Organometallics
Article
(experimental), 506.167882 [M + H]+ (calculated); all peaks showed
the expected isotopic pattern.
Caution! Thallium salts are toxic, and extra care must be taken to
handle the products and the waste.
triazole basicity may play a secondary role once the active
catalyst is formed.
4.3.3. [(TtzPh,Me*)Ru(p-cymene)Cl] (1; * = Rearranged Ligand). A
solution of Tl(TtzPh,Me) (0.054g, 0.078 mmol) in 10 mL of CH2Cl2
was combined with [RuCl2(p-cymene)]2 (0.024g, 0.039 mmol) in a
flask under an N2 atmosphere. The contents were then stirred at room
temperature for 16 h. A white precipitate formed during the reaction
and was filtered off, and an orange solution was obtained. After
removal of solvent from the filtrate an orange solid was isolated, which
was washed with hexane (2 × 5 mL) and dried under vacuum. The
crude product was purified by recrystallization from dichloromethane
solution layered with hexane in air at room temperature to produce
exclusively [(TtzPh,Me*)Ru(p-cymene)Cl] (1) in 81% yield (0.048 g,
0.063 mmol) (where the asterisk indicates a rearranged ligand).
4. EXPERIMENTAL SECTION
4.1. Reagents and Physical Measurements. All experiments
were performed under an atmosphere of dry N2 using Schlenk
techniques and an M. Braun UNILAB glovebox. K(Ttz),41
65
K(TtzMe,Me),64 Tl(TtzPh,Me),46 and [RuCl2(C6Me6)]2 were prepared
by following the literature procedures. [RuCl2(p-cymene)]2 [RuCl2(C6H6)]2,
all ketones and aldehydes, and styrene were obtained commercially.
Solvents were dried using an M. Braun solvent purification system with
alumina columns or were freshly distilled from drying agents using
standard methods. NMR spectra were recorded using either a 300 MHz
or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra
were recorded on a Perkin-Elmer Spectrum One Fourier-transform IR
absorption spectrophotometer. High-resolution (HR) mass spectrom-
etry was performed on a VG70SE double-focusing, triple-quadrupole
mass spectrometer equipped with FAB or CI ionization capability.
Samples for LIFDI MS were analyzed at the University of California at
Riverside. Elemental analyses were performed by Robertson Microlit,
Ledgewood, NJ.
4.2. Single Crystal X-ray Diffraction Studies. Diffraction data
for compounds 1−4 and 6 were collected using a Bruker AXS SMART
APEX CCD diffractometer using monochromated Mo Kα radiation
with the ω-scan technique. Single crystals of compounds were mounted
on Mitegen micromesh mounts, and data were collected at 100 K. Data
were collected, unit cells were determined, and the data were integrated
and corrected for absorption and other systematic errors using the
Apex2 suite of programs. The structures were solved by direct methods
and refined by full-matrix least squares against F2 with all reflections
using SHELXTL 6.14. All non-hydrogen atoms were refined
anisotropically. Hydrogen atoms were placed in calculated positions
and were refined with isotropic displacement parameters 1.2 (C−H) or
1.5 (CH3) times that of the adjacent carrier atom. CIF files for
structures of compounds were deposited with the Cambridge Structural
Database as CCDC Nos. 917041−917045. Further details are given
below.
3
1H NMR (CDCl3): δ 0.65 (d, 6H, CH3 (iPr), JH−H = 7.0 Hz), 1.19
(m, 1H, CH(iPr)), 1.35(s, 3H, CH3 (cymene)), (note that the
expected number of cymene resonances are not observed, perhaps due
to a fluxional process), 2.07 (s, 3H, CH3(tz)), 2.75 (s, 6H, CH3(tz)),
3
4.36 (d, 2H (cymene), JH−H = 6.0 Hz), 4.58 (d, 2H (cymene),
3JH−H = 6.0 Hz), 7.35−7.54 (m, 9H, meta, para Ph), 8.02−8.04 (m,
6H, ortho Ph). 13C NMR (CDCl3): δ 12.64, 15.20, 17.62, 22.98
(CH3), 30.00(CH(iPr)), 81.55, 83.38, 101.65, 107.98 (cymene),
126.26, 128.46, 128.80, 130.08, 130.39, 131.20, 132.22, 133.39
(phenyl), 155.85, 162.09 (5-tz), 161.71, 168.67 (3-tz). IR (cm−1):
2489.97 (νB−H). Anal. Found: C, 58.46; H, 5.27; N, 16.37. Calcd for 1:
C, 58.70; H, 5.19; N, 16.65.
In a manner similar to the preparation of 1, complexes 2−4 were
prepared using the amounts of reagent, temperature and time noted.
4.3.4. [(TtzPh,Me*)Ru(benzene)Cl] (2). Tl(TtzPh,Me) (0.143 g, 0.207
mmol), [RuCl2(benzene)]2 (0.052 g, 0.10 mmol), room temperature,
16 h. The product was purified by recrystallization from a mixture
of toluene and hexane (2/1) at −35 °C to produce [(TtzPh,Me*)Ru-
(benzene)Cl] (2) in 72% yield (0.105 g, 0.150 mmol). 1H NMR
(CDCl3): δ 2.05 (s, 3H, CH3), 2.76 (s, 6H, CH3), 4.51 (s, 6H
(benzene)), 7.33−7.52 (m, 9H, meta, para Ph), 7.99−8.09 (m, 6H,
ortho Ph). 13C NMR (CDCl3): δ 11.77, 13.47, 13.97, 15.69, 17.42
(CH3), 84.17, 86.49 (benzene), 124.97−132.93 (17 overlapping
resonances (phenyl)), 155.92, 161.81 (5-tz), 161.20, 168.54 (3-tz)
(some dynamic exchange processes may be occurring, perhaps to
interchange which 3-phenyl-5-methyltriazole ring is coordinated).
