Synthesis, structure and reactions of coordinatively unsaturated [RuCl(CO)(dppf)(PPh3)]BF4 where dppf is trans-spanning 1,1′-bis(diphenylphosphino)ferrocene

Article abstract of DOI:10.1039/b212096h

A novel coordinatively unsaturated cationic 16-electron ruthenium(II) complex having dppf as a bidentate ligand, [RuCl(CO)(dppf)(PPh ₃)]BF₄ (1·BF₄) is prepared from a hydride complex [RuClH(CO)(dppf)(PPh₃)] and an acetylide complex [RuCl(C≡CPh)(CO)(dppf)(PPh₃)] by treatment with HBF ₄·Et₂O. X-Ray structure analysis of 1 reveals that the complex is the first example of the trans-spanning dppf coordinated to a d⁶ ruthenium(II) centre and the vacant coordination site is sterically shielded effectively by the ferrocene moiety in the solid state. In solution complex 1 is fluxional, allowing the attack of two-electron monodentate ligands such as CO, ^tBuNC and CH₃CN to afford the corresponding six-coordinate octahedral 18-electron species with cis-chelating dppf. The Royal Society of Chemistry 2003.

Full text of DOI:10.1039/b212096h

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Synthesis, structure and reactions of coordinatively unsaturated
[RuCl(CO)(dppf)(PPh3)]BF4 where dppf is trans-spanning
1,1Ј-bis(diphenylphosphino)ferrocene
Hiroyuki Kawano,†a Yoshimasa Nishimurab and Masayoshi Onishi*b
a Graduate School of Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan
b Department of Applied Chemistry, Faculty of Engineering, Nagasaki University,
Nagasaki 852-8521, Japan. E-mail: onishi@net.nagasaki-u.ac.jp
Received 5th December 2002, Accepted 7th March 2003
First published as an Advance Article on the web 18th March 2003
A novel coordinatively unsaturated cationic 16-electron ruthenium() complex having dppf as a bidentate ligand,
[RuCl(CO)(dppf )(PPh3)]BF4 (1ؒBF4) is prepared from a hydride complex [RuClH(CO)(dppf )(PPh3)] and an acetylide
᎐
complex [RuCl(C᎐CPh)(CO)(dppf )(PPh )] by treatment with HBF ؒEt O. X-Ray structure analysis of 1 reveals that
᎐
3
4
2
the complex is the first example of the trans-spanning dppf coordinated to a d6 ruthenium() centre and the vacant
coordination site is sterically shielded effectively by the ferrocene moiety in the solid state. In solution complex 1 is
fluxional, allowing the attack of two-electron monodentate ligands such as CO, tBuNC and CH3CN to afford the
corresponding six-coordinate octahedral 18-electron species with cis-chelating dppf.
behaviour of 1 in solution has also been investigated. The
Introduction
trans–cis fluxionality of the dppf ligand allows the attack of
some additional monodentate ligands to afford six-coordinate
octahedral species with cis-chelating dppf.
Bisphosphine ligands with a large bite angle have been an
attractive subject in recent years, since their complexes show
remarkably different chemical reactivities from the complexes
with monodentate phosphines.1 Especially, late transition-metal
complexes containing bisphosphines spanning trans coordi-
nation sites on a single metal ion have been one of the most
captivating targets in coordination chemistry.2 However, when
potentially trans-spanning bisphosphine ligands with flexible
long chains are allowed to react with a transition metal, the
bisphosphines prefer bridging two metal centres to chelating
on a single metal centre.3 Thus, only a limited number of bis-
phosphines with rigid skeletons, for example, xanthene,4 1,1Љ-
biferrocene,5 and benzo[c]phenanthrene,6 which are structurally
tailored to an exceptionally large bite angle, have exhibited the
trans-spanning bidentate chelation mode. As for the metal
centres, a restricted range of metal ions, such as rhodium(),
iridium(), nickel(), palladium() and platinum() have been
complexed with those rigid trans-spanning bisphosphines,
except for the complexes of 2,11-bis(diphenylphosphino-
methyl)benzo[c]phenanthrene reported by Venanzi and co-
workers.6 It is noteworthy that few ruthenium() complexes
with trans-spanning bidentate bisphosphines have only
occasionally been reported by three independent research
groups.7
Results and discussion
When a dppf-containing hydridoruthenium complex, [RuCl-
H(CO)(dppf )(PPh3)]11 in dichloromethane was treated with an
equimolar amount of HBF4ؒEt2O, the novel five-coordinate
cationic complex 1 was formed in an almost quantitative yield.
The complex 1 was also prepared quantitatively from the
᎐
reaction between an alkynyl complex, [RuCl(C᎐CPh)(CO)-
᎐
(dppf )(PPh3)]11 (2) and HBF4ؒEt2O at Ϫ78 ЊC with release of
phenylacetylene (Scheme 1). The complex 1 was stable to air in
the solid state and also in solution. The stability observed for
1 against dioxygen was in a sharp contrast to that of the co-
ordinatively unsaturated ruthenium species [Cp*Ru(dppf )]ϩ.12
Sato and co-workers have shown that [Cp*Ru(dppf )]ϩ derived
from [Cp*RuCl(dppf )] is unstable in acetone and readily reacts
with dioxygen to give coordinatively saturated [Cp*Ru(η2-O2)-
(dppf )]ϩ. The intermediary [Cp*Ru(dppf )]ϩ species has not
been isolated.
