Giesbrecht et al.
shifts are given relative to residual C6D5H (7.15 ppm). Infrared
spectra were recorded on a Digilab FTS-40 FT-IR spectrometer;
solid-state spectra were taken as Nujol mulls between KBr plates.
Elemental analyses were performed on a Perkin-Elmer 2400 CHN
analyzer. Elemental analysis samples were prepared and sealed in
tin capsules in the glovebox prior to combustion.
hexane, forming a colorless solution. Al(i-Bu)3 (0.80 mL of a 1.0
M toluene solution, 0.80 mmol) was added followed by an ethereal
solution (5 mL) of HO-2,4,6-Me3C6H2 (650 mg, 4.8 mmol), forming
a purple solid. After filtration of the solid, the solvent was removed
in vacuo, yielding a slightly oily solid. Diethyl ether (50 mL) was
added and the solution concentrated to 20 mL, at which point a
pale solid began to precipitate from solution. Cooling to -10 °C
failed to deposit crystalline material from solution. The solution
was filtered again, pyridine (1 mL) was added, and the mixture
stirred for several minutes. Removal of the solvent yielded an oily
solid. Washing the solid with hexanes (3 × 5 mL) produced a pale
blue solid (240 mg, 38% yield). A 100 mg portion of this material
was taken up in toluene (5 mL) and the solution allowed to slowly
evaporate in the glovebox atmosphere. Over a period of several
days, large lavendar crystals were obtained. The paramagnetism
{[(i-Pr-O)(i-Bu)Al(µ-O-i-Pr)2Sm(O-i-Pr)(HO-i-Pr)](µ-O-i-
Pr)}2 (1). To a stirred solution of Sm[N(SiMe3)2]3 (0.500 g, 0.80
mmol) and Al(i-Bu)3 (0.80 mL of a 1.0 M toluene solution, 0.80
mmol) in toluene (5 mL) was added iso-propyl alcohol (0.36 mL,
4.8 mmol) at room temperature. After 2 days of stirring, all solvent
was removed under vacuum to leave a viscous oil. This was
dissolved in pentane (5 mL) and the volume reduced to 2 mL, at
which point the solution was placed in the -35 °C drybox freezer.
Over several days, a small number of colorless crystals were
1
1
of 4 did not allow for characterization by H NMR spectroscopy.
deposited (200 mg, 21% yield). H NMR (300 MHz, C6D6): δ
IR (Nujol, cm-1): 1599(m), 1308 (m), 1254 (m), 1240 (m), 1217
(m), 1160 (w), 1146 (w), 1030 (w), 852 (w), 804 (m), 777 (w),
740 (w), 721 (m), 700 (w). Anal. Calcd for C64H76N2Nd2O6 [4 -
2(pyridine)]: C, 61.11; H, 6.09; N, 2.23. Found: C, 55.19; H, 6.09;
N, 2.32. Independently prepared samples of 4 consistently analyzed
low in carbon because of incomplete combustion.
2.50 (br, OCHMe2), 2.29 (m, OCHMe2), 1.68 (m, CH2CHMe2),
3
0.78 (d, JH-H ) 6 Hz, CH2CHMe2), -1.20 (br m, AlCH2). IR
(Nujol, cm-1): 3100 (br w), 1462 (s), 1377 (s), 1366 (sh s), 1334
(w), 1161 (s), 1130 (s), 1069 (w), 1036 (w), 999 (s), 965 (s), 833
(m), 678 (m), 656 (m). Anal. Calcd for C44H104Al2O12Sm2: C,
44.78; H, 8.88. Found: C, 44.76; H, 8.74.
(ArO)3Sm[(µ-O-t-Bu)2Al2(O-t-Bu)4] (Ar ) 2,6-i-Pr2C6H3) (5).
[Sm(OAr)3]2 (1.0 g, 0.73 mmol) was dissolved in toluene (80 mL)
producing a bright yellow solution. A toluene solution (15 mL) of
Al2(O-t-Bu)6 (720 mg, 1.5 mmol) was added and stirred at room
temperature for 1 h. The solvent was then removed under vacuum
to yield a pale yellow solid (1.6 g, 93% yield). Slow evaporation
of a yellow-green toluene solution yielded X-ray quality crystals
[(THF)2Sm(O-t-Bu)2(µ-O-t-Bu)2Al(i-Bu)2] (2). To a stirred
solution of Sm[N(SiMe3)2]3 (0.500 g, 0.80 mmol) and Al(i-Bu)3
(0.80 mL of a 1.0 M toluene solution, 0.80 mmol) in toluene (5
mL) was added tert-butyl alcohol (0.45 mL, 4.8 mmol) at room
temperature. After stirring for 12 h, all solvent was removed under
vacuum to leave a viscous oil. This was redissolved in hexanes (5
mL) and the volume reduced to 2 mL, at which point 0.2 mL of
THF was added. The solution was then placed in a -35 °C freezer.
