4536 Organometallics, Vol. 17, No. 21, 1998
Communications
F igu r e 2. Molecular structure for Os(η2-8-quinolyl-C{O}-
Me-5)Cl(CO)(PPh3)2 (6) (ORTEP, thermal ellipsoids at 50%
probability). Selected bond distances (Å) and bond angles
(deg): Os-C(8), 1.832(15); Os-C(8), 2.077(14); Os-N,
2.196(11); O(2)-C(11), 1.225(17); C(8)-Os-N, 62.8(5);
P(2)-Os-P(1), 176.26(13).
F igu r e 1. Molecular structure for Os(η2-8-quinolyl-Br-5)I-
(CO)(PPh3)2 (2c) (ORTEP, thermal ellipsoids at 50% prob-
ability). Selected bond distances (Å) and bond angles
(deg): Os-C(1), 1.849(12); Os-C(8), 2.092(10); Os-N,
2.241(10); Os-I, 2.7082(14); C(8)-Os-N, 63.2(4); P(2)-
Os-P(1), 175.70(9).
pounds 4, 5, or 6, respectively, according to Scheme 1.9
The crystal structure of Os(η2-8-quinolyl-C{O}Me-5)Cl-
(CO)(PPh3)2 (6) has been determined,10 and the molec-
generated in situ, when treated with n-BuBr, Bu3SnCl,
or Me2NC{O}Me, was readily transformed into com-
(6) Synthesis of 2a -c: Os(η2-8-quinolyl)Cl(CO)(PPh3)2 (1) (200 mg,
0.221 mmol) was dissolved in dichloromethane (50 mL), and bromine
in the form of pyridine‚HBr3 (71 mg, 0.22 mmol), dissolved in methanol
(5 mL), was added. Iron powder (2 mg) was added, and the resulting
solution was stirred for 1 h. The orange solution was then washed with
water in a separating funnel. Because some halide exchange at the
metal center occurs during the bromination, the following procedure
was adopted to produce pure 2a , 2b, and 2c. The CH2Cl2 solution
containing the mixture of 2a and 2b obtained as above was stirred
with AgBF4 (100 mg) dissolved in water/ethanol (1:1, 10 mL). After 10
min the precipitated AgX was removed by fitration and an excess of
NaX (10 equiv) in H2O (20 mL) was added (X ) Cl, Br, I for 2a , 2b,
and 2c, respectively). This solution was stirred for a further 10 min,
then placed on a silica gel chromatography column (10 × 3.5 cm) and
eluted using dichloromethane. The first orange band was collected,
and crystals were obtained by addition of hexane and reduction of the
solvent volume in vacuo to give pure 2a (178 mg, 82%), 2b (173 mg,
76%), and 2c (183 mg, 77%). Data for 2a -c: IR (Nujol mull, cm-1) 2a
1901 ν(CO), 2b 1903 ν(CO), 2c 1903 ν(CO); 1H NMR (400.1 MHz,
CDCl3, δ in ppm, TMS at δ 0, J in Hz) 2a 7.14-7.49 (m, 30H, PPh3),
7.07 (d, 1H, H2, 3J (HH) 4.6), 6.48 (dd, 1H, H3, 3J (HH) 4.6, 8.6), 7.72
(d, 1H, H4, 3J (HH) 8.6), 6.93 (d, 1H, H6, 3J (HH) 7.3), 6.78 (d, 1H, H7,
3J (HH) 7.3); 2b 7.14-7.51 (m, 30H, PPh3), 7.06 (d, 1H, H2, 3J (HH)
4.6), 6.47 (dd, 1H, H3, 3J (HH) 4.6, 8.3), 7.70 (d, 1H, H4, 3J (HH) 8.3),
6.91 (d, 1H, H6, 3J (HH) 7.2), 6.76 (d, 1H, H7, 3J (HH) 7.2); 1c 7.13-
7.55 (m, 30H, PPh3), 7.11 (d, 1H, H2, 3J (HH) 4.5), 6.31 (dd, 1H, H3,
3J (HH) 4.5, 8.6), 7.58 (d, 1H, H4, 3J (HH) 8.6), 6.93 (d, 1H, H6, 3J (HH)
(9) Synthesis of 4, 5, and 6: Os(η2-8-quinolyl-Br-5)Cl(CO)(PPh3)2 (2a )
(100 mg, 0.102 mmol) was dissolved in dry deoxygenated tetrahydro-
furan (10 mL). n-Butyllithium (1.7 mol L-1 in hexanes) was added,
under nitrogen (1 equiv for the preparation of 4, 2 equiv for the
preparation of 5 or 6) at 0 °C, and the flask allowed to warm to room
temperature. For 5 or 6 the appropriate reagent was added after 5
min of stirring (4 equiv of Bu3SnCl for 5 or 4 equiv of Me2NC(O)Me
for 6), and the resulting mixture stirred at room temperature for 1 h.