Fluxional behavior of 1 in solution was observed on variable-
temperature (VT) NMR spectra (Fig. 1), similar to the case
of five-coordinate ruthenium() complexes with monodentate
tertiary phosphines.13 At 30 ЊC, the 31P{1H} NMR spectrum
in CD2Cl2 showed two broad signals at δ 52.7 and Ϫ20.2 in an
intensity ratio of 1 : 2. Upon cooling to Ϫ60 ЊC, these signals
turned into a set of a triplet at δ 53.1 and a doublet at δ Ϫ22.1
(J(PP) = 19 Hz). The chemical shifts of the 31P signals
apparently drifted along with the decrease in temperature,
probably showing that some structural isomers of 1 were in fast
equilibrium. The AX2 signal pattern of 1 observed at lower
than Ϫ60 ЊC corresponds to two equivalent phosphorus
atoms of dppf coupled with another phosphorus atom of
triphenylphosphine.
The solid-state molecular structure of 1ؒBF4 was consistent
with its VT-NMR spectra and revealed, notably, a trans-
spanning coordination mode of dppf (Fig. 2). The two cyclo-
pentadienyl rings in dppf are no longer parallel (dihedral angle
= 20.2(3)Њ), and the P–Ru–P bite angle of dppf was enlarged
unusually up to 151.15(5)Њ whereas typically bite angles for
dppf are 90Њ–120Њ.1,14 Although a similar coordination mode
of some dppf-related bisphosphines has been found for Pd()
Although 1,1Ј-bis(diphenylphosphino)ferrocene (dppf )
usually acts as a cis-chelating ligand, it is tolerant for bite angles
from 90Њ to over 120Њ.1 Two types of conformational flexibility
of dppf, a tilting motion of two cyclopentadienyl ring planes to
change their mutual dihedral angle and also torsionally rotative
motion around the axis through the centres of the two rings,
provide a wide range of bite angle allowance for dppf chelation.
Therefore, dppf can serve as a trans-spanning ligand and
thus several complexes of palladium8,9 and rhenium10 with
the
trans-spanning
dppf
have
been
characterized
crystallographically.
We have now prepared a novel coordinatively unsaturated
cationic d6 ruthenium() complex having dppf as a trans-s-
panning bidentate ligand; [RuCl(CO)(dppf )(PPh3)]BF4 (1ؒ
BF4). In the solid state, the dppf moiety spanning two trans
coordination sites effectively protects the vacant site. Fluxional
† Present address: Kogakuin University, 2665-1 Nakano, Hachioji,
Tokyo 192-0015, Japan. E-mail: ft13023@ns.kogakuin.ac.jp
D a l t o n T r a n s . , 2 0 0 3 , 1 8 0 8 – 1 8 1 2
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
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Fig. 2 Molecular structure of 1ؒBF4 with 50% thermal probability
ellipsoids. Hydrogen atoms and a BF4 anion are omitted for clarity.
Selected bond distances (Å) and angles (Њ): Ru(1)–Cl(1) 2.414(1),
Ru(1)–P(1) 2.357(1), Ru(1)–P(2) 2.373(1), Ru(1)–P(3) 2.325(1), Ru(1)–
C(1) 1.862(6), C(1)–O(1) 1.088(6); Cl(1)–Ru(1)–P(1) 89.32(5), Cl(1)–
Ru(1)–P(2) 93.90(5), Cl(1)–Ru(1)–P(3) 89.76(5), Cl(1)–Ru(1)–C(1)
174.7(2), P(1)–Ru(1)–P(2) 151.15(5), P(1)–Ru(1)–P(3) 104.34(5), P(1)–
Ru(1)–C(1) 88.8(2), P(2)–Ru(1)–P(3) 104.33(5), P(2)–Ru(1)–C(1)
85.4(2), P(3)–Ru(1)–C(1) 95.5(2), Ru(1)–C(1)–O(1) 175.9(5). Dihedral
angle between two Cp rings (Њ): 20.2(3).
(BF4)2 (bite angle = 155.9(1)Њ).8 In Sato’s Pd complex, the Pd–
Fe distance is 2.877(2) Å, indicative of a Pd–Fe dative bond,
i.e. a tridentate coordination mode of dppf through the two P
and the Fe atoms. On the contrary, the Ru ؒ ؒ ؒ Fe distance of 1
was 3.2828(8) Å, too long for the Ru and Fe atoms to be bound
to each other, and thus it was concluded that the dppf ligand in
1 was an essentially bidentate bisphosphine ligand. Another
example of trans-spanning dppf has recently been reported for
a dirhenium–dppf complex, [Cl4ReReCl2(dppf )],10 in which
the dppf spans the trans coordination sites of one of the two
square-pyramidal rhenium centres. The dppf bite angles for two
types of the crystals [Cl4ReReCl2(dppf )]ؒnC6H4Cl2 (n = 4 and 0)
are 140.31(18) and 141.99(6)Њ, and the non-bonding Re ؒ ؒ ؒ Fe
distances are 3.585 and 3.539 Å, respectively.
