The preparation of mixed ligand ruthenocenes containing bulky cyclopentadienyl ligands.

Article abstract of DOI:10.1016/S0022-328X(98)00622-6

The preparations of the mixed ligand ruthenocenes [Ru(η⁵-C₅R₅)(η⁵-C ₅H₅)] [R₅=Ph₅ (1),Ph₄H (2) and (p-MeC₆H₄)₅ (3)] and [Ru(η⁵-C₅Ph₅) (η⁵-C₅Me₅)] (4) are reported. The molecular structures of 1 (Pbca, a=14.234(3), b=20.276(3), c=20.625(4) A), 3 (P1, a=19.319(7), b=21.007(7), c=10.436(3) A, α=103.76, β=95.07(3), γ=112.59(2)°) and 4·H₂O (P1, a=12.145(2), b=12.696(4), c=14.281(2) A, α=80.41(2), β=66.43(1), γ=62.80(2)°) were determined by single crystal X-ray diffraction studies; the cyclopentadienyl rings in each structure are almost parallel and nearly eclipsed. For 1, 2 and 3, two oxidative processes, but no reductive electrochemical processes, were observed. The precipitated product from the reaction of Ru₃(CO)₁₂, C₅Ph₅Br and Zn in xylenes yielded, after subsequent reaction with NaBPh₄, [Ru(η⁵-C₅Ph₅){η⁶-C₆H₄(CH₃)₂}] ⁺BPh₄^- (5).

Full text of DOI:10.1016/S0022-328X(98)00622-6

Journal of Organometallic Chemistry 565 (1998) 283–296
The preparation of mixed ligand ruthenocenes containing bulky
cyclopentadienyl ligands. Crystal structures of pentaphenylruthenocene,
[Ru(p5-C5Ph5)(p5-C5H5)], pentaparatolylruthenocene,
[Ru{p5-C5(p-MeC6H4)5}(p5-C5H5)] and
pentaphenylpentamethylruthenocene, [Ru(p5-C5Ph5)(p5-C5Me5)]1
C.U. Beck, L.D. Field, T.W. Hambley, P.A. Humphrey *, A.F. Masters, P. Turner
School of Chemistry, The Uni6ersity of Sydney, Sydney, NSW 2006 Australia
Abstract
The preparations of the mixed ligand ruthenocenes [Ru(p5-C5R5)(p5-C5H5)] [R5=Ph5 (1), Ph4H (2) and (p-MeC6H4)5 (3)] and
5
5
˚
[Ru(p -C5Ph5)(p -C5Me5)] (4) are reported. The molecular structures of 1 (Pbca, a=14.234(3), b=20.276(3), c=20.625(4) A), 3
˚
(
(
(P1, a=19.319(7), b=21.007(7), c=10.436(3) A, h=103.76, i=95.07(3), k=112.59(2)°) and 4·H2O (P1, a=12.145(2),
b=12.696(4), c=14.281(2) A, h=80.41(2), i=66.43(1), k=62.80(2)°) were determined by single crystal X-ray diffraction
˚
studies; the cyclopentadienyl rings in each structure are almost parallel and nearly eclipsed. For 1, 2 and 3, two oxidative
processes, but no reductive electrochemical processes, were observed. The precipitated product from the reaction of Ru3(CO)12,
C5Ph5Br and Zn in xylenes yielded, after subsequent reaction with NaBPh4, [Ru(p5-C5Ph5){p6-C6H4(CH3)2}]+BPh4 (5). © 1998
−
Elsevier Science S.A. All rights reserved.
Keywords: Ruthenium; Cyclopentadienyl; Crystal structure
1. Introduction
or by oxidation to the corresponding metallocenium
salts, several of which have been structurally character-
ised [2,4,5]. Alternatively, the few reported pentaryl-
metallocenes are generally more soluble.
Interest in bulky cyclopentadienyl ligands stems from
their ability to confer unique steric, electronic and
stability properties on their metal complexes. The syn-
theses and characterisation of decaphenylmetallocenes
of chromium [1,2], molybdenum [3], iron [1,4–6], cobalt
[2], and nickel [1,7] have been described. Unfortunately,
although these species are air-stable, the development
of their chemistries is limited by their very low solubili-
ties. The solubilities can be improved by the introduc-
tion of appropriate substituents on the phenyl rings [8],
Although we, and others, have described the chem-
istry of iron sandwich derivatives of the pentaphenylcy-
clopentadienyl ligand, the authenticated chemistry of
ruthenium and osmium derivatives has been limited to
half sandwich compounds. Thus, the ruthenium com-
pounds [Ru(p5-C5Ph5)(CO)LX]n+(n=0, 1; L=CO,
PR3, C2H4, MeCꢀCMe; X=Br, R, COMe, MeC=
CMe2) [9–11], and the dimeric [Ru(p5-C5Ph5)(v-
CO)(CO)]2 [9] have been adequately characterised, with
structural characterisation being reported for the com-
pounds [Ru(p5-C5Ph5)(CO)2Br] [10] and [Ru(p5-
C5Ph5)(CO)(PPh3)Br] [11]. The starting material for
much of this chemistry is [Ru(p5-C5Ph5)(CO)2Br], pre-
pared from the reaction of Ru3(CO)12 with C5Ph5Br in
toluene. A series of osmium compounds of the type
* Corresponding author.
1 Dedicated to Professor Michael Bruce on the occasion of his 60th
birthday in recognition of his outstanding contributions to
organometallic and inorganic chemistry. Professor Bruce is thanked
by one of the authors (PAH) for the guidance and encouragement
given to him as a PhD student.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00622-6

284
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
Scheme 1.
[Os(p5-C5Ph5)(CO)LX] has also been recently reported
[12]. The possible existence of the mixed sandwich
compounds, [Ru(p5-C5Ph5)(p5-C5R5)] (R=H, Me), has
been briefly noted, but the formulation of these com-
pounds has not been established [13].
We report here the syntheses and characterisation of
the mixed sandwich compounds of ruthenium, [Ru(p5-
C5Ar5)(p5-C5R5)] (R=H, Ar5=Ph5 (1), Ph4H (2), (p-
MeC6H4)5 (3); R=Me, Ar5=Ph5 (4)) and of
[Ru(p5-C5Ph5)(p6-Me2C6H4)]BPh4 (5).
is consistent with the previous observation [15] that
ruthenocene derivatives are usually white to pale or
bright yellow when other chromophores are absent. An
alternative preparative method (as used [16] in the
synthesis of [Ru(p5-C5H5)(p5-C5Me5]) involved the re-
action of pentaphenylcyclopentadienyllithium with a
THF solution of [Ru(p5-C5H5)(COD)Cl] (COD=p4-
1,5-C8H12). In both reactions the yield of 1 was low. An
analogous reaction of [Ru(p5-C5H5)(COD)Cl] with the
less sterically demanding ligand (C5Ph4H)− produced a
pale yellow solid, [Ru(p5-C5Ph4H)(p5-C5H5)] (2), in a
much higher yield (58%). Compound 2 was character-
ised as above. The symmetrical complex, [Ru(p5-
C5Ph4H)2], has been prepared previously by the
reaction between KC5Ph4H and [Ru(p4-COD)Cl2]n or
[Ru(p-cymene)Cl2]n in refluxing diglyme [17].
2. Results and discussion
2.1. Syntheses
Pale yellow, crystalline [Ru(p5-C5Ph5)(p5-C5H5)] (1)
was initially prepared in low yield by the thermolysis of
the product of the reaction between [Ru(p5-
C5Ph5)(CO)2Br] and cyclopentadienylsodium. During
the course of the reaction, a precipitate formed which
has been identified by IR spectroscopy as the known
compound [Ru(p5-C5Ph5)(v-CO)(CO)]2 (Scheme 1) [9].
Complex 1 is probably formed via the intermediary of
[Ru(p5-C5Ph5)(p1-C5H5)(CO)2], as postulated for the
synthesis of [Fe(p5-C5Ph5)(p5-C5H5)] from [Fe(p5-
C5Ph5)(CO)2Br] and cyclopentadienyl sodium [14] and
established for the synthesis of [Fe{(p5-C5(p-
MeC6H4)5)}(p5-C5H5)] from [Fe{(C5(p-MeC6H4)5)}
(CO)2Br] and cyclopentadienylsodium in which [Fe{(p5-
C5(p-MeC6H4)5)(p1-C5H5)}(CO)2] was isolated [8].
Compound 1 was obtained as an air-stable solid after
purification on a silica gel column followed by crystalli-
sation from dichloromethane/n-hexane, and was char-
The reaction of penta-p-tolylcyclopentadienyllithium
with a THF solution of [Ru(p5-C5H5)(COD)Cl] yielded
small amounts of very pale yellow to colourless crystals
of [Ru{(p5-C5(p-MeC6H4)5)}(p5-C5H5)] (3). It was iso-
lated as an air-stable solid after purification on a silica
gel column and crystallisation from n-hexane, and was
1
characterised by elemental analysis, mass, IR and H-
and 13C-NMR spectroscopies, cyclic voltammetry and
single crystal X-ray diffraction.
Similarly, very pale yellow to colourless crystals of
[Ru(h5-C5Ph5)(p5-C5Me5)] (4) were isolated in very low
yield from the reaction of Li(C5Ph5) with [Ru(p5-
C5Me5)(COD)Cl] in THF followed by column chro-
matography and a number of recrystallisations from
dichloromethane/n-hexane to remove HC5Ph5 (Scheme
2). Compound 4 was characterised by mass, IR and
1H-NMR spectroscopies and by single crystal X-ray
diffraction. Attempts to improve the yield of 4 by using
alternative synthetic strategies have not so far proven
successful.
1
acterised by elemental analysis and mass, IR and H-
and 13C-NMR spectroscopies, cyclic voltammetry and
single crystal X-ray diffraction. The pale yellow colour

