Organometallics
Article
cannula over a period of 10 min to a solution of iPr2PCl (806 mg, 5.28
mmol) in THF (100 mL) at −95 °C. The reaction solution appeared
dark green. After stirring at −95 °C for 20 min, the solution was
allowed to slowly warm to room temperature, resulting in a color
change to red. This solution was maintained for 48 h at room
temperature, before volatiles were removed under reduced pressure.
The dark red residue was extracted into toluene (100 mL), which was
filtered through a plug of basic alumina to give a yellow solution.
Removal of volatiles under reduced pressure gave iPrPQpy as a thick
orange oil, which solidified on standing (1.67 g, 5.18 mmol, 98%
FeBr2(ArFPQpy). This complex was prepared as described for
FeBr2(iPrPQpy). X-ray quality crystals were obtained by two steps:
slow evaporation of a CH2Cl2 solution of the complex yields
crystalline products, which were dissolved in THF, and the vapor
diffusion of pentane into the THF solution of the complex generates
X-ray quality crystals. Anal. Calcd for C27.5H12Br2Cl3F10FeN2P
(FeBr2(ArFPQpy)·1.5 CH2Cl2) (found): C, 36.16 (35.77); H, 1.32
(1.18); N, 3.07 (3.33). When the reaction solution was allowed to stir
for 2−3 h, a red solid precipitated. The red form of “FeBr2(ArFPQpy)”
is poorly soluble in THF and is assumed to be [Fe(ArFPQpy)2]-
[FeBr4].
1
yield). 31P NMR (202 MHz, C63D6): δ 3.4 (1P, s br); H NMR (500
CoCl2(iPrPQpy). A slurry of CoCl2 (0.130 g, 1 mmol) in 5 mL of
THF was added to a solution of iPrPQpy (0.322 g, 1 mmol) in 20 mL
of THF. After stirring for 1 h at room temperature, the reaction
mixture was flooded with pentane to precipitate a gray-green solid. X-
ray quality crystals were obtained by two methods: (i) vapor diffusion
of pentane into CH2Cl2 solution of the complex and (ii) slow
evaporation of a C6D6 solution of the complex. 1H NMR (500 MHz,
CD2Cl2): δ 127.36 (2H, s); 78.25 (1H, s); 74.75 (1H, s); 57.25 (1H,
s); 39.62 (1H, s); 18.19 (1H, s); 17.39 (1H, s); 17.00 (1H, s); 10.30
(1H, s); −7.61 (1H, s); −12.80 (6H, s); −25.16 (6H, s). Anal. Calcd
for C20.5H24Cl3CoN2P [CoCl2(iPrPQpy)·0.5 CH2Cl2] (found): C,
49.77 (49.26); H, 4.89 (4.67); N, 5.66 (5.53).
MHz, C6D6): δ 9.15 (1H, ddd, JH−H = 7.9, 4JH−H = 1.2, 5JH−H = 0.9,
Ha); 8.92 (1H, d, 3JH−H = 8.6, Hf); 8.57 (1H, ddd, 3JH−H = 4.7, 4JH−H
= 1.8, 5JH−H = 0.9, Hd); 7.75 (1H, ddd, 3JH−H = 7.0, 3JH−P = 4.6, 4JH−H
3
3
= 1.3, Hi); 7.70 (1H, d, JH−H = 8.6, He); 7.38 (1H, dd, JH−H = 8.0,
4JH−H = 1.3, Hg); 7.31 (1H, ddd, 3JH−H = 7.9, 3JH−H = 7.5, 4JH−H = 1.8,
Hb); 7.20 (1H, dd, JH−H = 8.0, JH−H = 7.0, Hh); 6.71 (1H, ddd,
3JH−H = 7.5, 3JH−H = 4.7, 4JH−H = 1.2, Hc); 2.54 (2H, qqd, 3JH−H = 7.0,
3JH−H = 7.0, 2JH−P = 1.6, Hj); 1.26 (6H, dd, 3JH−P = 13.8, 3JH−H = 7.0,
3
3
3
3
Hk); 1.04 (6H, dd, JH−P = 12.0, JH−H = 7.0, Hl).
