Dimerisation and reactivity of HCCCCFc at ruthenium centres

Article abstract of DOI:10.1016/j.jorganchem.2010.09.035

In contrast to the simple diynyl complexes formed in reactions between HCCCCFc and MCl(dppe)Cp; (M = Fe, Ru), an analogous reaction with RuCl(PPh ₃)₂Cp; in the presence of KPF₆ and dbu resulted in dimerisation of the diyne at the Ru centre to afford a mixture of [Ru{η¹,η²-C(CCFc)C(L)CHCCCHFc}(PPh ₃)Cp]PF₆ (L = dbu 1, PPh₃ 2). Similar reactions with RuCl(PR₃)₂L gave [Ru{η¹, η²-C(CCFc)C(dbu)CHCCCHFc}(PR₃)L]PF₆ (L = Cp, R = Ph 3, m-tol 4; L = η⁵-C₉H₇, R = Ph 5). The reaction between 3 and I₂, followed by crystallization of the paramagnetic product from MeOH, afforded the dicationic [Ru{C(CCFc)C(dbu) CHC(OMe)C(OMe)CHFc}(PPh₃)Cp](I₃)₂ 6. The molecular structures of 2·2CH₂Cl₂ and 6.S (S = 2CH₂Cl₂, C₆H₆) were determined by single-crystal XRD studies.

Full text of DOI:10.1016/j.jorganchem.2010.09.035

Journal of Organometallic Chemistry 696 (2011) 461e467
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Communication
Dimerisation and reactivity of HC^CC^CFc at ruthenium centres
,
a
b
b
Michael I. Bruce a , Martyn Jevric , Brian W. Skelton , Allan H. White
*
a School of Chemistry & Physics, University of Adelaide, Adelaide, South Australia 5005, Australia
b Chemistry M313, SBSSC, University of Western Australia, Crawley, Western Australia 6009, Australia
a r t i c l e i n f o
a b s t r a c t
Article history:
In contrast to the simple diynyl complexes formed in reactions between HC^CC^CFc and MCl(dppe)
Cp*; (M ¼ Fe, Ru), an analogous reaction with RuCl(PPh3)2Cp*; in the presence of KPF6 and dbu resulted
Received 22 April 2010
Received in revised form
17 September 2010
Accepted 17 September 2010
Available online 25 September 2010
in dimerisation of the diyne at the Ru centre to afford a mixture of [Ru{h1 2-C(C^CFc)]C(L)CH]CC]
,h
CHFc}(PPh3)Cp*]PF6 (L ¼ dbu 1, PPh3 2). Similar reactions with RuCl(PR3)2L gave [Ru{h1
,h
2-C(C^CFc)]C
(dbu)CH]CC]CHFc}(PR3)L]PF6 (L ¼ Cp, R ¼ Ph 3, m-tol 4; L ¼
h
5-C9H7, R ¼ Ph 5). The reaction between 3
and I2, followed by crystallization of the paramagnetic product from MeOH, afforded the dicationic [Ru{C
(C^CFc)C(dbu)CH]C(OMe)C(OMe)]CHFc}(PPh3)Cp](I3)2 6. The molecular structures of 2$2CH2Cl2 and
6.S (S ¼ 2CH2Cl2, C6H6) were determined by single-crystal XRD studies.
Keywords:
Ferrocene
Ruthenium
Diyne
Ó 2010 Elsevier B.V. All rights reserved.
Dimerisation
Crystal structure
1. Introduction
[Ru{h1
,h
2-C(C^CFc)]C(X)CH]CC]CHFc}(PPh3)Cp*]PF6 [X ¼ dbu
1 (78%), PPh3 2 (14%)] (Scheme 1) as red and purple solids, respec-
As a continuation of our studies of Group 8 complexes contain-
ing di- and poly-ynyl ligands [2], we earlier described the synthesis
and some reactions of the complexes Ru(C^CC^CFc)(dppx)Cp
(x ¼ m, e) [1]. The syntheses followed precedent by reacting
FcC^CC^CSiMe3 with RuCl(dppx)Cp in the presence of KPF6 in thf/
dbu (dbu ¼ 1,8-diazabicyclo[5.4.0]undec-7-ene) to give these
complexes in 28 and 57% yields, respectively. During these studies,
there was no evidence for the formation of any other product.
