11560 Inorganic Chemistry, Vol. 49, No. 24, 2010
Mobarok et al.
1JRhP(A)=101 Hz, 2JP(A)P(B)=132 Hz, 2JP(A)P(C)=10 Hz), 15.4 (PC,
1P, ddd, 1JRhP(C)=105 Hz, 2JP(C)P(D)=130 Hz), -5.8 (PB, 1P, dd,
2JP(B)P(D)=8 Hz),-19.5 (PD, 1P, dd). 1H NMR (-78 °C; CD2Cl2,
2JPH=15.0 Hz). 2H{1H} NMR (27 °C; CD2Cl2, 61.4 MHz): δ
5.29 (b, Si-D, 1D), -10.44 (b, Si-D, 1D). 13C{1H} (CD2Cl2,
100.5 MHz): δ 203.9 (Rh-CO, ddd, 1C, 1JRhC=55.8 Hz, 2JPC
=
24.1 Hz, 3JPC=8.6 Hz, 2JCC*=29.1 Hz), 199.8 (Rh-CO, ddd,
1C, 1JRhC=55.6 Hz, 2JPC=22.3 Hz, 3JPC=9.4 Hz), 186.1 (Ir-
CO, bs, 1C), 59.2 (CH2, m, 1C), 37.3 (CH2, m, 1C). 29Si{1H}
NMR (27 °C; CD2Cl2, 78.5 MHz, DEPT, gHSQC): δ -2.3 (dd,
399.8 MHz): δ 5.35 (CH2, m, 1H), 4.94 (CH2, m, 1H), 3.13 (CH2,
1
bm, 1H), 2.94 (CH2, m, 1H), -9.76 (Rh-H, ddd, 1H, JRh-H
=
15.0 Hz, 2JtransP-H=120.0 Hz, 2JcisP-H=14.0 Hz), -11.09 (Ir-H,
dd, 1H, 2JtransP-H=114.0 Hz, 2JcisP-H=14.0 Hz). IR: νCO=1980
cm-1, 1937 cm-1
.
1JRh-Si=18.0 Hz, 2JP-Si=18.0 Hz), 146.0. IR: νSiH=2077 cm-1
,
ν
CO = 2032, 1943, 1972 cm-1
(m). [RhIr(H)(SiMe2H)(CO)3(K1-dppm)( μ-SiMe2)(dppm)] (13).
.
(k). [RhIr(CO)4(K1-dppm)( μ-SiHPh)(dppm)](10) and [RhIr-
(CO)2( μ-CO)(μ-SiHPh)(dppm)2] (11). A total of 20 mg of [RhIr-
(H)2(CO)2( μ-SiPh2)(dppm)2] (9) wasdissolvedin0.5mLofCD2Cl2
in an NMR tube and pressurized with CO (1.0 atm). After 18 h, the
31P{1H} NMR spectrum showed the presence of tetracarbonyl
species, 10, in about 75% yield, together with [RhIr(CO)3-
(dppm)2] (1) generated in 25% yield from 9 by the loss of silane.
The reaction mixture was then transferred to a 10 mL Schlenk flask,
and the solvent was removed under high vacuum conditions. The
deep orange residue was redissolved in 0.7 mL of CD2Cl2, and the
NMR analysis of this mixture indicated the formation of tricarbonyl
silylene species, 11, in approximately 10% yield (according to
NMR), leaving the solution as a mixture of 1, 10, and 11 in a
2.5:1:6.5 ratio. The addition of CO to 11 generates 10. Attempts to
isolate analytically pure samples of 10 and 11 failed. 31P{1H} NMR
A static atmosphere of dimethylsilane was placed over a solution of
[RhIr(CO)3(dppm)2] (1; 40 mg, 0.035 mmol in 3 mL of CH2Cl2),
and the reaction mixture was stirred for 1 h. The addition of 10 mL
of pentane caused the precipitation of a dull orange powdery solid
which was washed twice with 5 mL portions of pentane and dried
under Ar (44 mg, 88%). Anal. Calcd for C57H58IrO3P4RhSi2: C,
53.96; H, 4.57. Found C, 53.84; H, 4.24. 31P{1H} NMR (27 °C;
1
CD2Cl2, 161.9 MHz): δ 6.6 (PA, 1P, ddd, JRhP(A) = 100 Hz,
2JP(A)P(B)=111 Hz, 3JP(A)P(D)=6Hz),0.1(PD, 1P, dddd, 2JP(C)P(D)
=
3
2
50 Hz, JRhP(D) = 5 Hz), -9.9 (PB, 1P, ddd, JP(B)P(D) = 9 Hz,
