Chadha et al.
1219
1069 (11), 1220 (14), 1251 (7), 1442 (15), 1488 (6), 2158
(4), 2960 (13). ESI-MS (m/z): M+ – Cl (529). Elemental
anal. calcd: C, 63.72; H, 5.35; Found: C, 64.10; H, 5.49.
1158 (11), 1250 (9), 1346 (15), 1486 (10), 2146 (12). ESI-
MS (m/z): M+ – 268 (237.1, 100%). Elemental anal. calcd:
C, 71.26; H, 5.98. Found: C, 71.49; H, 5.99. lmax = 335
and 429 nm.
Synthesis of (C5H4SiMe2C2Ph)2TiMe2 (4Me2)
Synthesis of 7
(C5H4SiMe2C2Ph)2TiCl2 (4Cl2) (0.20 g, 0.35 mmol;
40 mL Et2O / n-hexane (1:1.5) was treated with 3 stoichio-
metric equiv of MeMgCl (0.35 mL, 1.05 mmol; 3 mol/L sol-
ution in THF) at –15 8C. The reaction mixture was stirred
for 4 h during which time it warmed to room temperature
and the colour changed from red to yellow-orange. The
LiCl was filtered off and the yellow-orange solution was
concentrated to give orange oil. Yield: 0.15 g, 80%. 1H
NMR (C6D6) d: 0.40 (s, 6H, Me), 0.42 (s, 12H, Me), 6.38
(pt, 4H, Cp), 6.47 (pt, 4H, Cp), 6.90–6.91 (m, 6H, Ph),
7.47–7.49 (m, 4H, Ph). 13C{1H}NMR (C6D6) d: 0.9 (Me),
48.3 (Me), 93.3 (SiCC), 107.57 (CCPh), 116.8 (Cpipso),
118.7 (Cp), 121.9 (Cp), 123.7 (Ph), 128.9 (Ph), 129.3 (Ph),
132.5 (Ph). 29Si NMR (C6D6) d: –25.8 ppm. FT-IR (cm–1)
(ranked intensity): 442 (13), 537 (11), 689 (4), 756 (3), 823
(1), 905 (10), 1027 (14), 1047 (7), 1070 (15), 1186 (9), 1251
(5), 1488 (8), 2159 (2), 2888 (12), 2958 (6). ESI-MS (m/z):
M+ – Me (507). Elemental anal. calcd: C, 73.26; H 6.92.
Found: C, 72.54; H, 6.23.
CpCo(CO)2 (0.04 g, 0.23 mmol) was added to a C6D6 sol-
ution of 5 (0.118 g, 0.335 mmol) in an NMR tube. The sol-
ution was then photolyzed with broad wavelength UV light
for 40–50 h. The reaction was monitored for completion by
1H NMR spectroscopy, after which the reaction mixture was
filtered, the solvent was removed in vacuo to give an orange
solid, which was washed with 0.5 mL n-pentane and dried
1
again. Yield: 0.136 g, 65%; mp 180 8C. H NMR (C6D6) d:
0.40 (s, 6H, Me), 0.60 (s, 6H, Me), 4.16 (b, 2H, Cp), 4.27
(b, 4H, Cp), 4.46 (b, 2H, Cp), 4.76 (s, 5H, Cp), 7.04–7.16
(m, 6H, Ph), 7.55 (d, 4H, Ph). 13C{1H} NMR (C6D6) d: 2.4
(Me), 4.1 (Me), 66.4 (SiC(Cb)), 69.3 (Cpipso), 71.9 (Cp),
72.6 (Cp), 74.5 (Cp), 75.2 (Cp), 82.8 (CpCo), 88.1
(CPh(Cb)), 126.9 (Ph), 128.5 (Ph), 129.7 (Ph), 138.4 (Ph).
29Si NMR (C6D6) d: –9.3 ppm. FT-IR (cm–1) (ranked inten-
sity): 666 (7), 696 (2), 765 (3), 813 (1), 898 (11), 1036 (6),
1110 (12), 1165 (5), 1245 (4), 1384 (8), 1439 (9), 1599 (10).
EI-MS (m/z): M+ (625.9, 100%). HRMS (EI) for
C35H35Si2FeCo (calcd: 626.09; found: 626.09. Elemental
anal. calcd: C, 71.69: H, 6.02. Found: C, 66.20; H, 5.50.
lmax = 357 and 423 nm.
