Organometallics
Article
3
3
4H, m-CH, C6H4, JHH = 8.5 Hz), 6.57 (d, 4H, o-CH, C6H4, JHH
=
1095 (s), 1053 (m), 1015 (w), 976 (s), 942 (w), 861 (s), 822 (s), 807
(s), 661 (s), 630 (s), 553 (s) cm−1. Anal. Calcd for C49H70O2SiYb
(892.24 g mol−1): C, 65.96; H, 7.91; Yb, 19.40. Found: C, 65.64; H,
7.65; Yb, 19.33.
Thermolysis of Complex 5. Complex 5 (0.100 g, 0.11 mmol)
was dissolved in C6D6 (0.7 mL) and placed into an NMR tube. The
tube was heated at 120 °C for 48 h to achieve a 70% conversion of the
complex. 1H and 13C{1H} NMR spectra of the reaction mixture
indicated the formation of (p-tBu-C6H4)2CH2 (lit.10), methyl vinyl
ether MeOCHCH2 (lit.16c−e), and [tBu4Carb]2Yb (lit.11c) (Figures
8.2 Hz), 3.28 (s, 1H, CH-benzhydryl), 2.34 (br s, 4H, −CH2CH2−,
DME), 2.03 (br s, 6H, OMe-DME), 1.84 (s, 18H, tBu-carbazolyl),
1.54 (s, 18H, tBu-carbazolyl), 1.29 (s, 18H, tBu-benzhydryl). 13C{1H}
NMR (100 MHz, C6D6, 293 K): δ 145.64 (s, C-carbazolyl), 143.66 (s,
ipso-C, benzhydryl), 140.31 (s, C-carbazolyl), 139.05 (s, C-
carbazolyl), 135.19 (s, ipso-C, benzhydryl), 126.50 (s, m-CH,
C6H4), 124.51 (s, C-carbazolyl), 119.84 (s, CH-carbazolyl), 117.55
(s, o-CH, C6H4), 115.22 (s, CH-carbazolyl), 70.11 (br s, −CH2CH2−,
DME), 69.59 (s, CH-benzhydryl), 59.70 (s, OMe-DME), 35.93 (s,
C(CH3)3, carbazolyl), 34.80 (s, C(CH3)3, carbazolyl), 33.38 (s,
C(CH3)3, benzhydryl), 31.88 (s, C(CH3)3, carbazolyl), 31.44 (s,
C(CH3)3, benzhydryl), 29.80 (s, C(CH3)3, carbazolyl). IR (KBr,
Nujol): ν 1592 (s), 1499 (s), 1399 (m), 1365 (s), 1311 (s), 1284 (w),
1269 (w), 1245 (w), 1219 (w), 1188 (s), 1049 (s), 1018 (w), 934
(w), 907 (w), 861 (s), 841 (m), 822 (s), 803 (s), 776 (m), 672 (s),
650 (m), 634 (w), 553 (s) cm−1. Anal. Calcd for C53H77NO2Yb
(933.19 g mol−1): C, 68.21; H, 8.32; N, 1.50; Yb, 18.54. Found: C,
67.83; H, 8.04; N, 1.28; Yb, 18.39.
Thermolysis of Complex 7. Complex 7 (0.100 g, 0.11 mmol)
was dissolved in C6D6 (0.7 mL) and placed into an NMR tube. The
tube was heated at 120 °C for 54 h to achieve a 70% conversion of the
complex. 1H and 13C{1H} NMR spectra of the reaction mixture
indicated the formation of (p-tBu-C6H4)2CH2 (lit.10), methyl vinyl
ether MeOCHCH2 (lit.16c−e), and [2,7-tBu2-9-SiMe3C13H7]2Yb-
(400 MHz, C6D6, 298 K) for [2,7-tBu2-9-SiMe3C13H7]2Yb(DME): δ
7.80 (s, 4H, 1.8-CH-fluorenyl), 7.78 (d, 4H, 4,5-CH-fluorenyl, 3JHH
=
Synthesis of [tBu4Carb]Yb[CH(C6H4-p-tBu)2](TMEDA) (6). 3
(0.776 g, 0.92 mmol) was dissolved in toluene (15 mL), and 1,3,6,8-
tetra-tert-butylcarbazole (0.360 g, 0.92 mmol) was added. The
solution was heated for 20 min at 80 °C, the volatiles were removed
under vacuum, and freshly distilled hexane (10 mL) was added to the
residue. Orange crystals of complex 6 were obtained by slow
3
8.5 Hz), 7.03 (d, 4H, 3,6-CH-fluorenyl, JHH = 7.5 Hz), 2.33 (s, 6H,
OMe-DME), 2.12 (s, 4H, −CH2CH2−DME), 1.46 (s, 36H, tBu),
0.47 (s, 18H, SiMe3). 13C{1H} NMR (100 MHz, C6D6, 298 K) for
[2,7-tBu2-9-SiMe3C13H7]2Yb(DME): δ 148.42 (s, ipso-C), 144.54 (s,
ipso-C), 142.22 (s, ipso-C), 120.45 (s, 4,5-CH-fluorenyl), 115.72 (s,
1,8-CH-fluorenyl), 113.69 (s, 3,6-CH-fluorenyl), 87.57 (s, C9), 69.80
(s, −CH2CH2− DME), 60.28 (s, OMe-DME), 34.80 (s, C(CH3)3),
31.80 (s, C(CH3)3), 2.32 (s, SiMe3).
