Inorganic Chemistry
Article
vigorously for 2 min before being allowed to stand still for 12 h.
During this course, crystals precipitated and were collected by
filtration, washed with 5 mL of n-hexane, and dried in vacuo (1.42 g,
90%). 1H NMR (500 MHz, C6D6, ppm): δ 7.45 (s, 4H, ArH), 7.24−
7.18 (m, 8H, ArH), 7.10−7.05 (m, 8H, ArH), 6.99−6.97 (m, 2H,
PyrH), 6.58 (s, 4H, PyrH), 6.22 (s, 2H, PyrH), 3.75 (s, 8H, thf), 2.40
(s, 3H, NMe), 1.35 (s, 8H, thf), −0.08 (s, 9H, SiMe3), −0.95 (d, 2JY−H
= 2.5 Hz, 2H, CH2SiMe3). 13C NMR (125 MHz, C6D6, ppm): 149.7,
149.6, 144.9, 144.2, 130.2, 127.2, 127.1, 126.2, 113.7, 110.0, 108.3,
4H, ArH), 7.24 (t, J = 7.5 Hz, 8H, ArH), 7.11 (t, J = 7.5 Hz, 4H,
ArH), 6.99−6.92 (m, 12H, ArH), 6.76 (d, J = 7.5 Hz, 8H, ArH), 6.61
(s, 4H, PyrH), 5.96 (t, 1JY−H = 28.0 Hz, 2H, Y-H), 5.95−5.94 (m, 4H,
PyrH), 5.84 (s, 4H, PyrH), 5.77 (t, J = 3.0 Hz, 4H, PyrH), 3.47 (s,
4H, thf), 2.25 (s, 6H, NMe), 1.61 (s, 4H, thf). 13C NMR (125 MHz,
thf-d8, ppm): 149.5, 149.3, 144.7, 144.2, 130.2, 128.2, 127.6, 126.8,
126.5, 124.9, 111.5, 109.3, 108.7, 67.6 (thf), 58.2 (CPh2), 37.1
(NCH3), 25.7 (thf). Anal. Calcd for C82H72N6OY2·C6H14: C, 74.36;
H, 6.10; N, 5.91. Found: C, 74.10; H, 5.96; N, 5.63%. IR (KBr pellets,
cm−1): ν 3084, 3067, 3025, 2953, 2868, 2129, 1664, 1583, 1491,
1445, 1413, 1297, 1258, 1219, 1184, 1117, 1095, 1038, 983, 963, 885,
848,,798, 762, 745, 703, 563, 543, 486, 466.
Synthesis of (L(thf)[Yb(μ-H)]2L) (6c). Following the same
procedure as described above for the preparation of 6a, the reaction
of 5c (0.51 mg, 0.30 mmoL) with triethoxysilane (55 μL, 0.30
mmoL) afforded 6c as pale yellow crystals (0.12 g, 32%). Anal. Calcd
for C82H72N6OYb2·C6H14: C, 66.48; H, 5.45; N, 5.29. Found: C,
66.66; H, 5.52; N, 4.80%. IR (KBr pellets, cm−1): ν 3100, 3057, 2954,
2870, 1956, 1899,1815,1597, 1553, 1491, 1445, 1322, 1297, 1231,
1217, 1184, 1157, 1117, 1094, 1038, 1002, 976, 963, 903, 798, 763,
745, 703, 652, 622, 544, 486.
Synthesis of (LYb(μ-OEt))2(7c). To a clear brown solution of the
complex 1c (0.30 g, 0.31 mmol) in 10.0 mL of toluene was added a
clear colorless solution of triethoxysilane (57 μL, 0.31 mmol) in 5.0
mL of toluene. The color of the solution changed from brown to
yellow quickly. Yellow crystals precipitated after the solution was
allowed to stand for 12 h, and they were collected by filtration,
washed with 5.0 mL of n-hexane, and dried in vacuo (0.42 g, 80%).
Anal. Calcd for C82H72N6O2Yb2·C6H14: C, 65.82; H, 5.40; N, 5.23.
