Synthesis and structures of metallocene complexes of iron(II) and ruthenium(II) derived from 9,9′-spirobifluorene

Article abstract of DOI:10.1016/j.jorganchem.2005.10.004

Reaction between 9,9′-spirobifluorene and [CpM]⁺ (where M = Fe and Ru) equivalents gives the complexes [CpRu(η ⁶-SBF)][PF₆] (1), [(CpRu)₂(η ⁶,η⁶-SBF)][PF₆]₂ (2) and [(CpFe)₂(η⁶,η⁶-SBF)][PF ₆]₂ (3), respectively. Single crystal X-ray structures of 1 and 3 show that the metal atoms exhibit distorted η ⁶-coordination to SBF phenyl moieties primarily as a consequence of steric interactions between Cp and SBF. The structure of 3 contains each of the possible C₂ enantiomers whereas NMR spectroscopy shows signals consistent with a 1:1 mixture of C₂ and C₁ stereoisomers for both 2 and 3. In conjunction with electrochemical data the observations are consistent with SBF acting as a molecule containing two independent biphenyl moieties.

Full text of DOI:10.1016/j.jorganchem.2005.10.004

Journal of Organometallic Chemistry 691 (2006) 711–716
www.elsevier.com/locate/jorganchem
Synthesis and structures of metallocene complexes of iron(II)
0
and ruthenium(II) derived from 9,9 -spirobifluorene
*
Richard E. Douthwaite , Neil Guillaume, Adrian C. Whitwood
Department of Chemistry, University of York, Heslington, York, N Yorkshire YO10 5DD, UK
Received 25 July 2005; received in revised form 4 October 2005; accepted 4 October 2005
Available online 9 November 2005
Abstract
0
+
6
Reaction between 9,9 -spirobifluorene and [CpM] (where M = Fe and Ru) equivalents gives the complexes [CpRu(g -SBF)][PF
6
] (1),
6
6
6
6
[
(CpRu) (g ,g -SBF)][PF ] (2) and [(CpFe) (g ,g -SBF)][PF ] (3), respectively. Single crystal X-ray structures of 1 and 3 show that the
2
6 2
2
6 2
6
metal atoms exhibit distorted g -coordination to SBF phenyl moieties primarily as a consequence of steric interactions between Cp and
SBF. The structure of 3 contains each of the possible C enantiomers whereas NMR spectroscopy shows signals consistent with a 1:1
mixture of C and C stereoisomers for both 2 and 3. In conjunction with electrochemical data the observations are consistent with
2
2
1
SBF acting as a molecule containing two independent biphenyl moieties.
2005 Elsevier B.V. All rights reserved.
ꢀ
0
Keywords: Metallocene; Sandwich complexes; 9,9 -Spirobifluorene; Iron; Ruthenium
1
. Introduction
incorporating this motif into molecular based solids.
Metallocene and related half sandwich complexes have
been at the vanguard of organometallic chemistry for over
50 years possessing a myriad of uses and applications
encompassing synthetic, catalytic, medicinal, and materials
science [12]. We therefore initiated a short study to investi-
gate the synthesis of SBF p-complexes to common metallic
fragments that exhibit coordination to arenes.
We have recently been interested in the chemistry of
0
9
,9 -spirobifluorene (SBF) (Fig. 1) and its derivatives pri-
marily because of its intriguing electronic properties and
aesthetic appeal. SBF can perhaps structurally best be
described as two orthogonal biphenyl moieties fused at a
central carbon atom. Electronically SBF has been charac-
terised as Ôp–r–pÕ [1,2], where each biphenyl can be consid-
ered essentially independent and this is reflected in the
reactivity where, for example, electrophilic substitution
Here, we report reactions between SBF and precursors
for the metallic fragments Cr(CO) , Mo(CO) , and
3
3
+
[CpM] (where M = Fe and Ru). Complexes described
herein represent the first metal complex derivatives of
SBF where SBF acts as a p-ligand.
0
0
occurs regioselectively at the 2,2 followed by 7,7 positions
3,4]. The structure and potentially interesting electronic
[
properties have previously prompted the synthesis and
study of compounds for molecular electronic and optical
applications [5–8], molecular recognition [9,10], and a
derivative of SBF has also recently been incorporated into
hydrogen-bonded networks that exhibit large porosity [11].
Our initial interest in SBF was to study its potential as a
p-arene ligand to metal moieties with the ultimate aim of
2. Results and discussion
We initially investigated reactions between 4 equivalents
of M(CO) (where M = Cr and Mo) and SBF under condi-
6
tions analogous to those used for the synthesis of
6
M(CO) (g -arene) complexes, including those derived
3
from biphenyl [13–15].