Scheme 1
The UV-vis absorption spectrum of 1 shows a strong charge
transfer band at λmax = 460 nm (ε = 9830 MϪ1cmϪ1) in CH2Cl2. A
similar band was observed also in the diffuse reflectance
spectrum of powdered 1. This band was characteristic for 1;
the related six-coordinate complexes with a cis-chelating dppf,
a neutral [RuClH(CO)(dppf )(PPh3)] and a cationic [RuH(CO)-
(NCCH3)(dppf )(PPh3)]ϩ,15 showed only a weak absorption
band of an intraligand transition in dppf at around λ = 400–500
nm (ε = 230–300 MϪ1cmϪ1). Morokuma16 pointed out that a
weak attractive charge transfer interaction can emerge even
when two atoms are situated at larger interatomic separations
than a bonding distance. The observation of the charge transfer
band for 1 implies that there is some weak attractive interaction
between the Ru and Fe atoms both in solution and in the solid
state. As indicated crystallographically, there was no bonding
between the two metals in the solid state. Nevertheless there is a
weak attractive interaction, somewhat stabilizing the unique
coordination mode of dppf in 1.
In spite of the unique coordination mode of dppf, the
Fig.1 Variable-temperature31P{1H}NMRspectraof1ؒBF4 indichloro-
methane-d2.
geometry of the five-coordinate RuCl(CO)P3 core in
1
resembled closely those in the six-coordinate hydridoruthenium
complexes [RuClH(CO)(dppf )(PPh3)] and [RuH(CO)(NC-
CH3)(dppf )(PPh3)]ϩ. The trans P–Ru–P angles were 151.15(5)Њ
for 1, 154.0(1)Њ for the neutral hydride complex, and 158.6 (1)Њ
for the cationic complex. The cis P–Ru–P angles were 104.34(5)
complexes,8,9 complex 1 is the first example for a ruthenium
complex having a bidentate trans-spanning dppf and its bite
angle is the largest ever reported for dppf complexes in all
geometries except for Sato’s square planar [Pd(dppf )(PPh3)]-
D a l t o n T r a n s . , 2 0 0 3 , 1 8 0 8 – 1 8 1 2
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t
and 104.33(5)Њ for 1, 102.2(1) and 103.1(1)Њ for the neutral
complex, and 99.3(1) and 102.15(9)Њ for the cationic complex.
The Cl–Ru–CO angles were 174.7(2)Њ for 1 and 177.6(5)Њ for the
neutral complex, and the corresponding CH3CN–Ru–CO angle
was 171.4(4)Њ for the cationic complex. The five-coordinate 1,
therefore, seems to have almost the same geometry as the six-
coordinate hydridoruthenium complexes. The conformational
flexibility of dppf1 allowed chelation with a large bite angle
for 1, minimizing the geometry change between the ruthenium
centres for the five-coordinate 1 and of the six-coordinate
hydridoruthenium complexes.
The structure of the five-coordinate 1 is therefore best
described as an octahedral geometry with one vacant coordi-
nation site sterically covered with the ferrocene moiety of the
trans-spanning dppf, on the basis of the following facts. First,
the dppf bite angle of 1 was quite similar to that found in
[Pd(dppf )(PPh3)](BF4)2, and even significantly larger than
that of [Cl4ReReCl2(dppf )]. Secondly, as described above, the
coordination geometry of 1 agreed fairly closely with those
of the six-coordinate hydridoruthenium complexes [RuClH-
(CO)(dppf )(PPh3)] and [RuH(CO)(NCCH3)(dppf )(PPh3)]ϩ.
Thirdly, the lack of a ligand trans to PPh3 strengthens the Ru–
PPh3 coordination. The Ru–PPh3 distance of 1 (2.325(1) Å) is
fairly short compared with the average distance (2.372 Å) of
five-coordinate Ru() complexes in the literature.17 Finally,
although a trigonal bipyramid with three phosphorus atoms on
an equatorial plane might be an alternative description for the
coordination geometry of 1, the dppf bite angle observed for 1
was quite deviated from the ideal value of 120Њ. If the coordi-
nation geometry of 1 was a trigonal bipyramid, the dppf bite
angle should be close to 120Њ since bite angles around 120Њ are
not impossible for dppf because of its flexibility and since
they have been described frequently for d10 trigonal-planar and
tetrahedral complexes.1,18
Similar reactions of 1 with BuNC and CH3CN gave [RuCl-
(CO)(CNtBu)2(dppf )]BF4 (4ؒBF4) and [RuCl(CO)(NCCH3)2-
(dppf )]BF4 (5ؒBF4), respectively. In the case of the nitrile
complex 5, one of the ligating nitriles was weakly bound
and easily dissociated. When 5 was dissolved in chloroform,
liberation of one nitrile molecule occurred, and an insoluble
salt of dicationic bis(µ-chloro)diruthenium [{Ru(µ-Cl)(CO)-
(NCCH3)(dppf )}2](BF4)2 (6ؒ(BF4)2) was deposited from the
solution. The X-ray structure analysis confirmed a chloride-
bridged structure of the dicationic 6 (Fig. 3), which has a centre
of symmetry at the node of the Ru ؒ ؒ ؒ Ru and Cl ؒ ؒ ؒ Cl axes,
and indicated the coordination geometry around each Ru
centre as a slightly distorted octahedron. The dppf ligand had a
cis coordination mode and was situated trans to the bridging
chloro ligands.
