227
4.250
4.268
6.706
6.742
7.034
7.100
7.162
7.189
7.363 7.312 7.268 7.256 7.247
7.395
7.417
7.453
7.617 7.603
7.633
7.659 7.652
7.688 7.680
7.719 7.712
7.863
7.928
8.541
3.953 3.941
4.054 4.026
4.187
4.208
4.227
4.250
4.268
6.706
6.742
7.189 7.162 7.100 7.034
7.247
7.256
7.312 7.268
7.363
7.417 7.395
7.603 7.453
7.617
7.633
7.719 7.712 7.688 7.680 7.659 7.652
7.928 7.863
8.560
FIGURE S3
3.50
ppm 150.0
150 145.0
140 130
125.841
136.859 120
135.0 130.0
110 125.0
100 120.0
90
10 80
115.0 72.00
70 71.50 71.00
60
70.50 70.00
50
69.50 69.081
69.233
69.855
70.501
70.638
70.797
70.883
71.847
118.598
119.753
120.988 120.894
121.998
122.263
122.479
123.205
123.472
125.277
125.841
126.161
127.535
127.723
129.174
40.449
69.233 69.081 60.044 59.899 58.979
69.855
71.847 70.883 70.797 70.638 70.501
110.571
111.798
112.400
118.598
119.753
121.998 120.988 120.894
122.479 122.263
123.205
125.277 123.472
126.161
137.076
129.697
140.0 136.706
127.723 127.535
129.174
129.697
137.076 136.859 136.706
137.766
150.085 149.085 148.992 148.837
155.758 151.551 150.560
137.766
148.837
149.085 148.992
150.560 150.085
151.551
FIGURE S4
69.00
40
FIGURE S5
FIGURE S6
11
FIGURE S7
12
FIGURE S8
13
FIGURE S9 Intens. x10 6
+M S, 0.1-5.1m in #(8-284) 453.7
1.25
454.7 1.00 454.2 455.7
0.75 455.2
0.50 456.2 0.25 456.7 457.2 0.00 450
m/z 453.7 454.2 454.7 455.2 455.7 456.2 456.7
451
452
453
454
455
456
457
458
459
460
m /z
relative intensity (%) 1409711 (100) 835890 (59.3) 1053838 (74.8) 681474 (48.3) 760059 (53.9) 359662 (25.5) 122393 (8.7)
CALCULATED ISO:C49H57N5O8Zn 100
453.6755
100
90
80 454.6750 70
% Intensity
60
454.1771 455.6744
50 455.1757 40
30 456.1754 20
10
456.6763 457.1772
0 453
454
455
456 Mass (m/z)
m/z 453.7 454.2 454.7 455.2 455.7 456.2 456.7
relative intensity (%) 100.0 57.2 75.1 45.2 54.3 25.6 8.8
14
457
0 458
FIGURE S10 Intens. x10 6
+M S, 1.7-2.9m in #(94-161)
1.2
462.3
1.0 463.3 0.8 462.8 0.6 463.8 0.4 464.3 0.2 464.8 461.3
458.8 459.3 0.0 458
m/z 462.3 462.8 463.3 463.8 464.3 464.8
459
460
461
465.3 462
463
464
465
467.2
465.7 466
467
468
m /z
relative intensity (%) 1155944 (100) 667345 (57.8) 919709 (79.6) 441130 (38.2) 245403 (21.2) 98008 (8.5)
CALCULATED ISO:C50H63N5O8Zn 100
462.6990
100
90
80
463.6985
70 463.2005
% Intensity
60
464.6979 50
464.1992
40
30
465.1989
20 465.6998
10
466.2007 0 462
463
464
465 Mass (m/z)
m/z Relative Intensity (%) 462.7 100 463.2 58.4 463.7 75.8 464.2 46.1 464.7 54.9 465.2 26.6 465.7 9.2
15
466
0 467
Spectrophotometric titrations Zn(ClO4)2•6H2O was an analytical grade product from Aldrich. Zn2+ stock solutions were titrated against EDTA following standard procedures (ammonium buffer at pH = 10 and Eriochrome Black T as indicator). Solutions for spectrophotometric measurements and titrations were prepared using HPLC-grade CH3CN. The binding constant determination for 2-Zn2+ and 3-Zn2+was performed by plotting the fluorescence changes as a function of [Zn2+] (see figure S12). Fitting of the titration curves was carried out with the software package Scientist 2.01 [1]. A model involving the formation of a 1:1 complex of Zn2+ with 2 and 3 was used. Total concentration of 2 and 3 was set as invariable parameter.
[1] Scientist 2.01, Micromath Scientific Software, Salt Lake City, 1995.
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FIGURE S11 480 nm
600
493 nm
500
Emission (u.a.)
2+
400
506 nm 300
200
[Zn ] 0M 0.0123 μM 0.0246 μM 0.0369 μM 0.0492 μM 0.0615 μM 0.0738 μM 0.0861 μM 0.0984 μM 0.1107 μM 0.123 μM
100
0 500
600
700
Wavelength (nm)
Fluorescence spectral changes observed upon the addition of Zn(ClO4)2•6H2O to 0.099 μM of 2 in CH3CN. λexc = 413 nm.
Change in the emission intensity as a function of [Zn2+] for 2. The apparent dissociation constant (pKd > 7) for Zn2+ was calculated from the above data with the software package Scientist 2.01.
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1200
573 nm
2+
[Zn ] 0M 0.0208 μM 0.0416 μM 0.0624 μM 0.0832 μM 0.104 μM 0.1248 μM 0.1456 μM 0.1664 μM 0.1872 μM 0.208 μM
Emission (u.a.)
1000
800
600
400
498 nm
200
λexc = 433 nm 0 500
600
700
800
Wavelength (nm)
Fluorescence spectral changes observed upon the addition of Zn(ClO4)2•6H2O to 0.104 μM of 3 in CH3CN. λexc = 433 nm.
Change in the emission intensity as a function of [Zn2+] for 3. The apparent dissociation constant (pKd > 7) for Zn2+ was calculated from the above data with the software package Scientist 2.01.
18
