Synthesis and non-linear optical properties of (g5- pentaphenylcyclopentadienyl)dicarbonylruthenium(II) r-alkenyl complexes

Article abstract of DOI:10.1016/j.ica.2004.09.045

The complexes [Ru{(Z)-HCCHPh}(CO)₂(η⁵-C ₅Ph₅)] (1) and [Ru{(Z)-HCCHC₆H ₄NO₂}(CO)₂(η⁵-C ₅Ph₅)] (2) have been synthesized and their identity confirmed by single-crystal X-ray diffraction studies. Reaction of 2 with PMe₂Ph and Me₃NO in tetrahydrofuran afforded [Ru{(Z)-HCCHC₆H₄NO₂}(CO)(PMe ₂Ph)(η⁵-C₅Ph₅)] (3). Cyclic voltammetry confirms the expected increase in ease of oxidation on proceeding from 2 to 1 and from 2 to 3. Hyper-Rayleigh scattering studies at 1064 nm reveal a dramatic increase in quadratic non-linearity on co-ligand replacement of CO by PMe₂Ph, in proceeding from 2 to 3. Z-scan studies at 800 nm are consistent with significant contribution from two-photon states, and with an increase in γ_real on co-ligand replacement of CO by PMe ₂Ph in proceeding from 2 to 3.

Full text of DOI:10.1016/j.ica.2004.09.045

Inorganica Chimica Acta 358 (2005) 1663–1672
www.elsevier.com/locate/ica
Synthesis and non-linear optical properties of
(g5-pentaphenylcyclopentadienyl)dicarbonylruthenium(II)
r-alkenyl complexes
a
a
a,
a
Paul A. Humphrey , Peter Turner , Anthony F. Masters *, Leslie D. Field ,
b
b,
c
c
Marie P. Cifuentes , Mark G. Humphrey , Inge Asselberghs , Andre Persoons ,
*
´
d
Marek Samoc
a
Centre for Heavy Metals Research and School of Chemistry, The University of Sydney, NSW 2006, Australia
b
Department of Chemistry, Australian National University, Acton, Canberra, ACT 0200, Australia
c
Laboratory of Chemical and Biological Dynamics, Centre for Research on Molecular Electronics and Photonics, University of Leuven,
Celestijnenlaan 200D, B-3001 Leuven, Belgium
d
Laser Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia
Received 13 August 2004; accepted 22 September 2004
Available online 28 October 2004
Dedicated to Professor Gordon Stone, in recognition of his outstanding contributions to organometallic chemistry
Abstract
The complexes [Ru{(Z)-HC@CHPh}(CO)2(g5-C5Ph5)] (1) and [Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-C5Ph5)] (2) have been syn-
thesized and their identity confirmed by single-crystal X-ray diffraction studies. Reaction of 2 with PMe2Ph and Me3NO in tetra-
hydrofuran afforded [Ru{(Z)-HC@CHC6H4NO2}(CO)(PMe2Ph)(g5-C5Ph5)] (3). Cyclic voltammetry confirms the expected increase
in ease of oxidation on proceeding from 2 to 1 and from 2 to 3. Hyper-Rayleigh scattering studies at 1064 nm reveal a dramatic
increase in quadratic non-linearity on co-ligand replacement of CO by PMe2Ph, in proceeding from 2 to 3. Z-scan studies at 800
nm are consistent with significant contribution from two-photon states, and with an increase in creal on co-ligand replacement of
CO by PMe2Ph in proceeding from 2 to 3.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Ruthenium; Pentaphenylcyclopentadienyl; Crystal structures; Alkenyl; Cyclic voltammetry; Non-linear optics
1. Introduction
that have been coordinated to organometallic com-
plexes, the majority of studies of the NLO merit of
organometallics have focussed on a limited range of
complex types, the most-studied being metallocenyl
and r-alkynyl complexes. Some of us have been investi-
gating alkynyl complexes, a class of organometallics that
has revealed large quadratic and cubic non-linearities –
see, for example, [6–17]. Experience with organic mole-
cules has revealed that NLO merit generally increases
for donor–bridge–acceptor compounds on replacing
phenyleneethynylene by phenylenevinylene bridge. The
The non-linear optical (NLO) properties of organo-
metallic complexes have come under considerable scru-
tiny [1–5]. However, despite the plethora of C-ligands
*
Corresponding authors. Tel.: +61 2 9351 3743; fax: +61 2 9351
3329 (A.F. Masters); Tel.: +61 2 6125 2927; fax: +61 2 6125 0760
(M.G. Humphrey).
