3644
P. Kumar et al. / Journal of Organometallic Chemistry 694 (2009) 3643–3652
procedures [38]. Hydrated ruthenium (III) chloride, dicyclopent-
adiene, triphenylphosphine, ammonium tetrafluoroborate and di-
phenyl-2-pyridylphosphine were obtained from Aldrich Chemical
Company, Inc. USA and were used without further purifications.
840 cmÀ1. UV–Vis, kmax, nm (
e): 242 (37 730), 268 (13 640), 308
(5500), 391(3140).
2.2.2.2. Method 2. To
a
suspension of [(g j
5-C5H5)Ru( 1-P-
The precursor complex [(g
5-C5H5)Ru(PPh3)2Cl] was prepared and
PPh2Py)(PPh3)Cl] (1) (0.108 g, 0.149 mmol) in methanol (25 mL)
NH4PF6 (0.078 g, 0.748 mmol) was added and stirred at room tem-
perature for 8 h. The clear orange yellow solution was then rota-
tory evaporated. Residue was extracted with dichloromethane
and filtered to remove any insoluble material. From the filtrate
1a was isolated in ꢀ70% yield.
purified by the literature procedure [39].
Elemental analyses on the complexes were performed by micro
analytical laboratory of the Sophisticated Analytical Instrument
Facility, Central Drug Research Institute, Lucknow. Infrared spectra
in KBr discs in the region 4000–400 cmÀ1 and electronic spectra
were recorded on a Shimadzu-8201 PC and Shimadzu UV-1601
spectrophotometers, respectively. 1H NMR spectra with tetrameth-
ylsilane as the internal reference and 31P{1H} NMR with
H3P04(85%) as the external reference were obtained at room tem-
perature on a Bruker DRX-300 NMR machine. Electrochemical
experiments were carried out in an airtight single compartment
cell using platinum as the counter electrode, glassy carbon as the
working electrode and Ag/Ag+ reference electrode on a CHI 620c
electrochemical analyzer. Fast atom bombardment (FAB) and ESI
mass spectra were recorded on a JOEL SX 102/DA-6000 Mass spec-
trometer using Xenon as the FAB gas (6 kV, 10 mA). The accelerat-
ing voltage was 10 kV and spectra were recorded at room
temperature using m-nitrobenzyl alcohol as the matrix.
2.2.3. Synthesis of [(g j
5-C5H5)Ru( 1-P-PPh2Py)(PPh3)(NCCH3)]BF4 1b
To a suspension of complex 1 (0.06 g, 0.092 mmol) in acetoni-
trile (15 ml) NH4BF4 (0.019 g, 0.184 mmol) was added and refluxed
under a nitrogen atmosphere for 2 h, whereupon the yellow solu-
tion turned pale yellow in color. The solvent was rotatory evapo-
rated and yellow mass thus obtained was dissolved in CH2Cl2
and filtered. The filtrate was concentrated to 2 ml and hexane
was added to induce precipitation. The light yellow product was
washed with diethyl ether and dried under vacuum. Yield:
0.724 g, 78%. M.P. 155 °C, Microanalytical data: BC42F4H38N2P2Ru,
requires: C, 61.47; H, 4.67; N, 3.41%. Found: C, 61.41; H, 4.62; N,
3.39%. 1H NMR (CDCl3, TMS, d, ppm): 7.82–6.95 (m, 15H, PPh3),
2.2. Syntheses
2.18 (s, 3H, CH3), 4.70 (s, 5H, g
5-C5H5), 7.26–7.04 (br. m, 14H, aro-
matic proton of PPh2Py), 7.89 (t, 1H, JH–H = 4.36 Hz), 8.01 (t, 1H,
JH–H = 4.42 Hz), 8.67 (d, 1H, J = 5.12 Hz), 31P{1H} NMR (CDCl3,
H3PO4 d, ppm): 59.72 (s, PPh2Py), 54.90 (s, PPh3). IR (cmÀ1, KBr):
2324(s), 1626 (s), 1440 (s), 1394 (m), 1102 (m), 844 (s), 758 (s),
698 (s),
272 (13 080), 398 (2900), 434 (2810).