*
Reaction between Mo(CO)6 and SBF in decane at
150 ꢁC for 48 h lead only to deposition of a metallic deposit
Corresponding author.
E-mail address: red4@york.ac.uk (R.E. Douthwaite).
0
022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.10.004

712
R.E. Douthwaite et al. / Journal of Organometallic Chemistry 691 (2006) 711–716
0
Fig. 1. Structure of 9,9 -spirobifluorene.
1
and recovery of at least 90% SBF on workup. H NMR
analysis of crude reaction mixtures did not indicate any
SBF containing species other than SBF, and IR spectros-
copy showed bands in the carbonyl region corresponding
only to Mo(CO) . Similar results were also obtained using
6
the other common precursor Mo(CO) (C H CN) which
3
2
5
3
can be used to coordinate arenes under milder reaction
conditions [16].
However, reaction between 4 equivalents of Cr(CO)6
and SBF in refluxing ditertbutyl ether and THF for 3 days
did indicate that a p-complex of SBF had formed. Filtra-
tion of the reaction mixture to remove metallic deposits
gave a yellow supernatant that on addition of hexane,
and cooling to ꢀ20 ꢁC, precipitated a yellow solid. IR spec-
troscopy in chloroform showed bands at 1967, 1898 and
ꢀ
1
1
793 cm that do not correspond to those of Cr(CO)6
Fig. 2. (a) Molecular structure of a cation of 1. (b) Views of the cation
showing distortion in the SBF moiety. Ellipsoids are at 50% probability
and hydrogen atoms have been removed for clarity.
and are indicative of a Cr(CO) moiety. In addition to a
peak for SBF, mass spectrometry also gave low intensity
3
peaks at m/z 452 and 588 that correspond to the composi-
1
tions SBFCr(CO) and SBF(Cr(CO) ) , respectively. H
3
3 2
NMR spectroscopy gave a spectrum containing signals
corresponding to SBF and also several low intensity signals
spanning the range d 4.1–8.0 ppm of which the high field
signals are indicative of protons from a p-arene complex.
Purification was attempted using recrystallisation, sublima-
tion, and column chromatography, however in no case was
attributable to the Cp moiety, twelve resolved signals of
cumulative relative intensity 16H that correspond to the
SBF protons. Mass spectrometry gave a single set of peaks
centred at 483 with an isotopic distribution pattern consis-
+
tent with the cation [CpRu(SBF)] . A single crystal diffrac-
tion study also confirmed the proposed formulation. The
structure of the cation is shown in Fig. 2 and select data
are given in Table 1.
1
a sample free from SBF obtained, and as judged by H
NMR spectroscopy the putative Cr(CO)3 complexes
decompose in minutes in solution and over several hours
in the solid state.
The asymmetric unit of 1 contains two equivalents of the
complex, however there is no significant difference between
the structures of the two cations. As shown in Fig. 2, SBF
Due to the problems encountered in the purification and
6
stability of the M(CO) derivatives, other metal moieties
is coordinated to the CpRu moiety as g -SBF, however as
3
were sought that are known to coordinate strongly to a
range of arene molecules. Arene complexes, including
biphenyl, of the fragments [Cp(Cp*)M] (where M = Fe
judged by bond lengths and angles there is significant steric
congestion between CpRu and SBF moieties. Perhaps the
clearest indicators are the Ru–CSBF and Ru–CCp bond
lengths, and the angles about the spiro carbon atom
C(1). The Ru–C bonds closest to the phenyl moiety
C(14)–C(19) exhibit the greatest bond lengths (cf. Ru(1)–
+
and Ru) have been previously investigated particularly
with respect to materials applications [17–21]. Conve-
niently the complex [CpRu(CH CN) ][PF ] facilitates coor-
3
3
6
+
˚
dination of [CpRu] under mild conditions [22] and
therefore stoichiometric reactions between SBF and 1–4
equivalents of [CpRu(CH CN) ][PF ] were investigated.
C(2) = 2.251(5) and Ru(1)–C(4) = 2.169(5) A), and the
biphenyl moiety containing C(14)–C(25) is tilted away
from the CpRu group (cf. C(2)–C(1)–C(14) = 117.9(4)
and C(2)–C(1)–C(25) = 109.4(1)ꢁ). In addition the two
planes defined by the Cp and C(2)–C(7) phenyl group,
respectively, are not parallel, the centroids subtending at
an angle of 176.9ꢁ at Ru(1).
