Silylene-Linked Cyclopentadienyl-Phosphido Complex
Organometallics, Vol. 20, No. 22, 2001 4571
extracted with hexane. The volatiles were removed under
reduced pressure to yield 1 as a white crystalline powder (5.63
g, 12.33 mmol, 92% yield). Colorless blocks of 1 suitable for
X-ray analysis were obtained from a concentrated hexane
solution. 1H NMR (C6D6, 22 °C): δ -0.28 (s, 3H, SiMe), -0.09
para-tBu), 2.19 (br s, 6H, C5Me4), 3.64 (q, J ) 3.23 Hz, 4H,
THF), 4.72 (br s, 18H, ortho-tBu), 8.36 (br s, 2H, C6H2). Anal.
Calcd for C41H71O3PSiSm (3): C, 59.95; H, 8.71; for C33H55
-
OPSiSm (3-2THF): C, 58.53; H, 8.19; for C29H47PSiSm (3-
3THF): C, 57.56; H, 7.83. Found: C, 52.84-53.31, H, 7.55-
7.59. The low value of the observed carbon content was
probably due to formation of incombustible carbide species.26
Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)Yb(th f)3 (4, n ) 3; 4′, n
) 0). Addition of 2′ (0.772 g, 0.57 mmol) to a THF solution (20
mL) of YbI2(thf)2 (0.651 g, 1.14 mmol) gave immediately a
cloudy orange solution. The solution was stirred for 45 min
and the solvent was removed under vacuum. Addition of
toluene to the orange residue resulted in formation of a bright
green solution with precipitation of KI. After filtration and
evaporation of the solvent under vacuum, a green oily residue
was obtained, which after being washed with hexane and dried
under vacuum yielded 4′ (4-3THF) as a green powder (0.579
g, 0.92 mmol, 81% yield). Orange needlelike crystals of 4 could
be obtained from a saturated THF solution. Leaving 4 under
vacuum for 2 h regenerated 4′. 1H NMR (C5D5N, 22 °C): δ
0.64 (s, 6H, SiMe), 1.42 (s, 9H, para-tBu), 2.08 (s, 6H, C5Me4),
2.13 (br s, 24H, ortho-tBu, C5Me4), 7.50 (s, 2H, C6H2). 1H NMR
(C4D8O, 22 °C): δ 0.05 (s, 6H, SiMe), 1.26 (s, 9H, para-tBu),
1.73 (s, 18H, ortho-tBu), 1.95 (s, 6H, C5Me4), 2.15 (s, 6H, C5-
Me4), 7.03 (s, 2H, C6H2). 31P NMR (C5D5N, 22 °C): δ -113.5
(s with 171Yb satellites, J P-Yb ) 992 Hz). Anal. Calcd for
3
(d, J P-H ) 3.8 Hz, 3H, SiMe), 1.32 (s, 9H, para-tBu), 1.64 (br
s, 18H, ortho-tBu), 1.80 (s, 6H, C5Me4), 1.95 (s, 3H, C5Me4),
1.99 (s, 3H, C5Me4), 3.12 (br s, 1H, C5Me4H), 4.45 (d, J P-H
)
215 Hz, 1H, PH), 7.45 (d, 4J P-H ) 2.2 Hz, 2H, C6H2). 13C NMR
(C6D6, 22 °C): δ -1.84 (s, 1C, SiMe2), -1.71 (s, 1C, SiMe2),
11.33 (s, 1C, C5Me4), 11.39 (s, 1C, C5Me4), 14.89 (s, 2C, C5Me4),
31.58 (s, 3C, CMe3), 33.64 (s, 6C, CMe3), 34.81 (s, 1C, para-
CMe3), 38.27 (s, 2C, ortho-CMe3), 55.75 (s, 1C, ipso-C5Me4),
121.57 (d, 2C, J P-C ) 3.0 Hz, meta-C6H2), 130.21 (d, 1C, J P-C
) 35.0 Hz, ipso-C6H2), 132.97 (d, J P-C ) 19.8 Hz, ortho-C6H2),
136.61 (d, J P-C ) 7.6 Hz, para-C6H2), 147.79 (s, 2C, C5Me4),
154.92 (s, 2C, C5Me4). 31P NMR (C6D6, 22 °C): δ -131.2 (d,
J P-H ) 215 Hz). Anal. Calcd for C29H49PSi: C, 76.26; H, 10.81.