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
285
Scheme 2.
The pentaphenylcyclopentadienyl and penta-p-tolyl-
cyclopentadienyl derivatives were all obtained in low
yields as soluble monomeric solids. A characteristic of
the reactions was that copious amounts of the ligand
precursor, C5Ar5H, were always produced in syntheses
using LiC5Ar5 as starting material. This contaminant
has a similar colour and spectroscopic properties to the
mixed sandwich products, from which it can be difficult
to separate. Isolation of pure ruthenocene derivatives,
therefore, can be non-trivial. Although [Ru(p5-
C5Ph4H)(p5-C5H5)] could be prepared in significantly
higher yields, the low yields of the C5Ar5 derivatives do
not seem to be due to steric interference, since [Fe(p5-
C5Ph5)(p5-C5H5)] was prepared in 58% yield [14]. For
example, in the reaction of [Ru(p5-C5Ph5)(CO)2Br)]
with NaC5Ph5, a significant product (obtained in vari-
able yields) is the stable, insoluble dimer, [Ru(p5-
C5Ph5)(v-CO)(CO)]2. The analogous dimer is obtained
in the iron system, but is much less stable and so the
iron mixed sandwich is the major product. In the
syntheses using [Ru(p5-C5H5)(COD)Cl], other prod-
uct(s) decompose during the chromatographic
separation.
nes. In an attempt to prepare [Ru(p5-C5Ph5)2] in a
similar manner, a mixture of Ru3(CO)12, bromopen-
taphenylcyclopentadiene and zinc dust was heated in
refluxing xylenes. A grey solid precipitated from the
crude reaction mixture. The major product in the super-
natant, as identified by IR spectroscopy, was [Ru(p5-
C5Ph5)(CO)2Br].
A pale coloured precipitate was
obtained after purification and crystallisation of the
grey solid. Further purification of the precipitate af-
forded a pale yellow solid, identified as [Ru(p5-
C5Ph5){p6-C6H4(CH3)2}]X (X=unidentified anion) by
1
mass, IR and H-NMR spectra. A white tetraphenylbo-
rate salt (5) was made by reacting [Ru(p5-C5Ph5){p6-
C6H4(CH3)2}]X with sodium tetraphenylborate (Scheme
3). This salt was isolated in ca. 50% overall yield (from
Ru3(CO)12) and was characterised by elemental analysis
1
and mass, IR and H-NMR spectroscopies. The cation
is analogous to the known [Ru(p5-C5R5){p6-C6R%}]+
6
species [19,20].
2.2. X-ray crystallography
The structures of 1, 3 and 4 were determined by
single crystal X-ray diffraction. Compounds 3 and 4
It has been shown previously that the reaction of
Fe(CO)5 (one equivalent), zinc dust (two equivalents)
and bromopentaphenylcyclopentadiene (two equiva-
lents) in refluxing benzene followed by column chro-
matography yields [Fe(p5-C5Ph5){(p6-C6H5)C5Ph4}]
with [Fe(p5-C5Ph5)(CO)2Br] and [Fe(p5-C5Ph5)(p6-
C6H6)]+as minor by-products [18]. Dark blue [Fe(p5-
(
crystallise in the triclinic space group P1 (No. 2),
compound 1 in the orthorhombic space group Pbca
(No. 61) (1). Compound 3 is only the second struc-
turally characterised complex containing the penta-p-
tolylcyclopentadienyl ligand. Its asymmetric unit
contains
two
crystallographically
independent
C5Ph5){(p6-C6H5)C5Ph4}] is
a
linkage isomer of
molecules. Figs. 1–3 show the molecules viewed side-on
and along the normals to the C5Ar5 planes. Selected
structural parameters are collected in Tables 1–3 and
pink/purple decaphenylferrocene, [Fe(p5-C5Ph5)2], to
which it can be converted by heating in refluxing xyle-

286
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
Scheme 3.
the crystallographic parameters are summarised in
Table 4. No intermolecular contacts of significance
were observed in the solids; the closest intermolecular
non-bonding approach between molecules being
with the C5 rings of 54.0° (1), 50.4(54.3)° (3) and 50.2°
(4). The methyl groups of the C5Me5 ligand are dis-
placed from the C5 plane by between 0.095 and 0.147
˚
˚
A, with the average displacement being 0.127 A. The
methyl substituents and the ruthenium atom are on
opposite sides of the C5 plane.
˚
˚
˚
3.430(8) A (1), 3.35(2) A (3) and 3.39(1) A (4).
The C5 rings of all compounds are not significantly
distorted from co-planarity. The maximum deviation of
the C5 carbon atoms from the C5R5 rings are: 1 0.010
˚
The Ru–(C5Ar5 ring centroid) distances are 1.796 A
˚
˚
˚
(1), 1.779(1.795) A (3) and 1.818 A (4); the Ru–(C5H5
˚
˚
˚
˚
˚
A, R=C6H5; 0.005 A, R=H; 3 0.019 A (0.016 A),
ring centroid) distances are 1.824 A (1), 1.810(1.817) A
(3) and the Ru–(C5Me5 ring centroid) distance is 1.836
˚
˚
R=C6H5; 0.004 A (0.005 A), R=H for the two
molecules in the unit cell; and 4 0.006 A, R=C6H5;
0.003 A, R=Me.
˚
˚
A (4). Therefore, the separations between the C5 ligand
˚
˚
˚
˚
planes are 3.620 A (1), 3.589(3.612) A (3) and 3.654 A
(4). These values can be compared with those obtained
The two C5 rings of each complex are almost parallel
(the angle between the normals to the rings 0.72°,
0.30(0.96)° and 0.68° for 1, 3 (both molecules) and 4,
respectively), and are nearly eclipsed in the solid state,
as is usual for most ruthenocene derivatives [15]. All
CꢁC bond distances are normal within statistical signifi-
at 293
K
for [Ru(p5-C5Me5)(p5-C5H5)] [1.792
A
˚
˚
˚
(RuꢁC5Me5) and 1.829 A (RuꢁC5H5) and separation
between planes of 3.621 A] [21], for [Ru(p -C5H5)2] [ca.
3.63 A, (X-ray) [22] ca. 3.68(1) A (electron diffraction)]
[23,24], [Ru(p -C5Me5)2] [3.60(1) A] [16,25] and for
5
˚
˚
5
˚
5
˚
˚
˚
cance [average 1.436 A (C5Ph5), 1.402 A (C5H5) for 1;
[Ru(p -C5Ph4H)2] [3.664(2) A] [17].
5
˚
˚
1.45(1.43) A (p -C5(p-MeC6H4)5), 1.41(1.41) A (C5H5)
The structures of 1, 3 and 4 provide comparisons of
the effects of substituting the C5Ph5 ligand by the
C5(p-MeC6H4)5 ligand and of the C5H5 ligand by the
C5Me5 ligand in these sterically demanding systems.
The only other structural comparison between the
C5Ph5 and the C5(p-MeC6H4)5 ligands is that involving
the analogous iron compounds [8,14]. The presence of a
solute molecule in 4 complicates the comparison of the
lattice parameters somewhat, however, the unit cell
volume of [Ru{(p5-C5(p-MeC6H4)5)}(p5-C5H5)], 3, is
substantially less than that of [Ru(p5-C5Ph5)(p5-C5H5)],
1.
˚
˚
for 3; and 1.439 A (C5Ph5), 1.419 A (C5Me5) for 4].
−
Those of the C5Ph5 ligands are similar to those in
5
˚
[Ru(p -C5Ph5)(CO)2Br] (1.441 A average) [10] and
[Ru(p -C5Ph5)(CO)(PPh3)Br] (1.42 A average) [11],
5
˚
which are the only other structurally characterised
Ru(C5Ph5) complexes. The CꢁC bond distances of the
(p5-C5(p-MeC6H4)5 ligand are similar to those in
[Fe(p5-C5(p-MeC6H4)5)(p5-C5H5)] [8]. The bond angles
in the C5 ring are normal for the C5 rings of cyclopen-
tadienyl and substituted cyclopentadienyl derivatives.
The ipso-carbon atoms of each of the arene rings of
the C5Ar5 ligands are displaced slightly from the C5
As might be expected on steric grounds, the substitu-
tion of the C5H5 ligand by the bulkier C5Me5 ligand
leads to increases in both the RuꢁC5Ph5 and RuꢁC5R5
(R=H, Me) distances.
˚
plane by between 0.003 and 0.176 A (1), 0.021(0.061)
˚
˚
and 0.144(0.187) A (3) and 0.129 and 0.200 A (4), with
˚
˚
the average distances being 0.096 A (1), 0.077(0.129) A
(3) and 0.159 A (4). These ipso-carbon atoms and the
˚
The C5Ph5 and C5(p-MeC6H4)5 ligands are expected
to make near equivalent steric demands at the metal
centre. However, the substitution of the C5Ph5 ligand
by the C5(p-MeC6H4)5 ligand results in a decrease in
both the RuꢁC5Ar5 and RuꢁC5H5 distances. These
effects, although small, are significant. A similar effect
was observed in the structures of the corresponding
iron compounds, [Fe(p5-C5Ar5)(p5-C5H5)] (Ar=Ph, p-
MeC6H4) [8,14]. The structural effect is small but is
observed in both the ruthenium and iron chemistries.
ruthenium atom are on opposite sides of the C5 plane,
similar to the orientations seen in other pentaarylcy-
clopentadienyl compounds. The aryl rings are all also
˚
˚
planar to within 0.011 A (1), 0.021(0.018) A (3) and
˚
0.012 A (4) with normal dimensions and are canted at
between 49.6 and 59.0° (1), 46.8(47.2) and 53.0(57.5)°
(3) and 48.2 and 53.0° (4) to the C5 ring of the C5Ar5
ligand in the usual paddlewheel arrangement, with an
average deviation of the phenyl rings from co-planarity

