Organometallics
Article
containing diphenyldiazomethane was added dropwise to the cold
solution containing 5. The reaction mixture was allowed to stir for 1 h.
The volatiles were removed in vacuo. The remaining solid was washed
with cold pentane to yield an analytically pure green-brown solid
(0.0202 g, 58%). X-ray quality crystals were grown from concentrated
liquor and drying the remaining solids in vacuo (0.0593 g, 54%). Red
X-ray quality crystals were grown at room temperature from a
concentrated toluene solution layered with pentane. H NMR (400
1
MHz, C6D6): δ 7.29−7.16 (m, ∼4H), 7.16−7.01 (m, ∼10H), 6.89 (t,
3
3
1H, JHH = 7.2 Hz, Ar), 6.74 (d, 2H, JHH = 7.2 Hz, Ar), 6.57 (s, 1H,
Mes), 6.48 (s, 1H, Mes), 6.42 (d, 3H, 3JHH = 7.2 Hz, Si−Ar and Mes),
1
pentane at room temperature over 24 h. H NMR (400 MHz, C6D6):
3
3
i
6.32 (d, 3H, JHH = 7.2 Hz, Si−Ar and Mes), 6.24 (d, 3H, JHH = 7.2
Hz, Si−Ar and Mes), 6.13 (s, 1H, Mes), 3.46 (br m, 1H,
PC(H)C(H)Ph), 3.16 (m, 2H, CH(CH3)2), 2.99 (m, 4H,
CH(CH3)2), 2.74 (s, 3H, Mes-Me), 2.60 (s, 3H, Mes-Me), 2.57 (s,
3H, Mes-Me), 2.47 (br m, 1H, PC(H)C(H)Ph), 2.34 (s, 3H, Mes-
Me), 2.25 (s, 3H, Mes-Me), 2.22 (s, 3H, Mes-Me), 2.09 (s, 3H, Mes-
Me), 1.76 (s, 3H, Mes-Me), 1.61 (m overlap with s, 9H + 3H,
CH(CH3)2 + Mes-Me), 1.34 (m, 15H, CH(CH3)2), 1.04 (m, 6H,
δ 22.6 (79 Hz, 2H, Ph2CNNH), 16.0 (273 Hz, 18H, PrMe), 14.1
(81 Hz, 2H, Ph2CNNH), 7.5 (18 Hz, 3H, Ph3Si), 6.8 (44 Hz, 12H,
2 overlapping Ph3Si or Mes-Ar peaks), 6.4 (32 Hz, 6H, Ph3Si or Mes-
Ar), 4.2 (42 Hz, 2H, Ph2CNNH), 1.9 (19 Hz, 27H, MesMe +
iPrMe), −1.1 (v br, 18H, MesMe), −34.9 (140 Hz, 2H, Ph2CN
NH), −39.9 (279 Hz, 2H, Ph2CNNH). Note: isopropyl methine
and Ph2CNNH resonances are not observed. UV−vis (C6H6, λ
(nm)) (ε, M−1 cm−1): 446 (25000), 582 (1600), 804 (1100). Evans’
method (μeff, C6D6): 3.25 μB. Anal. Calcd for C76H101N5OSiP3CoZr:
C, 66.54; H, 7.42; N, 5.10. Found: C, 66.42; H, 7.23; N, 5.06.
(OC(H)O)Co(iPr2PNMes)3ZrOSiPh3 (8). A solution containing
0.100 g (0.0830 mmol) of 5 in benzene (5 mL) was placed in a
Schlenk tube equipped with a stir bar and sealed with a Teflon valve.
