2666 Organometallics, Vol. 28, No. 9, 2009
Grochowski et al.
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37.92 (s, CH2), 36.48 (s, CH2), 30.30 (s, CH2), 29.79 (s, CH2), 23.16
(s, CH2), 22.82 (s, CH2), 21.61 (s, R-CH3), 19.22 (s, R-CH3), 14.15
(s, terminal CH3), 14.10 (s, terminal CH3), 9.98 (s, C5Me5), 9.95 (s,
C5Me5), 9.75 (s, C5Me5). Anal. Calcd (found) for C26H44SCl2Ir2: C,
37.00 (36.76); H, 5.25 (5.10). ESI-MS: see Supporting Information.
[(Cp*Ir)3(µ3-S)2](Cp*IrCl3)2 (2). Isolated as red-orange crystals
by vacuum to give a red and yellow solid. H NMR showed a 50:
50 mixture of 3 and 4. 3 showed peak shifts very similar to 1, with
Cp* methyl peaks at δ 1.91 and 1.86. Due to peak overlap, the
percentage of each diastereomer was difficult to determine but
appeared to be roughly equal. The Cp* methyl peak corresponded
to the hydrides at δ -15.48 and -15.51 in a 30:1 ratio. The mixture
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from solution. H NMR (500 MHz, CDCl3, 25 °C): δ 2.38 (s, 30H,
C5Me5), 1.59 (s, 45H, C5Me5).
was primarily 4 if the reaction was heated at 100 °C. H NMR
(400 MHz, CDCl3, 25 °C): δ 3.56 (m, 2H, R-CH), δ3.01 (m, 1H,
R-CH), 2.4-2.1 (m), 1.91 (s, C5Me5), 1.86 (s, C5Me5), 1.35 (m,
CH2), 0.99 (d, 3H, branched CH3), 0.98 (t, 3H, J ) 3 Hz, terminal
CH3), -15.48 (s, 1H, IrH), -15.51 (s, 1H, IrH). 13C{1H} NMR
(100 MHz, CDCl3, 25 °C): δ 90.97 (s, C5Me5), 90.91 (s, C5Me5),
90.24 (s, C5Me5), 90.18 (s, C5Me5), 89.89 (s, C5Me5), 41.33 (s),
39.09 (s), 38.95 (s), 38.06 (s), 37.91 (s), 33.16 (s), 30.58 (s), 29.14
(s), 23.96 (s), 23.20 (s), 21.78 (s), 21.55 (s), 21.20 (s), 21.12 (s),
20.81 (s), 19.38 (s), 18.60 (s), 14.93 (s), 14.88 (s), 14.57 (s), 14.26
(s), 10.19 (s, C5Me5), 9.98 (s, C5Me5), 8.54 (s, C5Me5). ESI-MS:
see Supporting Information.
Preparation of [Cp*IrCl(µ-S-2-pentyl)]2 (4). In a nitrogen-
filled glovebox 14 µL of 2-pentanethiol (0.113 mmol) was added
to a J-Young NMR tube containing [Cp*IrHCl]2 (23.6 mg, 0.0324
mmol) in 1 mL of C6D6. Evolution of H2 began immediately. The
NMR tube was placed in a 100 °C oil bath. After 5 min the dark
Reaction of 2-Methylthiophene with [Cp*IrHCl]2. In a
nitrogen-filled glovebox 1 mL of 2-methylthiophene was added to
[Cp*IrHCl]2 (0.0737 g, 0.101 mmol) in a 10 mL ampule fitted with
a Teflon valve. The solution was then freeze-pump-thaw de-
gassed to remove nitrogen from the system, and 1 atm of hydro-
gen gas was added. The solution was then heated in an oil bath
at 120 °C. After an hour the solution changed from blue to red
with the precipitation of orange crystals ([(Cp*Ir)3(µ3-S)2]Cl2, and
[Cp*IrCl2]2). After 1 day of heating, the solution was concen-
trated to dryness by vacuum. The residue was dissolved in THF
and eluted through a Pasteur pipet filled with silica. The solvent
was removed by vacuum to give a red-orange residue. The isolated
solid consisted of a mixture of compounds 3-7. Yield: 0.0536 g.
The chemical shifts of each compound were determined by
independent synthesis of each compound and then adding it to the
mixture. This method allowed the identification of each of the Cp*
methyl peaks as well as the hydride peaks. Many of the alkyl peaks
(i.e., terminal CH3) have common areas of overlap.