3
3
6
Reaction between 1 equivalent of [CpRu(CH CN) ]-
3
3
[
PF ] and SBF in dichloromethane at 50 ꢁC gave, after
6
6
workup, [CpRu(g -SBF)][PF ] (1) in good yield. Com-
6
pound 1 is soluble in chlorinated solvents and acetonitrile
1
and as a solid is stable in air. H NMR spectroscopy of 1
Reactions were also investigated between >1 equivalent
showed, in addition to a single resonance at d 5.22 ppm
of [CpRu(CH CN) ][PF ] and SBF. A potential complica-
3 3 6

R.E. Douthwaite et al. / Journal of Organometallic Chemistry 691 (2006) 711–716
713
Table 1
Reaction between SBF and 3 or 4 equivalents of
CpRu(CH CN) ][PF ] gave complex and excess
[CpRu(CH CN) ][PF ] as judged by H NMR spectros-
˚
Selected bond lengths (A) and angles (ꢁ) for complex 1
[
2
3
3
6
1
C(26)–Ru(1) 2.194(6) C(2)–C(1)–C(14)
C(27)–Ru(1) 2.198(6) C(2)–C(1)–C(25)
C(28)–Ru(1) 2.170(6) C(13)–C(1)–C(25)
C(29)–Ru(1) 2.150(6) C(13)–C(1)–C(14)
C(30)–Ru(1) 2.167(6) C(2)–C(1)–C(13)
C(2)–Ru(1)
C(3)–Ru(1)
C(4)–Ru(1)
C(5)–Ru(1)
C(6)–Ru(1)
C(7)–Ru(1)
117.9(4)
109.4(4)
111.8(4)
115.3(4)
101.0(4)
101.7(4)
176.9
3
3
6
copy and mass spectrometry. Although several examples
exist, where both phenyl groups of biphenyls can coordi-
6
+
nate g to metal moieties, including [CpRu] derivatives
[21], these complexes can minimise steric interaction via
Cipso–Cipso bond rotation. Therefore, in the case of the
rigid SBF motif, tri- and tetra addition is presumably pre-
vented by unfavourable steric interactions between metal
and SBF moieties. (vide infra).
2.251(5) C(14)–C(1)–C(25)
2.210(5) Cpcentroid–Ru(1)–(C(2)–C(7))centroid
2.169(5)
2.190(5)
2.215(5)
2.230(5)
In addition to the many complexes of the type
6
+
[
CpRu(g -arene)] some analogous iron complexes are
also known including one derived from biphenyl [23–26],
however the harsh synthetic routes to this class of com-
plexes has rendered them less well developed. Using a route
reported by Astruc [25] for the synthesis of the biphenyl
6
6
complex [(CpFe) (g ,g -C H )][PF ] , SBF, ferrocene,
2
12 10
6 2
Al, and AlCl were stirred as a viscous melt at 130 ꢁC for
3
1
6 h. On work up and ion exchange the complex
6
6
[
(CpFe) (g ,g -SBF)][PF ] (3) was isolated as a yellow
2 6 2
powder in good yield. Complex 3 is stable in air, in solution
and in the solid state and is soluble in polar organic sol-
1
vents. H NMR spectroscopy, mass spectrometry, and ele-
mental analysis again showed that (3) comprised closely to
Fig. 3. Physically reasonable isomers resulting from addition of two metal
fragments to SBF and the number of signals expected from SBF hydrogen
atoms in the H NMR spectrum.
1
a 1:1 mixture of C and C isomers. Attempts to separate
2
1
the isomers using column chromatography or recrystallisa-
tion did not give appreciable separation, however from
recrystallisation of an acetonitrile solution of 3 a few single
crystals of complex (3a) could be isolated. The structure of
a dication is shown in Fig. 4 and select data are given in
Table 2.
tion of multiple addition to SBF is the possible formation
of stereoisomers. For example Fig. 3 shows the point group
and number of signals expected from SBF in the H NMR
spectrum of physically reasonable isomers resulting from
addition of two metal moieties. The isomers shown in
Fig. 3 minimise steric interactions, and are favoured ther-
modynamically over isomers that have both Lewis acidic
metal fragments coordinated to a single biphenyl moiety.
1
Fig. 4 shows that each biphenyl moiety of SBF exhibits
g coordination to a CpFe group and that the dication is a
6
chiral C enantiomer. The overall structure contains a race-
2
It should also be noted that the C isomer is chiral.
mic mixture of both C isomers that are related through a
2
2
Reaction between SBF and
2
equivalents of
centre of inversion. Inspection of the packing diagram does
not reveal any close contacts between cations; the cations
[
1
CpRu(CH CN) ][PF ] in dichloromethane at 60 ꢁC for
3
3
6
6
6
6 h gave [(CpRu) (g ,g -SBF)][PF ] (2) in moderate
being separated by PF anions that exhibit hydrogen bond-
2
6 2
6
yield. In chlorinated solvents complex 2 is markedly less
soluble than 1 but is reasonably soluble in acetonitrile
and as a solid 2 is stable in air for weeks. The H NMR
spectrum of 2 showed three signals in a 2:1:1 ratio that
are assigned to Cp protons, and a complex set of overlap-
ping signals attributable to SBF moieties. With the aid of
ing between the Cp and SBF hydrogen and fluorine atoms,
respectively.