However, when a ruthenium precursor containing a more labile
monodentate phosphine ligand, namely RuCl(PPh3)2Cp*, reacted
with FcC^CC^CH, the reaction took a different course, resulting in
the formal dimerisation of the diyne and subsequent reaction with
nucleophiles present in the reaction mixture. Similar products were
tively. Spectroscopic properties of 1 and 2 included weak
n(C^C)
and (C]C]C) bands at 2155 and 1778 (for 1) and 2129 and 1881,
n
1782 cmꢀ1 (for 2). For 1, resonances for the Ru(PPh3)Cp* moiety
were found at dH 1.33, dC 9.21, 98.41 (RueCp*) and dP 51.5, with
singlets for the FeeCp group at dH 1.39, ca 4.3, dC 70.61, 70.75. Several
signals between dH 1.42 and 3.70 and dC 20.85 and 72.04 were
assigned to the dbu fragment. For 2, signals at dH 1.36 and 4.07, 4.60
(2 ꢁ FeeCp), dC 6.76, 101.42 (RueCp*) and two singlets at dP 0.95,
25.8 (2 ꢁ PPh3) were present; the spectra were simplified by the
absence of the dbu resonances in this case. In the electrospray mass
spectrum (ES-MS), molecular cations were found at m/z 1119 (1) and
1229 (2). The molecular structure of 2 was determined from
a single-crystal XRD study (see below).
obtained with P(m-tol)3 or
h
5-indenyl and Cp ligands. These studies
The reaction between RuCl(PPh3)2Cp and an excess of
FcC^CC^CH was carried out in a similar manner to that described
above. Conventional work-up and final purification by preparative
t.l.c. and recrystallisation from acetoneedichloromethane gave
are described below.
2. Results
maroon [Ru{h1 2-C(C^CFc)]C(dbu)CH]CC]CHFc}(PPh3)Cp]
,h
PF6 3 (Scheme 1). The 1H NMR spectrum contained resonances at
The reaction between FcC^CC^CH and RuCl(PPh3)2Cp* was
carried out in refluxing thf in the presence of KPF6 (to encourage
dissociation of the chloride) and dbu (as base) to afford a mixture of
two complexes, which could be separated by preparative t.l.c. to give
d
1.43 and 3.96 (2 ꢁ CpeFe), together with several signals between
d
1.49e2.79 (from dbu), 3.30e4.67 (C5H4 þ RueCp), 6.06e6.49 (3H
on C8 chain), and 7.00e7.80 (Ph). It was not possible to find the
resonances of the vinylic protons, which were probably masked by
the aromatic proton signals. Among the plethora of signals in the
13C NMR spectrum, those at
d
70.00, 70.07 (2 ꢁ CpeFe) and 91.49
* Corresponding author. Fax: þ61 8 8303 4358.
(CpeRu) were readily assigned. The 31P NMR spectrum contained
E-mail address: michael.bruce@adelaide.edu.au (M.I. Bruce).
0022-328X/$ e see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.09.035

462
M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
R
+
HC4
C3
C5
C6
C7
C8
Fc3
C2
HC2C2Fc
Fc2
Ru
RuCl(PR3)2L
C1
H
PR3
L
1 R = Ph, L = Cp
R =
N
2 R = m-tol, L = Cp
3 R = Ph, L = η5-C9H7
4 R = Ph, L = Cp*
N51
R = PPh3
5 R = Ph, L = Cp*
Scheme 1.
(5) A] and RueC(cp) [av. 2.28(5) A] are h1
,
h
2-coordinated to the C8
ꢀ
ꢀ
a singlet at
d
26.2 (PPh3) and a septet at
d
ꢀ142.2 (PF6). The
ꢀ
molecular cation was found at m/z 1049 in the ES-MS. Similar
complexes 4 (62%) and 5 (50%) were obtained from analogous
reactions of FcC^CC^CH with RuCl{P(m-tol)3}2Cp and RuCl
ligand by C(6) and C(2,3) [2.112(2), 2.136, 2.056(2) A]. Angles P(1)e
RueC(n) [n ¼ 6, mid-point of C(2)eC(3)] are 90.32(5), 98.6ꢂ, and
C(6)-Ru-C(2/3) are 92.3ꢂ. Along the carbon chain, the CeC separa-
tions are consistent with the structure as shown, with the C(7)eC
(PPh3)2(h
5-C9H7), respectively, and were characterised by micro-
ꢀ
analysis and the usual spectroscopic methods, including ES-MS
(molecular cations at m/z 1091,1099, respectively). The resonances
of these complexes were quite broad, possibly due to ring flips of
the dbu substituent.
(8) triple bond [1.215(3) A] and the C(2)eC(3) separation [1.342
ꢀ
(3) A] being as expected for a coordinated C]C double bond. The
ꢀ
FeeC(cp) bonds for Fe(2) [av. 2.051(9) A] and for Fe(3) [av. 2.046
ꢀ
(7) A] are similar.
Prior to crystallographic characterisation, some reactions of 3
were carried out to obtain further evidence for the structure.
Among these, a reaction between 3 and diiodine in thf afforded
a brown paramagnetic solid for which an acceptable microanalysis
for an I7 salt was obtained, but no useful structural information was
forthcoming from spectroscopic data. However, recrystallisation of
The structure of the dication in 6 (Fig. 2, selected bond para-
meters in Table 1) is closely related to that of the monocation in 2,
with the exceptions of replacement of PPh3 by dbu, introduction of
the OMe groups on C(2) and C(3), and the coordination of C(1)eC(2)
this complex from MeOH afforded the dicationic salt [Ru{h1 2-C
,h
(C^CFc)C(dbu)CH]C(OMe)C(OMe)]CHFc}(PPh3)Cp*](I3)2 6, as
revealed by single-crystal XRD structure determinations of its
CH2Cl2 and C6H6 solvates. Microanalysis and the ES-MS supported
this formulation, with ions at m/z 1111 (Mþ), 849 ([M ꢀ PPh3]þ) and
697 ([M ꢀ PPh3 ꢀ dbu]þ).