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blue solution turned orange. The reaction was monitored by H
NMR and was complete when the hydride peak at δ -13.4
disappeared. After 6 h the reaction was stopped and the solvent
removed by vacuum. The yellow solid was dried under vacuum at
90 °C to remove residual thiol (27.3 mg, 90%). 1H NMR (500 MHz,
CDCl3, 25 °C): δ 3.56 (m, 2H, R-CH), 1.55 (s, 30H, C5Me5), 1.33
(m, 8H, ꢀ-CH2, γ-CH2), 0.98 (d, 6H, J ) 3 Hz, branched CH3),
0.86 (t, 6H, J ) 7 Hz, terminal CH3). 13C{1H} NMR (100 MHz,
CDCl3, 25 °C): δ 89.88 (s, C5Me5), 38.02 (s, R-CH), 37.99 (s,
R-CH), 33.12 (s, CH2), 21.19 (s, CH2), 21.11 (s, CH2), 18.57 (s,
branched CH3), 18.52 (s, branched CH3), 14.93 (s, terminal CH3),
14.88 (s, terminal CH3), 8.52 (s, C5Me5). Anal. Calcd (found) for
C30H52S2Cl2Ir2: C, 38.65 (38.48); H, 5.62 (5.34).
Preparation of [Cp*IrCl(µ-S-n-pentyl)]2 (6). The complex was
prepared as for 4 using 12 µL of 1-pentanethiol (0.0967 mmol, 10
mg) and [Cp*IrHCl]2 (30.6 mg, 0.0420 mmol) in 1 mL of C6D6.
The NMR tube was heated in a 100 °C oil bath for 12 h. Yellow
solid (36.3 mg, 93%). 1H NMR (400 MHz, CDCl3, 25 °C): δ 2.48
(t, 4H, R-CH2, J ) 7 Hz), 1.60 (br s, 30H, C5Me5), 1.28 (m, 12H,
CH2), 0.86 (t, 6H, terminal CH3, J ) 7 Hz). 13C{1H} NMR (100
MHz, CDCl3, 25 °C): δ 89.77 (s, C5Me5), 31.39 (s, R-CH2), 29.95
(s, CH2), 27.13 (s, CH2), 22.93 (s, CH2), 14.33 (s, CH3), 8.46 (s,
C5Me5). Anal. Calcd (found) for C30H52S2Cl2Ir2: C, 38.65 (38.82);
H, 5.62 (5.52).
Preparation of [Cp*IrCl]2(µ-S-2-pentyl)(µ-S-n-pentyl) (7). 5
(38.7 mg, 0.0466 mmol) was dissolved in 1 mL of CDCl3 and
placed in a J-Young NMR tube. 2-Pentanethiol (5.8 µL, 0.0466
mmol) was added to the solution. The solution was heated at 90
°C for one day, during which time the solution changed from red
to orange. The final product contained a small amount (ap-
proximately 10% by NMR) of 4 that was carried over from the
first reaction in the formation of 5. 1H NMR (400 MHz, CDCl3, 25
°C): δ 3.59 (m, 1H, R-CH branched chain), 2.48 (t, 2H, J ) 7 Hz,
R-CH2 straight chain), 1.58 (s, 30H, C5Me5), 1.4-1.2 (m, 10H,
CH2), 0.99 (d, 3H,, J ) 7 Hz, CH3 branched chain), 0.89-0.84
(m, 6H, terminal CH3). 13C{1H} NMR (100 MHz, CDCl3, 25 °C):
89.85 (s, C5Me5), 38.09 (s, R-CH), 33.10 (s, CH2), 31.47 (s, CH2),
29.86 (s, CH2), 27.33 (s, CH2), 22.96 (s, CH2), 21.05 (s, CH2), 18.63
(s, branched CH3), 14.97 (s, terminal CH3), 14.36 (s, terminal CH3),
8.52 (s, C5Me5).
