SUPPORTING INFORMATION
Synthesis of ligands:
Benzimidazol, (L1): o-phenylene diamine (6.83 g, 63.2 mmol) and formic acid (3.27 ml)
were placed in a reaction tube and heated under reflux for 1 h. at 100 °C. After cooling to room
temperature, the reaction mixture was diluted with distilled water (20 mL) and NaOH solution
was added until the mixture was slightly basic. The precipitate was filtered and washed with
cold water. The residue crystallized from hot water.
Yield: 60%, 4.48g. m.p.: 171 °C. IR(cm-1): 3411, 3114, 3096, 3062, 3038, 3002, 2967,
2942, 2884, 2881, 2790, 2741, 2661, 2621, 2608, 2541, 1620, 1588, 1495, 1477, 1457, 1406,
1364, 1346, 1301, 1271, 1244, 1202, 1157, 1133, 1112, 1003, 958, 932, 887, 874, 847 ; 768,
744. UV(nm): 208, 244, 270.
1-Benzyl-1H-benzimidazol, (L2): Benzimidazole (0.5 g, 4.2 mmol) was dissolved in
acetone. Then, KOH (0.24 g, 4.2 mmol) was added and refluxing acetone continued for 3 hours.
After cooling to room temperature, benzyl chloride (0.6 ml, 4.3 mmol,) was added and refluxing
acetone continued for 1 h. The volatiles were removed under vacuum. Residues were treated
with 10 mL of distilled water and filtered with a cannula. The residue was crystallized from
methanol/diethyl ether. Yield: 65%, 0.56g. m.p.: 115 °C. IR (cm-1): 3081, 3030, 3018, 2971,
2943, 2926, 1613, 1584, 1493, 1452, 1443, 1428, 1365, 1333, 1286, 1265, 1229, 1217, 1203,
1188, 1029, 974, 887, 776, 765, 739, 730, 694. UV(nm): 213, 251, 272.
1-(2,3,5,6-Tetramethylbenzyl)-1H-benzimidazol, (L3): L3 was synthesized according to
L2 synthesis method using benzimidazole (0.5 g, 4.2 mmol), KOH (0.24 g, 4.2 mmol) and
2,3,5,6-tetramethylbenzyl chloride (0.78 g, 4.2 mmol).
Yield: 75%, 0.83g. m.p.: 180 °C. IR (cm-1): 3066, 3002, 2968, 2941, 2917, 2862, 1612,
1586 , 1497, 1474, 1458, 1385, 1326, 1301, 1287, 1226, 1210, 1202, 1193, 1168, 1153, 1145,
1121 , 1085, 1034, 1009, 974, 962, 940, 927, 901, 889, 879, 846, 805, 763, 744, 739, 718, 686,
655. UV(nm): 211, 250, 273.
Bzimpy, (L4): o-H3PO4 (20 mL) and P2O5 (10 g) were placed in a 500 mL were placed
in a reaction tube and heated to 120 °C for 1 day. Then pyridine-2,6-dicarboxylic acid (3.376
g, 20.2 mmol) and o-phenylendiamine (4.84 g, 44.7 mmol) was added and heated to 190 °C for
further 1 day. At the end of this time, the reaction mixture was cooled to room temperature.
Then, the colored melt was slowly poured into 250-300 mL of vigorously stirred cold water.
The bulk was collected by ordinary filter paper. The residue was washed three times with cold
water and dried. The precipitate was treated with hot 10% aqueous Na2CO3 solution. The
residue was filtered, washed with cold water and recrystallized from MeOH.
Yield: 60%, 3.77 g. m.p.: >280 °C. IR (cm-1): 3141; 3055; 2971; 1622, 1600; 1592; 1572;
1456; 1434; 1409; 1384; 1374; 1317; 1278; 1229; 1216; 1157; 1148; 1113; 1013; 994; 962;
916; 901; 890; 879; 844; 818; 804; 764; 725; 686; 654. UV(nm): 219, 311.
2,6-Bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine, (L5): L4 (0.5 g, 1.14 mmol) and
KOH (0.145 g, 3.0 mmol ) were dissolved in acetone. The mixture was stirred under reflux for
3 h. Then, benzyl chloride (0.26 ml, 2.28 mmol) was added and stirred under reflux for 6 h. At
the end this time, the volatiles were removed under vacuum. Residues were treated with 10 mL
of distilled water and filtered off. The residue was crystallized from methanol/diethyl ether.
Yield: 72%, 0.380 g. m.p.: 240 °C IR(cm-1): 3203, 3064, 2967, 2924, 1613, 1590, 1571,
1437, 1409, 1381, 1331, 1316, 1278, 1261, 1252, 1231, 1169, 1114, 1099, 1083, 1009, 994,
902, 879, 870, 844, 824, 766, 736, 729, 689, 670, 663. UV(nm): 215, 316.
2,6-Bis(2,3,5,6-tetramethylbenzyl-1H-benzo[d]imidazol-2-yl)pyridine, (L6): L6 was
synthesized according to the L5 synthesis method using L4 (0.5 g, 1.14 mmol), KOH (0,145 g,
3 mmol) and 2,3,5,6-tetramethylbenzyl chloride (0.420 g, 2.3 mmol).
Yield: 76%, 0.734 g. m.p.: 263 °C IR(cm-1): 3067, 3010, 2971, 2939, 2916, 2864, 1614,
1588, 1570, 1484, 1475, 1438, 1408, 1378, 1330, 1289, 1262, 1250, 1217, 1170, 1151, 1121,
1099, 1083, 1041, 1018, 1008, 994, 964, 956, 924, 918, 903, 878, 836, 824, 758, 736, 699, 688,
669, 663. UV(nm): 225, 313.
1.00
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0.60
0.55
Absorbance
Absorbance
1.00
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0.45
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0.40
No
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0.35
File Name
MYI-L1.JSP
MYI-L2.JSP
MYI-L3.JSP
0.40
Color
No
1
2
3
0.35
0.30
0.30
0.25
0.25
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0.20
0.15
0.15
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0.10
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0
File Name
MYI-K1.JSP
MYI-K2.JSP
MYI-K3.JSP
Color
0
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Wavelength (nm)
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Wavelength (nm)
650
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File Name
MYI-L4.JSP
MYI-L5.JSP
MYI-L6.JSP
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(b)
Absorbance
Absorbance
(a)
700
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4
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File Name
MYI-K4.JSP
MYI-K5.JSP
MYI-K6.JSP
MYI-K7.JSP
Color
0.25
0.20
0.20
0.15
0.15
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0.10
0.05
0.05
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Wavelength (nm)
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Wavelength (nm)
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(d)
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
Absorbance
0.60
0.55
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No
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0.25
File Name
MYI-K8.JSP
MYI-K9.JSP
Color
0.20
0.15
0.10
0.05
0
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Wavelength (nm)
650
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(e)
Figure S1. The normalized UV-Vis spectra of compounds.
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