2+
N
MeO31
H
N51
C4
C3
C5
C6
MeO21
C2
C1
C7
Ru
C8
Fc1
H
PR3
Fc8
crystallographic
numbering
6
2.1. Molecular structures
Fig. 1. Plot of the cation in [Ru{h1
PF6 2.
,h
2-C(C^CFc)]C(dbu)CH]CC]CHFc}(PPh3)Cp*]
Fig. 1 is a plot of the cation of 2; selected structural parameters
are listed in Table 1.The usual Ru(PPh3)Cp* moieties [RueP, 2.3155

M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
463
ꢀ
ꢀ
Table 1
to ruthenium [2.209(3), 2.184(3) A]; RueC(6) [2.114(3) A] is
Selected bond parameters for 2$2CH2Cl2 and 6$2CH2Cl2.
ꢀ
experimentally identical to that in 2 [2.112(2) A].
There is a small but significant difference in the average FeeC
(cp) distances [Fe(2)eC(cp) 2.08(2), Fe(3)eC(cp) 2.042(8) A] which
Complex
2$2CH2Cl2
6$2CH2Cl2
ꢀ
ꢀ
Bond distances (A)
Fe(2)eC(cp)
2.047e2.069(3),
2.036e2.059(3)
2.052, 2.050(10)
2.035e2.058(3),
2.039e2.045(5)
2.046(9), 2.046(5)
2.232e2.343(2)
2.28(5)
2.3155(5)
2.136(2)
2.056(2)
2.112(2)
1.837, 1.825, 1.828(2)
1.788(2)
1.807, 1.798, 1.797(2)
1.458(3)
1.340(3)
1.342(3)
1.350(3)
1.442(3)
1.395(3)
1.408(3)
2.027e2.178(4),
2.063e2.113(4)
2.08, 2.09(2)
2.036e2.052(4),
2.034e2.053(4)
2.042, 2.045(8)
2.215e2.293(3)
2.25(3)
2.3429(9)
2.184(3)
2.209(3) [C(1)]
2.114(3)
is of interest in respect of the site of oxidation. This suggests that
the former may be
a ferrocenium cation, by virtue of (a)
(av.)
Fe(3)eC(cp)
a comparison with the FeeC distances in the ferrocenium cation in
ꢀ
[FeCp2]BF4 [2.095 A] [3], and (b) the similarity of the Fe(1)eCp
ꢀ
distances in 6 [Fe(2) 2.052, Fe(3) 2.044 A] to those found in ferro-
(av.)
Ru(1)eC(cp)
(av.)
ꢀ
ꢀ
cene itself [2.064(1) A in the solid state [4], 2.056(2) A in the vapour
phase [5]]. However, some caution should be expressed, since
accurate values for changes in the FeeC(cp) distances can be
affected by libration of the Cp ligands and any asymmetry in their
coordination. Geiger, Ernst and their coworkers have suggested that
Ru(1)eP(1)
Ru(1)eC(2)
Ru(1)eC(3)
Ru(1)eC(6)
P(1)eC(Ph)
P(2)eC(5)
P(2)eC(Ph)
C(1)eC(201)
C(1)eC(2)
C(2)eC(3)
C(3)eC(4)
C(4)eC(5)
C(5)eC(6)
C(6)eC(7)
C(7)eC(8)
C(8)eC(801)
ꢀ
“an oxidative lengthening of ca 0.04 A seems reasonable, based
upon structural data obtained for Fe(h-C5H4SiMe3)2 and its cation”
1.833, 1.848, 1.838(4)
1.467(5) [C(101)]
1.425(4)
1.487(4)
1.333(6)
1.445(5)
1.365(4)
1.422(5)
1.208(5)
[6,7]. The longer distances found in the cation could relate to the
reduced back-bonding from Fe to the ring as a result of the positive
charge on the metal.
3. Discussion
1.215(3)
1.415(3)
The dimerisation of FcC^CC^CH at the Ru centre contrasts with
the earlier results obtained when RuCl(dppx)Cp (x ¼ m, e), which
contain a chelating diphosphine, was used, and can be rationalised
by the facile loss of a bulky PR3 ligand to generate a 16-e Ru centre.
Extensive work by Kirchner [8] has shown that ready dimerisation
of alkynes occurs via ruthenacyclopentatriene (dicarbene) inter-
mediates, which undergo ready nucleophilic attack, e.g., by coor-
dinated PPh3, or by exterior nucleophiles (Scheme 2). In these
studies, examples of complexes containing allyl- (A), butadienyl- (B)
and allenyl-carbene (C) ligands were found. Some related work
using RuCl(cod)Cp* as precursor has resulted in the formation of
some binuclear derivatives which incorporated the alkyne and the
cod ligand [9].