Fig. 3 Molecular structure of 6ؒ(BF4)2 with 50% thermal probability
ellipsoids. Hydrogen atoms and BF4 anions are omitted for clarity.
The atoms with an asterisk (*) are generated by the symmetry operator,
Ϫx, Ϫy, Ϫz. Selected bond distances (Å) and angles (Њ): Ru(1)–Cl(1)
2.456(2), Ru(1)–Cl(1)* 2.481(2), Ru(1)–P(1) 2.353(2), Ru(1)–P(2)
2.337(2), Ru(1)–N(1) 2.115(7), Ru(1)–C(1) 1.837(9), N(1)–C(2)
1.14(1), C(2)–C(3) 1.45(2), C(1)–O(1) 1.15(1); Cl(1)–Ru(1)–Cl(1)*
79.74(7), Cl(1)–Ru(1)–P(1) 169.81(8), Cl(1)–Ru(1)–P(2) 87.43(6),
Cl(1)–Ru(1)–N(1) 85.4(2), Cl(1)–Ru(1)–C(1) 91.8(3), Cl(1)*–Ru(1)–
P(1) 92.61(7), Cl(1)*–Ru(1)–P(2) 167.08(7), Cl(1)*–Ru(1)–N(1) 86.6(2),
Cl(1)*–Ru(1)–C(1) 87.1(2), P(1)–Ru(1)–P(2) 100.30(7), P(1)–Ru(1)–
N(1) 87.4(2), P(1)–Ru(1)–C(1) 94.5(3), P(2)–Ru(1)–N(1) 93.9(2), P(2)–
Ru(1)–C(1) 91.8(2), N(1)–Ru(1)–C(1) 173.5(3), Ru(1)–Cl(1)–Ru(1)*
100.26(7), Ru(1)–N(1)–C(2) 170.9(6), N(1)–C(2)–C(3) 177(1), Ru(1)–
C(1)–O(1) 174.6(7). Dihedral angle between two Cp rings (Њ): 4.3(4).
Recent papers reported some five-coordinate Ru() com-
plexes having sterically demanding tridentate trans-spanning
ligands (so-called ‘pincer’ ligands) such as a bis(oxazolinyl)-
19
phenylphosphonite ligand (NOPONMe2
)
and 1,5-bis(di-tert-
butylphosphino)pentanes.20 The bulky substituents of the
reported Ru() complexes, [RuCl2(NOPONMe2)] and [Ru-
HCl{tBu PCH CH ((E)-CH᎐CH)CH PtBu }] (Scheme 2)
᎐
2
2
2
2
2
prevented another ligand from getting access to the vacant
coordination site. The five-coordinate geometries of these
complexes resemble that of 1 with the trans-spanning dppf.
Hence the octahedral coordination geometries in these com-
plexes with the trans-spanning ligands were quite similar
whether the ligands served as bidentate or tridentate.
Experimental
General
Reactions and manipulations were performed under a dry,
oxygen-free nitrogen atmosphere with using Schlenk-type flasks
or a glove box. The starting hydride complex [RuClH(CO)-
(dppf )(PPh3)] was prepared according to the literature.11
Solvents were dried and purified in the usual manner, and
stored under nitrogen. All the other reagents were purchased
and used without further purification. UV-vis and diffuse
reflectance spectra were recorded on a Shimadzu UV-1600 and
a Shimadzu UV-2550 spectrophotometer, respectively. Infrared
spectra were recorded on a JASCO FT-IR 420 spectrometer
using KBr disks. All NMR spectra were obtained on a JEOL
GX-400 spectrometer operating at 400 MHz (1H), 100 MHz
(13C) or 162 MHz (31P). Chemical shifts were reported as
Scheme 2
Complex 1 exhibited its chemical reactivity as an unsaturated
five-coordinate 16-electron species when it reacted with
monodentate ligands. Bubbling CO into the solution of 1 led
readily to incorporation of one CO, yielding the coordinatively
saturated dicarbonyl complex [RuCl(CO)2(dppf )(PPh3)]BF4
(3ؒBF4). The 31P{1H} NMR spectrum of 3 showed an ABX
coupling pattern, which indicated three spectroscopically non-
equivalent phosphorus atoms, i.e. a cis coordination mode of
dppf. The ready conformational change of the dppf from the
trans-form to the cis-chelation mode occurring in solution was
assumed to be associated with the facile fluxional behavior of 1
as described above.