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concentration of a hexane solution in 65% yield (0.570 g). H NMR
(400 MHz, C6D6, 298 K): δ 8.19 (br s, 2H, CH-carbazolyl), 7.65 (s,
2H, CH-carbazolyl), 7.17−7.07 (m, 4H, m-CH, C6H4), 6.98 (d, 4H,
o-CH, C6H4, JHH = 7.2 Hz), 3.00 (s, 1H, CH-benzhydryl), 1.92 (s,
3
Reaction of Complex 5 with an Excess of DME. Orange
crystals of complex 5 (0.300 g, 0.32 mmol) were dissolved in a
minimal amount of THF (3 mL) to form a brownish yellow solution.
DME (2 mL, 19.3 mmol) was added to the solution, and a
voluminous straw yellow precipitate formed instantly. When the
mixture was heated to 60 °C, the precipitate dissolved completely,
and subsequent slow cooling to room temperature afforded light
18H, tBu-carbazolyl), 1.49 (s, 18H, tBu-carbazolyl), 1.31 (s, 18H,
tBu-benzhydryl), 1.21 (s, 12H, NMe2-TMEDA), 1.11 (br s, 4H,
−CH2CH2− TMEDA). 13C{1H} NMR (100 MHz, C6D6, 293 K): δ
147.13 (br s, C-carbazolyl), 146.48 (br s, ipso-C, benzhydryl), 140.07
(s, C-carbazolyl), 139.61 (s, C-carbazolyl), 136.52 (s, ipso-C,
benzhydryl), 126.22 (s, m-CH, C6H4), 125.24 (s, C-carbazolyl),
120.27 (s, CH-carbazolyl), 118.84 (s, o-CH, C6H4), 115.30 (s, CH-
carbazolyl), 67.89 (s, CH-benzhydryl), 55.97 (s, −CH2CH2−
TMEDA), 45,13 (br s, NMe2-TMEDA), 36.26 (s, C(CH3)3,
carbazolyl), 34.78 (s, C(CH3)3, carbazolyl), 33.47 (s, C(CH3)3,
carbazolyl), 31.95 (s, C(CH3)3, carbazolyl), 31.52 (s, C(CH3)3,
benzhydryl), 30.57 (s, C(CH3)3, carbazolyl). IR (KBr, Nujol): ν 1302
(m), 1280 (m), 1244 (s), 1216 (m), 1188 (w), 1120 (w), 1084 (m),
1020 (w), 970 (w), 900 (m), 865 (s), 841 (s), 777 (m), 757 (w), 670
(w), 651 (s), 580 (m), 541 (w), 510 (m) cm−1. Anal. Calcd for
C61H97N3Yb (1043.51 g mol−1): C, 70.21; H, 9.18; N, 4.03; Yb,
16.58. Found: C, 69.86; H, 8.84; N, 3.71; Yb, 16.45.
1
yellow crystals of complex 9 (0.18 g, 86%). H NMR (400 MHz,
pyridine-d5, 293 K): δ 8.52 (br s, 4 H, CH-carbazolyl), 7.68 (br s, 4 H,
CH-carbazolyl), 3.61 (br s, 8 H, THF), 3.42 (s, 16 H, −CH2CH2−
DME), 3.10 (s, 24 H, OMe-DME), 2.32 (br s, 36 H, tBu), 1.66 (br s,
36 H, tBu), 1.58 (br s, 12 H, THF). 13C{1H} NMR (100 MHz,
pyridine-d5, 298 K): δ 143.74 (s, C-carbazolyl), 138.03 (br s, C-
Carbazolyl), 134.18 (br s, C-carbazolyl), 133.50 (s, C-carbazolyl),
116.81 (br s, CH-carbazolyl), 114.87 (br s, CH-carbazolyl), 73.24 (s,
−CH2CH2− DME), 69.06 (s, α-CH2, THF), 59.85 (s, OMe, DME),