IR (cm−1): 2469.11 (νB−H). HR FAB-MS: m/z 702.160316 [M + H]+
(experimental), 702.160573 [M + H]+ (calculated); all peaks showed
the expected isotopic pattern. Anal. Found: C, 56.25; H, 4.59; N,
17.80. Calcd for 2: C, 56.54; H, 4.46; N, 17.98.
In the structure of 2 one of the two crystallographically independent
toluene molecules is located on and disordered around a crystallo-
graphic inversion center. The disorder also affects the methyl end of
one of the triazole ligands, and the NCCH3 unit is also disordered in a
1:1 ratio. In the disordered regions the aromatic atoms of the toluene
were constrained to resemble an ideal hexagon with C−C bond
lengths of 1.39 Å. In the disordered triazole equivalent bond distances
were restrained to be similar and equivalent atoms constrained to have
identical ADPs. The CNC(CH3)N units were restrained to be flat.
4.3. Synthesis. 4.3.1. Tl(Ttz). A 5 mL methanol solution of K(Ttz)
(0.554 g, 2.17 mmol) was combined with 5 mL of a water solution of
TlNO3 (0.600 g, 2.25 mmol). The contents were then stirred at room
temperature for 24 h. The solvents were removed, the product was
extracted into 50 mL of dichloromethane, and the extract was filtered.
The filtrate was dried to afford a white solid that was washed with
5 mL of hexane and dried under vacuum. The yield of Tl(Ttz) was
49% (0.448 g, 1.07 mmol). This complex was recrystallized from
4.3.5. [(TtzMe,Me)Ru(p-cymene)Cl] (3). Tl(TtzMe,Me) (0.073 g,
0.14 mmol), [RuCl2(p-cymene)]2 (0.044 g, 0.072 mmol), room
temperature, 16 h. The product was purified by recrystallization from
a mixture of dichloromethane and hexane (2/1) at room temperature
to produce [(TtzMe,Me)Ru(cymene)Cl] (3) in 67% yield (0.055g,
1
3
0.096 mmol). H NMR (CDCl3): δ 1.11 (d, 6H, CH3 (iPr), JH−H
=
6.9 Hz), 1.77(s, 6H, CH3), 1.98 (s, 3H, CH3), 2.25 (s, 3H, CH3 of
cymene), 2.36 (s, 3H, CH3), 2.72 (s, 6H, CH3), 5.29−5.37 (m, 4H,
cymene) (CH resonance of iPr group not observed). 13C NMR
(CDCl3): δ 12.80, 14.52, 15.34, 16.24, 17.07, 21.61 (CH3), 24.99
(CH), 83.83, 85.92, 101.71, 106.95 (cymene), 160.49 (5-tz), 165.74
(3-tz). IR (cm−1): 2436.79 (νB−H). HR CIMS: m/z 572.176558
[M + H]+ (experimental), 572.176223 [M + H]+ (calculated); all
peaks showed the expected isotopic pattern. Anal. Found: C, 46.04; H,
5.54; N, 21.90. Calcd for 3: C, 46.28; H, 5.83; N, 22.08.
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dichloromethane at 0 °C. H NMR (CDCl3): δ 8.05 (s, 3H, tz), 8.34
(s, 3H, tz). IR (cm−1): 2449.78 (νB−H). HR CIMS: m/z 422.074438
[M + H]+ (experimental), 422.073982 [M + H]+ (calculated); all
peaks showed the expected isotopic pattern.
4.3.2. Tl(TtzMe,Me). A 10 mL methanol solution of K(TtzMe,Me
)
(0.370 g, 1.09 mmol) was combined with 5 mL of a water solution
of TlNO3 (0.298 g, 1.12 mmol). The contents were then stirred at
room temperature for 24 h. A white precipitate formed and was
collected by filtration. The precipitate obtained was dissolved in 30 mL
of dichloromethane and the solution filtered. The filtrate was then
dried to afford a white solid that was washed with 5 mL of hexane
and dried under vacuum. The yield of Tl(TtzMe,Me) is 48% (0.262 g,
0.519 mmol). This complex was recrystallized from dichloromethane
4.3.6. [(TtzMe,Me)Ru(C6Me6)Cl] (4). Tl(TtzMe,Me) (0.191 g, 0.379
mmol), [RuCl2(C6Me6)]2 (0.124 g, 0.185 mmol), room temperature,
20 h. The product was purified by recrystallization from a mixture of
dichloromethane and hexane (2/1) at room temperature to produce
[(TtzMe,Me)Ru(C6Me6)Cl] (4) in 84% yield (0.187 g, 0.312 mmol).
1H NMR (CDCl3): δ 1.95 (s, 12H, CH3 of C6Me6), 2.01 (s, 6H, Me),
2.35 (s, 3H, Me), 2.36 (s, 3H, Me), 2.59 (s, 6H, Me). 13C NMR
(CDCl3): δ 13.73, 13.99, 16.11, 16.57 (CH3), 94.17 (CH3 of C6Me6),
125.58, 128.51, 129.32 (C of C6Me6), 161.23 (5-tz), 165.53 (3-tz). IR
1
at 0 °C. H NMR (CDCl3): δ 2.39 (s, 9H, CH3), 2.53 (s, 9H, CH3).
IR (cm−1): 2530.06 (νB−H). HR CIMS: m/z 506.168951 [M + H]+
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dx.doi.org/10.1021/om301260j | Organometallics 2013, 32, 2135−2144