10.1002/ejic.201801107
European Journal of Inorganic Chemistry
FULL PAPER
For synthesis of ligand 1a, to a solution of 2,6-dimethylaniline
(3.2 g, 26.4 mmol) in THF (50 mL) and triethylamine (4.2 mL,30
mmol) were added dropwise benzoyl chloride (24 mmol). The
reaction mixture was stirred overnight at ambient temperature.
After the filtration of (C2H5)3N·HCl and evaporated of THF under
reduced pressure, the residue solid was washed with water
several times and dried under vacuum at 40 oC. Finally, the
white solid amide product was obtained and used directly in the
next procedure.The thionyl chloride (1 mL, 13.3 mmol) was
added to the amide (2 g, 8.9 mmol), then, the reaction mixture
was heated to reflux 3 h. The remaining unreacted thionyl
chloride was removed by distillation under reduced pressure to
afford 1a, which was directly used for the next step. Toluene (50
mL), triethylamine (1.5 mL, 10.8 mmol) and pyrazole (0.61 g, 8.9
mmol) were added to the reaction mixture, then the mixture was
heated to reflux for 6 h. The (C2H5)3N·HCl was removed through
filtration, toluene was distilled under reduced pressure, and the
residue was recrystallized from hexane, the ligand 2a as light
yellow crystal in 21.6% yield (0.53 g) was obtained. M.p. 98-99
oC. 1H NMR(400 MHz, DMSO, δ, ppm): δ: 8.68 (s,1H, Pz-H);
7.74 (s,1H, Pz-H); 7.36~6.78 (m, 10H, Ar-H), 1.99 (s,6H, Ar-
CH3). 13C NMR (100 MHz, DMSO, δ, ppm):152.3, 142.4, 131.1,
129.5, 129.2, 127.7, 126.2, 123.1, 18.1. FT-IR (KBr; cm-1): 3066,
3014, 2970, 1660, 1588, 1558, 1493, 1444, 1416, 1386, 1346,
1238, 1193, 1181, 916, 903, 868, 783, 764, 693. Anal. calc. for
C18H17N3: C, 78.52; H, 6.22; N, 15.26. Found: C, 78.34; H, 6.26;
N, 15.4. MS (APCI, m/z): calcd. 275.1422; found 298.1320
(M+Na)+.
For synthesis of ligand 2c, a procedure similar to 2a was
adopted. Yield, 25.2%. M.p. 103-104 oC. 1H NMR (400
MHz,DMSO, δ, ppm): 8.61 (s,1H,Pz-H); 7.76 (s,1H,Pz-H);
7.64~6.98 (m, 8H,Ar-H); 6.63 (s,1H,Pz-H); 2.84 (s, 2H,iPr-H);
1.06~0.89 (d, 12H,iPr-CH3). 13C NMR (100 MHz, CDCl3, δ,
ppm):142.33, 136.18, 131.38, 130.06, 129.40, 127.57, 123.98,
122.85, 108.60, 27.89, 23.75, 21.66. FTIR (KBr; cm-1): 3063,
2959, 2867, 1660, 1558, 1523, 1492, 1458, 1384, , 1257, 1241,
1184, 1162, 1040, 936, 913,864, 842,797, 773, 757, 694.Anal.
calc. for C22H25N3: C, 79.72; H, 7.6; N, 12.68. Found: C, 79.68; H,
7.61; N, 12.68. MS (APCI, m/z): calcd. 331.2048; found
354.1928 (M+Na) +.
For synthesis of ligand 2d, a procedure similar to 2a was
adopted. Yield, 60.1%. M.p. 94-95 oC. 1H NMR (400
MHz,DMSO,δ, ppm): 7.28~6.99 (m, 8H, Ar-H); 6.18 (s,1H,Pz-H);
3.24 (s,3H,Pz-CH3); 2.89 (m,2H,iPr-H); 2.09 (s, 3H,Pz-
CH3);1.07~0.89 (d,12H,iPr-CH3). 13C NMR (100 MHz, DMSO, δ,
ppm):152.40, 145.93, 142.26, 135.64, 129.57, 128.93, 127.36,
123.56, 122.61, 109.16, 27.63, 23.87, 21.40, 13.11. FTIR (KBr;
cm-1): 3058, 3034, 2961, 2867, 1653, 1598, 1567, 1490, 1444,
1406, 1379, 1321, 1273,1184, 1108,1078,1021, 966, 913, 834,
775, 752, 696.Anal. calc. for C24H29N3: C, 80.18; H, 8.13; N,
11.69. Found: C, 80.01; H, 8.18; N, 11.81. MS (APCI, m/z):
calcd. 359.2361; found 382.2240 (M+Na) +.