Found: C, 66.05; H, 5.16; N, 5.15%. IR (KBr pellets, cm−1): ν 3084,
3057, 3025, 2955, 2924, 2856, 1956, 1895, 1814, 1654, 1597, 1552,
1491, 1444, 1413, 1389, 1321, 1296, 1259, 1231, 1184, 1150, 1115,
1094, 1038, 963, 903, 885, 797, 763, 744, 703, 622, 545, 484.
General Catalytic Procedures for the Dehydrogenative
Coupling Reaction. In a glovebox, to a 15 mL Schlenk tube
equipped with a magnetic stir bar was added the catalyst 1b (0.18 g,
0.20 mmol), toluene (2 mL), and the terminal alkyne (4.00 mmol) via
syringe sequentially, and the resulting solution was stirred for 5 min
before the addition of triethoxysilane (1.47 mL, 8.00 mmol). The
sealed tube was taken out of the glovebox and heated at 150 °C for 34
h. After that, the mixture was cooled to room temperature. The
reaction tube was uncapped carefully in a ventilated cabinet and
stirred for 5 min to release the flammable gas SiH4 in the case of
triethoxysilane being employed in the reaction. An aliquot (30 μL)
was taken out and diluted with hexane to 2 mL. After filtration, the
aliquot was subjected to GC-MS analysis to determine the yield with
mesitylene as an internal standard. Analytically pure samples of the
products suitable for spectroscopic analysis were obtained by
concentration of the reaction mixture under vacuum, and the residue
was extracted with hexane (10.0 mL). The extraction was purified by
fractional distillation under reduced pressure to give the product.
1
69.4 (thf), 58.3 (CPh2), 35.4 (NCH3), 31.5 (d, JY−C = 37.5 Hz, Y-
CH2SiMe3), 25.4 (thf), 4.2 (SiMe3). Anal. Calcd for C51H58N3O2SiY:
C, 71.06; H, 6.78; N, 4.87. Found: C, 70.51; H, 6.77; N, 4.73%. IR
(KBr pellets, cm−1): ν 3058, 3028, 2954, 2807, 2804, 2501, 1955,
1902, 1641, 1597, 1551, 1491, 1444, 1441, 1392, 1299, 1248, 1220,
1170, 1115, 1082, 1033, 1002, 962, 904, 863, 799, 763, 745, 702, 655,
568, 548.
Synthesis of LEr(CH2SiMe3)(thf)2 (1b). Following the same
procedure as described for the preparation of 1a, the reaction of H2L
(1.00 g, 1.84 mmol) with Er(CH2SiMe3)3(thf)2 (1.05 g, 1.84 mmol)
afforded 1b as pink crystals (1.54 g, 88%). Anal. Calcd for
C51H58N3O2SiEr: C, 65.14; H, 6.22; N, 4.47. Found: C, 64.78; H,
6.21; N, 4.42%. IR (KBr pellets, cm−1): ν 3085, 3057, 3028, 2869,
2808, 2664, 2507, 2344, 1956, 1900, 1817, 1774, 1672, 1653, 1596,
1550, 1490, 1444, 1441, 1394, 1321, 1298, 1248, 1231, 1184, 1155,
1115, 1094, 1033, 862, 763, 745, 704, 567, 548.
Synthesis of LYb(CH2SiMe3)(thf)2 (1c). Following the same
procedure as described for the preparation of 1a, the reaction of H2L
(1.00 g, 1.84 mmol) with Yb(CH2SiMe3)3(thf)2 (1.07 g, 1.84 mmol)
afforded 1c as brown crystals (1.55 g, 89%). Anal. Calcd for
C51H58N3O2SiYb: C, 64.74; H, 6.18; N, 4.44. Found: C, 64.97; H,
6.38; N, 4.52%. IR (KBr pellets, cm−1): ν 3088, 3057, 3028, 2955,
2869, 2664, 2506, 1956, 1901, 1817, 1774, 1652, 1596, 1550, 1490,
1444, 1394, 1320, 1298, 1248,1231, 1155, 1115, 1078, 1041, 904,
862, 800, 768, 745, 702, 567, 548.
