Ferrocenyl-Containing Ionic Liquids
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(TA Instruments Q50) was recorded as the 5% weight loss
temperature at a scan rate of 10 °C/min. IR spectra (BioRad FTS
3000 Excalibur series infrared spectrometer) were obtained using
KBr plates for neat liquids and KBr pellets for solids. Densities
were measured at 24 °C using a pycnometer. Elemental analyses
were performed by Desert Analytics Laboratory, Tucson, AZ, and
the Shanghai Institute of Organic Chemistry. The UV absorption
spectra of compounds in either Spectrograde methanol or acetonitrile
were recorded at ambient temperature using a Shimadzu UV-
2501PC spectrophotometer.
colorless: 0.40 g, 98% yield; yellow solid; H NMR δ 4.04 (s,
3H), 4.21 (t, J ) 1.7 Hz, 2H), 4.27 (s, 5H), 4.73 (t, J ) 1.7 Hz,
2H), 5.59 (s, 2H), 7.86 (s, 1H), 8.02 (s, 1H), 9.70 (s, 1H); 13C
NMR δ 137.0, 124.5, 123.0, 81.91, 70.66, 70.01, 69.95, 49.72,
37.45.
Data for 1-(ferrocenylmethyl)-4-methyltriazolium iodide (4b):
0.39 g, 95% yield; yellow solid; mp 169.2 °C; IR (KBr) 3120, 3060,
1578, 1482, 1359, 1229, 1159, 1096, 813, cm-1; H NMR (D2O)
δ 3.87 (s, 3H), 4.31 (s, 5H), 4.36 (s, 2H), 4.47 (s, 2H), 5.38 (s,
2H), 8.70 (s, 1H), 9.51 (s, 1H); 13C NMR (D2O) δ 145.6, 141.9 (t,
J ) 34.3 Hz), 77.92, 70.33, 70.13, 69.62, 52.72, 34.31.
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Preparation of N-(Ferrocenylmethyl)imidazole (3a). N-(Fer-
rocenylmethyl)imidazole was prepared in a manner according to a
1,1-Bis((1-(2,3-dimethyl)imidazolium)methyl)ferrocene Di-
iodide (9b). The preparation is the same as for 4a except methanol
is used as solvent: 0.64 g, 97% yield; yellow solid; mp 248.1 °C
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literature method:30 0.77 g, 58% yield; yellow solid; H NMR δ
4.18 (s, 5H), 4.21 (s, 4H), 4.88 (s, 2H), 6.92 (s, 1H), 7.04 (s, 1H),
7.50 (s, 1H); 13C NMR δ 137.0, 129.5, 119.2, 83.08, 69.12, 69.07,
68.85, 47.03.
dec; IR (KBr) 3046, 2907, 1574, 1526, 1231, 1138, 1040, cm-1
;
1H NMR (D2O) δ 2.57 (s, 6H), 3.67 (s, 6H), 4.36 (t, J ) 1.9 Hz,
4H), 4.47 (t, J ) 1.9 Hz, 4H), 5.08 (s, 4H), 7.19 (d, J ) 2.2 Hz,
2H), 7.21 (d, J ) 2.2 Hz, 2H); 13C NMR (D2O) δ 144.6, 122.9,
121.0, 81.62, 71.47, 71.00, 48.34, 35.43, 10.08.
1-(Ferrocenylmethyl)triazole (3b) was prepared similarly to
3a: 0.87 g, 65% yield; yellow solid; mp 81.2 °C; IR (KBr) 3101,
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2978, 1512, 1339, 1272, 1136, 1029, 812 cm-1; H NMR δ 4.19
(s, 5H), 4.24 (t, J ) 1.8 Hz, 2H), 4.30 (t, J ) 1.8 Hz, 2H), 5.12 (s,
2H), 7.93 (s, 1H), 7.99 (s, 1H); 13C NMR δ 152.5, 143.0, 81.60,
69.92, 69.80, 69.73, 50.49; MS (EI) m/z 267 (M+, 100). Anal. Calcd
for C13H13N3Fe: C, 58.46; H, 4.91. Found: C, 57.86; H, 5.27.