1.436(5)
Bond angles (ꢂ)
P(1)eRu(1)eC(2)
P(1)eRu(1)eC(3)
P(1)eRu(1)eC(6)
Ru(1)eC(6)eC(5)
Ru(1)eC(6)eC(7)
P(1)eC(5)eC(4)
P(1)eC(5)eC(6)
C(201)eC(1)eC(2)
C(1)eC(2)eC(3)
C(2)eC(3)eC(4)
C(3)eC(4)eC(5)
C(4)eC(5)eC(6)
C(5)eC(6)eC(7)
C(6)eC(7)eC(8)
C(7)eC(8)eC(401)
91.80(5)
104.24(5)
90.32(5)
116.0(1)
124.7(1)
120.9(1)
123.4(1)
122.2(2)
145.1(2)
160.7(2)
111.2(2)
115.1(2)
118.7(2)
177.8(2)
175.8(3)
88.85(9) [C(1)]
110.12(9) [C(2)]
87.07(9)
128.6(2)
116.4(2)
113.7(3) [N(51)]
118.7(3) [N(51)]
124.0(3)
117.5(3)
126.3(3)
122.1(3)
127.4(3)
114.9(3)
177.5(4)
The formation of the products obtained from the reactions
described above requires dissociation of chloride, which is a well-
established reaction in the Ru(PR3)2Cp series. This probably occurs
after initial coordination of the first molecule of diyne and its iso-
merisation to a butatrienylidene intermediate. While the latter have
176.3(4)
ꢀ
For 6: C(2)eO(2) 1.415(4), C(3)eO(3) 1.387(4) A; C(1,3)eC(2)eO(2) 114.1(3), 111.5
(3), C(2,4)eC(3)eO(3) 109.4(2), 124.3(3)ꢂ.
Fig. 2. Plot of the dication in [Ru{h1 2-C(C^CFc)C(dbu)CH]C(OMe)C(OMe)]CHFc}(PPh3)Cp](I3)2 6.
,h

464
M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
+
+
+
HC
CR'
Ru
L
Ru
Ru
R'
R'
PR3
H
L
PR3
H
PR3
H
R'
R'
H
Ru
Ru
Ru
A
B
C
Scheme 2.
been postulated as intermediates in several examples of ruthenium
chemistry [10,11], they have not been isolated or characterised in the
Ru(PP)Cp series. Rare examples have been obtained with Groups 6
[12], 7 [13] and IrCl(PP) centres [14] and metallabutatrienyli-
deneeiron complexes have been described by Lapinte [15]. Here,
coordination of a second molecule of the diyne and dissociation of
one PR3 ligand would afford intermediate D, which rapidly evolves
We were interested to study the oxidation of 3, in particular to
determine whether the electron would be lost from the electron-
rich Ru centre, or from one of the Fc nuclei. Addition of I2 to 3
afforded an intractable brown material which did, however, give an
X-ray quality single crystals from MeOH. The structural determi-
nation revealed that the product was the bis-triiodide salt of a new
dication, [Ru{C(C^CFc)C(dbu)CH]C(OMe)C(OMe)]CHFc}(PPh3)
Cp](I3)2 6. The precise mode of formation of 6 is not clear, formal
double addition of methoxide to two adjacent carbons of one C]C
double bond having occurred. While the double addition is unlikely
by coupling of the alkyne and trienylidene ligands to give an h1 h2
, -
cumulenylcarbene E, for which high reactivity would be expected
(Scheme 3). Related reactions have been observed with ethynylme-
tallocenes [8b,16]. Subsequent attack of the central carbon by the
earlier displaced PPh3, would afford the isolated product 3. When the
more bulky Cp* ligand is present, competing attack at the same site
by dbu, present in solution as a base to remove the proton expected
to be released in formation of the desired diynyl complex, and by
PPh3 affords a mixture of the two complexes 1 and 2.
to occur simultaneously at both carbons of an
h
2-C]C system,
migration of the metal centre along the unsaturated chain may
allow attack by the second MeO group to give the observed product
containing the C(OMe)C(OMe) group shown.
Of interest is the difference in structural parameters shown by
the two ferrocene nuclei. Thus, the Fe(3)eC(cp) separations may be
[Ru]
C
Fc
C
Fc
C
C
C
C
C
H
CH
D
Fc
C1H
[Ru]
[Ru]
C2
Fc
C8
C7
C6
Fc
C
C
C
C3
Fc
C
C
CH
C5
C4H
C
C
L+
(crystallographic numbering)
L
E
2
Scheme 3.

M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
465
Table 2
Crystal data and refinement details for 6$2CH2Cl2, 2$2C6H6 and 2$2CH2Cl2.
