Organometallics
ARTICLE
(9b,9c-arylC), 122.33 (4,5-arylC), 117.24 (CN), 94.33 (1,8-arylC),
35.12 (C(CH3)3), 31.92 (C(CH3)3). EI-MS: m/z 329 (M+).
1,8-Bis(40,40-dimethyloxazolin-20-yl)-3,6-di-tert-butyl-
carbazole (H-Czx), 14.
Yield: 0.77 g (92%). Mp: 206 °C (dec). 1H NMR (360 MHz, C6D6, 298 K):
δ81.2 (s, 12H, ν1/2 =567Hz, 40-(CH3)2), 76.5 (s, 4H, ν1/2 =158Hz, CH2),
42.9 (s, 2H, ν1/2 = 75 Hz, 2,7-arylH), 7.26 (s, 2H, ν1/2 = 20 Hz, 4,5-arylH),
6.45 (s, 18H, ν1/2 = 17 Hz, C(CH3)3), ꢀ62.2 (s, 18H, ν1/2 = 154 Hz,
Si(CH3)3), ꢀ185.0 (s, 4H, ν1/2 = 2360 Hz, CH2Si(CH3)3). IR (KBr):
ν 2955, 1635, 1576, 1476, 1363, 1176, 852, 730, 668 cmꢀ1. Anal. Calcd for
C38H60N3O2Si2Er: C 56.05, H 7.43, N 5.16. Found: C 56.52, H 7.38, N 5.29.
(Czx)Yb(CH2SiMe3)2, 17. This complex was prepared on the same
scale and using the same procedure reported for 15 above. Orange-red
cubes of 17 were isolated by recrystallization from a tolueneꢀhexane
mixture. Yield: 0.75 g (91%). Mp: 250 °C (dec). 1H NMR (360 MHz,
C6D6, 298 K): δ 69.2 (s, 16H, ν1/2 = 59 Hz, 40-(CH3)2 and CH2), 33.5
(s, 2H, ν1/2 = 18 Hz, 2,7-arylH), 2.61 (s, 18H, ν1/2 = 6 Hz, C(CH3)3),
ꢀ1.60 (s, 2H, ν1/2 = 9 Hz, 4,5-arylH), ꢀ39.9 (s, 18H, ν1/2 = 26 Hz,
Si(CH3)3), ꢀ174.8 (s, 4H, ν1/2 = 54 Hz, CH2Si(CH3)3). IR (KBr):
ν 2954, 1634, 1575, 1476, 1363, 1176, 852, 730, 668 cmꢀ1. Anal. Calcd
for C38H60N3O2Si2Yb: C 55.65, H 7.37, N 5.12. Found: C 52.60, H 6.28,
N 5.60. The crystals changed color from orange-red to yellow when
exposed to high vacuum.
(Czx)Y(Cl)2(THF), 18. YCl3(THF)x (0.45 g, 1.0 mmol) was par-
tially dissolved in 10 mL of THF in a 50 mL Erlenmeyer flask in the
glovebox. A solution of NaCzx (0.50 g, 1.0 mmol) in 5 mL of THF was
prepared in situ by deprotonation of H-Czx, 14 (0.48 g, 1.0 mmol), with
1 equiv of Na[N(SiMe3)2] (0.18 g, 1.0 mmol). The NaCzx solution was
added to the YCl3(THF)x suspension dropwise by Pasteur pipet,
resulting in an immediate color change to neon yellow-green. After 1
h at room temperature, the reaction mixture was filtered through Celite
to remove NaCl, and the solvent was removed from the filtrate under
reduced pressure using a rotary evaporator. Crude 18 was recrystallized
from benzene to afford yellow-green crystals of pure 18.Yield: 0.63 g
(90%). Mp: 272 °C (dec). 1H NMR (500 MHz, C6D6, 298 K): δ 8.54
(d, J = 2.2 Hz, 2H, 4,5-arylH), 8.48 (d, J = 2.1 Hz, 2H, 2,7-arylH), 3.53 (s,
4H, CH2), 3.38 (t, 4H, R-CH2 THF), 1.76 (s, 12H, 40-(CH3)2), 1.45 (s,
18H, C(CH3)3), 0.72 (t, 4H, β-CH2 THF). 13C{1H} NMR (125 MHz,
C6D6): δ 169.04 (CdN), 147.58 (9a,9d-arylC), 140.57 (3,6-arylC), 127.57
(9b,9c-arylC), 126.77 (2,7-arylCH), 123.31 (4,5-arylCH), 110.23 (1,
8-arylC), 79.85 (CH2), 69.34 (40-C(CH3)2)), 35.05 (C(CH3)3), 32.43
(C(CH3)3), 28.45 (40-C(CH3)2). Anal. Calcd for C46H58Cl2N3O3Y: C
64.25, H 6.75, N 4.89. Found: C 64.45, H 6.87, N 4.98.