E-mail addresses: a.masters@chem.usyd.edu.au (A.F. Masters),
mark.humphrey@anu.edu.au (M.G. Humphrey).
0020-1693/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.09.045

1664
P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
Ph
Ph
Ph
Ph
Ph Ru
CO
Ph
Ph
Ph
Ph
Ph Ru Br
OC
Ph
Ph
Ph
Ph
H
H
PMe Ph, Me NO
2
3
H
1. NaBH / thf
4
Ph Ru
OC
thf
H
2. 4-HC C H R / thf
CO
PhMe P
2
6
4
(2) only
2
CO
R = H, NO
2
R
NO
2
R = H (1), NO (2)
2
Scheme 1. Syntheses of complexes 1–3.
Table 1
analogous organometallic replacement has not been
thoroughly tested; while there have been many reports
of the NLO properties of phenylethynyl-bridged (i.e.
substituted phenylacetylide or phenylalkynyl) donor–
bridge–acceptor complexes, phenylethenyl-bridged com-
plexes are little explored. We report herein the synthesis,
structural and cyclic voltammetry studies of (pentaphe-
nylcyclopentadienyl)ruthenium complexes with r-phe-
nylethenyl ligands, together with their quadratic and
cubic NLO properties.
˚
Selected bond lengths (A) and angles (ꢁ) for [Ru{(Z)-HC@CHPh}-
(CO)2(g5-C5Ph5)] (1)
˚
Distance (A) Atoms
˚
Distance (A)
Atoms
Ru(1)–C(1)
Ru(1)–C(2)
Ru(1)–C(3)
Ru(1)–C(45)
C(45)–O(2)
C(36)–C(37)
2.320(4)
2.269(4)
2.286(4)
1.870(5)
1.140(6)
1.329(6)
Ru(1)–C(4)
2.277(4)
2.296(4)
1.876(5)
1.137(6)
2.091(4)
1.477(7)
Ru(1)–C(5)
Ru(1)–C(44)
C(44)–O(1)
Ru(1)–C(36)
C(37)–C(38)
Atoms
Angle (ꢁ)
Atoms
Angle (ꢁ)
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)
36.62(14)
36.36(13)
36.22(13)
61.44(13)
60.89(13)
C(2)–Ru(1)–C(3)
C(4)–Ru(1)–C(5)
C(1)–Ru(1)–C(3)
C(3)–Ru(1)–C(5)
C(5)–Ru(1)–C(2)
37.12(13)
37.08(13)
61.01(14)
61.31(13)
61.38(13)
2. Results and discussion
2.1. Syntheses
O(2)–C(45)–Ru(1) 173.6(5)
Ru(1)–C(36)–C(37) 134.2(4)
O(1)–C(44)–Ru(1) 177.4(5)
C(36)–C(37)–C(38) 127.6(5)
[Ru{(Z)-HC@CHPh}(CO)2(g5-C5Ph5)]
(1)
and
C(44)–Ru(1)–C(45)
C(45)–Ru(1)–C(36)
91.8(2)
91.7(2)
C(36)–Ru(1)–C(44)
85.1(2)
[Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-C5Ph5)] (2) were
prepared by firstly stirring a mixture of [RuBr-
(CO)2(g5-C5Ph5)] and NaBH4 in thf overnight, a reaction
that probably affords a hydrido complex intermediate
(1H NMR ꢀ9.83 ppm). This intermediate was not iso-
lated and fully characterized, but rather was reacted
with either HC2Ph or 4-HC2C6H4NO2 in tetrahydrofu-
ran to afford the desired complexes in reasonable yield
(Scheme 1). Complexes 1 and 2 were characterized by
elemental analysis, and mass, infrared and 1H NMR
spectra. The reaction of 2 with PMe2Ph and Me3NO
in thf resulted in replacement of CO by the phosphine,
Because of the obvious similarities between the struc-
tures of 1 and 2 they will be discussed simultaneously. In
each case, coordination by the g5-pentaphenylcyclopen-
tadienyl group, the alkenyl ligand and the two carbonyl
groups creates a ‘‘piano stool’’ environment about the
ruthenium atom. One of the CO ligands is close to
coplanarity with the vinyl group. The Ru-(ring centroid)
˚
distance is 1.93 A in both molecules, slightly above the
1
˚
mean (1.901 A) for the Ru(CO)2(C5R5) fragment,
˚
while the average Ru–C(C5Ph5) distances are 2.290 A
˚
for 1 and 2.276 A for 2, slightly above the mean
˚
(2.248 A) for the Ru(CO)2(C5R5) fragment. The Ru–
˚
CO distances (1.876(5) and 1.870(5) A for 1 and
affording
[Ru{(Z)-HC@CHC6H4NO2}(CO)(P-
Me2Ph)(g5-C5Ph5)] (3) (Scheme 1), the identity of which
was confirmed by elemental analysis, and infrared and
1H NMR spectra.
