400 MHz instrument and processed using MestReNova software.
Lanthanide analyses were performed by EDTA titration with a
xylenol orange indicator and a hexamine buffer. Elemental
analyses were performed by direct combustion using a Carlo-
Erba EA 1110 instrument. The IR spectra were recorded on a
Magna-IR 550 spectrometer as KBr pellets.
C39H62N5O2Si2Gd (846.37): calcd C 55.34, H 7.38, N 8.27, Gd
18.58; found C 55.03, H 7.56, N 8.11, Gd 18.79. IR (KBr):
3402 (m), 3335 (m), 2960 (s), 2871 (m), 1618 (s), 1542 (m),
1468 (m), 1439 (s), 1364 (m), 1247 (s), 1155 (s), 909 (w), 836
(s), 780 (m), 746 (s), 701 (s) cm−1
.
[Yb(μ2-NHPh)]2(μ2-L)2 (6). The synthesis of complex 6 was
carried out in the same way as that described for the synthesis of
complex 1, but LYbCl(THF)2 (2.21 g, 3.00 mmol) and LiNHPh
(0.29 g, 3.00 mmol) were used. Colourless single crystals suit-
able for X-ray analysis were obtained at −15 °C after several
days (yield: 1.19 g, 51% based on Yb). C58H78N10Si4Yb2
(1374.43): calcd C 50.71, H 5.72, N 10.20, Yb 25.19; found C
50.33, H 6.12, N 9.82, Yb 25.76. IR (KBr): 3413 (s), 2960 (m),
1646 (m), 1608 (m), 1568 (m), 1438 (m), 1384 (m), 1365 (m),
1245 (s), 1156 (s), 903 (w), 838 (m), 781 (m), 747 (m), 702 (m)
Preparations
LY(NHAr1)(DME) (1). A THF solution (20 mL) of LYCl
(THF)2 (2.07 g, 3.00 mmol) was added into a THF solution of
LiNHAr1 (0.55 g, 3.00 mmol) slowly under stirring. The
mixture was stirred at room temperature for 12 h. After the
solvent was removed under reduced pressure, the residue was
extracted with hot toluene and the LiCl was removed by centrifu-
gation. The resulting pale yellow solution was concentrated and
a small amount of DME was added. Colorless crystals suitable
for X-ray analysis were obtained (1.52 g, 65% yield based on Y)
upon crystallization from a mixture of toluene and DME at room
cm−1
.
[LYb]2(μ2-NHAr2)2 (7). The synthesis of complex 7 was
carried out in the same way as that described for complex 1, but
LYbCl(THF)2 (2.21 g, 3.00 mmol) and LiNHAr2 (0.38 g,
3.00 mmol) were used. Colourless crystals were isolated (yield:
1.41 g, 58% based on Yb). C60H84N10O2Si4Yb2 (1436.46):
calcd C 50.19, H 5.90, N 9.76, Yb 24.10; found C 50.66, H
6.10, N 9.68, Yb 24.75. IR (KBr): 3412 (s), 3336 (m), 2960 (m),
1645 (m), 1609 (m), 1566 (m), 1466 (m), 1438 (m), 1384 (m),
1368 (m), 1246 (s), 1157 (s), 909 (w), 837 (m), 751 (m), 702
1
temperature for several days. H NMR (400 MHz, C6D6): δ =
7.32 (2 H, d, J = 7.2 Hz, ArH), 7.20 (4 H, d, J = 7.6 Hz, ArH),
7.16–7.04 (5 H, m, ArH), 6.77–6.71 (1 H, m, ArH), 6.59 (1 H, t,
J = 7.7 Hz, ArH), 3.78–3.81 (4 H, m, OCH2), 3.13 (6 H, s,
OCH3), 2.77–2.80 (6 H, m, CH2CH2N and CH(CH3)2),
1.16–1.21 (12 H, m, CH(CH3)2), 1.58–1.61 (2 H, m,
CH2CH2N), 0.29 to −0.07 (18 H, m, Si(CH3)3). 13C NMR
(400 MHz, C6D6) δ = 162.13 (CvN), 141.92 (Ar), 133.47 (Ar),
128.62 (Ar), 128.42 (Ar), 128.03 (Ar), 124.32 (Ar), 120.13 (Ar),
86.35 (OCH2), 73.43 (OCH3), 29.37 (CH2CH2N), 23.82 (CH
(CH3)2), 4.29 (CH(CH3)2), 1.52 (Si(CH3)3). C39H62N5O2Si2Y
(778.03): calcd C 60.21, H 8.03, N 9.00, Y 11.43; found C
60.29, H 8.09, N 8.74, Y 12.19. IR (KBr): 3468 (m), 3335 (m),
2959 (s), 1646 (m), 1608 (s), 1569 (m), 1490 (m), 1438 (m),
1363 (m), 1245 (s), 1158 (s), 908 (w), 835 (s), 780 (m), 746
(m) cm−1
.