1H NMR (500 MHz, CDCl3, 25 °C): δ 3.57 (m, R-CH, 4), 3.02
(m), 2.48 (t, J ) 7 Hz, CH3, 6), 2.4-2.1 (m), 1.90 (s, C5Me5, 3),
1.88 (d, C5Me5, 5), 1.86 (d, C5Me5, 3), 1.60 (s, C5Me5, 6), 1.57 (s,
C5Me5, 7), 1.55 (s, C5Me5, 4), 1.51 (d, 14H, C5Me5), 1.35 (d, 6H,
J ) 7 Hz), 1.30-1.20 (m, CH2), 0.99-0.85 (m, CH3), -15.43 (s,
C5Me5, 5), -15.49 (s, C5Me5, 3), -15.52 (s, C5Me5, 3). 13C{1H}
NMR (100 MHz, CDCl3, 25 °C): δ 90.96 (s, C5Me5), 90.90 (s,
C5Me5), 90.23 (s, C5Me5), 90.17 (s, C5Me5), 89.89 (s, C5Me5), 86.44
(s, C5Me5), 41.32 (s), 39.34 (s), 39.08 (s), 38.94 (s), 38.01 (s), 37.90
(s), 33.14 (s), 33.08 (s), 31.46 (s), 31.36 (s), 31.23 (s), 29.84 (s),
28.72 (s), 27.30 (s), 22.96 (s), 22.78 (s), 21.78 (s), 21.56 (s), 21.21
(s), 21.13 (s), 21.04 (s), 20.80 (s), 19.38 (s), 18.63 (s), 18.54 (s),
14.98 (s, CH3), 14.94 (s, CH3), 14.89 (s, CH3), 14.58 (s, CH3), 14.36
(s, CH3), 10.19 (s, C5Me5), 10.10 (s, C5Me5), 10.05 (s, C5Me5),
9.99 (s, C5Me5), 9.59 (s, C5Me5), 9.49 (s, C5Me5), 8.52 (s, C5Me5).
Anal. Calcd (found) for C25H42SCl2Ir2 (57% by integration of the
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Cp* methyl peaks in the H NMR) and C30H52S2Cl2Ir2 (43% by
1
integration of the Cp* methyl peaks in the H NMR): C, 37.23
(37.35); H, 5.32 (5.25). ESI-MS: see Supporting Information.
Independent Synthesis of [Cp*IrCl]2(µ-H)(µ-S-n-pentyl)
(5). In a nitrogen-filled glovebox 1-pentanethiol (6 µL, 0.0484
mmol) was added to [Cp*IrHCl]2 (35 mg, 0.0481 mmol) in 3 mL
of benzene in a 10 mL ampule fitted with a Teflon valve. The
solution was then freeze-pump-thaw degassed to remove nitrogen
from the system, and 1 atm of hydrogen gas was added. The solution
was then heated in an oil bath at 130 °C for 19 h. The solution
changed from dark blue to deep red. The benzene was evaporated
by vacuum to give a red solid (10% of the product contains
[Cp*IrCl(µ-S-n-pentyl)]2, which cannot be separated).
1H NMR (400 MHz, CDCl3, 25 °C): δ 3.01 (m, 1H, R-CH),
2.47 (m, 1H, R-CH), 2.1-2.0 (m, 2H, ꢀ-CH2), 1.91-1.89 (d, 15H,
C5Me5), 1.59 (s, 15H, C5Me5), 1.36-1.32 (m, 4H, γ-CH2), 0.90 (t,
3H, J ) 7 Hz, CH3), -15.43 (s, 1H, IrH). 13C{1H} NMR (100
MHz, CDCl3, 25 °C): δ 90.97 (s, C5Me5), 90.26 (s, C5Me5), 31.38
(s, CH2), 31.23 (s, CH2), 22.77 (s, CH2), 14.27 (s, CH3), 10.09 (s,
C5Me5), 10.04 (s, C5Me5).
Independent Synthesis of [Cp*IrCl]2(µ-H)(µ-S-2-pentyl)
(3) and [Cp*IrCl(µ-S-2-pentyl)]2 (4). The complexes were
prepared as for 5 adding 2-pentanethiol (6 µL, 0.0484 mmol) to
[Cp*IrHCl]2 (34.1 mg, 0.0468 mmol) in 3 mL of benzene. The
solution was heated at 130 °C for 28 h. The benzene was evaporated
Preparation of [Cp*IrCl]2(µ-H)[µ-SCH(COCH3)C3H7] (8).
The complex was prepared as for 1 adding 2-acetylthiophene (89
µL, 0.824 mmol) to a benzene solution (2 mL) containing
[Cp*IrHCl]2 (29.6 mg, 0.0407 mmol). The solution was then heated