1,8-Dicyano-3,6-di-tert-butylcarbazole, 13 (2.00 g, 6.07 mmol),
was dissolved in 100 mL of chlorobenzene along with 2-methyl-
2-aminopropanol (1.62 g, 18.2 mmol) and anhydrous ZnCl2
(2.08 g, 15.3 mmol). The reaction mixture was refluxed for 72 h
and then cooled to room temperature. The reaction mixture was
poured into a solution of ethylenediamine (10 mL) and water
(100 mL) and stirred for 1 h. The resulting biphasic solution was
extracted with CH2Cl2 (3 ꢁ 100 mL), and the combined organic
layers were washed with brine (2 ꢁ 100 mL) and dried over
anhydrous MgSO4. After the filtration, the organic layer evapo-
rated to dryness and the residue was purified by column chroma-
tography on silica using CH2Cl2 as eluant. Pure H-Czx, 13, was
isolated as a white powder (1.15 g, 40%). Mp: 278ꢀ280 °C. 1H
NMR (500 MHz, CDCl3, 298 K): δ 11.87 (s, 1H, NH), 8.19 (d,
J = 1.8 Hz, 2H, 4,5-arylH), 7.89 (d, J = 1.8 Hz, 2H, 2,7-arylH), 4.16
(s, 4H, CH2), 1.47 (s, 12H, 40-(CH3)2), 1.45 (s, 18H, C(CH3)3).
13C{1H} NMR (125 MHz, CDCl3): δ 161.27 (CdN), 141.34
(3,6-arylC), 137.61 (9a,9d-arylC), 123.18 (9b,9c-arylC), 122.65
(2,7-arylCH), 119.56 (4,5-arylCH), 109.66 (1,8-arylC),78.32(CH2),
67.55 (40-C(CH3)2)), 34.68 (C(CH3)3), 32.26 (C(CH3)3), 28.84
(40-C(CH3)2). IR (KBr): ν 3336 (br s), 2961, 1648, 1490, 1363,
1286, 1152, 727, 668 cmꢀ1. EI-MS: m/z 473 (M+). Anal. Calcd
for C30H39N3O2: C 76.08, H 8.30, N 8.87. Found: C 75.66,
H 8.28, N 8.77.
(Czx)Y(CH2SiMe3)2, 15. In the glovebox, Y(CH2SiMe3)3(THF)2
(0.49 g, 1.0 mmol) was dissolved in 10 mL of toluene in a 50 mL
Erlenmeyer flask. A solution of H-Czx (0.47 g, 1.0 mmol) in 5 mL of
toluene was added by pipet, resulting in an immediate color change to
neon yellow. After 2 h at room temperature, the solvent was removed
under reduced pressure using a rotary evaporator, and the solid residue
obtained was recrystallized from a mixture of toluene and hexane to
afford 15 as pale yellow crystals (0.66 g, 90%). Mp: 196 °C (dec).
