1114 Organometallics, Vol. 17, No. 6, 1998
Lee et al.
394.1296. Anal. Calcd: C, 30.61; H, 4.11. Found: C, 30.75;
H, 4.14. Rf ) 0.88 by silica gel TLC analysis (hexane). Mp )
78 °C. IR spectrum (KBr pellet, cm-1): 2970 (w), 2940 (w),
2880 (w), 2600 (s), 2070 (s), 1985 (s), 1940 (vs), 1460 (w), 1260
(m), 1115 (w), 1040 (w), 950 (w), 920 (w), 870 (w), 850 (w), 830
(w), 800 (w), 730 (w), 690 (w), 670 (m), 660 (m), 630 (w).
(CO)5Cr [C(OMe)(P h C2B10H10)] (1b). 1b was prepared
from 3.0 mmol of the phenyl-o-carborane PhC2B10H11. After
chromatography on silica gel with hexane, 1b (0.48 g, 1.1
mmol, 37% yield) was isolated as a yellow solid. 11B NMR (64.2
MHz, ppm, C6D6): 1.7 (d, B9, J BH ) 150 Hz), -4.5 (d, B12, J BH
carboranyl)methoxycarbene]metal complexes 1a -d , with the
following variations in the procedure of purification. In each
case, the mother liquors were evaporated to dryness, and the
11B and 1H NMR spectra were studied.
(CO)5Cr [C(OMe)(MeC2B10H10)] (1a ). Reaction time: 10
h. Procedure variation: Evaporation of the benzene solution
to dryness and flash chromatography (hexane/CHCl3, 98/2) on
silica; 47% yield (0.53 g, 1.4 mmol).
(CO)5Cr [C(OMe)(P h C2B10H10)] (1b): reaction time, 10 h;
procedure variation, evaporation of the benzene solution to
dryness and flash chromatography (hexane/benzene, 95/5) on
silica; 53% yield (0.71 g, 1.6 mmol).
(CO)5W[C(OMe)(MeC2B10H10)] (1c): reaction time, 12 h;
procedure variation, evaporation of the benzene solution to
dryness and flash chromatography (hexane/CHCl3, 98/2) on
silica; 47% yield (0.75 g, 1.4 mmol).
) 200 Hz), -7.5 (d, B8,10, B4,5, J BH ) 140 Hz), -9.4 (d, B7,11
,
B
3,6, J BH ) 180 Hz). 1H NMR (200.13 MHz, ppm, C6D6): 7.56
(m, 2H, C6H5), 7.39 (m, 3H, C6H5), 3.99 (s, 3H, OCH3). 13C-
{1H} NMR (50.3 MHz, ppm, C6D6): 344.3 (s, CrdC), 205.3 (s,
CO), 198.2 (s, CO), 136.6, 134.2, 130.1 (s, C6H5), 58.6 (s, OCH3).
11
12
Exact mass: calcd for
B
C
52Cr1H1816O6 456.1439, found
10 15
(CO)5W[C(OMe)(P h C2B10H10)] (1d ): reaction time, 12 h;
procedure variation, evaporation of the benzene solution to
dryness and flash chromatography (hexane/benzene, 95/5) on
silica; 63% yield (1.13 g, 1.9 mmol).
456.1428. Anal. Calcd: C, 39.65; H, 3.99. Found: C, 39.58;
H, 3.95. Rf ) 0.66 by silica gel TLC analysis (benzene/hexane,
50/50). Mp ) 84 °C. IR spectrum (KBr pellet, cm-1): 3070
(w), 2970 (w), 2940 (w), 2600 (s), 2080 (s), 1990 (s), 1930 (vs),
1490 (w), 1445 (w), 1385 (w), 1330 (m), 1260 (w), 1220 (w),
1170 (w), 995 (w), 920 (w), 875 (w), 810 (w), 760 (w), 700 (w),
665 (w), 620 (w), 590 (w), 565 (w), 490 (w), 370 (m).