2.2.1. Preparation of [(
A mixture of [(
5-C5H5)Ru(PPh3)2Cl] (0.5 g, 0.68 mmol) and
g j
5-C5H5)Ru( 1-P-N-PPh2Py)(PPh3)] 1
g
PPh2Py (0.18 g, 0.68 mmol) in benzene (25 ml) was heated under
reflux 8 h. After cooling to room temperature, benzene was re-
moved under vacuo and resulting orange residue was subjected
to purification by flash silica gel chromatography (CH2Cl2/ethylace-
tate, 3/1 v/v). It afforded compound 1 as an orange solid. The
orange solid was recrystallised from CH2Cl2-petroleum ether (40–
60). Yield: 0.598 g, 69%. M.P. 145 °C Microanalytical data: C40
H34- Cl4NP2Ru, requires: C, 57.64; H, 4.11; N, 1.68. Found: C, 57.58;
m e): 240 (35 550),
(BF4À) 1056 cmÀ1. UV–Vis, kmax, nm (
2.2.4. Synthesis of [(g j
5-C5H5)Ru( 1-P-PPh2Py)(PPh3)CN] 1c
A mixture of complex 1 (0.06 g, 0.092 mmol) and sodium cya-
nide (NaCN) (0.048 g, 0.23 mol) in methanol (15 ml) were refluxed
for 3 h. The yellow suspension gradually turned light yellow in col-
or. Solvent was removed under reduced pressure and the yellowish
solid was dissolved in CH2Cl2 and filtered. The filtrate was concen-
trated to 2 ml and left for slow crystallization in a refrigerator.
Slowly, a yellow microcrystalline product separated which was fil-
tered, washed with diethyl ether and dried under vacuum. Yield:
0.624 g, 72%. M.P. 150 °C, Microanalytical data: C41H34N2P2Ru, re-
quires: C, 61.21; H, 4.26; N, 3.48. Found: C, 61.18; H, 4.24; N,
3.42%. 1H NMR (CDCl3, d): 1H NMR (CDCl3, TMS, d. ppm): 7.82–
H, 4.24; N, 1.34%. ESI-MS(calcd): m/z 691.2 (690), [(
2-P-N-PPh2Py)(PPh3)]+; 429.2 (427), [( 5-C5H5)Ru( 2-P-N-PPh2Py)]+.
1H NMR (CDCl3, TMS, d, ppm): 7.72–6.65 (m, 15H, PPh3), 4.68 (s, 5H,
5-C5H5), 7.24–7.08 (br. m, 14H, aromatic protons of PPh2Py), 7.90
g
5-C5H5)Ru
(j
g
j
g
(t, 1H, JH–H = 4.36 Hz), 8.11 (t, 1H, JH–H = 4.42 Hz), 8.67 (d, 1H,
J = 5.12 Hz), 31P{1H} NMR (CDCl3, H3PO4, d, ppm): 59.72 (s, PPh2Py)
and 54.90 (s, PPh3) ppm. IR (cmÀ1, KBr pellet): 1626 (s), 1440 (s),
1394 (m), 1102 (m), 844 (s), 758 (s), 698(s. UV–Vis, kmax, nm (e): 240
(37 728), 264 (13 540), 308 (5500), 391(3140).