1
It can be clearly seen from Fig. 4 that the SBF moiety is
significantly distorted from its equilibrium molecular struc-
ture presumably as a consequence of steric interactions
between CpFe and SBF phenyl moieties. The two planes
defined by the biphenyl moieties of 3a are twisted 10ꢁ rela-
tive to each other, giving an acute angle of 80ꢁ (Fig. 4(b)),
whereas for 1 these planes are essentially perpendicular
(Fig. 2(b)). Furthermore, a tilting distortion similar to 1
is observed, perhaps best exemplified by the compressed
angle C(13)–C(1)–C(25) = 101.8ꢁ subtended at the spiro
carbon C(1). Again similar to 1 the Fe–CSBF and Fe–CCp
bonds also reflect these distortions exhibiting longer Fe–
C bonds for carbon atoms closest to the spiro centre.
Attempts to prepare tri and tetra addition complexes of
SBF from reaction between 3 and 1 and 2 equivalents of
[CpRu(CH CN) ][PF ], respectively, in chlorinated
2
-D homo- and heteronuclear NMR spectroscopy it is pos-
sible to distinguish signals corresponding to two SBF con-
taining molecules. Mass spectrometry gave major signals
+
corresponding to [(CpRu) (SBF)][PF ] and [(CpRu)2-
(
2
6
+
SBF)] and elemental analysis was consistent with the
composition [(CpRu) (SBF)][PF ] . The data strongly sug-
2
6 2
gests that the product contains a 1:1 mixture of C and C
1
2
isomers shown in Fig. 3. Numerous attempts to separate
the isomers using various chromatography techniques,
including ion exchange chromatography, and fractional
crystallisation have to date proved fruitless. Growth of sin-
gle crystals has also proved elusive.
3
3
6

714
R.E. Douthwaite et al. / Journal of Organometallic Chemistry 691 (2006) 711–716
perature these complexes exhibit an irreversible reduction
and EC process indicative of loss of a CpM moiety at
ꢀ
1.80 and ꢀ1.32 V, respectively [21,25]. However, at
6 6 2+
ꢀ
38 ꢁC in DMF [(CpFe) (g ,g -biphenyl)] does exhibit
2
a reversible two electron process at E = ꢀ1.12 V [25]
1/2
2+
6
6
and at 25 ꢁC [(CpRu) (g ,g -biphenyl)] exhibits a single
2
electron reversible process E = ꢀ1.42 V but no second
1
/2
reduction down to ꢀ2.5 V [21].
Cyclic voltammetry of ruthenium complexes 1 and 2
showed that both exhibit irreversible reduction waves at
ꢀ
1.71 and ꢀ1.76 V at scan rates between 10 and
ꢀ1 6
n
5
00 mV s . It has been reported that for [(CpM) (g -
n+
biphenyl)] (where M = Fe and Ru) that there is a solvent
dependence on the reversibility of electron transfer, how-
ever we observed irreversible processes in both MeCN
and DMF at 25 and ꢀ40 ꢁC for the latter. Complex 3
exhibits a quasi-reversible process at E = ꢀ1.23 V with
1
/2
ꢀ
1
DE = 38 mV at 100 mV s that increases slightly with
p
increasing scan rate. In comparison to an internal reference
of ferrocene the DE value and current intensities indicate
p
that this is likely a two electron process similar to that
6
6
2+
observed for [(CpFe) (g ,g -biphenyl)] [25].
2
3. Conclusions
Fig. 4. (a) Molecular structure of complex 3a. (b) Views of 3a showing
distortions in SBF moiety. Ellipsoids are at 50% probability and hydrogen
atoms have been removed for clarity.