˚
1.864(14) and 1.786(13) A for 2) are not unusual, the
Ru–CO distances of 1 being at about the mean for this
2.2. X-ray crystallography
Single-crystal X-ray diffraction studies of 1 and 2
were undertaken. Selected interatomic bond distances
and angles for complexes 1 and 2 are given in Tables 1
and 2, respectively. Figs. 1 and 2 contain ORTEP depic-
1
Of the approximately 230 Ru(CO)2(C5R5) fragments with termi-
nal carbonyl ligands, the Ru–C(centroid) distances vary between 1.737
˚
and 2.094 A, with a mean value of 1.901 A, the Ru–C(cyclopentadie-
˚
nyl) distances range between 2.070 and 2.429 A, with a mean value of
˚
˚
2.248 A, and the Ru–CO distances vary between 1.724 and 1.875 A,
˚
with a mean value of 1.875 A.
˚
tions of the molecular geometries of
respectively.
1 and 2,

P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
1665
Table 2
54.2ꢁ for 2, which is similar to that in other pentaphenyl-
cyclopentadienyl complexes [18].
˚
Selected bond lengths (A) and angles (ꢁ) for [Ru{(Z)-
HC@CHC6H4NO2}(CO)2(g5-C5Ph5)] (2)
˚
Distance (A) Atoms
˚
Distance (A)
Atoms
2.3. Cyclic voltammetry
Ru(1)–C(1)
Ru(1)–C(3)
Ru(1)–C(5)
Ru(1)–C(45)
C(45)–O(4)
C(36)–C(37)
C(41)–N(1)
O(1)–N(1)
2.263(10) Ru(1)–C(2)
2.272(11) Ru(1)–C(4)
2.255(10) Ru(1)–C(44)
1.786(13) C(44)–O(3)
1.176(13) Ru(1)–C(36)
1.312(15) C(37)–C(38)
1.469(19) O(2)–N(1)
1.169(14)
2.284(11)
2.306(11)
1.864(14)
1.147(14)
2.048(12)
1.438(19)
1.185(17)
In order to gain insight into the electronic environ-
ment of the new alkenyl complexes, the redox properties
of 1, 2 and 3 were examined by cyclic voltammetry, the
results being summarized in Table 3.
Cyclic voltammograms for all three complexes con-
tain redox processes assigned to the metal-centered oxi-
dation. Redox potentials vary in a predictable manner,
based on the electronic properties of the ligands. Thus,
introduction of a more electron-withdrawing alkenyl lig-
and (in 2 by comparison with 1) results in an increase in
difficulty of oxidation, whereas introduction of a more
electron-donating co-ligand (in 3 by comparison with
2) results in the expected increased ease of oxidation;
the oxidation process in 3 is the only reversible process
in this system. Voltammograms for 2 and 3 contain
reversible electron transfers assigned to nitro-centered
reduction processes, the more electron-rich phosphine-
containing complex 3 being the more difficult to reduce.