For synthesis of ligand 2e, a procedure similar to 2a was
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adopted. M.p. 147-148 C. H NMR (400 MHz,DMSO,δ, ppm):
7.8~6.94 (m, 18H, Ar-H); 2.73 (m, 2H ,iPr-H); 1.23~0.73 (m,
12H,iPr-CH3). 13C NMR (100 MHz, DMSO, δ, ppm):151.01,
146.14, 135.68, 128.76, 128.43, 127.44, 125.59, 125.06, 124.03,
122.88, 28.13, 23.24, 21.96. FTIR (KBr; cm-1): 3067, 2971,1650,
1597, 1556, 1483, 1460, 1400, 1350, 1306, 1281, 1207, 1173,
1113, 1043, 999, 941, 917, 843, 804,755, 727,699. Anal. calc.
for C34H33N3: C, 84.43; H, 6.88; N, 8.69. Found: C, 84.39; H,
7.01; N, 8.58. MS (APCI, m/z): calcd. 483.2674; found 506.2572
(M+Na) +.
For synthesis of complex 3a, a solution of 2a (0.2 g, 0.73 mmol)
in 3 mL THF was added dropwise to a suspension of anhydrous
CoCl2 (0.094 g, 0.73 mmol) in 3 mL THF, the reaction solution
was stirred for 4 h, a blue suspension was obtained. The
resultant reaction solution was concentrated and diethyl ether
was added to precipitate the complex. The resultant precipitate
was filtered,subsequently washed with diethyl ether and dried in
vacuum at 40 oC overnight, finally, a blue powder 3a was
obtained in 82.3% yield. Single crystals for X-ray analysis grew
from n-hexane and dichloromethane mixed solution. FTIR (KBr;
cm-1): 2974, 1616, 1560, 1531, 1489, 1445, 1396, 1358, 1317,
1206, 1164, 1097, 1058, 1001, 944, 913, 881, 784, 756, 703.
Anal. calc. for C18H17N3Cl2Co: C, 53.36; H, 4.23; N, 10.37.
Found: C, 53.21; H, 4.16; N, 10.26.
For synthesis of complex 3b, a procedure similiar to 3a was
adopted using 2b and CoCl2, which gave 3b as a bluish violet
powder in 77.9% yield. FTIR (KBr; cm-1): 3109, 2956, 2924,
1611, 1589, 1567, 1494, 1459, 1385, 1258, 1212, 1173, 1159,
1114, 986, 918, 838, 797, 780, 744, 704.Anal. calc. for
C20H21N3Cl2Co: C, 55.45; H, 4.89; N, 9.7. Found: C, 55.29; H,
4.82; N, 9.58.
For synthesis of ligand 2b, a procedure similar to 2a was
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adopted. Yield, 0.41 g (55.2 %). M.p. 72-73 C. H NMR (400
MHz, CDCl3, δ, ppm): 7.29~7.12 (m, 5H, Ar-H); 6.91~6.82 (m,
3H, Ar-H); 6.05 (s,1H,Pz-H); 2.62 (s, 3H, Pz-CH3); 2.22 (s, 3H,
Pz-CH3); 2.06 (s, 6H, Ar-CH3). 13C NMR (100 MHz, DMSO, δ,
ppm):153.28, 148.54, 145.24, 142.48, 131.18, 129.60, 128.28,
127.36, 125.58, 122.66, 109.4, 18.07, 14.18, 13.10. FTIR (KBr;
cm-1): 3099, 2965, 2920, 1661, 1593, 1567, 1492, 1466, 1379,
1355, 1260, 1162, 1128, 1091, 1025, 982, 915, 841, 792, 776,
769, 752, 698. Anal. calc. for C20H21N3: C, 79.17; H, 6.98; N,
13.85. Found: C, 79.12; H, 7.21; N, 13.67. MS (APCI, m/z):
calcd. 303.1735; found 326.1616 (M+Na) +.
For synthesis of complex 3c, a procedure similiar to 3a was
adopted using 2c and CoCl2, which gave 3c as a green powder
in 71.2% yield. FTIR (KBr; cm-1): 2966, 2929, 2867, 1617, 1559,
1528, 1508, 1492, 1459, 1420, 1387, 1356, 1325, 1202, 1160,
1098, 1079, 1058, 995, 942, 913, 902, 779, 759, 696.Anal. calc.
for C22H25N3Cl2Co: C, 57.28; H, 5.46; N, 9.11. Found: C, 57.23;
H, 5.39; N, 9.01.
For synthesis of complex 3d, a procedure similiar to 2a was
adopted using 2d and CoCl2, which gave 3d as a bluish violet
powder in 80.1% yield. FTIR (KBr; cm-1): 2982, 2964, 2928,
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