We have shown that SBF can act as a p-ligand to a select
number of transition metals and have structurally charac-
terised complexes resulting from addition of one metal,
and an isomer resulting from addition of two metal moie-
ties to SBF, respectively. NMR spectroscopy of products
Table 2
+
˚
resulting from addition of two [CpM] (M = Fe, Ru) units
Selected bond lengths (A) and angles (ꢁ) for complex 3a
indicates that the synthesis of the two physically reasonable
C(26)–Fe(1)
C(27)–Fe(1)
C(28)–Fe(1)
C(29)–Fe(1)
C(30)–Fe(1)
C(8)–Fe(1)
C(9)–Fe(1)
C(10)–Fe(1)
C(11)–Fe(1)
C(12)–Fe(1)
C(13)–Fe(1)
C(31)–Fe(2)
C(32)–Fe(2)
C(33)–Fe(2)
C(34)–Fe(2)
C(35)–Fe(2)
C(20)–Fe(2)
C(21)–Fe(2)
2.058(3)
2.059(3)
2.055(3)
2.054(3)
2.066(3)
2.112(2)
2.087(2)
2.080(3)
2.087(3)
2.114(2)
2.120(2)
2.058(3)
2.052(3)
2.050(3)
2.053(3)
2.054(3)
2.112(2)
2.087(3)
C(22)–Fe(2)
C(23)–Fe(2)
C(24)–Fe(2)
C(25)–Fe(2)
C(2)–C(1)–C(14)
C(2)–C(1)–C(25)
C(13)–C(1)–C(25)
C(13)–C(1)–C(14)
C(2)–C(1)–C(13)
C(14)–C(1)–C(25)
Cpcentroid–Fe(1)–(C(8)–
C(13))centroid
2.075(3)
2.088(2)
2.111(2)
2.111(2)
isomers of C and C symmetry (Fig. 3) is unselective. This
1
2
observation indicates that the addition of one metal does
not affect the regioselectivity of addition of the second,
which further corroborates the hypothesis that SBF exhib-
its reactivity and properties reflective of two independent
biphenyl groups.
117.5(2)
116.54(19)
101.81(19)
117.96(19)
101.21(18)
101.44(18)
176.9
4
. Experimental
4
.1. General procedures
Cpcentroid–Fe(2)–(C(20)–
C(25))centroid
177.5
80
BiphenyFe(1)–BiphenylFe(2) twist
All manipulations were performed under argon using
standard Schlenk techniques unless stated otherwise. All
solvents were dried over the appropriate drying agent
and distilled under dinitrogen [27]. Reagents and solvents
were purchased from Aldrich, Acros or Lancaster and used
0
as supplied. 9,9 -spirobifluorene [2], Mo(CO) (C H CN)
3
2
5
3
solvents gave no reaction before decomposition of
CpRu(CH CN) ][PF ], which is perhaps unsurprising
[28] and [CpRu(MeCN) ][PF ] [29] were prepared using lit-
3 6
[
erature procedures. IR spectra were recorded on an Avatar
370 FT-IR spectrometer. NMR spectra were recorded at
3
3
6
given the steric congestion evident from the structure of 3a.
The electrochemistry of complexes 1–3 was investigated
to determine if reversible reduction(s) occur and to probe
any potential interaction between metal centres in 2 and
1
13
probe temperature on a JEOL ( H, 270 MHz;
C,
1
1
68 MHz), Br u¨ ker AMX ( H, 300 MHz), JEOL ( H,
400 MHz; C, 100.5 MHz), or DMX ( H, 400 MHz; C,
100.5 MHz). Chemical shifts are described in parts per mil-
1
3
1
13
6
+
3
[
.
Previous studies on [(CpRu)(g -biphenyl)]
and
6
6
2+
(CpFe) (g ,g -biphenyl)] have shown that at room tem-
lion downfield shift from SiMe and are reported consecu-
2
4

R.E. Douthwaite et al. / Journal of Organometallic Chemistry 691 (2006) 711–716
715
1
3
tively as position (dH or d ), relative integral, multiplicity
C (68 MHz, CD CN) C isomer 145.2, 139.3, 132.5,
C
3
2
(
s, singlet; d, doublet; t, triplet; m, multiplet), coupling con-
131.9, 126.5, 126.3, 120.2, 104.3, 85.1, 83.3, 83.2 (CCp),
1
3
stant (J/Hz) and assignment. C HSQC, PENDANT and
Gradient HMBC experiments were performed using stan-
dard Br u¨ ker pulse sequences. All spin splitting values for
80.4, 80.7 (Cspiro not found). C isomer: poor signal to
1
noise and significant overlap prevented unambiguous
1
3
determination of C signals.