We have previously correlated the parameter
DðE1=2 ꢀ E1=2 Þ with kmax for the relevant MLCT
Atoms
Angle (ꢁ)
Atoms
Angle (ꢁ)
C(1)–Ru(1)–C(2)
C(2)–Ru(1)–C(3)
C(3)–Ru(1)–C(4)
C(2)–Ru(1)–C(4)
C(4)–Ru(1)–C(1)
35.0(3)
37.3(4)
36.3(3)
61.4(4)
59.6(4)
C(4)–Ru(1)–C(5)
C(5)–Ru(1)–C(1)
C(1)–Ru(1)–C(3)
C(3)–Ru(1)–C(5)
C(5)–Ru(1)–C(2)
35.9(3)
36.2(4)
59.4(4)
60.2(4)
60.7(4)
O(3)–C(44)–Ru(1) 173.3(13)
Ru(1)–C(36)–C(37) 141.4(11)
O(4)–C(45)–Ru(1) 176.6(17)
C(36)–C(37)–C(38) 130.5(14)
C(45)–Ru(1)–C(44)
C(45)–Ru(1)–C(36)
94.5(7)
81.6(7)
C(36)–Ru(1)–C(44)
C(40)–C(41)–N(1) 116.1(17)
C(41)–N(1)–O(1) 122.7(17)
92.8(5)
C(42)–C(41)–N(1) 120.5(19)
C(41)–N(1)–O(2) 119.0(17)
fragment, whilst the introduction of the nitro acceptor
group in 2 results in one of the Ru–CO distances (that
of the ligand approximately normal to the vinyl group)
being at the shorter end of the range for this fragment.
The Ru–C(alkenyl) distances (2.091(4) A for 1 and
˚
2.048(12) A for 2) are consistent with the expected in-
RuII=III
NO02=ꢀI
transition, and with molecular quadratic optical non-lin-
earity bHRS, in ruthenium alkynyl complexes [19]; such a
procedure is not justifiable for 2, given the non-reversi-
bility of the metal-centered oxidation.
˚
crease in p-backbonding upon introduction of a nitro
acceptor group (in comparing 1 and 2). In summary,
the Ru-cyclopentadienyl distances are at about the mean
for Ru(CO)2(C5R5) fragments, as is the Ru–CO distance
of 1, but the structural effects of the introduction of a ni-
tro group (in 2) are manifest as a shortening of a Ru–CO
and Ru–C(alkenyl) distances.
The C5 nucleii of the pentaphenylcyclopentadienyl
˚
ligands are planar to within 0.019(5) A for 1 and
˚
0.02(2) A for 2. The C–C bond lengths of the C5 ring
2.4. Non-linear optical measurements
Quadratic optical non-linearities of 1–3 were deter-
mined by the hyper-Rayleigh scattering (HRS) tech-
nique at 1064 nm. The results of these studies are
given in Table 3, together with linear optical absorption
data, and two-level-corrected quadratic non-linearities.
[Note: it has been suggested that the two-state model
may be appropriate in the limited cases in which struc-
tural change is restricted to the molecular component
responsible for the charge-transfer band contributing
to the hyperpolarizability [20]. For the present series
of complexes, it is likely that higher energy bands are
associated with transitions involving ligands other than
the alkenyl ligand, with little change in dipole moment
between ground and excited states, and hence only a
small contribution to the optical non-linearity. It is pos-
sible, therefore, that the two-level-corrected values may
have some significance.] Introduction of the nitro sub-
stituent (in 2 by comparison with 1) affords an alkenyl
complex with a donor–bridge–acceptor composition,
but does not result in a large increase in observed
non-linearity. In contrast, co-ligand variation (compar-
ing 2 and 3) results in a dramatic change in non-linear-
ity. These trends also apply to two-level-corrected data.
There have been several studies exploring the quadratic
˚
range from 1.369(13) to 1.456(14) A for 1 and from
˚
1.424(5) to 1.450(5) A for 2, the average C–C bond
˚
˚
length being 1.413 A for 1 and 1.441 A for 2, which
are consistent with C5Ph5 rings in other metal
complexes.