The solution was frozen, and the headspace of the flask was evacuated
and backfilled with 10 equiv of CO2 using a known volume gas bulb
and partial pressure methods. The Schlenk tube was sealed, and the
solution was allowed to thaw. Immediately upon thawing, blue
microcrystals of the product formed and the solution color changed
from yellow to pale purple in color. The blue microcrystals were
isolated from the benzene solution, extracted into CH2Cl2, and dried
in vacuo (0.0403 g). The remaining benzene solution can be layered
with pentane to isolate additional 8 as a blue solid (0.0312 g). The
total combined yield was 0.0715 g, 71%. 1H NMR (400 MHz,
3
3
CH(CH3)2), 0.83 (dd, 3H, JHH = 7.2 Hz and JHP = 15.6 Hz,
3
3
CH(CH3)2), 0.66 (m, 3H, JHH = 7.2 Hz and JHP = 11.6 Hz,
CH(CH3)2). 31P{1H} NMR (161.8 MHz, C6D6): δ 62.7 (br s, 1P),
47.3 (br s, 1P), 45.9 (br s, 1P). 13C{1H} NMR (100.5 MHz, C6D6): δ
154.1, 150.4, 150.2, 149.1, 149.0, 144.2, 144.1, 139.9, 138.5, 138.0,
137.3, 137.0, 136.6, 135.8, 135.5, 133.6, 133.3, 132.8, 131.2, 130.8,
130.0, 129.2, 129.0, 127.1, 126.7, 126.6, 126.3, 41.7 (m), 40.3, 40.2,
37.4, 35.7, 35.0, 35.2, 35.0, 34.6, 25.9, 25.7, 24.4, 24.0, 23.9, 23.8, 22.9,
22.8, 22.7, 22.3, 21.8, 21.7, 21.6, 21.5, 21.3, 21.1, 21.0, 21.0, 20.9, 20.8,
20.5, 20.4, 18.7, 17.3. UV−vis (C6H6, λ (nm)) (ε, M−1 cm−1): 416
(4200). Anal. Calcd for C71H96N3OSiP3CoZr: C, 66.69; H, 7.57; N,
3.29. Found: C, 66.57; H, 7.58; N, 3.13.
1-Hexene Isomerization. A C6D6 solution was prepared
containing 0.0060 g (0.0050 mmol) of compound 5 and 63 μL
(0.50 mmol) of 1-hexene. The C6D6 reaction mixture was added to a J-
Young fitted NMR tube and was heated at 65 °C for 30 h. The
reaction mixture volatiles were vacuum-transferred to a second J-
Young fitted NMR tube. The integration of the 1H NMR spectrum of
the volatile products from the reaction mixture revealed a composition
of ∼98% cis/trans 2-hexene.
i
CD2Cl2): δ 18.9 (287 Hz, 18H, Pr-Me), 7.5 (17 Hz, 3H, Ph3Si), 7.1
(20 Hz, 6H, Ph3Si or Mes-Ar), 6.4 (44 Hz, 6H, Ph3Si or Mes-Ar), 6.1
(34 Hz, 6H, Ph3Si or Mes-Ar), 2.0 (13 Hz, 9H, Mes-Me), 1.6 (375 Hz,
i
18H, Pr-Me), −2.0 (v br, 18H, Mes-Me). Note: isopropyl methine
and −OCOH resonances are not observed. IR (CD2Cl2): 1616 cm−1
(νCO). UV−vis (CH2Cl2, λ (nm)) (ε, M−1 cm−1): 338 (3800), 578
(77), 868 (190). Evans’ method (μeff, CD2Cl2): 2.86 μB. Anal. Calcd
for C64H91N3O3SiP3CoZr: C, 62.93; H, 7.51; N, 3.44. Found: C,
62.81; H, 7.41; N, 3.56.
ASSOCIATED CONTENT
* Supporting Information
■
S
X-ray data collection, solution, and refinement details for 2 and
5−10, crystallographic data in CIF format, 1H NMR spectra for
complexes 2 and 5−10, variable-temperature 1H and 31P NMR
(PhHCN)Co(iPr2PNMes)3ZrOSiPh3 (9). Two solutions, one
containing 0.0507 g (0.0421 mmol) of 5 in toluene (2 mL) and
another containing 4.4 μL (0.043 mmol) of benzonitrile in toluene (2
mL), were cooled to near freezing. The thawing solution containing
benzonitrile was added dropwise to the cold solution containing 5,
resulting in a color change from yellow to dark purple. The reaction
mixture was stirred and heated at 80 °C for 4 h, during which the color
turned from purple to red-orange. The reaction mixture was
concentrated in vacuo and layered with pentane. After 24 h at room
temperature, red solids were isolated from the mother liquor and dried
in vacuo to afford analytically pure 9 (0.0391 g, 72%). Red X-ray
quality crystals were grown from a concentrated toluene solution at
1
spectra for complex 5, H NMR data showing intermediates
formed in the reactions of benzonitrile and phenylacetylene
1
with 5, and H NMR spectrum of 1-hexene isomerization
products. The Supporting Information is available free of
AUTHOR INFORMATION
Corresponding Author
■
1
room temperature. H NMR (400 MHz, C6D6): δ 25.1 (39 Hz, 2H,
i
PhHCN), 14.0 (78 Hz, 18H, Pr-Me), 7.5 (17 Hz, 3H, Ph3Si), 7.2
(6 Hz, 6H, Ph3Si or Mes-Ar), 6.9 (21 Hz, 6H, Ph3Si or Mes-Ar), 6.7
(12 Hz, 6H, Ph3Si or Mes-Ar), 6.4 (14 Hz, 2H, PhHCN), 1.9 (8 Hz,
27H, Mes-Me + iPrMe), −1.0 (219 Hz, 18H, Mes-Me), −11.6 (28 Hz,
1H, PhHCN), −16.2 (88 Hz, 1H, PhHCN). Note: isopropyl
methine resonances are not observed. UV−vis (C6H6, λ (nm)) (ε,
M−1 cm−1): 343 (9200), 442 (2400), 510 (980), 716 (770). Evans’
method (μeff, C6D6): 2.95 μB. Anal. Calcd for C70H96N4OSiP3CoZr: C,
65.65; H, 7.56; N, 4.37. Found: C, 65.43; H, 7.69; N, 4.24.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
We acknowledge financial support from the U.S. Department of
Energy under Award DE-SC0004019.
■
Co(PhHCCHPiPr2NMes)(iPr2PNMes)2ZrOSiPh3 (10). A solu-
tion containing 9.5 μL (0.087 mmol) of phenylacetylene in toluene (2
mL) was added dropwise to a stirring solution containing 0.1030 g
(0.08543 mmol) of 5 in toluene (3 mL) in a scintillation vial. The
reaction mixture initially changed color from yellow to green and was
allowed to stir for 24 h until the reaction mixture appeared red in
color. The reaction mixture was filtered through a pad of Celite, and
the filtrate was concentrated in vacuo. Pentane was layered onto the
concentrated toluene solution, and after 24 h, the red-brown product
was isolated as an analytically pure solid by decanting the mother
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