Ferrocene-1,1′-diylbis(methyltrimethylammonium iodide) (6)
was prepared as described.31 1,1′-Bis((1H-imidazol-1-yl)methyl)-
ferrocene (8a) was obtained from 6 by a published method30 as
modified by us: 5 mmol of 6 and 14 mmol of imidazole
(2-methylimidazole and 1,2,4-triazole, respectively) were dissolved
in 30 mL of DMF. The solution was heated at 150 °C for 8 h. 8a
precipitated as a yellow powder and was filtered, washed with
methanol, and then dried in vacuo at room temperature for 24 h:
1.38 g, 80% yield; yellow solid; mp 292.1 °C dec; IR (KBr) 3092,
1,1-Bis((1-(4-methyl)-1,2,4-triazolium)methyl)ferrocene Di-
iodide (9c). The preparation is the same as for 9b except acetonitrile
is used as solvent: 0.60 g, 95% yield; yellow solid; mp 199.3 °C
dec; IR (KBr) 3098, 2923, 1596, 1430, 1321, 1108, 996 cm-1; 1H
NMR (D2O) δ 3.86 (s, 6H), 4.43 (t, J ) 1.8 Hz, 4H), 4.53 (t, J )
1.8 Hz, 4H), 5.39 (s, 4H), 8.70 (s, 2H), 9.52 (s, 2H); 13C NMR
(D2O) δ 145.4 (t, J ) 6.29 Hz), 141.8 (t, J ) 34.3 Hz), 78.62,
71.18, 70.86, 52.08, 34.13.
Preparation of (Ferrocenylmethyl)trimethylammonium Bis-
(trifluoromethanesulfonyl)amide (2). To a magnetically stirred
solution of 1 (0.5 mmol) in methanol/water (1:1) (8 mL) in a 15
mL flask was added lithium bis(trifluoromethanesulfonyl)amide
(LiNTf2, 0.6 mmol). After 8 h at 40 °C, the yellow solid was filtered
and washed with water (2 × 2 mL) and dried in vacuo (0.3 mmHg)
at 40 °C for 24 h: 0.24 g, 89% yield; yellow solid; mp 84.5 °C; IR
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2971, 1503, 1345, 1219, 1076, 1019, 928 cm-1; H NMR (D2O/
DCl) δ 4.15 (s, 4H), 4.27 (s, 4H), 4.93 (s, 4H), 7.11 (s, 2H), 7.18
(s, 2H), 8.37 (s, 2H); 13C NMR (D2O/DCl) δ 134.4, 122.1, 120.2,
81.60, 71.65, 71.21, 49.13; MS (EI) m/z 346 (C18H18N4Fe+, 10);
HRMS m/z calc 346.0881, found 346.0884.
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(KBr) 3098, 3044, 1477, 1352, 1194, 1140, 1056, 872 cm-1; H
NMR δ 3.22 (S, 9H), 4.27 (S, 5H), 4.45 (t, J ) 1.8 Hz, 2H), 4.61
(t, J ) 1.8 Hz, 2H), 4.68 (s, 2H); 13C NMR δ 121.0 (q, J ) 321.2
Hz), 73.75, 73.01, 71.33, 69.99, 67.76 (t, J ) 2.1 Hz), 52.72 (t, J
) 4.2 Hz); 19F NMR δ -79.88 (s, 6F). Anal. Calcd for
C16H20N2S2O4F6Fe: C, 35.70; H, 3.74. Found: C, 35.78; H, 3.85.
Data for 1-(ferrocenylmethyl)-3-methylimidazolium bis(tri-
fluoromethanesulfonyl)amide (5a): 0.27 g, 96% yield; orange
liquid; d ) 1.68 g/cm-3; Tg ) -32.2 °C; IR (KBr) 3154, 3109,
1564, 1353, 1194, 1140, 1057, 829, cm-1; 1H NMR δ 4.03 (s, 3H),
4.26 (s, 5H), 4.30 (t, J ) 1.7 Hz, 2H), 4.51 (t, J ) 1.7 Hz, 2H),
5.39 (s, 2H), 7.66 (s, 1H), 7.71 (s, 1H), 8.95 (s, 1H); 13C NMR (75
MHz) δ 136.7, 124.7, 123.0, 121.0 (q, J ) 321.3 Hz), 80.95, 70.24,
70.18, 69.74, 50.13, 36.66; 19F NMR δ -79.89 (s, 6F); HRMS
(FAB) m/z calcd 281.0741, found 281.0730.