6.95 (m, 15H, PPh3), 4.70 (s, 5H, g
5-C5H5), 7.26–7.04 (br. m, 14H,
aromatic proton of PPh2Py), 7.89 (t, 1H, JH–H = 4.36 Hz), 8.01
(t, 1H, JH–H = 4.42 Hz), 8.67 (d, 1H, J = 5.12 Hz), 31P{1H} NMR (CDCl3,
H3PO4 d, ppm): 57.82 (s, PPh2Py), 54.90 (s, PPh3). IR (cmÀ1, nujol):
2227 (s), 1626 (s), 1440 (s), 1394 (m), 1102 (m), 844 (s), 758 (s),
698(s). UV–Vis, kmax, nm (e): 244 (38 470), 268 (13 640), 308
(5500), 388(3270).
2.2.2. Synthesis of [(
2.2.2.1. Method 1. The complex [(
g
5-C5H5)Ru(
j
2-P-N-PPh2Py)(PPh3)]PF6 1a
5-C5H5)Ru)(PPh3)2Cl] (0.108 g,
g
0.149 mmol) in methanol (25 mL) was treated with diphenyl-2-
pyridylphosphine (PPh2Py) (0.196 g, 0.748 mmol) and NH4PF6
(0.078 g, 0.748 mmol) and contents of the flask were stirred at
room temperature for 2 h. Slowly, it dissolved and gave a yellow
solution. It was filtered to remove any solid impurities and concen-
trated to half its volume and left for slow crystallization in a refrig-
erator. Slowly, microcrystalline product separated, which was
filtered washed with diethyl ether and dried in vacuo. Yield:
0.611 g, 72%. M.P. 140 °C, Microanalytical data: PC40F6H34N1P2Ru,
requires: C, 61.71; H, 4.40; N, 1.80. Found: C, 61.58; H, 4.74; N,
2.2.5. Synthesis of [(g j
5-C5H5)Ru( 1-P-PPh2Py)(PPh3)N3] 1d
This complex was prepared following the above procedure ex-
cept that sodium azide (NaN3) (0.048 g, 0.23 mmol) was used in
place of sodium cyanide (NaCN). It isolated in the form of yellow
microcrystalline solid. Yield: 0.686 g, 74%, M.P. 155 °C Microana-
lytical data: C40H35N4P2Ru requires: C, 58.48; H, 4.29; N, 6.82.
Found: C, 58.44; H, 4.24; N, 6.80%. 1H NMR (CDCl3, TMS, d, ppm):
1.34%. ESI-MS(calcd).: m/z 727 (726), [Ru(
PPh2Py)(PPh3)Cl]; 465 (464), [(
5-C5H5)Ru( 2-P-N-PPh2Py)Cl]. 1H
NMR (CDCl3,TMS d, ppm): 7.82–6.95 (m, 15H, PPh3), 4.70 (s, 5H,
5-C5H5), 7.26–7.04 (br. m, 14H, aromatic proton of PPh2Py), 7.89
g j
5-C5H5)( 1-P-N-
g
j
7.82–6.95 (m, 15H, PPh3), 2.18 (s, 3H, CH3), 4.70 (s, 5H, g
5-C5H5),
7.26–7.04 (br. m, 14H, aromatic protons of PPh2Py), 7.89 (t, 1H,
JH–H = 4.36 Hz), 8.01 (t, 1H, JH–H = 4.42 Hz), 8.67 (d, 1H,
J = 5.12 Hz). IR (cmÀ1, nujol): 2042, 1626 (s), 1440 (s), 1394 (m),
1102 (m), 844 (s), 758 (s), 698(s), UV–Vis, kmax, nm (e): 240
(25 210), 268 (22 320), 308 (10 500), 434(1650).
g
(t, 1H, JH–H = 4.36 Hz), 8.01 (t, 1H, JH–H = 4.42 Hz), 8.67 (d, 1H,
J = 5.12 Hz), 31P{1H} NMR (CDCl3, H3PO4 d, ppm): À11.25 (s,
PPh2Py) and 41.54 (s, PPh3) ppm. IR (cmÀ1, KBr pellet): 1626 (s),
À
1440 (s), 1394 (m), 1102 (m), 844 (s), 758 (s), 698(s),
m(PF6
)