Complex
Formula
6$2CH2Cl2
2$2C6H6
C74H65Fe2P2Ruþ$F6Pꢀ$2C6H6
2$2CH2Cl2
C74H65Fe2P2Ruþ$F6Pꢀ$2CH2Cl2
C62H62Fe2N2O2PRu2þ
2Iꢀ3 $2CH2Cl2
2042.1
$
MW
1530.2
1543.8
Crystal system
Space group
Monoclinic
P21/c
21.506(3)
12.451(2)
26.608(4)
Triclinic
P1
Triclinic
P1
ꢀ
a/A
14.408(7)
16.047(8)
17.079(8)
74.298(9)
74.629(9)
71.060(9)
3527(3)
1.441
14.5903(9)
15.651(1)
16.788(1)
74.863(2)
72.408(2)
69.811(2)
3376.7(4)
1.518
ꢀ
b/A
ꢀ
c/A
a
/deg.
/deg.
b
106.618(4)
g
/deg.
3
ꢀ
V/A
6827(2)
1.987
rc/g cmꢀ3
Z
4
2
2
2
m
qmax/deg.
(Mo K
)/mmꢀ1
70
3.6
45
0.75
75
0.94
a
Tmin/max
0.72
0.70
0.90
Crystal dimensions/mm3
0.27 ꢁ 0.15 ꢁ 0.07
0.11 ꢁ 0.06 ꢁ 0.04
0.21 ꢁ 0.17 ꢁ 0.13
Ntot
125549
25863
66534
N (Rint
No
)
30045 (0.060)
18297
12196 (0.14)
5468
33110 (0.046)
24670
R1
0.046
0.17
0.046
wR2 (a, b)
0.14 (0.078, e)
0.38 (0, 18.4)
0.15 (0.058, 4.6)
Variata. In 6, one of the triiodide ions was modeled as disordered over two sets of sites, occupancies 0.8296(3) and complement. The two solvates of 2 are isomorphous.
somewhat shorter than Fe(2)eC(cp) bonds, suggesting that the
former is an Fe(III) or ferrocenium centre, thus providing a potential
answer to the mode of oxidation of the initial complex, i.e., at the
ferrocene centre.
from samples dissolved in MeOH unless otherwise indicated. Solu-
tions were injected into a Varian Platform II spectrometer via a 10 ml
injection loop. Nitrogen was used as the drying and nebulising gas.
Chemical aids to ionisation were used as required [17]. Electro-
chemical samples (1 mM) were dissolved in CH2Cl2 containing 0.5 M
[NBu4]BF4 as the supporting electrolyte for the spectro-electro-
chemical experiments. Cyclic voltammograms were recorded using
a PAR model 263 apparatus, with a saturated calomel electrode, with
ferrocene as internal calibrant (FeCp2/[FeCp2]þ ¼ þ0.46 V vs SCE). A
1 mm path-length cell was used with a Pt-mesh working electrode,
Pt wire counter and pseudo-reference electrodes. Elemental anal-
yses were by Campbell Microanalytical Laboratory, University of
Otago, Dunedin, New Zealand.
4. Conclusion
The chemistry described above is consistent with that found
earlier for alkynes at similar Ru centres bearing monodentate
phosphine ligands studied earlier, with a characteristic dimerisation
of the alkyne, usually with incorporation of a tertiary phosphine
ligand. In contrast, under similar reaction conditions, the diyne
forms a simple diynyleruthenium complex if bidentate phosphine,
such as dppe, is present, because dissociation to give a vacant
coordination site is precluded.
5.3. Reagents
Complexes RuCl(PPh3)2L (L ¼ Cp [18], Cp* [19],
h
5-C9H7 [20]),
5. Experimental
RuCl{P(m-tol)3}2Cp (as for the PPh3 complex) and FcC^CC^CH
[21] were obtained as previously described.
5.1. General
All reactions were carried out under dry nitrogen, although nor-
mally no special precautions to exclude air were taken during
subsequent work-up. Common solvents were dried, distilled under
nitrogen and degassed before use. Separations were carried out by
preparative thin-layer chromatography on glass plates (20 ꢁ 20 cm2)
coated with silica gel (Merck, 0.5 mm thick).
5.4. Reaction between HC^CC^CFc and RuCl(PPh3)2Cp*
A
similar reaction between RuCl(PPh3)2Cp* (102 mg,
0.128 mmol), HC^CC^CFc (73 mg, 0.312 mmol), KPF6 (108 mg,
0.59 mmol) and dbu (5 drops) in refluxing thf (20 ml) gave two
products contained in a broad maroon band, containing [Ru{C
(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)Cp*]PF6
1 (red solid,
5.2. Instruments
126 mg, 78%) running below a broad blue band, containing [Ru{C
(C^CFc)]C(PPh3)CH]C]C]CHFc}(PPh3)Cp*]PF6 2 (purple solid,
25 mg, 14%).
IR spectra were obtained on a Bruker IFS28 FT-IR spectrometer.
Spectra in CH2Cl2 were obtained using a 0.5 mm path-length solu-
tion cell with NaCl windows. Nujol mull spectra were obtained from
samples mounted between NaCl discs. NMR spectra were recorded
on a Varian Gemini 2000 instrument (1H at 300.145 MHz, 13C at
75.479 MHz, 31P at 121.501 MHz). Unless otherwise stated, samples
were dissolved in CDCl3 contained in 5 mm sample tubes. Chemical
shifts are given in ppm relative to internal tetramethylsilane for 1H
and 13C NMR spectra and external H3PO4 for 31P NMR spectra.