1
δ values relative to SiMe4 for H and 13C, and to 85% H3PO4
for 31P. Elemental analyses were performed at the Center for
Instrumental Analysis, Nagasaki University.
Preparations
[RuCl(CO)(dppf)(PPh3)]BF4 (1ؒBF4). Using a hydridoruthe-
᎐
nium complex [RuHCl(CO)(dppf )(PPh )] or [RuCl(C᎐CPh)-
᎐
3
D a l t o n T r a n s . , 2 0 0 3 , 1 8 0 8 – 1 8 1 2
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᎐
(CO)(dppf )(PPh3)] (2), the complex 1 was obtained in a similar
manner. The following preparation is typical.
30 ЊC): 22.0 (s), δC (CD Cl , 30 ЊC): 194.9 (t, C᎐O, J(CP) =
᎐
2
2
14 Hz), 135–128 (m, overlapped, Ph), 77.5 (br s, C5H4), 77.4 (d,
C5H4, J(CP) = 55 Hz), 75.9 (br s, C5H4), 73.9 (br s, C5H4), 72.7
(br s, C5H4), 60.1 (s, C(CH3)3), 30.0 (s, CH3), IR (KBr): 2222
Under nitrogen, HBF4ؒEt2O (40.8 µL, 0.30 mmol) was added
to a solution of 2 (300 mg, 0.27 mmol) in dichloromethane
(10 cm3). The orange solution immediately turned red and was
stirred for 1 h at room temperature. Addition of diethyl ether
to the concentrated reaction mixture precipitated the product.
The resulting reddish orange powder of 1ؒBF4 was collected,
washed with diethyl ether and dried in vacuo (233 mg, 81%).
1ؒBF4: δH (CDCl3, 30 ЊC): 7.50–6.80 (m, 35H, overlapped, Ph),
5.57 (br s, 2H, C5H4), 5.34 (br s, 2H, C5H4), 4.05 (br s, 2H,
C5H4), 3.43 (br s, 2H, C5H4), δP (CD2Cl2, Ϫ60 ЊC): 53.1 (t, J(PP)
= 19 Hz), Ϫ22.1 (d, J(PP) = 19 Hz), δC(CD2Cl2, 30 ЊC): 196.8
and 2197 cmϪ1 ν(C᎐N), 2018 cm ν(C᎐O), 1058 cm ν(B–F).
Ϫ1
Ϫ1
᎐
᎐
᎐
᎐
Calc. for C45H46BClF4FeN2OP2RuؒCH2Cl2: C, 52.27; H, 4.58;
N, 2.65%. Found: C, 52.76; H, 4.92; N, 2.70%.
[RuCl(CO)(NCCH3)2(dppf)]BF4 (5ؒBF4). Addition of diethyl
ether (10 cm3) to a solution of 1ؒBF4 (50 mg, 0.05 mmol) in
acetonitrile (5 cm3) led to the solid product. One day later, a
yellow powder of 5ؒBF4 was collected, washed with diethyl
ether and dried in vacuo (36 mg, 81%). 5ؒBF4: IR (KBr): 2322
and 2296 cmϪ1 ν(C᎐N), 1987 cm ν(C᎐O), 1083 cm ν(B–F).
Ϫ1
Ϫ1
᎐
᎐
᎐
(q, C᎐O, J(CP) = 12 Hz), 137–127 (m, overlapped, Ph), 82.8 (br
᎐
᎐
᎐
s, C5H4), 81.3 (br s, C5H4), 73.8 (br s, C5H4), 72.0 (br s, C5H4),
Calc. for C39H34BClF4FeN2OP2Ru: C, 52.76; H, 3.86; N, 3.16%.
Found: C, 52.31; H, 4.45; N, 3.73%.
47.9 (t, C5H4, J(CP) = 20 Hz), IR (CH2Cl2): 1968 cmϪ1 ν(C᎐O),
᎐
᎐
1058 cmϪ1 ν(B–F). Calc. for C53H43BClF4FeOP3RuؒCH2Cl2: C,
56.26; H, 3.93%. Found: C, 55.96; H, 4.46%.