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
287
Fig. 1. ORTEP [39] (25% probability) illustration of the molecular structure of [Ru(p5-C5Ph5)(p5-C5H5)], 1. View (a) showing the numbering of
the non-hydrogen atoms, view (b) along the normal to the C5Ph5 plane, including the hydrogen atoms.
The difference between the C5Ph5 and C5(p-MeC6H4)5
ligands is thus suggested to be electronic in origin, with
the C5(p-MeC6H4)5 ligand acting as a slightly better
electron donor.
C5(p-MeC6H4)5 ligand is a better electron donor than
the C5Ph5 ligand. However, the comparison can be
complicated if the electron transfer processes involved
are not reversible. The reduction of [Fe(p5-C5Ph5)(p5-
C5H5)] is not simple—the C5Ph5 ligand exists in both
the p5-C5Ph5 and C5{(p6-C6H5)Ph4} configurations [14].
Fortunately, an opportunity for such a comparison
exists in the electrochemistry of the present compounds
2.3. Cyclic 6oltammetry
Cyclic voltammetric studies should establish if the

288
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
Fig. 2. ORTEP [39] (25% probability) illustration of the molecular structure of [Ru{p5-C5(p-MeC6H4)5}(p5-C5H5)], 3. View (a) showing the
numbering of the non-hydrogen atoms, view (b) along the normal to the C5Ar5 plane, including the hydrogen atoms.
for which reversible oxidations are observed.
Decamethylruthenocene undergoes a reversible one-
electron oxidation at a platinum electrode at 0.57 V
(versus [Fe(C5Me5)2]+/0 in dichloromethane) to the
monocation, [Ru(p5-C5Me5)2]+ [27]. A second, irre-
versible, oxidation is observed at 1.27 V (versus
The only electron transfer process observed for
ruthenocene at a platinum electrode at r.t. is an irre-
versible two-electron oxidation [26]. A reduction of
ruthenocene has been observed only at −50°C [15].

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
289
Fig. 3. ORTEP [39] (25% probability) illustration of the molecular structure of [Ru(p5-C5Ph5)(p5-C5Me5)], 4. View (a) showing the numbering of
the non-hydrogen atoms, view (b) along the normal to the C5Ph5 plane, including the hydrogen atoms.
[Fe(C5Me5)2]+/0 in dichloromethane). The cation can
be generated chemically by oxidation with AgBF4 and
is stable in solution for a short time at r.t. [27]. In the
present work performed at r.t., no reductive processes
were observed in preliminary cyclic voltammetric stud-
ies at platinum and glassy carbon electrodes for [Ru(p5-
C5Ph5)(p5-C5H5)] 1, [Ru(p5-C5Ph4H)(p5-C5H5)] 2, and
[Ru(p5-C5(p-MeC6H4)5)(p5-C5H5)] 3. However, all com-
pounds undergo overall two-electron oxidations to
form unstable dications. The three compounds differed