(CO)5W[C(OMe)(MeC2B10H10)] (1c). 1c was prepared
from 3.0 mmol of the methyl-o-carborane MeC2B10H11. After
chromatography on silica gel with hexane, 1c (0.63 g, 1.2
mmol, 40% yield) was isolated as a yellow solid. 11B NMR (64.2
MHz, ppm, C6D6): 1.4 (d, B9, J BH ) 150 Hz), -4.6 (d, B12, J BH
P r ep a r a tion of (CO)5Mn (P h C2B10H10) (6b). A solution
of 6.5 mmol of PhC2B10H10Li (3b) in 80 mL of anhydrous ethyl
ether was slowly added under a nitrogen atmosphere to a
rapidly stirred suspension of 1.76 g (6.4 mmol) of Mn(CO)5Br
in 150 mL of anhydrous ethyl ether. After it was stirred for
2 days at room temperature, the reaction mixture was evapo-
rated to give a dark oil. The oil was dissolved in 50 mL of
benzene, and the resulting solution was rotary-evaporated onto
2 g of predried silica gel. This mixture was placed on a 1 in.
× 6 in. column in hexane, and a yellow band was eluted from
the flash chromatograph with hexane. An additional 100 mL
of eluent was collected. Rotary evaporation of the eluent to
50 mL gave white crystalline needles of complex 6b. A total
of 1.50 g (3.6 mmol, 55%) was collected. Rotary evaporation
to dryness gave 0.30 g of a mixture of the product and Mn2-
(CO)10. The white crystals were sublimed and recrystallized
from hexane. 11B NMR (64.2 MHz, ppm, C6D6): 0.5 (d, B9,
J BH ) 130 Hz), -1.2 (d, B12, J BH ) 160 Hz), -4.2 (d, B8,10, J BH
) 200 Hz), -7.8 (d, B8,10, B4,5, J BH ) 140 Hz), -9.9 (d, B7,11
,
B
3,6, J BH ) 180 Hz). 1H NMR (200.13 MHz, ppm, C6D6): 3.87
(s, 3H, OCH3), 0.79 (s, 3H, CH3). 13C{1H} NMR (50.3 MHz,
ppm, C6D6): 337.2 (s, WdC), 204.1 (s, CO), 197.6 (s, CO), 64.9
(s, OCH3), 27.4 (s, CH3). Exact mass: calcd for
11
12
B
C
184W1H1616O6 526.1387, found 526.1398. Anal. Cal-
10
10
cd: C, 22.91; H, 3.08. Found: C, 22.88; H, 3.04. Rf ) 0.82 by
silica gel TLC analysis (hexane). Mp ) 88 °C. IR spectrum
(KBr pellet, cm-1): 2960 (m), 2870 (m), 2600 (s), 2080 (s), 1980
(s), 1940 (vs), 1470 (m), 1450 (m), 1400 (w), 1370 (w), 1260 (s),
1110 (w), 1055 (w), 1035 (w), 940 (w), 910 (w), 860 (m), 840
(m), 820 (s), 800 (w), 735 (w), 700 (w), 680 (w), 660 (w), 630
(w), 600 (w), 575 (w), 410 (w), 385 (s), 340 (w).
) 100 Hz), -5.3 (d, B4,5, J BH ) 140 Hz), -7.8 (d, B3,6, J BH
)
145 Hz), -9.4 (d, B7, J BH ) 140 Hz), -11.3 (d, B11, J BH ) 145
Hz). 1H NMR (200.13 MHz, ppm, C6D6): 7.74 (d, 2H, C6H5),
11
12
55
7.46 (m, 3H, C6H5). Exact mass: calcd for
B
C
-
13
10
(CO)5W[C(OMe)(P h C2B10H10)] (1d ). 1d was prepared
from 3.0 mmol of the phenyl-o-carborane PhC2B10H11. After
chromatography on silica gel with hexane, 1d (0.76 g, 1.3
mmol, 43% yield) was isolated as a yellow solid. 11B NMR (64.2
MHz, ppm, C6D6): 1.6 (d, B9, J BH ) 150 Hz), -4.4 (d, B12, J BH
Mn1H1516O5 416.1230, found 416.1239. Anal. Calcd: C, 37.69;
H, 3.65. Found: C, 37.88; H, 3.59. Rf ) 0.70 by silica gel TLC
analysis (benzene/hexane, 33/67). Mp ) 88-90 °C. IR spec-
trum (KBr pellet, cm-1): 3090 (w), 3060 (w), 3040 (w), 2580
(s), 2130 (s), 2030 (s), 2000 (s), 1495 (m), 1445 (m), 1075 (m),
1010 (w), 930 (w), 890 (w), 820 (w), 760 (w), 730 (w), 690 (m),
640 (s), 560 (w), 490 (w), 430 (w).