UVevis spectra were recorded on a Varian Cary 5 UVevis/NIR
spectrometer. Electrospray mass spectra (ES-MS) were obtained
5.4.1. [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)Cp*]PF6 1
Anal. Calcd (C65H66F6Fe2N2P2Ru): C, 61.77; H, 5.26; N, 2.22; M
(cation), 1119. Found: C, 61.72; H, 5.24; N, 2.21. IR (cmꢀ1):
n
(C^C)
(PF) 841s.
1.33 (s, 15H,
2155w,
n(C]C]C) 1778w, n(C]N) 1615s; 1543w, 1509w, n
UVevis: 409 (1308), 540 (1196). 1H NMR (C6D6):
d
RueCp*), 1.39 (s, 5H, FeeCp), 1.42e1.50 (m, 5H, dbu), 1.63e1.73 (m,
1H, dbu), 1.80e1.82 (m, 1H, dbu), 1.96e2.02 (m, 1H, dbu), 2.08e2.10
(m, 1H, dbu), 2.47e2.51 (m, 1H, dbu), 2.70e2.74 (m, 1H, dbu),
2.88e2.91 (m, 1H, dbu), 3.28e3.32 (m, 1H, dbu), 3.44e3.46 (m, 1H,

466
M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
dbu), 3.65e3.70 (m, 2H, dbu), 4.24e4.31 (m, 12H, incl. s for FeeCp),
4.37 (s,1H, C5H4), 4.57 (s, 2H, C5H4), 4.80e4.90, 4.95e5.15, 5.60e5.80
(br m, 3H), 6.59 (br, 2H), 7.01e7.15 (m, 2H, Ph), 7.25e7.27 (m, 9H, Ph),
130.74e130.85 (m, Ph), 132.42e132.63 (m), 133.33 (Ph),
137.45e137.56 (m, Ph), 167.07. 31P NMR (CDCl3):
d
ꢀ143.1 (sept,
J ¼ 712 Hz, PF6), 30.4 [s, P(m-tol)3]. ES-MS (MeOH, positive ion, m/z):
7.54e7.56 (m, 2H, Ph). 13C NMR (C6D6):
d 9.21 (RueC5Me5), 20.85,
1091, Mþ. Echem: þ0.32, þ0.59, þ0.89 V.
25.07, 26.94, 29.42, 30.33, 48.38, 55.45,65.40e67.20 (br), 67.68 (br),
70.28, 70.54, 70.61, 70.75 (2 ꢁ FeeCp),71.43, 71.75, 71.90, 72.04, 98.41
(RueC5Me5), 129.77 (Ph), 130.40 (Ph), 131.59e131.93 (m, Ph),
5.4.5. Synthesis of [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)-
(h 5
5-C9H7)]PF6
134.57e135.60 (m, Ph), 166.26. 31P NMR (C6D6):
d
ꢀ141.9 (sept,
Similarly, from a solution containing RuCl(PPh3)2(h
5-C9H7)
J ¼ 712 Hz, PF6), 51.5 (br, PPh3). ES-MS (MeOH, positive ion, m/z):
(99 mg, 0.128 mmol), HC^CC^CFc (83 mg, 0.355 mmol), KPF6
(143 mg, 0.777 mmol) and dbu (5 drops) in thf (15 ml) heated at
reflux point for 1 h, was obtained [Ru{C(C^CFc)]C(dbu)CH]C]
1119, Mþ. Echem: þ0.30, þ0.61, þ1.01 V.
5.4.2. [Ru{C(C^CFc)]C(PPh3)CH]C]C]CHFc}(PPh3)Cp*]PF6
Anal. Calcd (C74H65F6Fe2P3Ru): C, 64.69; H, 4.77; M (cation),1229.
Found: C, 64.66; H, 4.80; N, 2.39. IR (cmꢀ1):
(C^C) 2129w, (C]C]
C) 1881w, 1782w, (PF) 840s. UVevis: 297 (1943), 416 (864), 574
(985). 1H NMR (CDCl3):
1.36 (s, 15H, Cp*), 3.53 (s, 2H, C5H4), 4.07 (s,
2
C]CHFc}(PPh3)(
Anal. Calcd (C64H58F6Fe2N2P2Ru): C, 61.80; H, 4.70; N, 2.25; M
(cation), 1099. Found: C, 61.86; H, 4.62; N, 2.28. IR (cmꢀ1):
(C^C)
1957w, (C]C]C) 1795w, (C]N) 1614s; 1573w, 1548w, 1508w,
840s
(PF). UVevis: 407 (1057), 540 (693). 1H NMR (CDCl3):
1.60e2.00 (m, 9H, dbu), 2.50e2.80 (m, 2H, dbu), 3.60e4.00 (br,
h
5-C9H7)]PF6 5 as a dark red solid (79 mg, 50%).