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C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
Table 2
from each other and from ruthenocene in the stabilities
of the monocations, [Ru(p5-C5R5)(p5-C5H5)]+ (R5=
Ph5, Ph4H, p-MeC6H4)5). Thus, at low scan rates, the
pentaaryl compounds 1 and 3 were oxidised in two
consecutive one-electron steps, whereas oxidation of the
tetraaryl derivative 2 was an irreversible two-electron
process. At a scan rate of 100 mV s−1, the first oxida-
tions of 1 and 3 showed signs of reversibility. As the
scan rate was increased, the two anodic peaks separated
in each case and the oxidations to the monocations
were seen to be clearly reversible. The oxidation of 2,
however, appeared to be irreversible at scan rates below
1 V s−1. These results indicate that the monocations of
the penta-p-tolylcyclopentadienyl and pentaphenylcy-
clopentadienyl compounds are stabilised to a greater
extent than is that of tetraphenylruthenocene. This is
presumably due to the increased steric bulk around the
cyclopentadienyl ring, which slows the subsequent
chemical reactions. The peak potentials of the observed
processes and the Ef potentials of the reversible couples
are collected in Table 5, where the values are compared
5
˚
Selected bond lengths (A) and bond angles (°) for [Ru{p -C5(p-
MeC6H4)5}(p5-C5H5)] (3)
Molecule A
Bond lengths
Ru(1)ꢁC(1)
Ru(1)ꢁC(2)
Ru(1)ꢁC(4)
Ru(1)ꢁC(41)
Ru(1)ꢁC(42)
2.15(1) Ru(1)ꢁC(3)
2.15(1) Ru(1)ꢁC(5)
2.15(1) Ru(1)ꢁC(43)
2.17(1) Ru(1)ꢁC(44)
2.19(1) Ru(1)ꢁC(45)
2.18(1)
2.17(1)
2.16(1)
2.15(1)
2.18(1)
Bond angles
C(1)ꢁRu(1)ꢁC(2)
C(3)ꢁRu(1)ꢁC(4)
C(5)ꢁRu(1)ꢁC(1)
C(2)ꢁRu(1)ꢁC(4)
C(4)ꢁRu(1)ꢁC(1)
C(41)ꢁRu(1)ꢁC(42)
C(43)ꢁRu(1)ꢁC(44)
C(45)ꢁRu(1)ꢁC(41)
C(42)ꢁRu(1)ꢁC(44)
C(44)ꢁRu(1)ꢁC(41)
C(1)ꢁRu(1)ꢁC(41)
C(1)ꢁRu(1)ꢁC(42)
C(1)ꢁRu(1)ꢁC(43)
C(1)ꢁRu(1)ꢁC(44)
C(1)ꢁRu(1)ꢁC(45)
C(2)ꢁRu(1)ꢁC(41)
C(2)ꢁRu(1)ꢁC(42)
C(2)ꢁRu(1)ꢁC(43)
C(2)ꢁRu(1)ꢁC(44)
C(2)ꢁRu(1)ꢁC(45)
C(5)ꢁRu(1)ꢁC(41)
C(5)ꢁRu(1)ꢁC(42)
C(5)ꢁRu(1)ꢁC(43)
38.4(4)
39.3(4)
38.8(4)
66.3(5)
65.2(5)
37.4(5)
36.8(5)
37.7(5)
63.4(5)
63.6(5)
112.6(5)
128.8(7)
164.1(9)
157.1(9)
122.7(6)
122.6(7)
111.3(6)
129.5(8)
163.7(9)
154.1(7)
129.9(7)
164.1(8)
156(1)
C(2)ꢁRu(1)ꢁC(3)
40.1(4)
38.5(4)
65.4(5)
65.1(5)
65.2(5)
37.7(6)
39.8(5)
62.2(6)
63.6(6)
C(4)ꢁRu(1)ꢁC(5)
C(1)ꢁRu(1)ꢁC(3)
C(3)ꢁRu(1)ꢁC(5)
C(5)ꢁRu(1)ꢁC(2)
C(42)ꢁRu(1)ꢁC(43)
C(44)ꢁRu(1)ꢁC(45)
C(41)ꢁRu(1)ꢁC(43)
C(43)ꢁRu(1)ꢁC(45)
C(45)ꢁRu(1)ꢁC(42)
C(3)ꢁRu(1)ꢁC(41)
C(3)ꢁRu(1)ꢁC(42)
C(3)ꢁRu(1)ꢁC(43)
C(3)ꢁRu(1)ꢁC(44)
C(3)ꢁRu(1)ꢁC(45)
C(4)ꢁRu(1)ꢁC(41)
C(4)ꢁRu(1)ꢁC(42)
C(4)ꢁRu(1)ꢁC(43)
C(4)ꢁRu(1)ꢁC(44)
C(4)ꢁRu(1)ꢁC(45)
C(5)ꢁRu(1)ꢁC(44)
C(5)ꢁRu(1)ꢁC(45)
63.8(5)
155.7(8)
123.2(7)
112.5(6)
128.0(7)
164.7(7)
164.3(8)
156.3(8)
124.1(8)
111.8(5)
128.9(7)
124.3(7)
111.9(6)
Table 1
5
5
˚
Selected bond lengths (A) and bond angles (°) for [Ru(p -C5Ph5)(p -
C5H5)] (1)
Molecule B
Bond lengths
Ru(2)ꢁC(46)
Ru(2)ꢁC(47)
Ru(2)ꢁC(48)
Ru(2)ꢁC(49)
Ru(2)ꢁC(50)
Bond lengths
Ru(1)ꢁC(1)
Ru(1)ꢁC(2)
Ru(1)ꢁC(4)
Ru(1)ꢁC(36)
Ru(1)ꢁC(38)
2.165(4) Ru(1)ꢁC(3)
2.173(4) Ru(1)ꢁC(5)
2.167(5) Ru(1)ꢁC(37)
2.190(6) Ru(1)ꢁC(39)
2.168(5) Ru(1)ꢁC(40)
2.176(4)
2.181(4)
2.181(5)
2.176(5)
2.180(5)
2.19(1) Ru(2)ꢁC(86)
2.17(1)
2.18(2)
2.18(2)
2.18(1)
2.17(1)
2.20(1) Ru(2)ꢁC(87)
2.17(1) Ru(2)ꢁC(88)
2.13(1) Ru(2)ꢁC(89)
2.15(1) Ru(2)ꢁC(90)
Bond angles
Bond angles
C(1)ꢁRu(1)ꢁC(2)
C(3)ꢁRu(1)ꢁC(4)
C(5)ꢁRu(1)ꢁC(1)
C(2)ꢁRu(1)ꢁC(4)
C(4)ꢁRu(1)ꢁC(1)
C(36)ꢁRu(1)ꢁC(37)
C(38)ꢁRu(1)ꢁC(39)
C(40)ꢁRu(1)ꢁC(36)
C(37)ꢁRu(1)ꢁC(39)
C(39)ꢁRu(1)ꢁC(36)
C(1)ꢁRu(1)ꢁC(36)
C(1)ꢁRu(1)ꢁC(37)
C(1)ꢁRu(1)ꢁC(38)
C(1)ꢁRu(1)ꢁC(39)
C(1)ꢁRu(1)ꢁC(40)
C(2)ꢁRu(1)ꢁC(36)
C(2)ꢁRu(1)ꢁC(37)
C(2)ꢁRu(1)ꢁC(38)
C(2)ꢁRu(1)ꢁC(39)
C(2)ꢁRu(1)ꢁC(40)
C(5)ꢁRu(1)ꢁC(36)
C(5)ꢁRu(1)ꢁC(37)
C(5)ꢁRu(1)ꢁC(38)
38.7(2)
38.5(2)
C(2)ꢁRu(1)ꢁC(3)
38.5(2)
38.7(2)
64.8(2)
64.5(2)
64.5(2)
38.0(2)
37.1(2)
63.0(2)
62.4(2)
C(46)ꢁRu(2)ꢁC(47)
C(48)ꢁRu(2)ꢁC(49)
C(50)ꢁRu(2)ꢁC(46)
C(47)ꢁRu(2)ꢁC(49)
C(49)ꢁRu(2)ꢁC(46)
C(86)ꢁRu(2)ꢁC(87)
C(88)ꢁRu(2)ꢁC(89)
C(90)ꢁRu(2)ꢁC(86)
C(87)ꢁRu(2)ꢁC(89)
C(89)ꢁRu(2)ꢁC(86)
C(46)ꢁRu(2)ꢁC(86) 112.7(6)
C(46)ꢁRu(2)ꢁC(87) 129.0(7)
C(46)ꢁRu(2)ꢁC(88) 162.4(9)
C(46)ꢁRu(2)ꢁC(89) 157.7(9)
C(46)ꢁRu(2)ꢁC(90) 124.0(8)
C(47)ꢁRu(2)ꢁC(86) 123.3(7)
C(47)ꢁRu(2)ꢁC(87) 111.8(6)
C(47)ꢁRu(2)ꢁC(88) 127.4(7)
C(47)ꢁRu(2)ꢁC(89) 162.7(9)
C(47)ꢁRu(2)ꢁC(90) 155.7(9)
C(50)ꢁRu(2)ꢁC(86) 130.8(7)
C(50)ꢁRu(2)ꢁC(87) 165.2(8)
C(50)ꢁRu(2)ꢁC(88) 157(1)
38.7(4)
38.6(4)
39.3(4)
65.4(5)
65.0(5)
37.4(5)
38.2(6)
37.6(5)
62.8(6)
63.5(5)
C(47)ꢁRu(2)ꢁC(48)
38.3(4)
37.8(4)
63.9(5)
63.5(4)
65.0(4)
36.8(6)
39.0(6)
62.7(7)
64.1(6)
C(4)ꢁRu(1)ꢁC(5)
C(1)ꢁRu(1)ꢁC(3)
C(3)ꢁRu(1)ꢁC(5)
C(5)ꢁRu(1)ꢁC(2)
C(37)ꢁRu(1)ꢁC(38)
C(39)ꢁRu(1)ꢁC(40)
C(36)ꢁRu(1)ꢁC(38)
C(38)ꢁRu(1)ꢁC(40)
C(40)ꢁRu(1)ꢁC(37)
C(3)ꢁRu(1)ꢁC(36)
C(3)ꢁRu(1)ꢁC(37)
C(3)ꢁRu(1)ꢁC(38)
C(3)ꢁRu(1)ꢁC(39)
C(3)ꢁRu(1)ꢁC(40)
C(4)ꢁRu(1)ꢁC(36)
C(4)ꢁRu(1)ꢁC(37)
C(4)ꢁRu(1)ꢁC(38)
C(4)ꢁRu(1)ꢁC(39)
C(4)ꢁRu(1)ꢁC(40)
C(5)ꢁRu(1)ꢁC(39)
C(5)ꢁRu(1)ꢁC(40)
C(49)ꢁRu(2)ꢁC(50)
C(46)ꢁRu(2)ꢁC(48)
C(48)ꢁRu(2)ꢁC(50)
C(50)ꢁRu(2)ꢁC(47)
C(87)ꢁRu(2)ꢁC(88)
C(89)ꢁRu(2)ꢁC(90)
C(86)ꢁRu(2)ꢁC(88)
C(88)ꢁRu(2)ꢁC(90)
C(90)ꢁRu(2)ꢁC(87)
C(48)ꢁRu(2)ꢁC(86)
C(48)ꢁRu(2)ꢁC(87)
C(48)ꢁRu(2)ꢁC(88)
C(48)ꢁRu(2)ꢁC(89)
C(48)ꢁRu(2)ꢁC(90)
C(49)ꢁRu(2)ꢁC(86)
C(49)ꢁRu(2)ꢁC(87)
C(49)ꢁRu(2)ꢁC(88)
C(49)ꢁRu(2)ꢁC(89)
C(49)ꢁRu(2)ꢁC(90)
C(50)ꢁRu(2)ꢁC(89)
C(50)ꢁRu(2)ꢁC(90)
38.6(2)
64.5(2)
64.9(2)
38.2(2)
37.3(2)
37.1(2)
62.9(2)
62.2(2)
63.0(2)
62.9(6)
114.0(2)
135.1(2)
172.0(2)
149.3(2)
120.3(2)
121.1(2)
114.0(2)
135.2(2)
171.3(2)
150.3(2)
134.6(2)
171.7(2)
148.8(2)
150.6(2)
119.9(2)
113.7(2)
134.7(2)
170.6(2)
170.6(2)
149.1(2)
119.3(2)
113.4(2)
134.4(2)
119.8(2)
113.8(2)
155.7(8)
123.9(7)
112.5(6)
129.1(8)
165.1(9)
164.7(8)
156.0(8)
124.1(9)
112.3(6)
129.7(7)
124.6(7)
113.5(5)