) 200 Hz), -7.3 (d, B8,10, B4,5, J BH ) 140 Hz), -10.2 (d, B7,11
,
B
3,6, J BH ) 180 Hz). 1H NMR (200.13 MHz, ppm, C6D6): 7.54
(m, 2H, C6H5), 7.40 (m, 3H, C6H5), 3.88 (s, 3H, OCH3). 13C-
{1H} NMR (50.3 MHz, ppm, C6D6): 321.5 (s, WdC), 202.5 (s,
CO), 196.1 (s, CO), 133.2, 130.1, 128.6 (s, C6H5), 53.4 (s, OCH3).
Gen er a l P r oced u r e for th e P r ep a r a tion of (CO)4-
(RC2B10H10)Mn [C(OCH3)(CH3)] (2: R ) CH3, C6H5). In a
typical experiment, 1.0 mmol of 6 was dissolved in 25 mL of
THF and the solution cooled to -78 °C. CH3Li (1.0 M, 1.2
mL, 1.2 mmol) was added to the reaction mixture, and the
mixture was stirred for 1 h at -78 °C. The mixture was then
allowed to react at 0 °C for 1 h, and the solution was stirred
for another 2 h at room temperature. The solution gradually
turned dark brown, suggesting the formation of a metal acyl
complex. IR spectra taken at this point confirmed the exclu-
sive formation of the corresponding metal acyl complexes.
Methylation with CF3SO3CH3 (3.0 mmol, 3 equiv) followed by
extraction with hexane gave a yellow solid. Subsequent
separation was performed on the flash column with hexane
to give >95% pure metal carbene complexes 2a ,b as crystals.
(CO)4(MeC2B10H10)Mn [C(OCH3)(CH3)] (2a ). 2a was pre-
pared from 1.0 mmol of 6a . After chromatography on silica
gel with hexane, 0.18 g (0.47 mmol) of 2a was isolated as a
yellow solid. This corresponds to a 47% yield based on the
consumed complex 6a . 11B NMR (64.2 MHz, ppm, C6D6): -1.8
(d, B9, J BH ) 140 Hz), -5.0 (d, B12, J BH ) 145 Hz), -6.8 (d,
11
12
Exact mass: calcd for
B
C
1H1816O6184W 588.1543, found
10 15
588.1539. Anal. Calcd: C, 30.73; H, 3.09. Found: C, 30.69;
H, 3.07. Rf ) 0.79 by silica gel TLC analysis (benzene/hexane,
50/50). Mp ) 92 °C. IR spectrum (KBr pellet, cm-1): 3070
(w), 2970 (w), 2940 (w), 2600 (s), 2080 (s), 1990 (s), 1930 (vs),
1445 (w), 1385 (w), 1330 (m), 1260 (w), 1220 (w), 1170 (w),
995 (w), 920 (w), 810 (w), 760 (w), 700 (w), 590 (w), 565 (w),
490 (w), 370 (m).
Meth od B. In a typical reaction, 3.0 mmol of B10H12(CH3-
CN)2 (5) and 3.2 mmol of alkynylcarbene complexes7 4a -d
9
were mixed in 30 mL of benzene. The mixture was then
allowed to react at 25 °C for 1 h. The solution was stirred for
another 10-12 h at reflux temperature, resulting in the
formation of a dark brown solution. 11B NMR spectra taken
at this point indicated that the starting material had been
completely consumed and that complex 1 was the sole product.
Concentration followed by flash column chromatographic
separation of the resulting reaction mixture gave complex 1.
The same procedure was applied for the rest of the [(o-
B
8,10, B4,5, J BH ) 135 Hz), -7.4 (d, B7,11, B3,6, J BH ) 100 Hz).