4JP(B)P(C) =6 Hz), -26.7 (PC, 1P, dd). 1H NMR (27 °C; CD2Cl2,
399.8 MHz): δ4.84(CH2,m,1H),4.40(CH2,m,1H),4.20(Si-H, d,
3
1H, JPH =7.9 Hz), 2.92 (CH2, m, 2H), 0.84 (CH3, m, 3H), 0.75
for 10 (27 °C; CD2Cl2, 161.9 MHz): δ 18.1 (PA, 1P, ddd, 1JRhP(A)
=
(CH3, m, 3H), 0.24 (CH3, m, 3H), 0.17 (CH3, m, 3H), -11.20
(Ir-H, dd, 1H, 2JP-H=15.0 Hz, 2JP-H=14.0 Hz). 13C{1H} NMR
(27 °C; CD2Cl2, 100.5MHz):δ204.5 (Rh-CO, ddd, 1C, 1JRhC=55.0
Hz, 2JPC=19.1 Hz, 3JPC=6.3 Hz, 2JCC* =22.3 Hz), 203.4 (Rh-CO,
ddd, 1C, 1JRhC = 55.0 Hz, 2JPC=19.0 Hz, 3JPC=8.9 Hz), 187.4 (Ir-
101 Hz, 2JP(A)P(B) = 125 Hz, 3JP(A)P(D) = 5 Hz), -10.3 (PD, 1P,
dddd, 2JP(C)P(D) = 40 Hz, 2JRhP(D) = 12 Hz), -10.4 (PB, 1P, ddd,
2JP(B)P(D) = 6 Hz, 4JP(B)P(C) = 5 Hz), -26.2 (PC, 1P, dd). 1H NMR
for 10 (27°C; CD2Cl2, 399.8MHz):δ3.17(CH2, m, 2H), 2.84(CH2,
m, 2H). 13C{1H} NMR for 10 (27 °C; CD2Cl2, 100.5 MHz): δ 212.4
(semibridging CO, dm, 1C, 1JRhC=5.6 Hz), 201.7 (Rh-CO, dm, 1C,
1JRhC=71.8 Hz), 201.6 (Rh-CO, dm, 1C, 1JRhC=73.6 Hz), 185.3
(Ir-CO, bs, 1C), 60.3 (CH2, m, 1C), 37.9 (CH2, m, 1C).
CO, bs, 1C). IR: νCO=1999, 1977 cm-1
.
(n). [RhIr(CH3)(SiHPh2)(CO)( μ-H)( μ-CO)(dppm)2][CF3SO3]
(14). Under Ar, 28 mg (0.022 mmol) of [RhIr(CH3)(CO)2(dppm)2]-
[CF3SO3] (2) was taken into an NMR tube, dissolved in 0.7 mL
of CD2Cl2, and cooled to -78 °C in an acetone-dry ice bath. A
total of 4.1 μL (0.022 mmol) of diphenylsilane was added using a
microliter syringe, and the reaction was observed by low-temperature
NMR. Immediately after the addition of diphenylsilane, the dark
orange color of the solution lightened. Between -80 and -60 °C,
NMR analysis indicates the formation of [RhIr(CH3)(SiHPh2)-
(CO)( μ-H)( μ-CO)( μ-dppm)2][CF3SO3] (14) as the major product
(95%) in the solution. No attempts were made to isolate this product
at this temperature. 13C-enriched compound 14 was prepared under
similar conditions to those noted above, by reacting 13C-enriched
[RhIr(13CH3)(13CO)2(dppm)2][CF3SO3] (2) with Ph2SiH2. 31P{1H}
NMR (-78 °C; CD2Cl2, 161.9 MHz): δ 29.0 (PAPC, 2P, dm,
31P{1H} NMR for 11 (27 °C; CD2Cl2, 161.9 MHz): δ 37.8 (PA,
1P, ddd, 1JRhP(A) = 107 Hz, 2JP(A)P(B) = 255 Hz, 2JP(A)P(C) = 30
Hz), 27.5 (PC, 1P, ddd, 1JRhP(C) = 98 Hz, 2JP(C)P(D) = 156 Hz),
1.5 (PB, 1P, dd, 2JP(B)P(D) = 22 Hz), -5.3 (PD, 1P, dd). 1H NMR
NMR (27 °C; CD2Cl2, 399.8 MHz): δ 4.37 (CH2, m, 1H), 3.98
(CH2, m, 1H), 2.66 (CH2, m, 1H), 2.32 (CH2, m, 1H). 13C{1H}
NMR for 11 (27 °C; CD2Cl2, 100.5 MHz): δ 227.6 (μ-CO, dm,
1C, 1JRhC = 40.7 Hz), 201.3 (Rh-CO, dm, 1C, 1JRhC = 70.0 Hz),
186.0 (Ir-CO, bs, 1C).
(l). [RhIr(H)(SiPh2H)(CO)3(K1-dppm)( μ-SiPh2)(dppm)] (12).