Synthesis of (C5H4SiMe2C2Ph)2Fe (5)
A solution of LiC5H4SiMe2C2Ph (2) (0.36 g, 1.58 mmol;
3 mL THF) was added to a solution of anhydrous FeCl2
(0.1 g, 0.79 mmol; 5 mL THF) at room temperature. The re-
action mixture was stirred for 4 h, during which time the
colour turned dark yellow. The volatiles were then removed,
the residue redissolved in n-pentane, and filtered to remove
LiCl. The filtrate was then concentrated to give an orange
solid. Yield: 0.317 g, 80%; mp 75 8C. The orange solid was
Synthesis of [(C5H4SiMe2C2Ph)2Co(III)][OTf] ([6][OTf])
Addition of a solution of 8 (0.20 g, 0.40 mmol; 1 mL of
CH3CN or C6H6) to 1 equiv of AgOTf (0.11 g, 0.40 mmol)
resulted in the instantaneous formation of [6][OTf]. The
yield was quantitative by 1H NMR spectroscopy, but the
product could not be obtained as a solid. Removing the sol-
vent always resulted in a sticky mass, which was 90% pure
by 1H NMR spectrum. Yield: 0.233 g, 90%. 1H NMR
(C6D6) d: 0.47 (s, 12H, Me), 5.73 (b, 4H, Cp), 5.93 (b, 4H,
Cp), 7.05–7.09 (m, 6H, Ph), 7.61 (d, 4H, Ph). 1H NMR
(CD3CN) d: 0.56 (s, 12H, Me), 5.81 (pt, 4H, Cp), 5.92 (pt,
4H, Cp), 7.42–7.45 (m, 6H, Ph), 7.58 (d, 4H, Ph). 13C{1H}
NMR (CD3CN) d: –0.5 (Me), 89.2 (Cp), 90.6 (Cp), 91.0
(Cp), 92.7 (SiCC), 109.3 (CCPh), 122.9 (Ph), 130.0 (Ph),
130.9 (Ph), 133.2 (Ph). 19F NMR (CD3CN) d: –78.9 ppm.
29Si NMR (C6D6) d: –22.5 ppm. FT-IR (cm–1) (ranked inten-
sity): 691 (9), 737 (14), 759 (7), 805 (6), 825 (8), 851 (2),
1043 (3), 1117 (12), 1164 (4), 1230 (10), 1255 (1), 1385
(15), 1489 (11), 2159 (5), 2973 (13). ESI-MS (m/z): M+ –
OTf (505.1, 100%), M+ + [M – OTf]+ (1159.3).
1
then sublimed at 140 8C onto a cold finger at –18 8C. H
NMR (C6D6) d: 0.52 (s, 12H, Me), 4.35 (pt, 4H, Cp), 4.51
(pt, 4H, Cp), 6.91–6.95 (m, 6H, Ph), 7.49–7.53 (m, 4H, Ph).
13C{1H}NMR (C6D6) d: 0.6 (Me), 69.4 (Cp), 73.1 (Cp), 74.5
(Cp), 94.2 (SiCC), 106.8 (CCPh), 124.1 (Ph), 128.9 (Ph),
129.1 (Ph), 132.6 (Ph). 29Si NMR (C6D6) d: –21.5 ppm. FT-
IR (cm–1) (ranked intensity): 690 (7), 776 (2), 802 (4), 846
(1), 897 (14), 1036 (8), 1166 (3), 1220 (11), 1249 (6), 1383
(15), 1421 (13), 1442 (12), 1488 (9), 2158 (5), 2960 (10).
ESI-MS (m/z): M+ (502.2, 100%).14 lmax = 312 and 348 nm.
Synthesis of (C5H4SiMe2C2Ph)2Co (6)
LiC5H4SiMe2C2Ph (2) (0.17 g, 0.77 mmol) was added to a
solution of anhydrous CoCl2 (0.05 g, 0.38 mmol; 5 mL
Et2O), followed by the addition of 1 mL THF at room tem-
perature. The reaction mixture was stirred for 3–4 h, during
which time the colour turned dark red. The reaction mixture
was then filtered to remove the LiCl and the clear solution
was pumped down to give a sticky solid mass, which was
then washed twice with n-pentane and dried to yield a dark
maroon solid. Yield: 0.175 g, 90%; mp 80 8C. X-ray quality
crystals were obtained from concentrated Et2O solution
Synthesis of 8
CpCo(CO)2 (0.03 g, 0.18 mmol) was added to a C6D6 sol-
ution of 6 (0.09 g, 0.18 mmol) in an NMR tube. The solu-
tion was then photolyzed with broad wavelength UV light
for 40–50 h. The reaction was monitored for completion by
1H NMR spectroscopy, after which the solution was filtered,
the solvent was removed in vacuo to give a brown solid,
which was washed with 0.5 mL of n-pentane four times and
1
at –30 8C. H NMR (C6D6) d: 3.62 (b, 12H, Me), 6.81 (t,
1
2H, Ph), 7.07 (t, 4H, Ph), 7.46 (d, 4H, Ph); Cp protons were
not observed within the range of –2 to 14 ppm. FT-IR
(cm–1) (ranked intensity): 536 (13), 599 (14), 676 (8), 688
(7), 756 (2), 774 (4), 802 (1), 822 (3), 840 (5), 1034 (6),
dried again. Yield: 0.086 g, 75%. H NMR (C6D6) d: 3.77
(b, 12H, Me), 4.91 (b, 5H, Cp), 7.05 (b, 2H, Ph), 7.11 (b,
4H, Ph), 7.69 (b, 4H, Ph); other Cp protons were not ob-
served within the range of –2 to 14 ppm. FT-IR (cm–1)
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