n
n
n
n
n
n
d
n
5H, FeeCp), 4.14 (s 2H, C5H4), 4.35 (s, 2H, C5H4), 4.44 (s, 2H, C5H4),
4.60 (br s, FeeCp), 6.60e6.75 (m, 4H, Ph), 6.85e7.00 (m, 4H, Ph),
d
5H, dbu), 4.00e4.50 (m, 20H, incl. FeeCp at 4.12), 5.05 (s, 1H), 5.16
7.45e7.76 (m, 22H, Ph). 13C NMR (CDCl3):
d 6.76 (RueC5Me5), 69.61
(s, 1H), 5.90e6.90 (br, 4H, Ph), 7.00e7.62 (m, 16H, Ph). 13C NMR
(2 ꢁ FeeCp), 71.14 (C5H4), 71.64 (C5H4), 73.76 (C5H4), 74.46 (C5H4),
77.20, 101.42 (RueC5Me5), 123.40, 123.96, 127.38, 127.97, 129.25,
129.47e129.56 (m, Ph), 129.92, 130.21, 131.16, 131.40, 133.48e133.55
(CDCl3): d 20.00, 23.77, 26.55, 29.07, 29.69, 30.19, 47.29, 49.21,
55.29, 68.89,69.58e69.87 (m), 70.03 (2 ꢁ FeeCp), 70.13e70.30 (m),
71.18 (br), 71.36 (br), 72.00e73.00 (br), 79.95, 80.44, 97.08, 108.26,
112.35, 123.18 (Ph), 124.37 (Ph), 126.04 (Ph), 127.25e128.56 (m, Ph),
130.12 (Ph), 131.87e132.17 (m, Ph), 132.40e134.00 (br, Ph), 166.32.
(m, Ph), 133.35, 133.78e133.80 (m, Ph). 31P NMR (CDCl3):
d
ꢀ146.2
(sept, J ¼ 712 Hz, PF6), 0.95, 25.8 (2 ꢁ s, PPh3). ES-MS (MeOH, positive
ion, m/z): 1229, Mþ; 967, [M ꢀ PPh3]þ. Echem: þ0.37, þ0.67, þ1.17 V.
Crystals from benzeneehexane or CH2Cl2ehexane.
31P NMR (CDCl3):
d
ꢀ141.9 (sept, J ¼ 712 Hz, PF6), 20.2 (s, PPh3). ES-
MS (MeOH, positive ion, m/z): 1099, Mþ, 837, [M ꢀ PPh3]þ. Echem:
þ0.32, þ0.61, þ0.97 V.
5.4.3. Synthesis of [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)-
Cp]PF6
3
5.5. Reaction of [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)-
A solution containing RuCl(PPh3)2Cp (99 mg, 0.136 mmol),
HC^CC^CFc (78 mg, 0.33 mmol), KPF6 (135 mg, 0.73 mmol) and
dbu (5 drops) in thf (25 ml) was heated at reflux point for 2 h, after
which time solvent was removed. The residue was purified by
preparative t.l.c. (acetoneeCH2Cl2, 5/95) to give [Ru{C(C^CFc)]C
(dbu)CH]C]C]CHFc}(PPh3)Cp]PF6 3 as a maroon solid (109 mg,
67%). Anal. Calcd (C60H56F6Fe2N2P2Ru): C, 60.37; H, 4.73; N, 2.35; M
Cp]PF6 with I2
Iodine (35 mg, 0.14 mmol) was added to a solution of [Ru{C
(C^CFc)]C(dbu)CH]C]C]CHFc}(PPh3)Cp]PF6 (42 mg, 0.035
mmol) in thf (10 mL) and the mixture was stirred for 10 min.
Removal of solvent, extraction of the residue with CH2Cl2 (10 mL)
and filtration into cyclohexane (30 mL) afforded a brown solid
(58 mg, 86%) which was filtered off and washed with hexane. This
material was not completely characterised, with microanalyses
being consistent with the formation of a bis-triiodide salt of
a dication similar in composition to the precursor cation. Anal.