ArFPQpy. A solution of 8-bromo-2-(pyrid-2′-yl)quinoline (500 mg,
1.75 mmol) in THF (10 mL) was frozen in a glovebox cold well
before a solution of BuLi in hexane (1.6 M, 1.15 mL, 1.84 mmol) was
added dropwise over a period of 5 min to the thawing solution,
resulting in a color change to red. The solution was stirred for 3 min
before being refrozen in the cold well. The solution was removed
from the cold well, and as it thawed, it was added dropwise over a
period of 5 min to a stirred solution of (C6F5)2PBr (783 mg, 1.76
mmol) in thawing THF (10 mL), which had been frozen in the cold
well. Once addition was complete, the resulting solution was allowed
to slowly warm to room temperature. This solution was stirred for 16
h at room temperature, before all volatiles were removed under
reduced pressure to give a pale residue. The residue was extracted into
CH2Cl2 (2 × 30 mL), and the extract was evaporated. After washing
the pale yellow solid residue with cold pentane (2 × 10 mL), ArFPQpy
was obtained as an off-white solid (890 mg, 1.56 mmol, 89% yield).
CoBr2(iPrPQpy). A slurry of CoBr2 (0.219 g, 1 mmol) in 5 mL of
THF was added to a solution of iPrPQpy (0.322 g, 1 mmol) in 20 mL
of THF. After stirring for 1 h, the reaction mixture was flooded with
pentane to precipitate the blue-green solid. X-ray quality crystals were
obtained from vapor diffusion of pentane into the CH2Cl2 solution of
1
the complex. H NMR (500 MHz, CD2Cl2): δ 66.54 (2H, s); 56.90
(1H, s); 44.00 (1H, s); 36.67 (1H, s); 26.55 (1H, s); 21.63 (1H, s);
20.89 (1H, s); 13.59 (1H, s); 10.26 (1H, s); 0.80 (1H, s); −3.74 (6H,
s); −12.79 (6H, s). Anal. Calcd for C20H23Br2CoN2P (found): C,
44.39 (44.28); H, 4.28 (4.24); N, 5.18 (4.61).
CoCl2(ArFPQpy). A slurry of CoCl2 (0.130 g, 1 mmol) in 5 mL of
THF was added to a solution of ArFPQpy (0.570 g, 1 mmol) in 20 mL
of THF. After stirring for 1 h at room temperature, the solution was
flooded with pentane to precipitate a green solid. X-ray quality crystals
were obtained from vapor diffusion of pentane into the CH2Cl2
solution of the complex, followed by vapor diffusion of Et2O into the
3
31P NMR (202 MHz, CD2Cl2): δ −58.19 (1P, quin, JP−F = 38); 19F
NMR (470.4 MHz, CD2Cl2); δ −129.42 (2F, m); −150.69 (1F, t,
1
3JF−F = 20.4); −161.37 (2F, m); H NMR (500 MHz, CD2Cl2): δ
1
acetonitrile solution of the complex. H NMR (500 MHz, CD2Cl2):
8.69 (1H, d, JH−H = 8.6); 8.68 (1H, m); 8.37 (1H, d, JH−H = 8.6); 8.09
(1H, d, JH−H = 8.0); 7.98 (1H, dt, JH−H = 8.0, JH−H = 1.1); 7.75 (1H,
td, JH−H = 7.7, JH−H = 1.8); 7.54 (1H, td, JH−H = 7.6, JH−H = 1.7); 7.42
120.28 (1H, s); 72.28 (1H, s); 63.21(1H, s); 55.77 (1H, s); 43.55
(1H, s); 32.41 (1H, s); 21.88 (1H, s); 18.26 (1H, s); 17.16 (1H, s).
Anal. Calcd for C27.5H12Cl5F10CoN2P [CoCl2(ArFPQpy)·1.5 CH2Cl2]
(found): C, 39.91 (39.78); H, 1.46 (1.33); N, 3.39 (3.62).
(1H, dd, JH−H = 6.8, JH−H = 4.1); 7.34 (1H, dd, JH−H = 7.6, JH−H
=
FeBr2(MesNQpy). A slurry of FeBr2 (0.216 g, 1 mmol) in 5 mL of
THF was added to a solution of MesNQpy (0.365 g, 1 mmol) in 20
mL of THF. After stirring for 1 h, the reaction mixture was flooded
with pentane to precipitate a green solid. X-ray quality crystals were
obtained from vapor diffusion of pentane into a CH2Cl2 solution of
4.6).
