6
S. Saha et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
[29] while additional crystallographic calculations were performed
by the programs PLATON [30]. The crystallographic figures have
been generated using Diamond 3 software [31] (50% probability
thermal ellipsoids). The hydrogen atoms were included into
geometrically calculated positions in the final stages of the refine-
ment and were refined according to ‘riding model’. Crystallographic
data and pertinent refinement parameters for 1, and 2 are pre-
sented in Table S1. CCDC 1403193, 1407915 contain the supple-
mentary crystallographic data for all compounds. This data can be
obtained free of charge from The Cambridge Crystallographic Data
4.4. Synthesis of [CoIII(L1)3](PF6)3.KPF6 (1.KPF6)
A suspension of [L1H]PF6 (80 mg, 0.23 mmol), Co(OAc)2.4H2O
(14.3 mg, 0.056 mmol), and K2CO3 (26.5 mg, 0.19 mmol) in THF
(20 mL) was refluxed for 12 h. The mixture was cooled to room
temperature and filtered over a pad of celite. The resultant solution
was concentrated under reduced pressure and 10 mL hexane was
added while stirring to get a yellow precipitate. The precipitate was
washed with hexane (3 ꢁ 10 mL) and dried under vacuum. X-ray
quality crystals of compound 1.KPF6 were obtained by layering
hexane onto a mixed solution of dichloromethane/acetonitrile (5/1)
of the yellow precipitate inside an 8 mm o.d. vacuum-sealed glass
tube. Yield: 50 mg (60%). ESIeMS, m/z: 946.41 [1 e PF6]þ, 400.69 [1
e2PF6]2þ, 218.78 [1 e 3PF6]3þ 1H NMR (400 MHz, CD3CN, 294 K):
;
Scheme 4. Metal catalysed hydrogenation of nitriles to symmetrical and unsymmet-
rical secondary amines.
d
8.43 (t, J ¼ 8 Hz, 1H), 8.33 (d, J ¼ 2 Hz, 1H), 8.17 (d, J ¼ 8 Hz, 1H),
7.55 (m, 2H), 7.00 (d, J ¼ 6 Hz 1H), 5.32 (m, 1H), 4.89 (m, 2H) 3.63
(m, 1H), 2.72 (m, 1H), 2.21 (m, 1H), 2.12 (m, 1H); 13C NMR (125 MHz,
CD3CN, 294 K): 185.1, 150.9, 148.8, 145.1, 131.9, 128.4, 126.9, 121.0,
catalyst. Further studies are being carried out in our laboratory for
wider applications of this catalytic system.
118.9, 115.2, 50.0, 33.3; IR (KBr, cmꢂ1):
n
(PF6) 841 (s); Anal. Calcd for
C36H39N9CoKP3F24: C, 33.88; H, 3.08; N, 9.88. Found: C, 33.48; H,
2.89; N, 9.08.
4. Experimental section
4.5. Synthesis of [RuIIL1( 6-p-cymene)Cl]PF6 (2)
h
4.1. General Procedures and Materials
A solution of [L1H]PF6 (60 mg, 0.17 mmol) in dichloromethane
(20 mL) was treated with Ag2O (46 mg, 0.20 mmol), and the sus-
pension was stirred for 4 h at room temperature under the exclu-
Solvents were dried by conventional methods, distilled over
nitrogen and deoxygenated prior to use. RuCl3.nH2O (39% Ru) was
purchased from Arora Matthey, India. [RuCl2(h
6-p-cymene)]2 [25],
sion of light and in N2 atmosphere. After 4 h, [RuCl2(h
6-p-cymene)]2
[L1H]PF6, [L2H]PF6 and [L3H]Br was synthesized following the
literature procedures [26].
(52 mg, 0.085 mmol) was added and the solution was further
stirred for 12 h at room temperature. The mixture was subse-
quently filtered over a pad of celite and the solution was concen-
trated under reduced pressure and 10 mL hexane was added while
stirring to get a greenisheyellow precipitate. The precipitate was
washed with hexane (3 ꢁ 10 mL) and dried under vacuum. X-ray
quality crystals were grown by layering hexane onto a dichloro-
methane solution of 2 inside an 8 mm o.d. vacuum-sealed glass
tube. Yield: 90 mg (85%). ESIeMS, m/z: 470.09 [2ePF6]þ; 1H NMR
4.2. Physical measurements
1H NMR spectra were obtained on a JEOL JNM-LA 400 MHz
spectrometer. 1H NMR chemical shifts were referenced to the re-
sidual hydrogen signal of the deuterated solvents. Elemental ana-
lyses were performed on a Thermoquest EA1110 CHNS/O analyzer.
The crystallized compounds were powdered, washed several times
with dry diethyl ether and dried in vacuum for at least 48 h prior to
elemental analyses. ESIeMS was recorded on a Waters Micromass
Quattro Micro triple-quadrupole mass spectrometer using aceto-
nitrile as solvent.
(500 MHz, CD2Cl2, 294 K)):
d
9.07 (d, J ¼ 5.96 Hz, 1H), 8.06 (t,
J ¼ 7.8 Hz, 1H), 7.69 (d, J ¼ 2.32 Hz,1H), 7.64 (d, J ¼ 8.24 Hz, 1H), 7.42
(t, J ¼ 6.84 Hz 1H), 7.30 (d, J ¼ 1.84 Hz 1H), 6.01 (m, 2H) 5.81 (d,
J ¼ 6.88 Hz, 1H), 5.42 (d, J ¼ 6.4 Hz, 1H), 5.29 (m, 2H), 5.16, (d,
J ¼ 10.5 Hz, 1H), 4.55 (m, 1H), 4.42 (m, 1H), 2.76 (m, 2H), 2.41 (m,
1H), 2.18 (s, 3H), 0.95 (m, 6H); 13C NMR (125 MHz, CD2Cl2, 294 K):
184.1, 155.3, 141.5, 133.1, 124.8, 123.6, 118.9, 116.3, 112.2, 107.7, 106.1,
91.2, 90.5, 86.6, 82.9, 51.2, 34.4, 31.3, 29.8, 22.5, 21.9, 19.1; IR (KBr,
4.3. X-ray data collections and refinement
Single crystal X-ray structural studies were performed on a CCD
Bruker SMART APEX diffractometer equipped with an Oxford In-
struments low-temperature attachment. Data were collected at
cmꢂ1):
n(PF6) 855 (s); Anal. Calcd for C22H27N3RuPF6Cl: C, 42.92; H,
4.42; N, 6.83. Found: C, 42.12; H, 4.05; N, 6.21.
100(2)
K
using graphite-monochromated Mo-K
a
radiation
4.6. General Procedure for the catalytic hydrogenation of nitriles
(
la ¼ 0.71073 Å). The frames were indexed, integrated and scaled
using SMART and SAINT software package [27], and the data were
corrected for absorption using the SADABS program [28]. The
structures were solved and refined using SHELX suite of programs
All of the hydrogenation reactions were performed at constant
pressures using a stainless steel 50 mL Parr hydrogenation reactor.
The reactor was flushed three times with hydrogen gas at 2e4 bar