Inorganic Chemistry
Article
mixture until all effervescence ceased. The organic layer was separated
and dried over anhydrous sodium sulfate. The solution was filtered and
the solvent was removed under reduced pressure to give tris(3-
bromopropyl)phosphine as a clear liquid (4.2 g, 11 mmol, 29%). This
product was used immediately in the next step without further
purification.
C26H49Cl2RuP3 (MW 626.57) requires C 49.84, H 7.88. 31P{1H}
NMR (162 MHz, dichloromethane-d2): δ 94.4 (1P, t, 2JP−P = 12.6 Hz,
PhP(CH2)2); δ 92.3 (2P, br s, PC(CH3)3). 1H NMR (300 MHz,
dichloromethane-d2): δ 8.16 (2H, m, ArH); 7.45 (3H, m, ArH); 2.4−
3
2.1 (6H, m, CH2); 1.44 (18H, d, JH−P = 12.7 Hz, C(CH3)3); 1.19
3
(18H, d, JH−P = 12.7 Hz, C(CH3)3); 1.15−1.05 (2H, m, CH2).
LiP(C(CH3)3))2. n-Butyllithium (2.5 M in hexane, 16 mL, 40 mmol)
was added to a solution of di(tert-butyl)phosphine (5.3 g, 36 mmol) in
THF (50 mL) at 0 °C with stirring. The solution remained colorless
during the addition, until the reaction was complete when a pale
yellow color persisted. The reaction mixture was allowed to warm to
room temperature and THF (40 mL) was added, resulting in a bright
yellow solution which was used directly in the next step.
31C{1H} NMR (100.6 MHz, dichloromethane-d2): δ 137.7 (d, 1JC−P
=
36.3 Hz, CAr); 132.4 (d, JC−P = 8.7 Hz, CAr); 130.4 (d, JC−P = 2.4 Hz,
1
CAr); 128.8 (d, JC−P = 9.3 Hz, CAr); 40.7 (d, JC−P = 17.9 Hz,
1
PC(CH3)3); 36.9 (d, JC−P = 11.4 Hz, PC(CH3)3); 31.9 (dd, JC−P
=
2
31.0 Hz, JC−P = 6.3 Hz, CH2); 31.8 (d, JC−P = 2.9 Hz, PC(CH3)3);
29.2 (s, PC(CH3)3); 25.3 (dd, JC−P = 22.7 Hz, JC−P = 13 Hz, CH2).
Synthesis of RuCl2(P3P3tBu) (6). Solid di-μ-chlorobis[(p-cymene)-
chlororuthenium] (100 mg, 0.163 mmol) was added to a solution of
tBu
P3P3 (3). The lithium di(tert-butyl)phosphide solution from the
tBu
P3P3 (6), (185 mg, 0.312 mmol) in toluene (50 mL) under
previous step was added to a stirring solution of tris(3-bromopropyl)-
phosphine (4.20 g, 10.6 mmol) in THF (approximately 40 mL) at 0
°C. During the addition, a pink/orange color formed before the color
returned to yellow once addition was complete. The reaction mixture
was left to stir at room temperature for 18 h. The solvent was removed
under reduced pressure and deaerated water (approximately 30 mL)
added, with care, until all excess lithium phosphide had been
destroyed. Benzene (approximately 40 mL) was added and the
mixture was stirred for 1 h. The organic layer was decanted, dried over
anhydrous sodium sulfate, and filtered to give a clear solution. The
solvents were removed under reduced pressure and the resulting oil
was heated under reduced pressure (0.4 mbar) to remove volatile
impurities, leaving tris(3-di(tert-butyl)phosphinopropyl)phosphine as
a clear wax (3.82 g, 6.44 mmol, 61% from tris(3-bromopropyl)-
phosphine). 31P{1H} NMR (121.5 MHz, benzene-d6): δ 26.2 (3P, s,
PT); −35.5 (1P, s, PC). 1H{31P} NMR (300 MHz, benzene-d6): δ 1.87
nitrogen. The solution was stirred and refluxed overnight to afford an
extremely dark green solution with a suspended brown solid. The
solution was filtered, the residue was discarded, and the volatiles of the
filtrate removed under vacuum. The resulting green solid residue was
dried under vacuum for 3 h to afford dichloro(tris(2-di(tert-
butyl)phosphinopropyl)phosphine-κ3P)ruthenium(II) (132 mg,
tBu
0.173 mmol, 55% by P3P3 (6)). Anal. found C 51.54, H 9.28
C33H72Cl2RuP4 (MW 764.81) requires C 51.83, H 9.49. 31P{1H}
2
NMR (121 MHz, THF-d8): δ 60.8 (1P, t, JP−P = 35 Hz, PC); 31.1
2
1
(2P, d, JP−P = 35 Hz, PE); 25.5 (1P, s, PF). H NMR (300 MHz,
acetone-d6): δ 1.89 (2H, m, CH2); 1.79 (4H, m, CH2); 1.62 (8H, m,
CH2); 1.48−1.62 (18H, m, CH3); 1.62 (4H, m, CH2); 1.12 (36H, m,
CH3).
X-ray Structure Determinations. Single crystals of 5 and 6 were
attached, with Exxon Paratone N, to a short length of fiber supported
on a thin piece of copper wire inserted in a copper mounting pin. The
crystal was quenched in a cold nitrogen gas stream from an Oxford
Cryosystems Cryostream. A Bruker kappa APEXII area detector
diffractometer employing graphite monochromated Mo Kα radiation
generated from a fine focus sealed tube was used for the data
collection. The data integration and reduction were undertaken with
APEX2, and subsequent computations were carried out with the X-
Seed graphical user interface. The structures were solved by direct
methods with SHELXS-97 and extended and refined with SHELXL-
97. The non-hydrogen atoms in the asymmetric unit were modeled
with anisotropic displacement parameters. A riding atom model with
group displacement parameters was used for the hydrogen atoms.