Found: C, 76.31; H, 11.01.
[Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)K2(th f)n ]2 (2, n ) 4; 2′,
n ) 2). BuLi (2.52 M, 14.8 mL, 37.30 mmol) was added to a
THF solution (40 mL) of 1 (7.71 g, 16.88 mmol) at -78 °C.
The resulting mixture was warmed to room temperature and
t
stirred for 2 h. BuOK (4.16 g, 37.07 mmol) was then added.
After the mixture was stirred for 2 days, the solvent was
removed under vacuum. The residue was washed with hexane
t
C
41H71O3PSiYb (4): C, 58.34; H, 8.48; for C29H47PSiYb (4-
to remove BuOLi and dried under vacuum for 1 h to yield
3THF): C, 55.48; H, 7.55. Found: C, 48.01-49.84; H, 7.31-
7.41. The low value of the observed carbon content was
probably due to formation of incombustible carbide species.26
Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)Sm (h m p a )2 (5). Addition
of HMPA (52 µL, 0.296 mmol) to 3′ (0.100 g, 0.148 mmol) in
toluene (5 mL) gave a dark green solution. After evaporation
of the solvent under vacuum, the residue was washed with
hexane and dried to yield 5 as pale green powder (0.134 g,
0.139 mmol, 94%). Cubic dark green crystals of 5 were grown
in a saturated toluene solution in a few days. 1H NMR (C5D5N,
22 °C): δ -1.04 (br s, 6H, SiMe), 0.77 (br s, 6H, C5Me4), 2.06
(br s, 9H, para-tBu), 2.21 (br d, J P-H ) 8.70 Hz, 36H, NMe),
2.79 (br s, 6H, C5Me4), 4.76 (br s, 18H, ortho-tBu), 8.27 (br s,
orange powder of 2′ (2-4THF) (10.12 g, 7.47 mmol, 88% yield).
Large orange prisms of 2 could be grown from a concentrated
THF solution. 1H NMR (C5D5N, 22 °C) (2′): δ 0.56 (s, 12H,
SiMe), 1.45 (s, 18H, para-tBu), 1.60 (q, J ) 3.23 Hz, 16H, THF),
2.17 (s, 12H, C5Me4), 2.30 (s, 36H, ortho-tBu), 2.60 (s, 12H,
C5Me4), 3.63 (q, J ) 3.23 Hz, 16H, THF), 7.48 (s, 4H, C6H2).
13C NMR (C5D5N, 22 °C): δ 8.29 (s, 1C, SiMe2), 8.38 (s, 1C,
SiMe2), 11.99 (s, 2C, C5Me4), 15.35 (s, 1C, C5Me4), 15.40 (s, 1C,
C5Me4), 25.84 (s, 2C, THF), 32.27 (s, 3C, CMe3), 34.61 (s, 1C,
para-CMe3), 34.86 (s, 3C, CMe3), 35.01 (s, 3C, CMe3), 39.68 (s,
2C, ortho-CMe3), 67.87 (s, 2C, THF), 111.21 (s, 2C, C5Me4),
116.48 (s, 2C, C5Me4), 117.81 (s, 2C, meta-C6H2), 135.91 (s, 1C,
ipso-C5Me4), 141.20 (s, 1C, para-C6H2), 155.40 (d, 1C, J P-C
)
1
73.3 Hz, ipso-C6H2), 157.31 (s, 2C, ortho-C6H2). 31P NMR
(C5D5N, 22 °C): δ -124.4 (s). Anal. Calcd for C90H158K4O8P2-
Si2 (2): C, 65.80; H, 9.69; for C74H126K4O4P2Si2 (2-4THF): C,
65.63; H, 9.38; for C58H94K4P2Si2 (2-8THF): C, 65.36; H, 8.89.
Found: C, 64.24-64.83, H, 9.58-9.51. The low value of the
observed carbon content was probably due to formation of
incombustible carbide species.26
2H, C6H2). H NMR (C6D6, 22 °C): δ -4.53 (br s, 6H, SiMe),
0.06 (br s, 36H, NMe); 2.67 (br s, 9H, para-tBu), 6.86 (br s,
6H, C5Me4), 8.36 (br s, 18H, ortho-tBu), 9.55 (br s, 2H, C6H2),
14.73 (br s, 6H, C5Me4). Anal. Calcd for C41H83N6O2P3SiSm
(5): C, 51.11; H, 8.68. Found: C, 48.08-50.17; H, 8.47-8.65.