The ipso-carbon atoms of each of the phenyl rings are
displaced slightly from the C5 plane by between 0.0997
˚
and 0.2282 A for 1 and between 0.1035 and 0.2312 A
˚
˚
for 2, with the average distance being 0.1693 A for 1
˚
and 0.1737 A for 2. These ipso-carbon atoms and the
ruthenium are on opposite sides of the C5 plane in both
complexes. The phenyl rings are all also planar to within
˚
˚
0.009(7) A for 1 and 0.025(2) A for 2, and are canted at
between 40.7(2)ꢁ and 61.4(2)ꢁ for 1 and between 44.5(5)ꢁ
and 66.4(5)ꢁ for 2 to the C5 ring in a paddlewheel
arrangement. The average deviation of the phenyl rings
from co-planarity with the C5 ring is 53.4ꢁ for 1 and

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P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
Fig. 1. Molecular geometry and atomic labelling scheme for [Ru{(Z)-HC@CHPh}(CO)2(g5-C5Ph5)] (1), viewed along (a) and perpendicular to (b)
the C5 plane of the C5Ph5 ligand.
ꢀ
NLO potential of alkynyl complexes, the results from
which have afforded design rules to enhance non-linear-
ity [13]. In contrast, alkenyl complexes are compara-
tively little explored [4], the limited previous examples
including the bridged complexes Fe2{l-C@CHCH
@CH–R–CH@C(CN)2}(l-CO)(CO)2(g-C5H5)2 (R = 4-
C6H4, 2,5-C4H2S) [21]. The non-linearity of 3 is, to
the best of our knowledge, the largest observed thus

P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
1667
Fig. 2. Molecular geometry and ꢀatomic labelling scheme for [Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-C5Ph5)] (2), viewed along (a) and perpendicular
to (b) the C5 plane of the C5Ph5 ligand.
far for an alkenyl complex, but there is a paucity of
data. This is likely to be the result of lack of suitable
syntheses; despite the presence of an electron-withdraw-
ing co-ligand (CO), and unfavourable Z-stereochemis-
try at the alkenyl ligand, the large quadratic non-
linearity observed for 3 suggests that alkenyl complexes
are worthy of further investigation as quadratic NLO
materials.

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P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
Cubic optical non-linearities of 1–3 were determined
by the Z-scan technique at 800 nm, the results being pre-
sented in Table 3. The negative creal and significant cimag
values are strongly suggestive of the dispersion effect of
two-photon states contributing to the observed re-
sponses, a result noted with other cyclopentadienylru-
thenium complexes [22,23]. Nevertheless, an increase in
the magnitude of creal is apparent on replacing elec-
tron-withdrawing co-ligand CO (in 2) with electron-
donating PMe2Ph (in 3). The errors in the data for 1 are
too large to permit comment on the effect of introducing
the nitro substituent. Cubic non-linearities for 1–3 are
small, and similar in magnitude to other small cyclopen-
tadienylruthenium complexes [22,23]. Few third-order
NLO data for alkenyl complexes are extant [5], the lim-
ited examples including several mono- and bimetallic
zirconocene complexes measured by third-harmonic
generation at 1.91 lm [24]. Although small in magni-
tude, the cubic non-linearity of 3 is, to the best of our
knowledge, the largest observed thus far for an alkenyl
complex.
3. Conclusion
The
complexes
[Ru{(Z)-HC@CHPh}(CO)2(g5-
C5Ph5)] (1), [Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-
C5Ph5)] (2) and [Ru{(Z)-HC@CHC6H4NO2}(CO)(P-
Me2Ph)(g5-C5Ph5)] (3) have been synthesized and the
identity of the former two complexes confirmed by sin-
gle-crystal X-ray diffraction studies. Replacement of
co-ligand CO by PMe2Ph results in increased ease of
oxidation, a dramatic increase in quadratic non-linear-
ity, and an increase in the refractive component of the
cubic non-linearity. The quadratic non-linearity of 3
is large, despite the presence of the remaining CO co-
ligand affording a metal center that has additional scope
for electron enrichment, and a Z- rather than E-config-
ured alkenyl ligand; this last-mentioned result suggests
that alkenyl complexes have promise as organometallic
NLO materials.