[{Ru(ꢀ-Cl)(CO)(NCCH3)(dppf)}2](BF4)2 (6ؒ(BF4)2). The
compound 5ؒBF4 was dissolved in chloroform-d. Orange-
coloured dimeric product 6ؒ(BF4)2 was crystallized quantita-
tively on standing for 1 h. The crystals were collected, washed
with diethyl ether and dried in vacuo. 6ؒ(BF4)2: IR (KBr): 2320
᎐
[RuCl(C᎐CPh)(CO)(dppf)(PPh )] (2). In a Schlenk tube, a
᎐
3
yellow suspension of [RuHCl(CO)(dppf )(PPh3)] (2.33 g, 2.37
mmol) in a mixture of phenylacetylene (1.26 g, 12.39 mmol)
and ethanol (80 cm3) was refluxed under nitrogen. After 24 h,
phenylacetylene (1.15 g, 11.27 mmol) was added to the suspen-
sion and the reaction mixture was allowed to reflux for further
24 h. After cooling, the resulting orange powder of 2 was
collected, washed with ethanol and diethyl ether, successively,
and dried in vacuo (1.86 g, 72%). 2: δH (CDCl3, 30 ЊC): 8.60–6.50
(m, 40H, Ph), 5.37 (br, 1H, C5H4), 4.88 (br, 1H, C5H4), 4.49 (br,
1H, C5H4), 4.30 (br, 1H, C5H4), 4.24 (br, 1H, C5H4), 4.19 (br,
1H, C5H4), 4.16 (br, 1H, C5H4), 3.91 (br, 1H, C5H4), δP (CDCl3,
30 ЊC): 21.7 (dd, J(PP) = 344 and 17 Hz), 20.1 (dd, J(PP) =
Ϫ1
Ϫ1
and 2291 cmϪ1 ν(C᎐N), 1990 cm ν(C᎐O), 1084 cm ν(B–F).
᎐
᎐
᎐
᎐
Calc. for C74H62B2Cl2F8Fe2N2O2P4Ru2: C, 52.48; H, 3.69; N,
1.65%. Found: C, 52.01; H, 4.14; N, 1.60%.
Since the sparingly soluble compound 6ؒ(BF4)2 was
deposited immediately from the chloroform-d solution of
the compound 5ؒBF4, NMR data for 5ؒBF4 and 6ؒ(BF4)2 were
not available.
X-Ray crystallography
Single crystals suitable for structure analyses were obtained by
recrystallization from dichloromethane–hexane for 1ؒBF4ؒ
CH2Cl2 and from chloroform-d solutions of 5ؒBF4 for 6ؒ(BF4)2ؒ
4.3CDCl3. The intensity data were collected on a Rigaku
AFC7S diffractometer equipped with an ADSC Quantum
CCD area detector using graphite monochromated Mo-Kα
radiation (λ = 0.71069 Å). The structures were solved by direct
methods21 for 1 and heavy-atom Patterson methods22,23 for 6.
Calculations were performed using the teXsan crystallographic
software package.24 Details of the disorder and refinement are
given in the CIF.
344 and 22 Hz), Ϫ2.3 (dd, J(PP) = 22 and 17 Hz), δC (CD2Cl2,
᎐
30 ЊC): 200.3 (q, C᎐O, J(CP) = 12 Hz), 139–124 (m, overlapped,
᎐
᎐
᎐
Ph), 115.6 (d, RuC᎐C, J(CP) = 24 Hz), 107.8 (dt, RuC᎐C,
᎐
᎐
J(CP) = 90 and 26 Hz), 81–70 (m, overlapped, C5H4), IR (KBr):
Ϫ1
2105 cmϪ1 ν(C᎐C), 1952 and 1928 cm ν(C᎐O). Calc. for
᎐
᎐
᎐
᎐
C61H48ClFeOP3Ru: C, 67.69; H, 4.47%. Found: C, 68.09; H,
5.15%.
[RuCl(CO)2(dppf)(PPh3)]BF4 (3ؒBF4). Atmospheric CO was
bubbled through a dichloromethane (10 cm3) solution of 1ؒBF4
(50 mg, 0.05 mmol) for 1 h. The reddish orange solution turned
pale yellow at once. After the reaction, the solvent was removed
under reduced pressure. The residue was dissolved in a small
amount of dichloromethane again. A yellow powder of 3ؒBF4
as a CH2Cl2 solvate was precipitated by addition of diethyl
ether, collected on a filter, washed with diethyl ether and dried
in vacuo (30 mg, 51%). 3ؒBF4: δH (CDCl3, 30 ЊC): 7.80–7.10 (m,
35H, overlapped, Ph), 4.84 (br s, 1H, C5H4), 4.74 (br s, 1H,
C5H4), 4.51 (br s, 2H, overlapped, C5H4), 4.49 (br s, 1H, C5H4),
4.46 (br s, 1H, C5H4), 4.45 (br s, 1H, C5H4), 4.35 (br s, 1H,
C5H4), δP (CDCl3): 18.5 (dd, J(PP) = 294 and 24 Hz), 16.8 (dd,
J(PP) = 294 and 29 Hz), 5.6 (dd, J(PP) = 29 and 24 Hz),
Crystal data: for 1ؒBF4: C53H43ClFeOP3RuؒBF4ؒCH2Cl2, M =
1152.95, monoclinic, space group P21/c (no.14), a = 15.684(1),
b = 14.740(2), c = 22.685(2) Å, β = 107.982(1)Њ, V = 4987.9(9) Å3,
Z = 4, Dc = 1.535 g cmϪ3, T = 296 K, µ(Mo-Kα) = 9.05 cmϪ1; no.
of observations 44166, no. of unique reflections 11775 (Rint
=
0.096); R = 0.116 and wR2 = 0.145 for all data, R1 = 0.061 for
I > 2σ(I ) (6055 reflections), GOF = 1.08 for 623 variables.