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
291
with data for ruthenocene obtained in the present work
under the same conditions.
C5H5)] (i.e. the C5(p-MeC6H4)5 ligand being the better
electron donor) is consistent with the structural results.
It is somewhat surprising that the electronic effects of
the methyl substituent on the arene ring should be
observable at the metal centre. The methyl substituent
is remote from the metal. Furthermore, in these com-
pounds, the aryl groups are canted at some 55° to the
C5 rings, rather than the two rings being coplanar as
required for optimal transmission of any electronic
effects. However, the simplicity of the solution NMR
spectra suggest that there is free rotation of the aryl
rings.
With regard to variations in the central metal atom,
[Ru(p5-C5Me5)2] has been shown to be harder to oxi-
dise (by 0.57 V) than [Fe(p5-C5Me5)2] [27]. Similarly,
[Ru(p5-C5Ph5)(p5-C5H5)] is harder to oxidise (by 0.486
V) than is [Fe(p5-C5Ph5)(p5-C5H5)].
A more complete description of the electrochemistry
with full simulations will be reported later.
These results indicate that the addition of phenyl and
p-tolyl substituents onto the cyclopentadienyl ring
causes an increase in oxidation potentials. Compound 3
is easier to oxidise than 1 and 2 due to the greater
electron donating nature of the p-tolyl substituent,
which promotes oxidation. The tetraphenylcyclopenta-
dienyl derivative (2) is easier to oxidise than the pen-
taphenylcyclopentadienyl derivative (1) perhaps
because of the change in the angles between the phenyl
groups and the C5 ring, which results in a change in the
electronic coupling of the phenyl substituents to the C5
core. However, the tetraphenylruthenocenium cation
appears to be more reactive than the pentaphenyl-
ruthenocenium cation.
3. Conclusion
This study provides the first fully characterised exam-
ples of ruthenocenes containing the bulky pentaphenyl-
and penta-p-tolyl-cyclopentadienyl ligands. As ex-
pected, the pentaparatolylcyclopentadienyl compound
has the greatest solubility, being soluble in hexane.
Structural and cyclic voltammetric studies indicate that
the pentaparatolylcyclopentadienyl ligand is a better
electron donating ligand than is the pentaphenylcy-
clopentadienyl ligand.
The observation that [Ru{(p5-C5(p-MeC6H4)5)}(p5-
C5H5)] is easier to oxidise than is [Ru(p5-C5Ph5)(p5-
Table 3
5
5
˚
4. Experimental
Selected bond lengths (A) and bond angles (°) for [Ru(p -C5Ph5)(p -
C5Me5)] (4)
4.1. Instrumentation
Bond lengths
Ru(1)ꢁC(2)
Ru(1)ꢁC(4)
Ru(1)ꢁC(36)
Ru(1)ꢁC(38)
Ru(1)ꢁC(40)
2.189(5) Ru(1)ꢁC(1)
2.201(5) Ru(1)ꢁC(3)
2.191(6) Ru(1)ꢁC(5)
2.196(6) Ru(1)ꢁC(37)
2.201(6) Ru(1)ꢁC(39)
2.196(5)
2.190(5)
2.181(5)
2.202(6)
2.198(6)
Elemental analyses (C, H) were performed by either
the Australian National University or University of
Sydney Microanalytical Service. The melting points
were determined on a Gallenkamp melting point ap-
paratus and are uncorrected. FTIR spectra were
recorded on a Digilab FTS40 spectrometer. 1H- and
13C-NMR spectra were recorded on a Bruker AC200F
(1H-NMR 200.13 MHz, 13C-NMR 50.33 MHz) spec-
trometer. The spectra were referenced internally to
Bond angles
C(1)ꢁRu(1)ꢁC(2)
C(3)ꢁRu(1)ꢁC(4)
C(5)ꢁRu(1)ꢁC(1)
C(2)ꢁRu(1)ꢁC(4)
C(4)ꢁRu(1)ꢁC(1)
C(36)ꢁRu(1)ꢁC(37)
C(38)ꢁRu(1)ꢁC(39)
C(40)ꢁRu(1)ꢁC(36)
C(37)ꢁRu(1)ꢁC(39)
C(39)ꢁRu(1)ꢁC(36)
C(1)ꢁRu(1)ꢁC(36)
C(1)ꢁRu(1)ꢁC(37)
C(1)ꢁRu(1)ꢁC(38)
C(1)ꢁRu(1)ꢁC(39)
C(1)ꢁRu(1)ꢁC(40)
C(2)ꢁRu(1)ꢁC(36)
C(2)ꢁRu(1)ꢁC(37)
C(2)ꢁRu(1)ꢁC(38)
C(2)ꢁRu(1)ꢁC(39)
C(2)ꢁRu(1)ꢁC(40)
C(5)ꢁRu(1)ꢁC(36)
C(5)ꢁRu(1)ꢁC(37)
C(5)ꢁRu(1)ꢁC(38)
38.1(2)
37.9(2)
C(2)ꢁRu(1)ꢁC(3)
38.8(2)
38.6(2)
64.3(2)
64.0(2)
64.0(2)
37.2(2)
37.5(2)
62.5(3)
62.9(2)
C(4)ꢁRu(1)ꢁC(5)
C(1)ꢁRu(1)ꢁC(3)
C(3)ꢁRu(1)ꢁC(5)
C(5)ꢁRu(1)ꢁC(2)
C(37)ꢁRu(1)ꢁC(38)
C(39)ꢁRu(1)ꢁC(40)
C(36)ꢁRu(1)ꢁC(38)
C(38)ꢁRu(1)ꢁC(40)
C(40)ꢁRu(1)ꢁC(37)
C(3)ꢁRu(1)ꢁC(36)
C(3)ꢁRu(1)ꢁC(37)
C(3)ꢁRu(1)ꢁC(38)
C(3)ꢁRu(1)ꢁC(39)
C(3)ꢁRu(1)ꢁC(40)
C(4)ꢁRu(1)ꢁC(36)
C(4)ꢁRu(1)ꢁC(37)
C(4)ꢁRu(1)ꢁC(38)
C(4)ꢁRu(1)ꢁC(39)
C(4)ꢁRu(1)ꢁC(40)
C(5)ꢁRu(1)ꢁC(39)
C(5)ꢁRu(1)ꢁC(40)
38.3(2)
64.2(2)
64.4(2)
37.8(2)
1
TMS or to residual solvent resonances (CD2Cl2, H l
5.30 ppm, 13C l 53.8 ppm). Electron impact mass
spectra were obtained using a Kratos MS 9 geometry
mass spectrometer with a direct insertion probe, a
280°C source temperature, 70 eV ionisation voltage and
4 kV acceleration voltage.
38.1(2)
37.8(2)
63.2(2)
62.9(2)
63.3(2)
113.7(2)
122.5(2)
153.1(2)
167.4(2)
132.2(2)
132.7(2)
113.8(2)
122.6(2)
153.3(2)
168.1(2)
122.1(2)
153.2(2)
167.8(2)
168.7(2)
132.7(2)
113.7(2)
121.6(2)
151.9(2)
152.7(2)
167.6(2)
132.1(2)
112.4(2)
121.3(2)
131.5(2)
112.8(2)
Electrochemical experiments were performed using a
BAS 100B electrochemical analyser and BAS 100W
version 2.0 software. A three-electrode system was used,
in which the working electrode was either a 3 mm
glassy carbon disc electrode or a 1.2 mm platinum disc
electrode. Both electrodes were polished with an alu-
mina suspension (0.04 mm grade) before each cyclic
voltammogram was recorded. The auxiliary electrode
was a platinum wire (0.5 mm diameter, 5 cm length)
and a Ag/AgCl/NaCl(sat.) electrode was used as the

292
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
Table 4
Crystallographic data and refinement details for 1, 3 and 4·H2O
Compound
1
3
4·H2O
Molecular formula
M
C40H30Ru
611.76
C45H40Ru
681.88
C45H40ORu
697.88
Crystal colour, shape
Crystal system
Space group
Colourless, blade Colourless, blade
Colourless, blade
Triclinic
Orthorhombic
Pbca (No. 61)
14.234(3)
20.276(3)
20.625(4)
90.0000
90.0000
90.0000
5952(1)
Triclinic
(
(
P1 (No. 2)
P1 (No. 2)
˚
a (A)
19.319(7)
21.007(7)
10.436(3)
103.76(3)
95.07(3)
112.59(2)
3721(2)
4
12.145(2)
12.696(4)
14.281(2)
80.41(2)
˚
b (A)
˚
c (A)
h (°)
i (°)
k (°)
66.43(1)
62.80(2)
1794.8(8)
2
1.291
4.70 (0.71069)
—
724.00
3
˚
U (A )
Z
8
Dcalc (g cm−3
)
1.365
1.217
v(Mo–Kh) (cm−1) (l (A))
5.54 (0.71069)
—
2512.00
—
˚
˚
v(Cu–Kh) (cm−1) (l (A))
F(000)
36.13 (1.54178)
1416.00
Crystal dimensions (mm)
2qmax (°)
hkl range
No. of reflections collected
No. of unique reflections, Rmerge
No. of observed data used
0.50×0.22×0.05 0.40×0.32×0.05
49.9 130.2
0, 16; 0, 24; 0, 24 0, 20; −23, 22; −12, 12
0.28×0.20×0.05
54.9
−14, 15; −16, 16; 0, 18
8833
8230, 0.025
5404 (I\3.00(|)I)
5791
10198
5781
9782, 0.040
3633 (I\3.00(|)I)
2898 (I\
2.50(|)I)
0.036; 0.031
0.30, −0.39
a
R; Rw
0.050; 0.062
0.60, −0.43
0.050; 0.057
0.97, −0.46
−3
˚
Final electron density difference features (max, min) (e A
)
a R=ꢀ(ꢁFoꢁ−ꢁFcꢁ)/ꢀꢁFoꢁ; Rw=(ꢀ w(ꢁFoꢁ−ꢁFcꢁ)2/ꢀ wꢁFoꢁ2)1/2, w=1/(|2(Fo)).
reference electrode. The electroactive species were ex-
amined as ca. 0.1 mM solutions in dichloromethane
and the supporting electrolyte was ca. 0.1 M tetrabuty-
lammonium perchlorate (Fluka). All samples were de-
gassed with high purity argon (BOC) for 5–10 min
prior to use. The argon was passed through a H2O/O2
removal assembly which consisted of an indicating
4.3. Starting materials
Ru(p5-C5Ph5)(CO)2Br [9], Ru(p5-C5H5)(COD)Cl [28],
Ru(p5-C5Me5)(COD)Cl [29], HC5Ph5 [30] and HC5(p-
MeC6H4)5 [8] were prepared as described previously.
Cyclopentadienylsodium, butyllithium (2.5 M solution
in hexanes), 1,2,3,4-tetraphenyl-1,3-cyclopentadiene
(90%) and sodium tetraphenylborate (Aldrich) and
Ru3(CO)12 (Strem) were used as-received. Flash silica
(240–400 mesh) was obtained from Merck.
˚
moisture trap (5 A molecular sieves with Dryerite,
Activon, RDMT400D), a high capacity coiled O2 trap
(Alltech, 4003) and an indicating O2 trap (Alltech,
4004). All potentials are quoted relative to the fer-
rocinium/ferrocene redox couple, which was observed
at +470 mV versus the Ag/AgCl/NaCl(sat.) electrode.
4.4. Preparation of [Ru(p5-C5Ph5)(p5-C5H5)] (1)
4.4.1. From Ru(p5-C5Ph5)(CO)2Br and NaCp
4.2. General reaction conditions
NaC5H5 (0.82 ml of a 2.0 M solution in THF, 1.64
mmol) was added at r.t. to a stirred solution of [Ru(p5-
C5Ph5)(CO)2Br] (0.686 g, 1.01 mmol) in THF (50 ml).
After stirring for 18 h, the supernatant was filtered
from a solid identified as [Ru(p5-C5Ph5)(m-CO)(CO)]2
All manipulations were performed at atmospheric
pressure under an atmosphere of dinitrogen by using
conventional Schlenk techniques, but no special precau-
tions were taken to exclude oxygen during work-up.
THF (Merck) was predried over sodium wire and dis-
tilled from sodium benzophenone ketyl. n-Hexane
(yield 0.132 g, 22%) by IR (KBr wCO 1962, 1779 cm−1
)
and mass (m/e 1092 ([Ru2(C5Ph5)2ꢁ2H]+, 17%), 991
([Ru(C5Ph5)2ꢁH]+, 100%), 546 ([Ru(C5Ph5)ꢁH]+, 19%)
spectroscopies. The solvent was removed in vacuo. The
resultant solid was heated at 200°C for 5 h in vacuo.
After CH2Cl2 (40 ml) was added and filtration by
gravity, column chromatography was performed. Elu-
(BDH)
was
distilled
from
sodium
wire.
Dichloromethane (Ajax) and methanol (Biolab) were
distilled from calcium hydride. Xylenes (Ajax) was dis-
tilled from sodium.