For the preparation of 4, the butyl bromide required as reagent is
generated in situ, and to complete the reaction, the solution was
allowed to stir for 1 h. Ethanol (10 mL) was added to quench the
reaction, and the solution was placed on a silica gel chromatography
column (10 × 3.5 cm) and eluted with dichloromethane. The yellow or
light orange band was collected, and product obtained by adding
ethanol and reducing the solvent volume in vacuo to give pure 4 (27
mg, 28%), 5 (68 mg, 56%), or 6 (31 mg, 32%). Data for 4: IR (Nujol
mull, cm-1) 1893 ν(CO); 1H NMR (400.1 MHz, CDCl3, δ in ppm TMS
at δ 0, J in Hz) 7.15-7.50 (m, 31H, PPh3 and H2), 6.38 (dd, 1H, H3,
3J (HH) 4.6, 8.7), 7.63 (d, 1H, H4, 3J (HH) 8.7), 6.87 (d, 1H, H6, 3J (HH)
7.0) 6.57 (d, 1H, H7, 3J (HH) 7.0), 2.55 (t, 2H, CH2quinolyl, 3J (HH) 7.24),
1.41 (m, 2H, CH2), 1.20 (m, 2H, CH2), 0.87 (t, 3H, CH3, 3J (HH) 7.02).
Anal. Calcd for C50H44ClNOOsP2‚1/2CH2Cl2: C, 61.35; H, 4.56; N, 1.42.
Found: C, 61.70; H, 4.77; N, 1.47C, 61.35; H, 4.56; N, 1.42. Data for 5:
IR 1895 ν(CO); 1H NMR 7.12-7.51 (m, 30H, PPh3), 7.04 (d, 1H, H2,
3J (HH) 4.6), 6.38 (dd, 1H, H3, 3J (HH) 4.6, 8.3), 7.36 (d, 1H, H4, 3J (HH)
8.3), 6.95 (d, 1H, H6, 3J (HH) 6.3), 6.75 (d, 1H, H7, 3J (HH) 6.3), 0.99 (t,
2H, CH2Sn, 3J (HH) 8.06), 1.42 (m, 2H, CH2), 1.24 (m, 2H, CH2), 0.82
(t, 3H, CH3, 3J (HH) 7.24). Anal. Calcd for C58H62ClNOOsP2Sn: C,
58.27; H, 5.23; N, 1.17. Found: C, 58.55; H, 4.98; N, 1.35. Data for 6:
IR 1894 ν(CO), 1656 η(acyl); 1H NMR 7.11-7.52 (m, 30H, PPh3), 7.02
(d, 1H, H2, 3J (HH) 4.5), 6.56 (dd, 1H, H3, 3J (HH) 4.5, 8.4), 8.93 (d,
1H, H4, 3J (HH) 8.4), 7.31 (d, 1H, H6, 3J (HH) 7.1), 6.98 (d, 1H, H7,
3J (HH) 7.1), 2.43 (s, 3H, CH3). Anal. Calcd for C48H38ClNO2OsP2‚
THF: C, 61.20; H, 4.54; N, 1.37. Found: C, 61.55; H, 4.78; N, 1.68.
