C.-B. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 499–506
501
˚
obtained. The solid was recrystallised in the mixture of 1:2
of CH2Cl2 to CH3OH to form a lot of beautiful red crys-
tals. The product was filtered and washed with a mixture
(1:2) of methanol to diethyl ether to give 0.15 g red crystals.
Yield: 58%. Calc. for C48H48Cl4O3P2Ru2: C, 53.44; H,
4.48. Found: C, 52.93; H, 4.51. 31P{1H} NMR: d (ppm)
(k = 0.71073 A) radiation from a rotating-anode generator
operating at 50 kV and 90 mA. All calculations were per-
formed with Siemens SHELXTL PLUS (PC Version) system.
The crystal data and data refinements for complexes 1, 2
and 3 were listed in Table 1.
1
33.18 (s). H NMR: d (ppm) 3.49 (s, 4H), 5.35 (s, 12H),
4. Results and discussion
6.6–7.5 (m, 26H).
These complexes were obtained as air stable crystals.
They were very soluble in CH2Cl2 and CHCl3, partially sol-
uble in benzene, toluene, and alcohol. Their solutions were
air sensitive. In complex 1, a singlet at 33.18 ppm in
31P{1H} NMR spectrum indicated that the two phospho-
3.2. [(g6-C6H6)RuCl(l-BDNA)(l-Cl)RuCl(g6-C6H6)]-
(BF4) 2
A
suspension of [(g6-C6H6)RuCl2(l-BDNA)Ru(g6-
1
C6H6)Cl2] (0.102 g, 0.1 mmol) and AgBF4 (0.040 g,
0.20 mmol) in the mixture solvent of CH2Cl2 (7 ml) and
methanol (10 ml) was stirred for 2 h at room temperature,
and then precipitated AgCl was filtered off. The filtrate was
evaporated to about 6 ml in vacuum and was put in refrig-
erator over night. A lot of brown red crystals were formed.
The crystals was filtered, washed for two times with meth-
anol, and then dried in vacuum. 0.0675 g red crystals were
obtained (yield 63%). Calc. for C49H46BCl3F4OP2Ru2: C,
53.11; H, 4.18. Found: C, 52.95; H, 4.21. 1H NMR
(CDCl3) d (ppm): 3.48 (s, 4H), 5.85 (s, 12H), 6.59–7.66
(m, 26H). 31P{1H} NMR: d (ppm) 29.48.
rus atoms in the complex were equivalent. In H NMR
spectrum, a singlet at d 3.49 ppm should be from the meth-
ylene protons in BDNA. The protons on the coordinated
benzene ring showed a singlet at 5.35 ppm. Results of ele-
mental analysis indicated that the complex was a binuclear
compound containing two ruthenium atoms to share a
BDNA (Scheme 2 D) and it was consistent with the results
of X-ray diffraction of single crystal showed in Table 2, and
Fig. 1.
If [(g6-C6H6)RuCl2]x complex was used as a starting
materials, two metal atoms bridged by one diphosphine
ligand was generally formed by using the diphosphine with
the flexible backbone as a ligand, such as Ph2P(CH2)nPPh2
(n = 1–4) [13,14]. However, [(g6-C6H6)RuCl2]x reacted
with a rigid backbone diphosphine ligand, the diphos-
phine-bridged complex would be difficult to form and it
was generally considered as a contaminating material or
a side-product in the process of forming [RuCl(g6-C6H6)-
(P-P)]+ (P-P = bidentate phosphine) [15]. Faraone [14]
reported that the reaction of {(g6-C6H6)RuCl2[l-Ph2P-
(CH2)nPPh2]RuCl(g6-C6H6)2} with Ph2P(CH2)nPPh2 gave
a mononuclear complex {(g6-C6H6)RuCl-[Ph2P(CH2)n-
PPh2]}+ as the principal product. James [15] also
described the similar results as FaraoneÕs and thought that
bridged species was an intermediate to form the cationic
mononuclear complex {(g6-C6H6)RuCl[Ph2P(CH2)n PPh2]}+.
However, [(g6-C6H6)RuCl2(l-BDNA)RuCl2(g6-C6H6)] did
not further react with the diphosphine BDNA in methanol
at room temperature. Complex 1 appeared to be very stable
under this reaction condition. In spite of ruthenium and
BDNA was mixed in the molar ratio of 1:1 and the reaction
time was extended over 48 hours, the excess ligand did not
react further with the binuclear complex 1 to form the mono-
meric complex [RuCl(g6-C6H6)(P-P)]Cl. If the coordinated
benzene was thought to be tridentate ligand, complex 1 had
a stable structure of six coordination atoms. On the other
hand, the rigid backbone of BDNA and the formation of a
large 8-membered chelating ring would be unfavourable for
the substitution of chloride with one phosphorus atom at
room temperature. Yamamoto synthesized mononuclear
[(arene)RuCl(BDNA)]+ by reacting the coordination unsatu-
rated [(arene)RuCl]+ with BDNA [22].
3.3. [(g6-C6H6)RuCl(l-BDNA)2RuCl(g6-C6H6)](BF4)2 3
0.063 g (0.25 mmol) of [RuCl2(g6-C6H6)]x and 0.27 g
(0.5 mmol) of BDNA were suspended in 30 ml methanol.
The mixture was refluxed for 5 h, the solid were gradually
dissolved and the color of solution slowly changed to yel-
lowish brown with a trace amount of white precipitate.
At the end of reaction, the solution was filtered to remove
the white precipitate and 0.097 g (0.5 mmol) of AgBF4 was
added to the filtrate. After the mixture was stirred for 2 h at
room temperature, it was filtered to remove AgCl and the
volume of the filtrate was reduced to ca. 3 ml under vac-
uum. The concentrated solution was put in refrigerator
overnight to form lots of orange microcrystals. The prod-
uct was filtrated, washed with the mixture solution (1:2)
of methanol and diethyl ether, and dried under vacuum
to give 0.128 g (63%) orange microcrystals. Anal. Calc.
for C86H76B2Cl6F8P4Ru2: C, 56.69; H, 4.20. Found: C,
1
56.43; H, 4.17. H NMR: d (ppm) 4.58 (d, 8H), 5.30 (s,
12H), 6.56–7.60 (m, 52H). 31P{1H} NMR: d (ppm) 38.82
(s). 3 could be also prepared by the reaction of 1 with
BDNA under the same reaction conditions.
3.4. Crystallography
The crystals were grown from solvent mixtures of
CH2Cl2, CH3OH and Et2O. They were covered with a thin
layer of paraffin oil as a precaution against the possible
decomposition in air, and mounted on a Rigaku RAXIS
IIC imaging-plate diffractometer. Intensity data were
collected using graphite-monochromatized Mo Ka
The reactions of complex 1 with AgBF4 give the com-
plex 2 as the major product (Scheme 3). The data of
Yu, Chang-Bin