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
293
Table 5
Electrochemical dataa for [Ru(p5-C5Ph5)(p5-C5H5)] (1), [Ru(p5-C5Ph4H)(p5-C5H5)] (2), [Ru{(p5-C5(p-MeC6H4)5)}(p5-C5H5)] (3), [Ru(p5-C5H5)2]
and [Ru(p5-C5Me5)2]
Compound
Ep1a (V)
Ep2a (V)
Ep1c (V)
Ep3c (V)
Ef (V)
[Ru(p5-C5Ph5)(p5-C5H5)] (1)
[Ru(p5-C5Ph4H)(p5-C5H5)] (2)
[Ru{(p5-C5(p-MeC6H4)5)}(p5-C5H5)] (3)
[Ru(p5-C5H5)2]
0.770
0.830
0.680
0.490
—
0.981
—
0.796
—
0.682
0.510
0.683
—
0.340
0.150
0.280
0.250
—
0.726
0.670
0.632
—
[Ru(p5-C5Me5)2]b
0.738
—
0.038
a All data measured at r.t. at scan rates of 1 V s−1 in dichloromethane/0.1 M tetrabutylammonium perchlorate vs. [Fe(p5-C5H5)2]+/0
.
b Data from [27], measured at r.t. at a scan rate of 20 mV s−1 in dichloromethane. Potentials quoted in [27] vs. [Fe(p5-C5Me5)2]+/0; converted to
potentials vs. [Fe(p5-C5H5)2]+/0 using the data of [40].
tion with 30% CH2Cl2/70% n-hexane afforded, after
evaporation to dryness and crystallisation of the solid
from CH2Cl2/n-hexane, very pale yellow crystals of
[Ru(p5-C5Ph5)(p5-C5H5)] (1) (127 mg, 21%) m.p.\
250°C (decomp.). (Found C, 78.8; H, 4.9. C40H30Ru
4.5. Preparation of [Ru(p5-C5Ph4H)(p5-C5H5)] (2)
A solution of Li(C5Ph4H) [prepared from HC5Ph4H
(90%, 415 mg, 1.01 mmol) and BuLi (0.5 ml of a 2.5 M
solution in hexanes, 1.25 mmol)] in THF (30 ml) was
1
addded via
a canula to a
solution of [Ru(p5-
requires C, 78.5; H, 4.9%). H-NMR (CD2Cl2, 200.13
MHz): l 7.07–6.95 (m, 25H, ArꢁH), 4.73 (s, SH, C5H5)
C5H5)(COD)Cl] (262 mg, 0.846 mmol) in THF (20 ml).
The reaction mixture was stirred for 18 h, filtered, the
solvent was removed and the crude product purified by
column chromatography. Elution with 30% CH2Cl2/
70% n-hexane initially afforded a pale yellow solution
which, after evaporation to dryness and crystallisation
of the solid from CH2Cl2/n-hexane, yielded HC5Ph4H
(57 mg, 14%) identified by comparison of its KBr IR
spectrum with that of an authentic sample. Further
elution yielded, after evaporation to dryness and crys-
tallisation of the solid from CH2Cl2/n-hexane, pale
yellow [Ru(p5-C5Ph4H)(p5-C5H5)] (2) (261 mg, 58%)
m.p. 181–184°C. (Found C, 76.5; H, 4.6. C34H26Ru
requires C, 76.24; H, 4.89%). 1H-NMR (CD2Cl2, 200.13
ppm. 13C-NMR (CD2Cl2, 50.33 MHz):
l 136.0
(qArꢁC), 133.0, 127.3, 126.5 (ArꢁCH), 94.6 (C5 of
C5Ar5), 76.6 (C5 of C5H5) ppm. MS-EI (m/e) 612
([M]+, 100%). IR (KBr) wmax 3106 vw, 3093 vw, 3083
vw, 3056 w, 3044 (sh), 3028 vw, 3010 vw, 2988 vw, 1653
vw, 1601 w, 1576 vw, 1559 vw, 1540 vw, 1502 m, 1443
w, 1407 vw, 1176 vw, 1155 vw, 1102 vw, 1072 w, 1027
w, 999 vw, 919 vw, 840 vw, 829 vw, 810 w, 802 w, 784
w, 740 vs, 699 vs, 674 vw, 669 vw, 622 vw, 575 m, 556
m, 545 w, 415 w cm−1. Elution with 50% CH2Cl2/50%
n-hexane yielded, after evaporation to dryness and
crystallisation of the solid from CH2Cl2/n-hexane, yel-
low–orange crystals of [Ru(p5-C5Ph5)(CO)2Br] (72 mg,
10%) identified by comparison of its wCO (CH2Cl2) IR
spectrum with that of an authentic sample [9].
MHz):
l
7.24–7.05 (m, 20H, ArꢁH), 5.36 (s,
1H, C5Ph4H), 4.61 (s, 5H, C5H5) ppm. 13C-NMR
(CD2Cl2, 50.33 MHz): l 137.5, 136.0 (qArꢁC), 133.2,
130.4, 127.8, 127.5, 126.7, 126.7 (ArꢁCH), 95.6,
92.3 (C5 of C5Ar5), 75.4, 73.0 (C5 of C5H5) ppm. MS-EI
(m/e) 536 ([M]+, 100%). IR (KBr) wmax: 3108 vw,
3084 vw, 3057 w, 3030 vw, 1600 w, 1577 vw, 1507 w,
1501 w, 1448 w, 1407 w, 1178 vw, 1153 vw, 1101 w, 997
w, 919 vw, 914 vw, 814 w, 791 w, 764 s, 735 m, 698 vs,
634 w, 618 w, 567 w, 558 w, 544 w, 526 w, 483 w, 419
4.4.2. From [Ru(p5-C5H5)(COD)Cl] and LiC5Ph5
A solution of Li(C5Ph5) [prepared from HC5Ph5 (605
mg, 1.35 mmol) and BuLi (0.56 ml of a 2.5 M solution
in hexanes, 1.4 mmol)] in THF (15 ml) was added via a
canula to a solution of [Ru(p5-C5H5)(COD)Cl] (350
mg, 1.13 mmol) in THF (25 ml). The reaction mixture
was stirred for 18 h, the solvent was removed and the
crude product was purified by column chromatography.
Elution with 30% CH2Cl2/70% n-hexane afforded a
pale yellow solution which, after evaporation to dryness
and fractional crystallisation of the solid from CH2Cl2/
n-hexane, initially gave HC5Ph5 (241 mg, 40%), iden-
tified by comparison of its KBr IR spectrum with that
of an authentic sample. Subsequent crystallisation of
the solid obtained from the filtrate from CH2Cl2/n-hex-
ane yielded [Ru(p5-C5Ph5)(p5-C5H5)] (1) (84 mg, 12%)
identified by comparison of its KBr IR spectrum with
that of a sample prepared as in Section 4.4.1.
w cm−1
.
4.6. Preparation of [Ru{p5-C5(p-MeC6H4)5}(p5-C5H5)]
(3)
A solution of Li[C5(p-MeC6H4)5] [prepared from
HC5(p-MeC6H4)5 (650 mg, 1.26 mmol) and BuLi (0.46
ml of a 2.5 M solution in hexanes, 1.15 mmol) in THF
(15 ml) was added via a canula to a solution of [Ru(p5-
C5H5)(COD)Cl] (341 mg, 1.10 mmol) in THF (30 ml).