MesNQpy. 8-Acetyl-2-(pyrid-2′-yl)quinoline (0.496 g, 2 mmol) was
mixed with 2,4,6-trimethylaniline (0.324 g, 2.4 mmol) and p-toluene
sulfonic acid (0.017 g, 0.1 mmol) in toluene (40 mL). The resulting
mixture was refluxed for 24 h to yield a dark yellow solution. The
solution was evaporated to dryness, and the crude product was
purified by chromatography using basic alumina, eluting with ethyl
acetate (1−10%)/petroleum ether. The second fraction from the
column gives the desired yellow colored product (0.51 g, 70% yield).
1H NMR (500 MHz, CDCl3): δ 2.26 (s, 6 H); 2.34 (s, 3 H); 2.41 (s,
3 H); 6.96 (s, 2 H); 7.35−7.39 (m, 1 H); 7.64 (dd, J = 7.93, 7.02 Hz,
1 H); 7.85 (td, J = 7.78, 1.83 Hz, 1 H); 7.93 (dd, J = 8.09, 1.37 Hz, 1
H); 8.00 (dd, J = 7.02, 1.53 Hz, 1 H); 8.34 (d, J = 8.85 Hz, 1 H); 8.58
(dt, J = 8.01, 1.03 Hz, 1 H); 8.67 (d, J = 8.55 Hz, 1 H); 8.74−8.77
(m, 1 H).
1
the complex. H NMR (500 MHz, CD2Cl2): δ 59.54, 53.56, 52.87,
43.32, 30.98, 26.34, 15.60, 13.89, 6.66, 0.95, −1.95, −2.28.
CoCl2(MesNQPy). A slurry of CoCl2 (0.130 g, 1 mmol) in 5 mL of
THF was added to a solution of MesNQpy (0.365 g, 1 mmol) in 20
mL of THF. After stirring for 1 h at room temperature, the reaction
mixture was flooded with pentane to precipitate a yellow solid. X-ray
quality crystals were obtained either by slow evaporation of CD2Cl2
solution or by vapor diffusion of pentane to the dichloromethane
1
solution of the complex. H NMR (500 MHz, CD2Cl2): δ 66.05,
64.81, 63.06, 59.48, 40.06, 37.00, 34.97, 22.30, 20.86, 17.86, 14.89,
14.44, 13.97, 13.69, 12.84, −5.35. Anal. Calcd for C25.5H24Cl3CoN3
[CoCl2(MesNQPy)·0.5 CH2Cl2] (found): C, 56.95 (57.26); H, 4.50
(4.03); N, 7.81 (7.59).
X-ray Crystallographic Determinations. Data for Fe-
Br2(iPrPQpy), FeBr2(ArFPQpy), CoCl2(iPrPQpy), CoBr2(iPrPQpy),
CoCl2(ArFPQpy), FeBr2(MesNQpy), and CoCl2(MesNQPy) were
collected on a Bruker D8 Venture instrument equipped with a four-
circle kappa diffractometer and Photon 100 detector. An Iμs
microfocus Mo (λ = 0.71073 Å) source supplied the multimirror
monochromated incident beam. The samples were mounted on a 0.3
mm loop with the minimal amount of Paratone-N oil. Data were
FeBr2(iPrPQpy). A slurry of FeBr2 (0.216 g, 1 mmol) in 5 mL of
THF was added to a solution of iPrPQpy (0.322 g, 1 mmol) in 20 mL
of THF. After stirring for 1 h, the reaction mixture was flooded with
pentane to precipitate a green solid. X-ray quality crystals were
obtained from vapor diffusion of pentane into a CH2Cl2 solution of
the complex. 1H NMR (500 MHz, CD2Cl2): δ 181.55 (2H, s); 144.23
(1H, s); 85.32 (1H, s); 79.04 (1H, s); 56.52 (1H, s); 27.12 (1H, s);
25.77 (1H, s); 15.69 (1H, s); 14.28 (1H, s); 10.00 (6H, s); 3.88 (6H,
s); −20.1 (1H, s). Anal. Calcd for C20H23Br2FeN2P (found): C, 44.65
(44.90); H, 4.31 (4.38); N, 5.21 (5.18). The yields of this and other
metal complexes were 70−90%.
G
Organometallics XXXX, XXX, XXX−XXX