For 6ؒ(BF4)2: C74H62Cl2Fe2N2O2P4Ru2ؒ2BF4ؒ4.3CDCl3, M =
¯
2206.88, triclinic, space group P1 (no. 2), a = 12.363(1),
b = 13.627(2), c = 14.457(2) Å, α = 99.377(5), β = 110.241(1),
γ = 93.587(2)Њ, V = 2236.0(5) Å3, Z = 1, Dc = 1.639 g cmϪ3, T =
296 K, µ(Mo-Kα) = 12.28 cmϪ1; no. of observations 19548,
no. of unique reflections 9652 (Rint = 0.053). The R values were
not so good because of a significant loss of a CDCl3 molecule
in the crystal when measuring the intensities. The CDCl3
molecules were treated as CHCl3 in the final least-squares
refinement; R = 0.115 and wR2 = 0.258 for all data, R1 = 0.082
for I > 2σ(I ) (6707 reflections), GOF = 1.07 for 551 variables.
CCDC reference numbers 175670 for 1ؒBF4ؒCH2Cl2 and
175671 for 6ؒ(BF4)2ؒ4.3CDCl3.
᎐
᎐
δ (CD Cl , 30 ЊC): 195.2 (m, C᎐O), 191.0 (dt, C᎐O, J(CP) = 102
᎐
᎐
C
2
2
and 16 Hz), 137–127 (m, overlapped, Ph), 78–71 (m, over-
lapped, C5H4), IR (CH2Cl2): 2064 and 2000 cmϪ1 ν(C᎐O), 1084
᎐
᎐
cmϪ1 ν(B–F). Calc. for C54H43BClF4FeO2P3RuؒCH2Cl2: C,
55.94; H, 3.84%. Found: C, 55.40; H, 4.18%.
[RuCl(CO)(CNtBu)2(dppf)]BF4 (4ؒBF4). To a dichlromethane
(10 cm3) solution of 1ؒBF4 (50 mg, 0.05 mmol), tBuNC
(12.5 mg, 0.15 mmol) was added and the mixture was stirred for
1 h. The resulting yellow solution was concentrated under
reduced pressure. Addition of diethyl ether to the residue pre-
cipitated a yellow powder of 4ؒBF4, as a CH2Cl2 solvate, which
was collected on a filter, washed with diethyl ether and dried
in vacuo (39 mg, 74%). 4ؒBF4: δH (CDCl3, 30 ЊC): 7.72–6.87 (m,
20H, Ph), 5.23 (br s, 2H, C5H4), 4.50 (br s, 2H, C5H4), 4.34 (br s,
2H, C5H4), 4.16 (br s, 2H, C5H4), 1.27 (s, 18H, tBu), δP (CDCl3,
See http://www.rsc.org/suppdata/dt/b2/b212096h/ for crystal-
lographic data in CIF or other electronic format.
Acknowledgements
We are grateful to the referees for the suggestive comments
prompting us to examine the UV-vis absorption spectra of
D a l t o n T r a n s . , 2 0 0 3 , 1 8 0 8 – 1 8 1 2
1811

View Article Online
9 M. A. Zuideveld, B. H. G. Swennenhuis, M. D. K. Boele, Y. Guari,
G. P. F. van Strijdonck, J. N. H. Reek, P. C. J. Kamer, K. Goubitz,
J. Fraanje, M. Lutz, A. L. Spek and P. W. N. M. van Leeuwen,
J. Chem. Soc., Dalton Trans., 2002, 2308; O. V. Gusev, A. M. Kalsin,
M. G. Peterleitner, P. V. Petrovskii, K. A. Lyssenko, N. G. Akhmedov,
C. Bianchini, A. Meli and W. Oberhauser, Organometallics, 2002,
21, 3637.
complex 1 and related complexes. We also thank Associate
Professor Isamu Moriguchi of Nagasaki University, for his help
in diffuse reflectance spectrum measurements.
References
10 N. D. Reddy, P. E. Fanwick and R. A. Walton, Inorg. Chem., 2001,
40, 1732.
1 P. Dierkes and P. W. N. M. van Leeuwen, J. Chem. Soc., Dalton
Trans., 1999, 1519 and references therein.
2 C. A. Bessel, P. Aggarwal, A. C. Marschilok and K. J. Takeuchi,
Chem. Rev., 2001, 101, 1031 and references therein.
11 A. Santos, J. Lopez, J. Montoya, P. Noheda, A. Romero and
A. M. Echavarren, Organometallics, 1994, 13, 3605; S. Huh, Y. Cho,
M.-J. Jun, D. Whang and K. Kim, Polyhedron, 1994, 13, 1887.
12 M. Sato and M. Asai, J. Organomet. Chem., 1996, 508, 121; M. Sato
and M. Sekino, J. Organomet. Chem., 1993, 444, 185.
13 P. R. Hoffman and K. G. Caulton, J. Am. Chem. Soc., 1975, 97,
4221.