1H NMR (500 MHz, C6D6, 298 K): δ 8.65 (d, J = 2.2 Hz, 2H, 4,5-arylH),
8.51 (d, J = 1.8 Hz, 2H, 2,7-arylH), 3.72 (s, 4H, CH2), 1.56 (s, 12H,
40-(CH3)2), 1.39 (s, 18H, C(CH3)3), 0.04 (s, 18H, Si(CH3)3), 0.00 (s,
JY,H = 2.6 Hz, 4H, CH2Si(CH3)3). 13C{1H} NMR (125 MHz, CDCl3):
δ 170.28 (CdN), 148.05 (9a,9d-arylC), 140.78 (3,6-arylC), 127.84
(9b,9c-arylC), 126.46 (2,7-arylCH), 123.31 (4,5-arylCH), 109.76 (1,
8-arylC), 79.09 (CH2), 69.14 (40-C(CH3)2)), 37.46 (JY,C = 38.5 Hz,
CH2Si(CH3)3)), 35.01 (C(CH3)3), 32.30 (C(CH3)3), 27.89 (40-
C(CH3)2), 4.76 (Si(CH3)3). IR (KBr): ν 2956, 1634, 1596, 1472, 1362,
1176, 861, 776, 668 cmꢀ1. This compound decomposed after several
hours at room temperature in the glovebox so an elemental analysis was
not obtained.
(Czx)Er(Cl)2(THF), 19. This complex was prepared on the same
scale and using the same procedure reported for 18 above. Yellow
crystals of 19 were isolated by recrystallization from a tolueneꢀhexane
mixture. Yield: 0.74 g (95%). Mp: 270 °C (dec). 1H NMR (360 MHz,
C6D6, 298 K): δ 41.9 (s, 16H, ν1/2 = 2730 Hz, 40-(CH3)2 and CH2), 20.2
(s, 2H, ν1/2 = 1080 Hz, 2,7-arylH), 0.80 (s, 18H, ν1/2 = 60 Hz,
C(CH3)3), ꢀ2.44 (s, 2H, ν1/2 = 34 Hz, 4,5-arylH), ꢀ14.1 (s, 4H, ν1/
2 = 114 Hz, β-THF), ꢀ30.6 (s, 4H, ν1/2 = 578 Hz, R-THF). Anal. Calcd
for C46H58Cl2N3O3Er: C, 58.96, H 6.20, N 4.49. Found: C 57.80, H
5.86, N 4.66.
(Czx)Yb(Cl)2(THF), 20. This complex was prepared on the same
scale and using the same procedure reported for 18 above. Yellow-green
crystals of 20 were isolated by recrystallization from a tolueneꢀhexane
mixture. Yield: 0.73 g (93%). Mp: 270 °C (dec). 1H NMR (360 MHz,
C6D6, 298 K): δ 49.3 (s, 4H, ν1/2 = 670 Hz, CH2), 43.8 (s, 12H, ν1/2
=
680 Hz, 40-(CH3)2), 20.0 (s, 2H, ν1/2 = 102 Hz, 2,7-arylH), ꢀ0.97 (s,
18H, ν1/2 = 6 Hz, C(CH3)3), ꢀ8.63 (s, 2H, ν1/2 = 26 Hz, 4,5-arylH),
ꢀ9.6 (s, 4H, ν1/2 = 42 Hz, β-CH2 THF), ꢀ26.0 (s, 4H, ν1/2 = 266 Hz,
R-CH2 THF). Anal. Calcd for C46H58Cl2N3O3Yb: C 58.46, H 6.14, N
4.45. Found: C 58.23, H 6.39, N 4.41.
[(Czx)Y(CH2SiMe3)]+[B(C6F5)4]ꢀ, 21. Treatment of a solution of
15 (0.012 g, 0.016 mmol) dissolved in toluene-d8 (0.6 mL) with 1 equiv
of Ph3C+ [B(C6F5)4]ꢀ (0.015 g, 0.016 mmol) resulted in an orange-brown
solution. This complex decomposed during attempted isolation. The prod-
uct was characterized in situ by NMR spectroscopy in toluene-d8. 1H NMR
(Czx)Er(CH2SiMe3)2, 16. This complex was prepared on the same
scale and using the same procedure reported for 15 above. Yellow cubes
of 16 were isolated by recrystallization from a tolueneꢀhexane mixture.
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dx.doi.org/10.1021/om200588y |Organometallics 2011, 30, 4958–4967