294
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
4.8. Reaction of Ru3(CO)12 with C5Ph5Br in the
presence of Zn
The reaction mixture was stirred at r.t. overnight
and filtered by canula. After evaporation to dry-
ness, the residue was dissolved in CH2Cl2 (50 ml) and
after filtration, and evaporation to dryness, the crude
product was purified by column chromatography.
Elution with 30% CH2Cl2 /70% n-hexane afforded
a pale yellow solution which, after evaporation to
dryness, was identified as HC5(p-MeC6H4)5 (267
mg, 41%) by comparison of its KBr IR spectrum
with that of an authentic sample. Elution with 70%
CH2Cl2 /30% n-hexane afforded, after evaporation
to dryness and crystallisation of the solid from n-
hexane, very pale yellow crystals of [Ru{p5-C5
(p-MeC6H4)5}(p5-C5H5)] (3) (40 mg, 5%) m.p.\280°C.
(Found C, 79.1; H, 6.3. C45H40Ru requires C, 79.27;
A mixture of Ru3(CO)12 (250 mg, 0.391 mmol),
C5Ph5Br (1.20 g, 2.28 mmol) and Zn (150 mg, 2.29
mmol) in xylenes (150 ml) was heated at reflux for 42 h,
to give a red–orange solution and pale coloured precip-
itate. After filtration via canula, the pale coloured
precipitate was extracted with hot MeOH to give an
orange–yellow filtrate and an insoluble grey material.
Evaporation of the filtrate to dryness and crystallisation
of the resultant solid from CH2Cl2/n-hexane afforded a
pale yellow solid which was collected on a sintered glass
funnel and washed with n-hexane. The solid was iden-
tified as [Ru(p5-C5Ph5){p6-C6H4(CH3)2}]+X− where X
is an unidentified anion (520 mg) m.p.\250°C (de-
1
H, 5.91%). H-NMR (CD2Cl2, 200.13 MHz): l 6.91–
1
comp.). (Found C, 57.3; H, 3.9%). H-NMR (CD2Cl2,
6.81 (AB quartet, J(HH)=8.1 Hz, 20H, ArꢁH),
200.13 MHz): l 7.27–6.85 (m, 25H, ArꢁH), 6.42–6.05
(m, 4H, C6H4), 2.24, 2.23, 2.19 (3×s, 6H, C6H4(CH3)2
mixture of isomers) ppm. MS-EI (m/e) 652 ([Ru(p5-
C5Ph5){p6-C6H4(CH3)2}ꢁH]+, 15%), 545 ([Ru(p5-
C5Ph5)ꢁH]+, 1%), 106 ([C6H4(CH3)2]+, 44%), 91
([C6H4(CH3)]+, 100%). IR (KBr) wmax: 3110 vw, 3085
(sh), 3057 w, 3032 vw, 2973 vw, 1558 vw, 1540 w, 1506
w, 1505 (sh), 1457 w, 1445 w, 1417 w, 1410 w, 1408
(sh), 1403 (sh), 1076 vw, 1027 w, 801 vw, 783 vw, 740
4.68 (s, 5H, C5H5), 2.22 (s, 15H, CH3) ppm. 13C-
NMR (CD2Cl2, 50.33 MHz):
l
136.0, 133.2
(qArꢁC), 132.9, 128.0 (ArꢁCH), 94.5 (C5 of C5Ar5),
76.3 (C5 of C5H5), 21.2, (CH3) ppm. MS-EI (m/e)
682 ([M]+, 100%). IR (KBr) wmax: 3087 vw, 3055
vw, 3030 vw, 3014 w, 2988 vw, 2977 vw, 2954 vw,
2944 vw, 2920 w, 2864 vw, 1654 vw, 1559 vw, 1540 vw,
1520 vs, 1457 w, 1182 w, 1112 vw, 1102w, 1021 w, 998
vw, 840 w, 817 m, 811 m, 805 m, 747 m, 727 m, 700 vw,
679 vw, 643 vw, 566 w, 544 w, 526 vs, 451 vw, 416 w
s, 704 (sh), 700 vs, 575 m, 556 m, 551 w cm−1
.
A tetraphenylborate salt of the above compound was
obtained by adding NaBPh4 (70 mg, 0.205 mmol) to
[Ru(p5-C5Ph5){p6-C6H4(CH3)2}]+X− (150 mg) in
CH2Cl2/MeOH (25 ml/4 ml). After stirring for 15 min,
evaporation to ca. 5 ml in vacuo precipitated a white
cm−1
.
4.7. Preparation of [Ru(p5-C5Ph5)(p5-C5Me5)] (4)
solid, which was recrystallised from CH2Cl2/n-hexane
A solution of Li(C5Ph5) [prepared from HC5Ph5 (901
mg, 2.02 mmol) and BuLi (0.85 ml of a 2.5 M solution
in hexanes, 2.02 mmol)] in THF (50 ml) was added via
a canula to a solution of [Ru(p5-C5Me5)(COD)Cl] (767
mg, 2.02 mmol) in THF (20 ml). The reaction mixture
was stirred for 16 h and after filtration and evaporation
to dryness, the crude product was purified by column
chromatography. Elution with 25% CH2Cl2/75% n-hex-
ane afforded a pale yellow solution which, after evapo-
ration to dryness and crystallisation of the solid from
CH2Cl2/n-hexane, gave HC5Ph5 (100 mg, 11%) iden-
tified by comparison of its KBr IR spectrum with that
of an authentic sample. Repeated recrystallisations of
the filtrate from CH2Cl2/n-hexane and removal of more
HC5Ph5 finally yielded very pale yellow crystals of
[Ru(p5-C5Ph5)(p5-C5Me5)] (4) (22 mg, 2%). 1H-NMR
(CD2Cl2, 200.13 MHz): l 7.57–6.80 (m, 25H, ArꢁH),
1.67 (s, 15H, CH3) ppm. MS-EI (m/e) 682 ([M]+,
100%). IR (KBr) wmax: 3079 vw, 3056 w, 3026 vw, 1653
w, 1601 w, 1576 w, 1559 w, 1540 w, 1506 m, 1489 w,
1443 w, 1407 w, 1102 vw, 1071 w, 1027 w, 999 w, 810
w, 802 w, 784 w, 740 s, 697 vs, 668 w, 575 m, 555 m,
yielding [Ru(p5-C5Ph5){p6-C6H4(CH3)2}]+BPh4
(5)
−
(110 mg, 50%) m.p.\250°C (decomp.). (Found C,
81.7; H, 5.6. C67H55BRu requires C, 82.79; H, 5.70%).
1H-NMR (CD2Cl2, 200.13 MHz): l 7.31–6.79 (m, 45H,
ArꢁH), 5.87–5.71 (m, 4H, C6H4), 2.12, 2.08, 2.06 (3×
s, 6H, C6H4(CH3)2 mixture of isomers) ppm. MS-EI
(m/e) 653 ([Ru(p5-C5Ph5){p6-C6H4(CH3)2}]+, 3%), 242
([BPh3)]+, 18%), 164 ([BPh2ꢁH]+, 100%), 78 (Ph+,
44%). IR (KBr) wmax 3112 vw, 3083 (sh), 3054 w, 3029
w, 3002 vw, 2983 vw, 1579 w, 1502 w, 1477 vw, 1457
vw, 1446 w, 1425 w, 1410 w, 1262 vw, 1254 (sh), 1223
vw, 1179 vw, 1157 vw, 1133 vw, 1075 vw, 1071 (sh),
1031 w, 1002 vw, 842 vw, 803 vw, 784 vw, 769 vw, 744
m, 735 s, 705 vs, 701 vs, 623 vw, 613 m, 575 m, 556 m,
549 w, 470 vw cm−1
.
4.9. X-ray structure determinations
For 1 and 4, colourless blade-like (1) or approxi-
mately hexagonal plate-like (4) crystals (approximate
dimensions of 0.50×0.22×0.05 mm (1), 0.28×0.20×
0.05 mm (4)) were attached to thin glass fibres, and
mounted on an Enraf-Nonius CAD4 diffractometer
545 w cm−1
.