38.08 (s, C(CH3)3), 36.36 (s, C(CH3)3), 34.47 (s, CH3), 32.62 (s,
CH3), 27.02 (s, β-CH2, THF). IR (KBr, Nujol): ν 1292 (m), 1245
(w), 1220 (w), 1186 (w), 1114 (w), 1060 (s), 851 (s), 776 (w), 650
(m) cm−1. Anal. Calcd for C84H144N2O11Yb (1529.12 g mol−1): C,
65.98; H, 9.36; N, 1.83; Yb, 11.32. Found: C, 65.67, H, 9.08; N, 1.45;
Yb, 11.23. The mother liquor was separated from the crystals and
ananlyzed. GC/MS analysis of the products detected the presence of
of (p-tBu- C6H4)2CH2 and (p-tBu-C6H4)2CHMe in the ratio 55:45
Synthesis of [2,7-tBu2-9-SiMe3C13H7]Yb[CH(C6H4-p-tBu)2]-
(DME) (7). A synthetic protocol analogous to that for 5 was applied.
3 (0.579 g, 0.69 mmol) in toluene (10 mL) and 2,7-tBu2-9-
SiMe3C13H8 (0.241 g, 0.69 mmol) were used in the synthesis. The
reaction was carried out in toluene at 60 °C, and the reaction time
was 20 min. Deep red crystals of complex 7 were obtained by slow
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concentration of the reaction mixture in 80% yield. H NMR (400
MHz, C6D6/THF-d8 90/10, 298 K): δ 8.07 (s, 2H, 1,8-CH-
3
fluorenyl), 7.98 (d, 2H, 3,6-CH-fluorenyl, JHH = 8.2 Hz), 7.20 (d,
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge at
■
2H, 4,5-CH-fluorenyl, 3JHH = 9.8 Hz), 7.01 (d, 4H, m-CH-benzhydryl,
3JHH = 8.4 Hz), 6.79 (d, 4H, o-CH-benzhydryl, 3JHH = 7.7 Hz), 3.32−
3.07 (compl. m, 5H, −CH2CH2− DME and CH-benzhydryl), 3.01
(br s, 6H, OMe-DME), 1.44 (s, 18H, tBu-fluorenyl), 1.24 (s, 18H,
tBu-benzhydryl), 0.64 (s, 9H, SiMe3). 13C{1H} NMR (100 MHz,
C6D6/THF-d8 90/10, 293 K): δ 145.51 (s, ipso-C-fluorenyl), 144.48
(br s, ipso-C, benzhydryl), 141.09 (s, ipso-C-fluorenyl), 135.51 (s,
ipso-C, benzhydryl), 126.34 (s, m-CH, benzhydryl), 121.04 (s, ipso-C-
fluorenyl), 120.77 (s, CH-fluorenyl), 117.60 (s, o-CH-benzhydryl),
116.20 (s, 1,8-CH-fluorenyl), 115.13 (s, CH, fluorenyl), 85.81 (s, 9-C,
fluorenyl), 71.61 (br s, −CH2CH2− DME), 67.73 (br s, CH-
benzhydryl), 58.43 (br s, OMe-DME), 34.82 (s, C(CH3)3-fluorenyl),
33.38 (s, C(CH3)3-benzhydryl), 31.60 (s, C(CH3)3-fluorenyl), 31.41
(s, C(CH3)3-benzhydryl), 2.12 (s, SiMe3). IR (KBr, Nujol): ν 1592
(s), 1326 (w), 1303 (w), 1265 (m), 1245 (w), 1199 (m), 1180 (s),
S
Crystal data for 4−7 and 9 and characterization data for
Accession Codes
tallographic data for this paper. These data can be obtained
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
G
Organometallics XXXX, XXX, XXX−XXX