All calculations were performed using the crystallographic and
structure refinement data summarized in Table 3.
3
(6H, m, CH2CH2CH2); 1.63 (6H, t, JH−H = 7.1 Hz, CH2P); 1.49
3
3
(6H, t, JH−H = 7.4, CH2P); 1.12 (54H, d, JH−P = 10.6 Hz, CH3).
13C{1H} NMR (100.6 MHz, benzene-d6): δ 31.3 (d, JC−P = 30 Hz,
1
C(CH3)3); 29.9 (d, 1JC−P = 14 Hz, C(CH3)3); 29.7 (dd, JC−P = 26 Hz,
JC−P = 14 Hz, CH2); 27.3 (dd, JC−P = 28 Hz, JC−P = 14 Hz, CH2); 23.6
(dd, JC−P = 23 Hz, JC−P = 11 Hz, CH2). HRMS (ES) m/z [M + H]+
593.4647 (calcd 593.4663).
Synthesis of RuCl2(P2P3tBu), (4). A solution of dichlorotris-
(triphenylphosphine)ruthenium(II) (1.18 g, 1.23 mmol) in THF (50
mL) was added to a solution of tris(2-di(tert-butyl)phosphinoethyl)-
phosphine, P2P3tBu (1), (5.0 mL, 245 mM, 1.23 mmol) in THF under
nitrogen. The brown solution was to stirred overnight and a tan solid
precipitated. The solid was collected by filtration and washed with
THF (5 mL) to afford dichloro(tris(2-di(tert-butyl)phosphinoethyl)-
phosphine-κ3P)ruthenium(II) (0.40 g, 0.55 mmol 45%). Anal. found:
C 49.88, H 9.05 C30H66Cl2RuP4 (MW 722.72) requires C 49.86, H
9.20. 31P{1H} NMR (162 MHz, dichloromethane-d2): δ 106.2 (1P, dt,
ASSOCIATED CONTENT
■
S
* Supporting Information
3
3JP−P = 37 Hz, JP−P = 17.5 Hz, PC); 91.4 (2P, br s, PE); 34.3 (1P, d,
CIF with crystallographic data for compounds [RuCl2(P2P2tBu)]
(5) and [RuCl2(P3P3tBu)] (6). This material is available free of
3JP−P = 37 Hz, PF). 1H NMR (400 MHz, dichloromethane-d2): δ 2.45
(2H, m, CH2); 2.28−1.92 (6H, m, CH2); 1.83 (2H, m, CH2); 1.35
(18H, d, 3JH−P = 12.5 Hz, CH3); 1.24 (18H, d, 3JH−P = 12.5 Hz, CH3);
3
1.14 (18H, d, JH−P = 10.8 Hz, CH3); 1.07 (2H, m, CH2). 13C{1H}
1
AUTHOR INFORMATION
Corresponding Author
NMR (100.6 MHz, dichloromethane-d2): δ 39.9 (d, JC−P = 18 Hz,
■
1
1
PC(CH3)3); 36.2 (d, JC−P = 10.5 Hz, PC(CH3)3); 32.1 (d, JC−P
=
2
22.4 Hz, PC(CH3)3) 31.9 (d, JC−P = 2.9 Hz, PC(CH3)3); 30.8 (dd,
JC−P = 28.3 Hz, JC−P = 22.2 Hz, CH2 (pendant arm)) 30.0 (d, 2JC−P
13.6 Hz, PC(CH3)3); 28.8 (s, PC(CH3)3); 27.2 (dd, JC−P = 28.0 Hz,
JC−P = 6.5 Hz, CH2 (bound arm)); 24.9 (dd, JC−P = 21.1 Hz, JC−P
=
Notes
The authors declare no competing financial interest.
=
12.6 Hz, CH2 (bound arm)); 16.3 (dd, JC−P = 25.6 Hz, JC−P = 5.7 Hz,
CH2 (pendant arm)).
ACKNOWLEDGMENTS
■
Synthesis of RuCl2(PhP2P2tBu) (5). A solution of dichlorotris-
(triphenylphosphine)ruthenium(II) (1.06 g, 1.11 mmol) in THF (30
mL) was added to a solution of bis(2-di(tert-butyl)phosphinoethyl)-
phenylphosphine, PhP2P2tBu, (0.520 g, 1.14 mmol) in THF (10 mL)
under nitrogen. The brown solution was stirred overnight, and a
yellow solid precipitated. Hexane (50 mL) was added to assist
precipitation of the solid. The cloudy suspension was stirred for 1 h,
then the solid was isolated by filtration to give dichloro(bis(2-di(tert-
butyl)phosphinoethyl)phenylphosphine-κ3P)ruthenium(II) (0.255 g,
0.407 mmol, 37%) as a yellow solid. Anal. found C 49.52, H 7.60
The authors wish to thank Dr. Hsiu Lin Li and Dr. Alison
Magill for technical assistance, proofreading, and discussions.
The authors also thank the Australian Research Council for
financial support, and R.G.-W. thanks the Australian Govern-
ment and the University of New South Wales for postgraduate
scholarships. NMR spectra and mass spectra were obtained
through the Mark Wainwright Analytical Centre at the
University of New South Wales. Subsidized access to these
facilities are gratefully acknowledged.
3245
dx.doi.org/10.1021/ic2027169 | Inorg. Chem. 2012, 51, 3239−3246