LY[NPhCNAr1](PhCN) (8). LY(NHAr)(DME) (1) (2.33 g,
3.00 mmol) were dissolved in toluene solution (30 mL), then
PhCN (0.61 mL, 6.00 mmol) was added into the solution of
complex 1 quickly under stirring. The mixture was stirred at
100 °C for 12 h. After the solvent was removed under reduced
pressure, the residue was extracted with toluene, centrifuged, and
the centrifugal clear liquid was concentrated. Colourless crystals
suitable for X-ray analysis were obtained (yield: 1.64 g, 61%
based on Y) upon crystallization from toluene at room tempera-
ture for several days. 1H NMR (400 MHz, C6D6): δ 7.58 (2 H, d,
J = 7.1 Hz, ArH), 7.43 (4 H, d, J = 7.3 Hz, ArH), 7.34 (2 H, d,
J = 7.6 Hz, ArH), 7.27 (7 H, t, J = 8.0 Hz, ArH), 7.19 (2 H, d, J
= 7.3 Hz, ArH), 7.08–6.99 (3 H, m, ArH), 6.95 (1 H, t, J = 7.6
Hz, ArH), 6.79 (2 H, t, J = 7.7 Hz, ArH), 3.05–2.99 (4 H, m,
CH2CH2N), 2.19–2.08 (2 H, m, CH(CH3)2), 2.03–1.92 (2 H, m,
CH2CH2N), 1.61–1.63 (6 H, m, CH(CH3)2), 1.30–1.32 (6 H, m,
CH(CH3)2), 0.35 (18 H, s, Si(CH3)3). 13C NMR (400 MHz,
C6D6) δ = 153.51 (CvN), 146.63 (Ar), 140.39 (Ar), 137.08
(Ar), 133.18 (Ar), 131.60 (Ar), 130.06 (Ar), 129.75 (Ar), 128.61
(Ar), 128.26 (Ar), 125.04 (Ar), 62.39 (CH2CH2N), 49.55
(CH2CH2N), 29.98 (CH(CH3)2), 25.12 (CH(CH3)2), 24.85 (CH
(CH3)2), 4.30 (Si(CH3)3). C49H62N7Si2Y (894.15): calcd C
65.82, H 6.99, N 10.97, Y 9.94; found C 65.31, H 7.27, N
10.99, Y 9.89. IR (KBr): 3498 (s), 3384 (m), 2960 (s), 2867
(m), 2230 (s), 1637 (s), 1600 (m), 1566 (m), 1494 (s), 1466 (s),
1368 (s), 1331 (m), 1289 (s), 1246 (s), 1157 (s), 1021 (s), 922
(m), 701 (s) cm−1
.
LPr(NHAr1)(DME) (2). The synthesis of complex 2 was
carried out in the same way as that described for complex 1, but
corresponding LPrCl(THF)2 were used. Light green crystals of
complex 2 were isolated (yield 1.50 g, 60% based on Pr).
C39H62N5O2Si2Pr (830.03): calcd C 56.43, H 7.53, N 8.44, Pr
16.98; found C 56.62, H 7.73, N 8.31, Pr 17.02. IR (KBr): 3327
(s), 2960 (s), 2871 (m), 1647 (m), 1608 (s), 1569 (m), 1490 (m),
1439 (m), 1364 (m), 1248 (s), 1155 (s), 907 (w), 837 (s), 780
(m), 747 (s), 701 (s) cm−1
.
LNd(NHAr1)(DME) (3). The synthesis of complex 3 was
carried out in the same way as that described for complex 1, but
corresponding LNdCl(THF)2 were used. The light purple crys-
tals of complex 3 were isolated (yield 1.70 g, 68% based on
Nd). C39H62N5O2Si2Nd (833.36): calcd C 56.21, H 7.50, N
8.40, Nd 17.31; found C 56.54, H 7.67, N 8.27, Nd 17.22. IR
(KBr): 3406 (m), 3331 (m), 2960 (s), 2872 (m), 1609 (s), 1541
(m), 1491 (m), 1439 (s), 1365 (m), 1246 (s), 1156 (s), 908 (w),
836 (s), 780 (m), 746 (m), 701 (s) cm−1
.
(m), 837 (s), 752 (s), 701 (s) cm−1
.
LGd(NHAr1)(DME) (4). The synthesis of complex 4 was
carried out in the same way as that described for complex 1, but
corresponding LGdCl(THF)2 were used. Light yellow crystals of
complex 4 were isolated (yield 1.63 g, 64% based on Gd).
LYb[NPhCNAr1](PhCN) (9). The synthesis of complex 9 was
carried out in the same way as that described for the synthesis
of complex 8, but complex 5 (2.59 g, 3 mmol) was
8258 | Dalton Trans., 2012, 41, 8252–8260
This journal is © The Royal Society of Chemistry 2012