Synthesis of (L(thf)[Y(μ-CCPh)]2L) (5a). To a clear solution of
the complex 1a (0.23 g, 0.26 mmol) in 14.0 mL of toluene was added
a clear solution of phenylacetylene (29 μL, 0.26 mmol) in 14.0 mL of
toluene at room temperature. Colorless crystals appeared after the
solution was allowed to stand for 12 h. The solids were collected by
filtration, washed with 7 mL of n-hexane, and dried in vacuo (0.28 g,
1
70%). H NMR (500 MHz, thf-d8, ppm): δ 7.80 (s, 4H, ArH), 7.30
(s, 6H, ArH), 7.22 (s, 12H, ArH), 7.07 (s, 16H, ArH), 6.99−6.96 (m,
16H, ArH and PyrH), 6.24 (s, 4H, PyrH), 6.11 (s, 4H, PyrH), 5.77 (s,
4H, PyrH), 3.51 (s, 4H, thf), 2.37 (s, 6H, NMe), 1.66 (s, 4H, thf). 13C
NMR (125 MHz, thf-d8, ppm): 149.8, 149.5, 146.5, 145.9, 142.4,
132.1, 131.3, 130.6, 130.0, 128.5, 128.0, 127.5, 126.2, 125.4, 108.8,
108.1, 105.8, 67.6 (thf), 58.3 (CPh2), 36.3 (NCH3), 25.7 (thf). Anal.
Calcd for C98H80N6OY2·C6H14: C, 77.02; H, 5.84; N, 5.18. Found: C,
77.21; H, 5.58; N, 4.99%. IR (KBr pellets, cm−1): ν 3084, 3057, 3030,
2956, 2871, 1955, 1901, 1819, 1776, 1595, 1553, 1490, 1443, 1414,
1392, 1320, 1298, 1231, 1222, 1184, 1115, 1094, 963, 907, 887, 851,
797, 759, 744, 703.
Synthesis of (LYb(μ-CCPh))2 (5c). Following the same
procedure as described above for the preparation of 5a, the reaction
of 1c (0.23 g, 0.24 mmol) with phenylacetylene (27 μL, 0.24 mmol)
afforded 5c as yellow crystals (0.23 g, 62%). Anal. Calcd for
C94H72N6Yb2·C6H14: C, 69.91; H, 5.05; N, 4.89. Found: C, 69.54; H,
5.33; N, 4.53%. IR (KBr pellets, cm−1): ν 3084, 3057, 3030, 2958,
2869, 1953, 1899, 1814, 1595, 1550, 1492, 1445, 1416, 1389, 1332,
1296, 1260, 1229, 1182, 1153, 1119, 1036, 963, 902, 887, 853, 795,
764, 744, 704.
Synthesis of (L(thf)[Y(μ-H)]2L) (6a). The complex 5a (0.50 mg,
0.32 mmoL) was dissolved in hot toluene (15.0 mL). Next,
triethoxysilane (60 μL, 0.32 mmoL) was added, and the reaction
mixture was stirred at 90 °C for 6 h. The colorless solution was
concentrated to ∼10 mL and filtered, and then 5.0 mL of n-hexane
was added to the clear solution. Colorless crystals appeared after the
solution was allowed to stand at 0 °C for 12 h. The solids were
collected by filtration, washed with 7.0 mL of cold n-hexane, and dried
in vacuo (0.14 g, 30%). 1H NMR (500 MHz, thf-d8, ppm): δ 7.30 (s,
ASSOCIATED CONTENT
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sı
* Supporting Information
The Supporting Information is available free of charge at
Structures of complexes 1b−c; Crystallographic data of
1 and 5-7; Compounds data and H and 13C NMR
1
spectra; CCDC: 1943681−1943683 (1b-c), 1943684
(5a), 2010984 (5c), 1943685−1943686 (6c and 7c)
Accession Codes
mentary crystallographic data for this paper. These data can be
G
Inorg. Chem. XXXX, XXX, XXX−XXX