14 I. R. Butler, W. R. Cullen, T.-J. Kim, S. J. Rettig and J. Trotter,
Organometallics, 1985, 4, 972.
15 S.-H. Han, K.-M. Sung, S. Huh, M.-J. Jun, D. Whang and K. Kim,
Polyhedron, 1996, 15, 3811.
16 K. Morokuma, Acc. Chem. Res., 1977, 10, 294.
17 A. G. Orpen, L. Brammer, F. H. Allen, O. Kennard, D. G. Watson
and R. Taylor, J. Chem. Soc., Dalton Trans., 1989, S1.
18 S. P. Neo, Z.-Y. Zhou, T. C. W. Mak and T. S. A. Hor, J. Chem. Soc.,
Dalton Trans., 1994, 3451.
19 P. Braunstein, F. Naud, A. Pfaltz and S. J. Rettig, Organometallics,
2000, 19, 2676.
20 D. G. Gusev and A. J. Lough, Organometallics, 2002, 21, 2601;
V. F. Kuznetsov, A. J. Lough and D. G. Gusev, Chem. Commun.,
2002, 2432.
21 SIR 92: A. Altomare, M. C. Burla, M. Camalli, M. Cascarano,
C. Giacovazzo, A. Guagliardi and G. Polidori, J. Appl. Crystallogr.,
1994, 27, 435.
22 PATTY: P. T. Beurskens, G. Admiraal, G. Beurskens, W. P. Bosman,
S. Garcia-Granda, R. O. Gould, J. M. M. Smits and C. Smykalla,
The DIRDIF program system, Technical Report of the
Crystallography Laboratory, University of Nijmegen, The
Netherlands, 1992.
23 DIRDIF94: P. T. Beurskens, G. Admiraal, G. Beurskens, W. P.
Bosman, R. de Gelder, R. Israel and J. M. M. Smits, The DIRDIF-
94 program system, Technical Report of the Crystallography
Laboratory, University of Nijmegen, The Netherlands, 1994.
24 teXsan; Crystal Structure Analysis Package, Version 1.10b,
Molecular Structure Corporation, Houston, TX, 1985 and 1999.
3 K. Issleib and G. Hohfeld, Z. Anorg. Allg. Chem., 1961, 312, 170;
A. J. Pryde, B. L. Shaw and B. Weeks, J. Chem. Soc., Chem.
Commun., 1973, 947; A. R. Sanger, J. Chem. Soc., Chem. Commun.,
1975, 893; N. W. Alcock, J. M. Brown and J. C. Jeffrey, J. Chem. Soc.,
Dalton Trans., 1977, 888; C. Crocker, J. Errington, R. Markham,
C. J. Moulton, K. J. Odell and B. L. Shaw, J. Am. Chem. Soc.,
1980, 102, 4373; W. E. Hill, D. M. A. Minhan, J. G. Taylor and
C. A. McAuliffe, J. Am. Chem. Soc., 1982, 104, 6001; S. Onaka,
T. Moriya, S. Takagi, A. Mizuno and H. Furuta, Bull. Chem. Soc.
Jpn., 1992, 65, 1415; J.-F. Mai and Y. Yamamoto, J. Organomet.
Chem., 1998, 560, 223.
4 Y. Guari, G. P. F. van Strijdonck, M. D. K. Boele, J. N. H. Reek,
P. C. J. Kamer and P. W. N. M. van Leeuwen, Chem. Eur. J., 2001,
7, 475.
5 M. Sawamura, H. Hamashima and Y. Ito, Tetrahedron: Asymmetry,
1991, 2, 593.
6 N. J. DeStefano, D. K. Johnson and L. M. Venanzi, Angew. Chem.,
Int. Ed. Engl., 1974, 13, 133; N. J. DeStefano, D. K. Johnson,
R. M. Lane and L. M. Venanzi, Helv. Chim. Acta, 1976, 59,
2674; H.-B. Bürgi, J. Murray-Rust, M. Camalli, F. Caruso and
L. M. Venanzi, Helv. Chim. Acta, 1989, 72, 1293 and references
therein.
7 R. Holderegger and L. M. Venanzi, Helv. Chim. Acta, 1979,
62, 2155; R. Holderegger, L. M. Venanzi, F. Bachechi, P. Mura and
L. Zambonelli, Helv. Chim. Acta, 1979, 62, 2159; G. M. Gray,
A. Varshney and C. H. Duffey, Organometallics, 1995, 14, 238;
R. A. Leising, J. J. Grzybowski and K. J. Takeuchi, Inorg. Chem.,
1988, 27, 1020; W. J. Perez, C. H. Lake, R. F. See, L. M. Toomey,
M. R. Churchill, K. J. Takeuchi, C. P. Radano, W. J. Boyko and
C. A. Bessel, J. Chem. Soc., Dalton Trans., 1999, 2281.
8 M. Sato, H. Shigeta, M. Sekino and S. Akabori, J. Organomet.
Chem., 1993, 458, 199.
D a l t o n T r a n s . , 2 0 0 3 , 1 8 0 8 – 1 8 1 2
1812