1
3
H NMR spectra are J(H–H). Mass spectra were recorded
6
6
on LCQ Classic or AutoSpec spectrometers. Electrospray
ionisation (ESI) was recorded using acetonitrile as the
mobile phase. Major fragments were given as percentages
of the base peak intensity (100%). Cyclic voltammetry data
were collected using a Voltalab radiometer analytical
PST050 and Pt working and auxiliary electrodes. Potentials
were referenced to SCE separated from the test solution
using a fine frit. Test solutions comprised electrolyte
4.4. Synthesis of [(CpFe) (g ,g -SBF)][PF ] (3)
2 6 2
A 50 mL two-necked round-bottomed flask was charged
with SBF (0.608 g, 1.92 mmol), Al powder (0.211 g,
7.82 mmol), ferrocene (7.152 g, 38.44 mmol), and AlCl3
(5.128 g, 38.46 mmol). The reactants were then stirred
and heated at 130 ꢁC as a viscous melt for 16 h. On cooling
to room temperature the dark green solid was hydrolysed
n
ꢀ4
ꢀ1
(
0.1 M Bu NBF in DMF) and analyte (10 mol L ).
with deionised water (80 mL) and concentrated NH OH
4
4
4
added until pH 10 was obtained giving a white precipitate
and yellow supernatant. After filtration the yellow solution
6
4
.2. Synthesis of [(CpRu)(g -SBF)][PF ] (1)
6
was treated with 40% HPF (0.34 mL) to give crude 3 as a
6
An ampoule was charged with [CpRu(MeCN) ][PF ]
yellow precipitate. The precipitate was dissolved in acetoni-
3
6
(
101 mg, 0.23 mmol), SBF (81 mg, 0.26 mmol) and dichlo-
romethane (20 mL). The resulting solution was stirred at
0 ꢁC for 16 h and the volatiles removed from the resulting
trile (75 mL) filtered and dried over MgSO overnight. The
4
volatiles were removed under reduced pressure and washed
with diethyl ether (2 · 20 mL) to give 3 as an orange solid.
Yield = 1.453 g (89.1%). Anal. Calc. for C H F P Fe :
5
solution to give a brown solid. The solid was rinsed with
diethyl ether (2 · 20 mL) to give 1 as a grey solid.
Yield = 130 mg (93%). Anal. Calc. for C H F PRu: C,
3
5
26 12
2
2
C, 49.56; H, 3.09. Found: C, 49.65; H, 3.15%. MS (ESI);
+
2+
1
m/z: 437 (M ꢀ PF ), 279 (M ꢀ 2(PF )). H NMR
3
0
21
6
6
6
5
7.42; H, 3.37. Found: C, 57.35; H, 3.41%. MS (ESI);
(270 MHz, CD CN) C isomer d 8.31 (d, J = 6.3, 2H),
3 2
+
1
m/z: 483.5 (M ꢀ PF ) H NMR (270 MHz, CD CN) d
7.86 (m, 2H), 7.78 (m, 2H), 7.56 (m, 2H), 7.14 (d,
J = 6.3, 2H), 6.35 (t, J = 6.3, 2H), 5.94 (m, 2H), 5.46 (d,
6
3
8
.02 (d, J = 10.4, 2H), 7.94 (d, J = 9.0, 1H), 7.60 (t,
J = 8.1, 1H), 7.54 (t, J = 8.1, 1H), 7.45 (t, J = 8.1, 1H),
.39 (m, 2H), 7.07 (m, 3H), 6.75 (d, J = 8.1, 1H), 6.49 (d,
J = 8.1, 1H), 6.17 (t, J = 6.8, 1H), 5.85 (t, J = 6.8, 1H),
J = 6.0, 2H), 4.75 (s, 10H); C isomer d 8.19 (d, J = 7.0,
1
7
1H), 8.09 (d, J = 7.0, 1H), 8.0–7.8 (m, 2H), 7.6–7.7 (m,
3H), 7.3–7.5 (m, 3H), 7.00 (t, J = 7.0, 1H), 6.87 (d,
J = 7.0, 1H), 6.61 (d, J = 7.0, 1H), 6.25 (d, J = 7.0, 1H),
6.03 (t, J = 7.0, 1H), 5.66 (d, J = 7.0, 1H) 4.87 (s, 5H),
4.76 (s, 5H). (68 MHz, CD CN) C isomer d 144.3, 139.8,
1
3
5
.62 (d, J = 6.8, 1H), 5.22 (s, 5H). C NMR (68 MHz,
CD CN) d 148.6, 147.8, 147.3, 144.3, 142.9, 141.7, 140.4,
3
1
1
8
37.0, 131.2, 129.7, 129.1, 129.0, 128.7, 128.0, 124.9,
23.0, 122.7, 121.0, 120.8, 104.3, 83.4, 83.2, 81.4,
1.0(CCp), 78.3. (Cspiro not found).
3
2
132.1, 131.5, 126.8, 124.4, 114.0, 102.1, 87.5, 85.9, 82.9,
81.3, 79.0 (CCp) (Cspiro not found); C isomer d 149.4,
1
1
44.2, 141.5, 138.9, 131.0, 130.5, 129.9, 128.4, 128.0,
126.5, 124.6, 124.2, 124.0, 123.8, 121.4, 121.0, 86.3, 85.7,
4.4, 83.8, 83.5, 83.2, 82.6, 81.0, 79.5 (CCp), 79.1 (CCp
6
6
4
.3. Synthesis of [(CpRu) (g ,g -SBF)][PF ] (2)
2 6 2
8
)
An ampoule was charged with [CpRu(MeCN) ][PF ]
(Cspiro not found).