C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
295
Acknowledgements
employing graphite monochromated Mo–Kh radia-
tion. Cell constants were obtained from a least-squares
refinement using the setting angles of 25 reflections in
the range 19.00B2qB24.22° (1) or 16.66B2qB
24.02° (4). Diffraction data were collected at a temper-
ature of 2191°C using ꢀ:4/3q scans to a maximum
2q value of 49.9° (1) or 54.9° (ꢀ:1/3q scans) (4). The
intensities of three representative reflections measured
every 60 min either (1) decreased by 2.1% and a linear
correction factor was accordingly applied to the data,
or (4) did not change significantly during the data
collection. In both cases an analytical absorption cor-
rection was applied and the data were also corrected
for Lorentz and polarisation effects.
For 3, a colourless blade-like crystal (approximate
dimensions, 0.40×0.32×0.05 mm) was attached to a
thin glass fibre, and mounted on a Rigaku AFC7R
diffractometer employing graphite monochromated
Cu–Kh radiation from a rotating anode generator.
Primitive triclinic cell constants were obtained from a
least-squares refinement using the setting angles of 25
reflections in the ranges 18.80B2qB27.87°. The unit
cell volume of 3 suggested two complexes in the asym-
metric unit. Diffraction data were collected at a tem-
perature of 2191°C using ꢀ-2q scans to a maximum
2q value of 130.2°. The intensities of three representa-
tive reflections measured every 150 reflections did not
change significantly during the data collection. An an-
alytical absorption correction was applied and the
data were also corrected for Lorentz and polarisation
effects.
We thank the Australian Research Council and the
University of Sydney Major Equipment Grant for
financial support and Professor P.A. Lay for valuable
discussions.
References
[1] L.D. Field, T.W. Hambley, T. He, P.A. Humphrey, C.M. Lin-
dall, A.F. Masters, Aust. J. Chem. 49 (1996) 889.
[2] L.D. Field, T.W. Hambley, T. He, A.F. Masters, P. Turner,
Aust. J. Chem. 50 (1998) in press.
[3] W. Heubel, R. Merenyi, J. Organomet. Chem. 2 (1964) 213.
[4] L.D. Field, C.M. Lindall, T. Maschmeyer, A.F. Masters, Aust.
J. Chem. 47 (1994) 1127.
[5] H. Schumann, A. Lentz, R. Weimann, J. Pickardt, Angew.
Chem. Int. Ed. Engl. 33 (1994) 1731.
[6] L.D. Field, G.J. Gainsford, T.W. Hambley, P.A. Humphrey,
C.M. Lindall, A.F. Masters, T.G. St. Pierre, J. Webb, Aust. J.
Chem. 48 (1995) 851.
[7] A. Schott, H. Schott, G. Wilke, J. Brandt, H. Hoberg, E.G.
Hoffmann, Liebigs Ann. Chem. (1973) 508.
[8] L.D. Field, A.F. Masters, M. Gibson, D.R. Latimer, T.W.
Hambley, I.E. Buys, Inorg. Chem. 32 (1993) 211.
[9] N.G. Connelly, I. Manners, J. Chem. Soc. Dalton Trans. (1989)
283.
[10] D.W. Slocum, M. Matusz, A. Clearfield, R. Peascoe, S. Duraj, J.
Macromol. Sci. Chem. 27A (1990) 1405.
[11] H. Adams, N.A. Bailey, A.F. Browning, J.A. Ramsden, C.
White, J. Organomet. Chem. 387 (1990) 305.
[12] L.D. Field, T.W. Hambley, P.A. Humphrey, A.F. Masters, P.
Turner, Polyhedron (1998) in press.
[13] D.W. Slocum, S. Duraj, M. Matusz, J.L. Cmarik, K.M. Simp-
son, D.A. Owen Jr., in: J.E. Sheats, C.A. Carraher Jr., C.V.
Pittman (Eds.), Metal Containing Polymeric Systems, Plenum,
New York, 1985, p. 59.
[14] M.J. Aroney, I.E. Buys, G.D. Dennis, L.D. Field, T.W. Hamb-
ley, P.A. Lay, A.F. Masters, Polyhedron 12 (1993) 2051.
[15] M.I. Bruce, in: E.W. Abel, F.G.A. Stone, G. Wilkinson (Eds.),
Comprehensive Organometallic Chemistry, Pergamon, Oxford,
1995, p. 603.
[16] M.O. Albers, D.C. Liles, D.J. Robinson, A. Shaver, E. Single-
ton, M.B. Wiege, J.C.A. Boeyens, D.C. Levendis, Organometal-
lics 5 (1986) 2321.
[17] R.J. Hoobler, J.V. Adams, M.A. Hutton, T.W. Francisco, B.S.
Haggerty, A.L. Rheingold, M.P. Castellani, J. Organomet.
Chem. 412 (1991) 157.
[18] K.N. Brown, L.D. Field, P.A. Lay, C.M. Lindall, A.F. Masters,
J. Chem. Soc. Chem. Commun. (1990) 408.
[19] R.M. Moriarty, U.S. Gill, Y.-Y. Ku, J. Organomet. Chem. 350
(1988) 157.
[20] H. Le Bozec, D. Touchard, P.H. Dixneuf, Adv. Organomet.
Chem. 29 (1989) 163.
All calculations were undertaken with the teXsan
[31] crystallographic software package. Neutral atom
scattering factors were taken from Cromer and Waber
[32]. Anomalous dispersion effects were included in
Fcalc [33] and the values for Df% and Df%% were those
of Creagh and McAuley [34]. The values for the mass
attenuation coefficients were those of Creagh and
Hubbell [35]. The structures were solved by direct
methods (1) [36] (3, 4) [37] and expanded using
Fourier techniques [38]. The solution of 3 confirmed
the presence of two crystallographically independent
complexes in the asymmetric unit. In general, the non-
hydrogen atoms were modelled anisotropically, the ex-
ception being the phenyl C(17) of 4 which was
modelled isotropically. In the structure of 4, two resid-
[21] I.E. Zanin, M.Y. Antipin, Y.T. Struchkov, Sov. Phys. Crystal-
logr. 36 (1991) 225.
˚
ual electron density peaks separated by 0.83 A are
assumed to be associated with the oxygen atom of a
water molecule partially occupying each of the two
sites. For all structures, hydrogen atoms were included
in the models at calculated positions with group ther-
mal parameters; no hydrogen atoms were included for
the water molecule of 4. Figures were produced using
the program ORTEP [39].
[22] P. Seiler, J.D. Dunitz, Acta Cryst. B36 (1980) 2946.
[23] A. Haarland, J.-E. Nilsson, J. Chem. Soc. Chem. Commun.
(1968) 88.
[24] A. Haarland, J.-E. Nilsson, Acta Chem. Scand. 22 (1968) 2653.
[25] D.C. Liles, A. Shaver, E. Singleton, M.B. Wiege, J. Organomet.
Chem. 286 (1985) 33.
[26] S.P. Gubin, S.A. Smirnova, L.I. Denovich, A.A. Lubovich, J.
Organomet. Chem. 30 (1971) 243.

296
C.U. Beck et al. / Journal of Organometallic Chemistry 565 (1998) 283–296
[27] U. Koelle, A. Salzer, J. Organomet. Chem. 1983 (1983) C27.
[28] M. Albers, D.J. Robinson, A. Shaver, E. Singleton,
Organometallics 5 (1986) 2197.
[29] P.J. Fagan, W.S. Mahoney, J.C. Calabrese, I.D. Williams,
Organometallics 9 (1986) 1843.
[30] L.D. Field, K.M. Ho, C.M. Lindall, A.F. Masters, A.G. Webb,
Aust. J. Chem. 43 (1990) 281.
[31] TeXsan, Single Crystal Structure Analysis Software, Molecular
Structure Corporation, 1993.
[32] D.T. Cromer, J.T. Waber, in: J.A. Ibers, W.C. Hamilton (Eds.),
International Tables for X–Ray Crystallography, Kynock Press,
Birmingham, UK, 1974, p. 71.
[33] J.A. Ibers, W.C. Hamilton, Acta Crystallogr. 17 (1964) 781.
[34] D.C. Creagh, W.J. McAuley, in: A.J.C. Wilson (Ed.), Interna-
tional Tables for Crystallography, Kluwer, Boston, 1992, p. 219.
[35] D.C. Creagh, J.H. Hubbell, in: A.J.C. Wilson (Ed.), Interna-
tional Tables for Crystallography, Kluwer, Boston, 1992, p. 200.
[36] G.M. Sheldrick, SHELXS-86, Oxford University Press, Oxford,
UK, 1985.
[37] A. Altomare, M. Cascarano, C. Giacovazzo, A. Guagliardi, J.
Appl. Cryst. 26 (1993) 343.
[38] P.T. Beurskens, G. Admiraal, G. Beurskens, W.P. Bosman,
R. de Gelder, R. Israel, J.M.M. Smits, The DIRDIF-94 Pro-
gram System. Technical Report Crystallography Laboratory,
University of Nijmegen, The Netherlands, DIRDIF-94 Nijme-
gen, 1994.
[39] C.K. Johnson, ORTEP: a Thermal Ellipsoid Plotting Program,
Report ORNL-5138, Oak Ridge National Laboratories, 1976.
[40] I. Noviandri, K.N. Brown, D.S. Fleming, P.T. Gulyas, P.A. Lay,
A.F. Masters, L. Phillips, J. Phys. Chem. (1997) submitted.
.
.