4. Experimental
4.1. Instrumentation
Elemental analyses (C, H and N) were performed by
the University of Sydney Microanalytical Service. Melt-
ing points were recorded on a Reichert hot platform in
air and are uncorrected. Fourier transform infrared
spectra were recorded on a Digilab FTS-40 spectrome-
ter. 1H NMR spectra were recorded on Bruker
AC200F (1H NMR 200.13 MHz) or Bruker AMX400
(1H NMR 400.21 MHz) spectrometers. The spectra were
referenced internally to TMS or to residual solvent reso-

P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
1669
1
nances (CD2Cl2, H d 5.30 ppm). Electron impact mass
1002 vw, 970 vw, 921 vw, 847 vw, 820 vw, 802 w, 782
w, 768 vw, 740 m, 700 s, 677 vw, 669 vw, 647 vw, 618
vw, 593 w, 573 m, 563 m, 542 w, 514 w, 502 w, 427
spectra were obtained using a Kratos MS 9 geometry
mass spectrometer with a direct insertion probe, a 280
ꢁC source temperature, 70 eV ionization voltage and 4
kV acceleration voltage.
vw cmꢀ1. IR (CH2Cl2): m(CO) 2023 vs, 1967 vs cmꢀ1
.
4.5. Preparation of [Ru{(Z)-HC@CHC6H4NO2}(CO)2
(g5-C5Ph5)] (2)
4.2. General experimental conditions
All manipulations were performed at atmospheric
pressure under an atmosphere of dinitrogen by using
conventional Schlenk techniques. Tetrahydrofuran
(thf) (Merck) was pre-dried over sodium wire and dis-
tilled from sodium benzophenone ketyl. n-Hexane
(BDH) was distilled from sodium wire. Dichlorometh-
ane (Ajax) was distilled from calcium hydride.
To a sample of [RuBr(CO)2(g5-C5Ph5)] (604 mg,
0.884 mmol) in thf (40 ml) was added NaBH4 (158
mg, 4.18 mmol). The reaction was stirred at RT over-
night. Further amounts of NaBH4 were added until con-
sumption of the starting material [IR (CH2Cl2): m(CO)
absence of 2000 vs, 2048 vs due to [RuBr(CO)2(g5-
C5Ph5)]]. After filtration the solvent was removed (ro-
tary evaporator) to give a brown powder, which was
dissolved in thf (50 ml) in a Schlenk flask and 4-
HC2C6H4NO2 (103 mg, 0.70 mmol) was added. After
stirring overnight the reaction mixture was filtered by
gravity. The solvent was removed, then column chroma-
tography was performed. Elution with 50% CH2Cl2/50%
n-hexane yielded an orange band which eluted as a yel-
low-green solution. Evaporation and crystallization of
the solid from CH2Cl2/n-hexane gave yellow-green crys-
tals of [Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-C5Ph5)]
(2) (198 mg, 30%). (C45H31NO4Ru requires: C, 71.99;
H, 4.16; N, 1.87. Found: C, 71.67; H, 4.06; N,
4.3. Starting materials
NaBH4 (Ajax) and HC2Ph (Aldrich) were used as re-
ceived. 4-HC2C6H4NO2 was prepared by literature pro-
cedures [25]. Trimethylamine N-oxide dihydrate
(Aldrich) was dehydrated by sublimation prior to use.
Silica for flash column chromatography (240–400 mesh)
was obtained from Merck.
4.4. Preparation of [Ru{(Z)-HC@CHPh}(CO)2(g5-C5-
Ph5)] (1)
1
1.78%.). H NMR (CD2Cl2, 400.21 MHz): d 8.14 (2H,
To a sample of [RuBr(CO)2(g5-C5Ph5)] (574 mg,
0.841 mmol) in thf (40 ml) was added NaBH4 (150
mg, 3.98 mmol). The reaction was stirred at RT over-
night. Further amounts of NaBH4 were added until con-
sumption of the starting material [IR (CH2Cl2): m(CO)
absence of 2000 vs, 2048 vs due to [RuBr(CO)2(g5-
C5Ph5)]]. After filtration the solvent was removed (ro-
tary evaporator) to give a brown powder which was
dissolved in thf (40 ml) in a Schlenk flask and HC2Ph
(71 mg, 0.70 mmol) was added. After stirring at RT
overnight, the reaction mixture was filtered by gravity.