3
6
(
170 mg, 0.23 mmol), SBF (55 mg, 0.17 mmol) and dichlo-
romethane (20 mL). The resulting solution was stirred at
0 ꢁC for 16 h to give a grey precipitate and a dark brown
4.5. Structure determinations
6
supernatant. The mixture was filtered and the grey residue
washed with dichloromethane (2 · 20 mL) that on drying
gave 2 as a grey powder. Yield = 95 mg (59.5%). Anal.
Calc. for C H F P Ru : C, 44.79; H, 2.79. Found: C,
Diffraction data were collected at 115 K on a Bruker
Smart Apex diffractometer with Mo Ka radiation
˚
(k = 0.71073 A) using a SMART CCD camera. Diffrac-
tometer control, data collection and initial unit-cell deter-
mination was performed using ‘‘SMART’’ (v5.625 Bruker-
AXS). Frame integration and unit-cell refinement software
was carried out with the ‘‘SAINT+’’ (v6.22, Bruker AXS).
Absorption corrections were applied by SADABS (v2.03,
Sheldrick). Structures were solved by direct methods using
SHELXS-97 (Sheldrick, 1990) and refined by full-matrix least
squares using SHELXL-97 (Sheldrick, 1997) [30]. All non-
hydrogen atoms were refined anisotropically. Hydrogen
atoms were placed using a ‘‘riding model’’ and included
in the refinement at calculated positions.
3
5
26 12
2
2
+
4
6
4.59; H 2.85%. MS (FAB); m/z: 794.9 (M ꢀ (PF )),
6
+ 1
48.9 (M ꢀ 2(PF )) H NMR (270 MHz, CD CN) C iso-
6
3
2
mer d 8.08 (m, 2H), 7.71 (m, 2H), 7.64 (m, 2H), 7.10 (d,
J = 5.4, 2H), 7.05 (d, J = 5.4, 2H), 6.24 (t, J = 5.4, 2H),
5
.86 (t, J = 5.4, 2H), 5.61 (d, J = 5.4, 2H), 5.17 (s, 10 H);
C isomer 8.10 (m, 1H), 7.98 (d, J = 5.4, 1H), 7.6–7.8 (m,
1
3
1
H), 7.52 (t, J = 5.4, 1H), 7.29 (t, J = 5.4, 1H), 7.19 (m,
H), 7.00 (d, J = 5.4, 1H), 6.55 (d, J = 5.4, 1H), 6.39 (t,
J = 5.4, 1H), 6.3–6.15 (m, 2H), 6.05 (d, J = 5.4, 1H), 5.85
m, 1H), 5.58 (d, J = 5.4, 1H), 5.38 (s, 5H), 5.22 (s, 5H);
(

7
16
R.E. Douthwaite et al. / Journal of Organometallic Chemistry 691 (2006) 711–716
[3] G. Haas, V. Prelog, Helv. Chim. Acta. 52 (1969) 1202.
(
1) Colourless crystals, C H F P Ru , dimensions
30 21 6 1 1
[
[
4] V. Prelog, D. Bedekovic, Helv. Chim. Acta. 62 (1979) 2285.
5] K.T. Wong, Y.Y. Chien, R.T. Chen, C.F. Wang, Y.T. Lin, H.H.
Chiang, P.Y. Hsieh, C.C. Wu, C.H. Chou, Y.O. Su, G.H. Lee, S.M.
Peng, J. Am. Chem. Soc. 124 (2002) 11576.
0
.15 · 0.15 · 0.25 mm; M = 627.51; Monoclinic P2 /c,
r
1
˚
a = 12.218(6), b = 26.847(12), c = 15.132(7) A, V =
4
3
˚
˚
964(4) A , Z = 8, k(Mo Ka) = 0.71073 A, q = 1.679
calc
ꢀ3
g cm , T = 115(2) K, F(000) = 2512, h range for data col-
lection 1.52–25.15 ꢁ, limiting indices ꢀ14 6 h 6 13,
[6] Y. Chien, K.-T. Wong, P.-T. Chou, Y.-M. Cheng, Chem. Commun.
(2002) 2874.
[7] X.W. Chen, J.L. Liao, Y.M. Liang, M.O. Ahmed, H.E. Tseng, S.A.
Chen, J. Am. Chem. Soc. 125 (2003) 636.
ꢀ
28 6 k 6 32, ꢀ13 6 l 6 17 27649/8802 collected/unique
2
reflections (R
= 0.0738), goodness of fit on F = 0.973,
int)
(
[8] C.C. Wu, T.L. Liu, W.Y. Hung, Y.T. Lin, K.T. Wong, R.T. Chen,
Y.M. Chen, Y.Y. Chien, J. Am. Chem. Soc. 125 (2003) 3710.