Calcd (C60H55Fe2I7N2PRu): C, 37.17; H, 2.84; N,1.45. Found: C, 37.11;
H, 2.76; N, 1.39. IR (nujol/cmꢀ1): 2106s, 1752w, 1615s, 1507m,
(cation), 1049. Found: C, 60.22; H, 4.80; N, 2.39. IR (cmꢀ1):
2196w, (C]C]C) 1795w, (C]C) 1651m, (C]N) 1615s; 1586w,
1546w, 1508w,
(PF) 841s. UVevis: 396 (866), 536 (670). 1H NMR
(CDCl3): 1.43 (s, 5H, FeeCp), 1.49e2.79 (m, 11H, dbu), 3.30e3.64
n(C^C)
n
n
n
n
d
(m, 5H, FeeCp), 3.79 (s, 1H), 3.90 (s, 1H), 3.96 (s, 5H, FeeCp), 4.02 (s,
1H), 4.14e4.67 (m,12H, incl. RueCp), 6.09e6.49 (br s, 3H), 7.00e7.80
(m, 12H, Ph). 13C NMR:
d
19.99, 23.51, 26.49, 29.07, 29.86, 48.41,
1500m. 31P NMR (CDCl3):
d 38.7. The NMR spectra of this para-
49.08, 55.21, 70.00, 70.07 (2 ꢁ FeeCp), 70.32, 70.56, 72.70, 73.61,
magnetic solid were broad and uninformative; no satisfactory ES-
MS could be obtained. Attempted recrystallisation from MeOH
afforded a few well-formed crystals, shown to be [Ru{C(C^CFc)C
(dbu)CH]C(OMe)C(OMe)]CHFc}(PPh3)Cp](I3)2 6 by a single-
crystal XRD structure determination. ES-MS (MeOH, positive ion,
m/z): 1111, Mþ; 849, [M ꢀ PPh3]þ; 817, [M ꢀ PPh3 ꢀ MeOH]þ; 697,
[M ꢀ PPh3 ꢀ dbu]þ.
91.49 (RueCp), 127.95 (Ph), 128.05e128.56 (m), 130.00 (Ph), 130.11,
131.95e132.20 (m), 133.05, 168.04. 31P NMR (CDCl3):
d
ꢀ142.2 (sept,
J ¼ 712 Hz, PF6), 26.2 (s, PPh3). ES-MS (MeOH, positive ion, m/z):
1049, Mþ. Echem: þ0.31, þ0.58, þ0.90 V.
5.4.4. Synthesis of [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}{P(m-
tol)3}Cp]PF6
4
Similarly, a solution containing RuCl{P(m-tol)3}Cp (102 mg,
0.126 mmol), HC^CC^CFc (79 mg, 0.34 mmol), KPF6 (164 mg,
0.89 mmol) and dbu (5 drops) in thf (10 ml) was heated at reflux
point for 2 h, [Ru{C(C^CFc)]C(dbu)CH]C]C]CHFc}{P(m-tol)3}
Cp]PF6 4 was obtained as a maroon solid (97 mg, 62%). Anal. Calcd
(C63H62F6Fe2N2P2Ru): C, 61.23; H, 5.06; N, 2.27; M (cation), 1091.
5.6. Structure determinations
Full spheres of diffraction data were measured at ca 153 K using
a Bruker AXS CCD area-detector instrument. All data were measured
ꢀ
using monochromatic Mo K
a
radiation,
l
¼ 0.71073 A. Ntot reflec-
tions were merged to N unique (Rint cited) after “empirical”/multi-
Found: C, 61.19; H, 4.99; N, 2.15. IR (cmꢀ1):
C) 1758w,
(C]N) 1616s. UVevis: 388 (1064), 534 (770). 1H NMR
(CDCl3): 1.40e2.00 (m, 9H, dbu), 2.25 (s, 9H, tol), 2.60e2.90 (m, 3H,
n(C^C) 2135w,
n(C]C]
scan absorption correction (proprietary software) and used in the
n
full matrix least squares refinements on F2. No with F > 4
s(F) were
d
considered “observed”. Anisotropic displacement parameter forms
were refined for the non-hydrogen atoms; hydrogen atoms were
dbu), 3.40e3.90 (m, 4H, dbu), 4.05 (s, 5H, FeeCp), 4.08 (s, 1H),
4.19e4.42 (m, 8H), 4.69 (s, 1H), 4.72 (s, 5H, FeeCp), 6.60 (br, H, Ph),
treated with a riding model [weights: (
s
2(Fo)2 þ (aP)2 (þbP))ꢀ1
]
6.90e7.21 (m, 12H, Ph). 13C NMR (CDCl3):
d
20.40, 21.73 (Me), 23.56,
[P ¼ (Fo2 þ 2F2c)/3]. Neutral atom complex scattering factors were
used; computation used the SHELXL 97 program [22]. Pertinent
results are given in the figures (which show non-hydrogen atoms
26.49, 29.02, 30.17, 47.84, 49.12, 69.72, 69.78, 69.91, 70.00
(2 ꢁ FeeCp), 71.60, 71.99, 90.77 (RueCp), 127.73e128.29 (m, Ph),

M.I. Bruce et al. / Journal of Organometallic Chemistry 696 (2011) 461e467
467
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Acknowledgements
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We thank Professor Brian Nicholson (University of Waikato,
Hamilton, New Zealand) for providing the mass spectra, the ARC for
support of this work and Johnson Matthey plc, Reading, for
a generous loan of RuCl3.nH2O.
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Appendix A. Supplementary material
Full details of the structure determinations (except structure
factors) have been deposited with the Cambridge Crystallographic
Data Centre as CCDC 747080-747082. Copies of this information
may be obtained free of charge from The Director, CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (fax: þ44 1223 336 033; e-mail:de-
posit@ccdc.cam.ac.ukor www: http://www.ccdc.cam.ac.uk).
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