The low value of the observed carbon content was probably
due to formation of incombustible carbide species.26
Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)Sm (d m e)2 (6). Dissolving
of 3′ (0.100 mg, 0.148 mmol) in dimethoxyethane (DME) gave
a dark brown solution. After removal of the solvent under
vacuum, the residue was washed with hexane and dried to
yield 6 as a dark brown powder (0.096 g, 0.122 mmol, 83%
yield). Black cubic crystals of 6 were obtained by layering of
Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)Sm (th f)n (3, n ) 3; 3′, n
) 1). To a dark blue THF solution (15 mL) of SmI2(thf)2 (0.548
g, 1 mmol) was added 2′ (0.677 g, 0.5 mmol), which resulted
in immediate formation of a cloudy dark brown solution. After
the mixture was stirred for 45 min, toluene (7 mL) was added
and was then stirred for 5 min to fully precipitate KI. After
filtration and evaporation of the solvent, the residue was
dissolved in THF. The THF solution was concentrated under
reduced pressure, and hexane was layered to precipitate dark
crystals of 3, which after being dried under vacuum for 3 h
yielded 3′ (3-2THF) as a brown powder (0.447 g, 0.660 mmol,
66% yield). 1H NMR (C4D8O, 22 °C): δ -1.53 (br s, 6H, SiMe),
1.36 (br s, 6H, C5Me4), 1.94 (br s, 9H, para-tBu), 3.21 (br s,
6H, C5Me4), 4.55 (br s, 18H, ortho-tBu), 7.73 (br s, 2H, C6H2).
1H NMR (C5D5N, 22 °C): δ -0.60 (br s, 6H, SiMe), 0.31 (br s,
6H, C5Me4), 1.60 (q, J ) 3.23 Hz, 4H, THF), 2.11 (br s, 9H,
1
hexane to a concentrated DME solution. H NMR (C5D5N, 22
°C): δ -0.74 (br s, 6H, SiMe), 0.13 (br s, 6H, C5Me4), 2.08 (br
s, 9H, para-tBu), 2.25 (br s, 6H, C5Me4), 3.28 (s, 12H, OMe),
3.47 (s, 8H, OCH2), 4.65 (s, 18H, ortho-tBu), 8.27 (s, 2H, C6H2).
1H NMR (C4D8O, 22 °C): δ -1.65 (br s, 6H, SiMe), 1.15 (br s,
6H, C5Me4), 1.98 (br s, 9H, para-tBu), 2.70 (br s, 6H, C5Me4),
2.83 (s, 8H, OCH2), 4.31 (s, 12H, OMe), 4.73 (br s, 18H, ortho-
tBu), 7.80 (br s, 2H, C6H2). Anal. Calcd for C37H67O4PSiSm
(6): C, 56.59; H, 8.60. Found: C, 53.34-53.54; H, 8.27-8.42.
The low value of the observed carbon content was probably
due to formation of incombustible carbide species.26
[Me2Si(C5Me4)(P C6H2tBu 3-2,4,6)Sm (th f)]2(µ:η2-OCP h 2)‚
THF (7‚THF ). To 3′ (0.272 g, 0.402 mmol) was added ben-
zophenone (0.037 g, 0.201 mmol) in THF (10 mL). The
resulting green solution was stirred at room temperature for
1 h. After reduction of the solution volume under reduced
pressure, hexane was layered to give 7‚THF as dark green
crystals, which after being dried, yielded 7 (0.200 g, 0.129
(26) Failure in obtaining satisfactory microanalytical data for some
lanthanide complexes bearing P atom-containing ligands was also
mentioned previously by other groups. For examples, see: (a) Nief,
F.; Ricard, L. J . Organomet. Chem. 1994, 464, 149; 1997, 529, 357. (b)
Rabe, G. W.; Ziller, J . W. Inorg. Chem. 1995, 34, 5378. (c) Gro¨b, T.;
Seybert, G.; Massa, W.; Weller, F.; Palaniswami, R.; Greiner, A.;
Dhnicke, K. Angew. Chem., Int. Ed. 2000, 39, 4373. See also refs 4,
11d.