Method 1. A total of 30 mg of [RhIr(H)2(CO)2( μ-SiPh2)(dppm)2]
(9; 0.023 mmol) in a Schlenk tube was dissolved in 4 mL of benzene,
and the tube was pressurized with 1 atm of CO followed by the
addition of 4.25 μL (1 equiv) of Ph2SiH2. The reaction flask was
sealed and left for 24 h, after which the solvent was removed under
high vacuum conditions, and the solid redissolved in 1 mL of
benzene. The slow addition of pentane resulted in the formation of a
lemon yellow precipitate, which was again recrystallized from the
benzene/pentane to give analytically pure compound 12.
1
1JRhP =140 Hz), -6.1 (PB, br, 1P), -8.6 (PD, br, 1P). H NMR
(-78 °C; CD2Cl2, 399.8 MHz): δ 5.50 (Si-H, td, 1H, 1JSiH = 170.0
Hz, 3JPH = 13.5 Hz, 3JHH=2.0 Hz), 4.12 (CH2, m, 2H), 3.59 (CH2,
m, 2H), 0.49 (CH3, t, 3H, 3JP-H=6.9 Hz), -8.44 (μ-H, ddm, 1H,
1JRhH=13.8 Hz, 3JHH=2.0 Hz, 2JCH(trans)*=24.0 Hz). 13C{1H}
NMR (-78 °C; CD2Cl2, 100.5 MHz): δ 216.6 (Rh-CO, dm, 1C,
1JRhC = 31.2 Hz), 173.8 (Ir-CO, t, 1C, 2JPC=9.8 Hz, 2JCH(trans)*=
1
2
Method 2. In a Schlenk tube, 200 mg of [RhIr(CO)3(dppm)2]
(1; 0.174 mmol) was dissolved in 10 mL of benzene. Three freeze-
pump-thaw cycles were applied to the solution, followed by the
addition of 128 μL (4 equiv) of Ph2SiH2. The reaction was stirred
for 48 h in the sealed Schlenk tube. The solution was concentrated
to 2 mL and layered with pentane. After 24 h, orange crystals were
separated by the removal of solvent. Yield: 202 mg (76.8%). Anal.
24.0 Hz), 14.8 (CH3, dt, 1C, JRhC = 29.0 Hz, JPC = 6.0 Hz).
29Si{1H} NMR (-78 °C; CD2Cl2, 79.5 MHz, DEPT, gHSQC): δ -
25.7 (t, 2JSi-P=10.0 Hz).
(o). [RhIr(CH3)(CO)2( μ-H)(η1:η2-SiHPh2)(dppm)2][CF3SO3]
(15). Method 1. As the solution of 14, as discussed above, warmed
to -20 °C, the color of the solution turned yellow from light orange.
31P{1H} NMR spectroscopy showed that compound 15 was formed
in 83% yield, with 17% of 14 still present in the solution.
Calcd for C77H66IrO3P4RhSi2 1.5C6H6: C, 63.25; H, 4.59. Found:
3
C, 63.16; H, 4.60. Under the conditions noted in method 1, the
reaction of compound 9 with PhSiD3 resulted in deuterium scram-
bling in the silyl and hydride positions of 12 to give 12d. 31P{1H}
Method 2. A total of 40 mg of [RhIr(CH3)(CO)2(dppm)2]-
[CF3SO3] (2) in a Schlenk tube was dissolved in 2 mL of CH2Cl2,
and the reaction was carried out as described above at -15 °C
(ethylene glycol/dry ice bath). The addition of 5 mL of ether precipi-
tated a yellow solid. The solvent was removed by cannula, and the
solid was dried under vacuum conditions at 0 °C. The solid was
again washed with 1 mL of CH2Cl2 at -15 °C, which preferentially
removed species 14 (which had precipitated with 15), leaving 15 as a
pure product. The compound was stable at room temperature in the
solid state; however, in solution, it decomposed within 30 min.
NMR (27 °C; CD2Cl2, 161.9 MHz): δ 3.1 (PA, 1P, ddd, 1JRhP(A)
=
94 Hz, 2JP(A)P(B)=103 Hz, 3JP(A)P(D)=6 Hz), -2.5 (PD, 1P, dddd,
2JP(C)P(D)=36 Hz, 3JRhP(D)=5 Hz), -9.5 (PB, 1P, ddd, 2JP(B)P(D)=9
Hz, 4JP(B)P(C)=8 Hz), -27.9 (PC, 1P, dd). 1H NMR (27 °C; CD2-
Cl2, 399.8 MHz): δ 5.45 (CH2, m, 1H), 5.30 (Si-H, d, 1H, 1JSi-H
=
180 Hz 3JPH=7.1 Hz), 3.80 (CH2, m, 1H), 3.20 (CH2, m, 1H),
2
2.70 (CH2, m, 1H), -10.50 (Ir-H, dd, 1H, JPH = 19.1 Hz,