ꢀ
3
˚
Dqmax/min = 2.349/ꢀ0.678 e A , final R indices (I > 2r(I))
R = 0.0455, wR = 0.0967.
1
2
[9] V. Alcazar, F. Diederich, Angew. Chem., Int. Edit. Engl. 31 (1992)
(
3a) Yellow crystals, C H F Fe P , dimensions
1521.
3
5
26 12
2 2
[
[
10] J. Cuntze, L. Owens, V. Alc a´ zar, P. Seiler, F. Diederich, Helv. Chim.
0
.25 · 0.20 · 0.20 mm; M = 848.20; Monoclinic P2 /c,
a = 8.8052(8), b = 18.3273(17), c = 20.1367(19) A, V =
200.7(5) A , Z = 4, k(Mo Ka) = 0.71073 A, q = 1.760
calc
r
1
Acta. 78 (1995) 367.
11] J.H. Fournier, T. Maris, J.D. Wuest, J. Org. Chem. 69 (2004)
1762.
[12] A. Togni, R.L. Halterman, Metallocenes, Wiley-VCH, 1998.
[13] A.N. Nesmeyanov, V.V. Krivykh, V.S. Kaganovich, M.I. Rybins-
kaya, J. Organomet. Chem. 102 (1975) 185.
[14] C.A.L. Mahaffy, P.L. Pauson, Inorg. Synth. 19 (1979) 154.
15] R.D. Rieke, I. Tucker, S.N. Milligan, D.R. Wright, B.R. Willeford,
L.J. Radonovich, M.W. Eyring, Organometallics 1 (1982) 938.
[16] G.J. Kubas, Inorg. Chem. 22 (1983) 692.
˚
3
˚
˚
3
ꢀ3
g cm , T = 115(2) K, F(000) = 1704, h range for data col-
lection 1.51–25.03ꢁ, limiting indices ꢀ10 6 h 6 10, ꢀ21 6
k 6 19, ꢀ23 6 l 6 21 17607/5636 collected/unique reflec-
2
tions (R( = 0.0275), goodness of fit on F = 1.052,
int)
[
ꢀ
3
˚
Dqmax/min = 0.938/ꢀ0.588 e A , final R indices (I > 2r(I))
R = 0.0378, wR = 0.0989.
1
2
[
[
[
17] P.J. Fagan, M.D. Ward, J.C. Calabrese, J. Am. Chem. Soc. 111
1989) 1698.
18] M.D. Ward, P.J. Fagan, J.C. Calabrese, D.C. Johnson, J. Am.
Chem. Soc. 111 (1989) 1719.
(
5
. Supplementary material
Crystallographic data for the structural analysis has
19] D. Astruc, Accounts Chem. Res. 30 (1997) 383.
been deposited with the Cambridge Crystallographic Data
Centre, CCDC No. 279231 and 279232 for compounds 1
and 3a, respectively. Copies of this information may be
obtained free of charge on application to The Director,
CCDC, 12 Union Road, Cambridge CB2 2EZ, UK (fax:
[20] S. Barlow, D. Ohare, Chem. Rev. 97 (1997) 637.
[21] M. Yamamoto, K. Onitsuka, M. Uno, S. Takahashi, J. Chem. Soc.,
Dalton Trans. (2002) 1473.
[22] C. Slugovc, E. Ruba, R. Schmid, K. Kirchner, K. Mereiter, Mon.
Chem. 131 (2000) 1241.
[23] W.H. Morrison, E.Y. Ho, D.N. Hendrickson, J. Am. Chem. Soc. 96
(1974) 3603.
+
44 1223 336033; e-mail: deposit@ccdc.cam.ac.uk or
http://www.ccdc.cam.ac.uk).
[24] W.H. Morrison, E.Y. Ho, D.N. Hendrickson, Inorg. Chem. 14
1975) 500.
(
[25] M. Lacoste, H. Rabaa, D. Astruc, N. Ardoin, F. Varret, J.Y.
Saillard, A. Lebeuze, J. Am. Chem. Soc. 112 (1990) 9548.
Acknowledgement
[
26] H. Rabaa, M. Lacoste, M.H. Delvilledesbois, J. Ruiz, B. Gloaguen,
N. Ardoin, D. Astruc, A. Lebeuze, J.Y. Saillard, J. Linares, F.
Varret, J.M. Dance, E. Marquestaut, Organometallics 14 (1995)
The authors thank the University of York for financial
support.
5
078.
[27] W.L.F. Armarego, D.D. Perrin, Purification of Laboratory Chemi-
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