Data for 1-(ferrocenylmethyl)-4-methyltriazolium bis(tri-
fluoromethanesulfonyl)amide (5b): 0.27 g, 96% yield; orange
liquid; d ) 1.85 g/cm-3; Tg ) -16.4 °C; IR (KBr) 3140, 3032,
1582, 1352, 1193, 1137, 1056, 827 cm-1; 1H NMR δ 4.12 (s, 3H),
4.28 (s, 5H), 4.31 (t, J ) 1.9 Hz, 2H), 4.49 (t, J ) 1.9 Hz, 2H),
5.55 (s, 2H), 8.98 (s, 1H), 9.78 (s, 1H); 13C NMR δ 145.7, 142.4,
120.5 (q, J ) 321.3 Hz), 78.66, 69.93, 69.78, 69.31, 52.81, 34.45;
19F NMR δ -79.81 (s, 6F). Anal. Calcd for C16H16N4S2O4F6Fe:
C, 34.18; H, 2.87. Found: C, 34.22; H, 2.97.
1,1′-Bis{[1H-(2-methyl)imidazol-1-yl]methyl}ferrocene (8b).
The reaction procedure is the same as for 8a. The brown solution
was hydrolyzed with 300 mL of water and extracted with 3 × 50
mL of methylene chloride. The combined organic layer was washed
with 3 × 50 mL of water, dried with Na2SO4, evaporated on a
Rotavap, and heated in vacuo at 50 °C for 3 h. Then the crude
product was purified by column chromatography (Al2O3) using
methylene chloride/acetone (7:3) as an eluent, affording 8b: 0.84
g, 45% yield; yellow solid; mp181.3 °C; IR (KBr) 3088, 2931,
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1500, 1423, 1264, 1041, 980, cm-1; H NMR (CDCl3) δ 2.35 (s,
6H), 4.12 (s, 8H), 4.66 (s, 4H), 6.74 (s, 2H), 6.82 (s, 2H); 13C
NMR (CDCl3) δ 144.9, 127.9, 119.8, 84.75, 70.38, 70.04, 46.26,
14.17; MS (EI) m/z 374 (C20H22N4Fe+, 30). Anal. Calcd for
C20H22N4Fe: C, 64.18; H, 5.92, Found: C, 64.20; H, 6.03.
1,1′-Bis[(1H-1,2,4-triazol-1-yl)methyl]ferrocene (8c). The prepa-
ration is the same as for 8b: 0.84 g, 48% yield; yellow solid; mp
114.3 °C; IR (KBr) 3105, 2993, 1508, 1442, 1333, 1271, 1138,
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1018, 878 cm-1; H NMR (CDCl3) δ 4.23 (t, J ) 1.8 Hz, 4H),
4.28 (t, J ) 1.8 Hz, 4H), 5.09 (s, 4H), 7.95 (s, 2H), 8.01 (s, 2H);
13C NMR (CDCl3) δ 152.7, 143.3, 82.98, 70.74, 70.43, 49.93; MS
(EI) m/z 348 (C16H16N6Fe+, 10); HRMS (FAB) m/z calcd 348.0786,
found 348.0782.
Preparation of 1-(Ferrocenylmethyl)-3-methylimidazolium
Iodide (4a).30 A 1 mmol sample of 3a was dissolved in 2 mL of
methyl iodide and refluxed for 2 h. The resulting precipitate was
filtered and washed with ether until the ether fraction was
Data for ferrocene-1,1′-diylbis(methyltrimethylammonium
bis(trifluoromethanesulfonyl)amide) (7): 0.43 g, 96% yield;
yellow solid; mp 195.3 °C; IR (KBr) 3107, 3044, 1478, 1354, 1195,
1141, 1056, 872, cm-1; 1H NMR δ 3.21 (s, 18H), 4.56 (t, J ) 1.8
Hz, 4H), 4.69 (s, 4H), 4.75 (t, J ) 1.8 Hz, 4H); 13C NMR (125
Inorganic Chemistry, Vol. 43, No. 11, 2004 3411