Over several days, a small number of colorless crystals were
1
of 5. The H NMR spectrum consisted of peaks corresponding to
unreacted starting materials only. IR (Nujol, cm-1): 1587 (m), 1397
(w), 1320 (m), 1255 (m), 1227 (m), 1200 (m), 1168 (w), 1071 (w),
1038 (w), 937 (m), 910 (w), 874 (m), 848 (w), 809 (w), 795 (m),
775 (w), 749 (m), 717 (m), 691 (w). Anal. Calcd for C60H105Al2O9-
Sm: C, 61.34; H, 9.01. Found: C, 61.10; H, 9.03.
1
deposited (100 mg, 17% yield). H NMR (300 MHz, C6D6): δ
2.29 (br s, t-Bu), 0.78 (br, CH2CHMe2), -0.15 (v br, R-THF), -0.54
(br, â-THF), CH2CHMe2 obscured by THF. IR (Nujol, cm-1): 1462
(s), 1380 (s), 1358 (s), 1308 (w), 1223 (s), 1187 (s), 1034 (s), 999
(s), 978 (s), 933 (s), 883 (sh m), 818 (w), 771 (s), 661 (s), 620
(m). Anal. Calcd for C32H70AlO6Sm: C, 52.78; H, 9.69. Calcd for
C24H54AlO4Sm [2 - 2THF]: C, 49.35; H, 9.32. Found: C, 49.65;
H, 8.90.
Crystallographic Studies. Crystals of 1-5 were mounted on a
thin glass fiber using a small dot of silicone grease. The crystal
was then immediately placed on a Siemens P4/PC diffractometer
(for 1 and 2) or a Bruker P4/CCD/PC diffractometer (for 3-5)
and cooled to 203 K. The data were collected using a sealed,
graphite monochromatized Mo KR X-ray source. A hemisphere of
data was collected using ω scans (for 1 and 2) or a combination of
æ and ω scans (3-5), with 30 s frame exposures and 0.3° frame
widths. Data collection and initial indexing and cell refinement were
handled using XSCANS software61 (for 1 and 2) or SMART
software62 (for 3-5). For compounds 1 and 2, all data reduction,
including Lorentz and polarization corrections and structure solution
and graphics, were performed using SHELXTL.63 Frame integration
and final cell parameter calculations for 3-5 were carried out using
SAINT64 software. The data were corrected for absorption using
the ellipsoid option in the XEMP facility of SHELXTL or the
SADABS65 program. Decay of reflection intensity was not observed.
The structures were solved using direct methods and difference
Fourier techniques. The initial solutions revealed all non-hydrogen
Sm(OAr)3(THF)3 (Ar ) 2,4,6-Me3C6H2) (3). Sm[N(SiMe3)2]3
(500 mg, 0.80 mmol) was dissolved in 50 mL of hexanes, forming
a colorless solution. Al(i-Bu)3 (0.80 mL of a 1.0 M toluene solution,
0.80 mmol) was added followed by an ethereal solution (5 mL) of
HO-2,4,6-Me3C6H2 (650 mg, 4.8 mmol), forming an instantaneous
blue precipitate. The reaction mixture was then filtered to yield a
yellow-green solution. The solution was left to evaporate, producing
a viscous oil. This was redissolved in approximately 5 mL of
hexanes, and pyridine (0.5 mL) was added. After stirring for 5 min,
the solvent was removed under vacuum, yielding a slightly oily
solid. Hexanes (10 mL) were added, and the resulting pale solid
was collected by filtration, washed with hexanes (5 mL), and dried
to yield a slightly yellow solid (180 mg, 28% yield). A portion of
this solid (84 mg) was dissolved in a 1:1 mixture of hexanes/THF
(approximately 2 mL). Cooling to -10 °C yielded pale yellow
crystals of 3. 1H NMR (400 MHz, C6D6): δ 7.80 (br s, 6H, m-Ph),
3.80 (br s, 12H, THF), 2.90 (br s, 18H, o-CH3Ph), 2.80 (br s, 9H,
p-CH3Ph), 2.10 (br s, 12H, THF). IR (Nujol, cm-1): 1607 (m),
1465 (m), 1310 (s), 1277 (s), 1262 (m), 1160 (w), 1150 (w), 1025
(m), 955 (w), 915 (w), 860 (m), 830 (s), 821 (s), 742 (m), 722 (w).
Anal. Calcd for C39H57O6Sm: C, 60.66; H, 7.44. Found: C, 60.52;
H, 7.47.
(61) XSCANS version 4.2/360; Siemens Analytical X-ray Instruments,
Inc.: Madison, WI, 1993.
(62) SMART version 4.210; Bruker Analytical X-ray Systems, Inc.:
Madison, WI, 1996.
(63) SHELXTL PC version 4.2/360; Siemens Analytical X-ray Instruments,
Inc.: Madison, WI, 1993.
(64) SAINT version 4.05; Bruker Analytical X-ray Systems, Inc.: Madison,
WI, 1996.
[Nd(µ-OAr)(OAr)2(py)2]2 (Ar ) 2,4,6-Me3C6H2) (4). Nd-
[N(SiMe3)2]3 (500 mg, 0.80 mmol) was dissolved in 50 mL of
(65) Sheldrick, G. SADABS, first release; University of Gottingen: Got-
tingen, Germany, 1996.
6378 Inorganic Chemistry, Vol. 41, No. 24, 2002
Giesbrecht, Garth R.