(10) Single crystals of 6 were grown from dichloromethane/ethanol.
7.1), 6.78 (d, 1H, H7, 3J (HH) 7.1). Anal. Calcd for 2a , C46H35
-
BrClNOOsP2‚1/2CH2Cl2: C, 54.34; H, 3.53; N, 1.36. Found: C, 54.61;
H, 3.18; N, 1.47. Anal. Calcd for 2b, C46H35Br2NOOsP2‚CH2Cl2: C,
50.64; H, 3.35; N, 1.26. Found: C, 50.65; H, 3.38; N, 1.22. Anal. Calcd
for 2c, C46H35BrINOOsP2: C, 51.31; H, 3.28; N, 1.30. Found: C, 51.03;
H, 3.16; N, 1.20.
(7) Butler, J . L.; Gordon, M. J . Heterocycl. Chem. 1975, 12, 1015.
(8) Single crystals of 2c were grown from chloroform/ethanol. Crystal
data for 2c:
C
46H34BrINOOsP2‚CHCl3, orange plate (0.25 × 0.13 ×
0.05 mm), triclinic, space group P1h, a ) 9.0426(1) Å, b ) 12.2465(1) Å,
c ) 20.4051(2) Å, R ) 92.0(1)°, â ) 95.746(1)°, γ )104.719(2)°, V )
2167.72(4) Å3, Z ) 2, Dc ) 1.831 g cm-3, F(000) ) 1154, µ(Mo KR) )
4.87 mm-1. A total of 21 762 (9600 unique) reflections (1.0° < θ < 28°;
area detector, T ) 200 K) were measured on a Siemens SMART
diffractometer using graphite-monochromated Mo KR radiation (λ )
0.710 73 Å). Data were corrected for Lorentz and polarization effects
and absorption (SADABS min. and max. corrections 0.375, 0.793). The
structure was solved by Patterson methods (SHELXL-97) and differ-
ence Fourier techniques and refined by full-matrix least-squares on
F2 (SHELXL-97) to R1 ) 0.073 (8125 reflections with I > 2σ(I)), wR2
) 0.227, S ) 1.044. Hydrogen atoms were introduced in calculated
positions and allowed to ride on the carrier atom. All non-hydrogen
atoms were refined with anisotropic thermal motion. The chloroform
solvate shows evidence of disorder, and one chlorine has been split
into two half-atoms. Residual density in a final difference Fourier map
Crystal data for 6:
C
48H38ClNO2OsP2, yellow prism (0.17 × 0.11 ×
0.08 mm), monoclinic, space group P21/c, a ) 14.4664(1) Å, b )
17.8919(1) Å, c ) 16.9623(2) Å, â ) 112.499(1)°, V ) 4056.21(6) Å3, Z
) 4, Dc ) 1.553 g cm-3, F(000) ) 1888, µ(Mo KR) ) 3.33 mm-1. A total
of 30 550 (7103 unique) reflections (1.0° < θ < 25°; area detector, T )
200 K) were measured on a Siemens SMART diffractometer using
graphite-monochromated Mo KR radiation (λ ) 0.710 73 Å). Data were
corrected for Lorentz and polarization effects and absorption (SADABS
min. and max. corrections 0.601, 0.776). The structure was solved by
Patterson methods (SHELXL-97) and difference Fourier techniques
and refined by full-matrix least-squares on F2 (SHELXL-97) to R1 )
0.077 (4174 reflections with I > 2σ(I)), wR2 ) 0.188, S ) 0.949.
Hydrogen atoms were introduced in calculated positions and allowed
to ride on the carrier atom. All non-hydrogen atoms were refined with
anisotropic thermal motion. Residual density in a final difference
Fourier map was +3.62 and -3.16 e Å-3, the residual density being
concentrated in the region of the osmium atom.
was +1.16 and -2.17 e Å-3
.