The solvent was removed, then column chromatography
was performed. Elution with 50% CH2Cl2/50% n-hexane
and evaporation and crystallization of the resultant so-
lid from CH2Cl2/n-hexane gave pale yellow-green crys-
tals of [Ru{(Z)-HC@CHPh}(CO)2(g5-C5Ph5)] (1) (180
mg, 30%) (C45H32O2Ru requires: C, 76.58; H, 4.57.
Found: C, 76.79; H, 4.51%.). 1H NMR (CD2Cl2,
400.21 MHz): d 7.59 (1H, d, J(HH) = 10.0 Hz, RuCH),
7.30–6.95 (31H, m, C5Ph5 + Ph + @CHPh) ppm. Mass
spectrum: EI (m/e) 707 ([M + H]+, 1%), 679
([M ꢀ CO + H]+, 100%), 650 ([M ꢀ 2CO]+, 48%), 547
([M ꢀ 2CO ꢀ HC2HPh]+, 22%), 446 (HC5Ph5+, 4%),
d, J(HH) = 8.6 Hz, HCCNO2), 7.62 (1H, d,
J(HH) = 10.7 Hz, RuCH), 7.48 (2H, d, J(HH) = 8.6
Hz, @CHCCH), 7.32 (1H, d, J(HH) = 10.7 Hz,
@CHC6H4NO2), 7.19–6.95 (25H, m, C5Ph5) ppm. Mass
spectrum:
EI
(m/e)
751
([M]+,
3%),
724
([M ꢀ CO + H]+, 100%). IR (KBr) mmax 3108 vw, 3087
vw, 3059 vw, 3039 vw, 3035 vw, 2954 vw, 2021 vs,
1964 vs, 1938 vw, 1599 w, 1578 vw, 1558 vw, 1516 m,
1489 vw, 1456 vw, 1445 vw, 1419 vw, 1406 vw, 1341
m, 1309 vw, 1181 vw, 1158 vw, 1109 vw, 1076 vw,
1028 vw, 920 vw, 873 vw, 856 w, 802 vw, 782 vw, 767
vw, 740 w, 699 m, 677 vw, 669 vw, 594 vw, 580 w, 561
w, 538 vw, 502 vw cmꢀ1. IR (CH2Cl2): m(CO) 2024 vs,
1968 vs cmꢀ1
.
4.6. Preparation of [Ru{(Z)-HC@CHC6H4NO2}(CO)
(PMe2Ph)(g5-C5Ph5)] (3)
To
a
stirred solution of [Ru{(Z)-HC@CH-
C6H4NO2}(CO)2(g5-C5Ph5)] (2) (108 mg, 0.144 mmol)
in thf (35 ml) was added PMe2Ph (0.040 ml, 0.28 mmol)
and Me3NO (18 mg, 0.24 mmol), giving a colour change
to red-yellow. After stirring overnight the reaction mix-
ture was evaporated to dryness in vacuo. Column chro-
matography was performed and elution with 50%
CH2Cl2/50% n-hexane yielded a yellow-orange solution
which, after evaporation to dryness and crystallization
of the bright orange solid from CH2Cl2/n-hexane,
104 (H2C2HPh+, 53%), 28 (CO+, 45%). IR (KBr) mmax
:
3108 vw, 3086 vw, 3058 w, 3029 vw, 2952 vw, 2021 vs,
1965 vs, 1935 vw, 1601 w, 1577 vw, 1559 vw, 1541 vw,
1502 w, 1489 w, 1444 w, 1420 vw, 1406 vw, 1304 w,
1287 vw, 1267 vw, 1181 vw, 1156 vw, 1074 w, 1028 w,

1670
P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
yielded
[Ru{(Z)-HC@CHC6H4NO2}
(CO)(P-
atoms. An ORTEP [33] depiction of the molecule with
20% displacement ellipsoids is provided in Fig. 1.
Me2Ph)(g5-C5Ph5)] (3) as an orange powder (79 mg,
64%) m.p. >250 ꢁC (dec.). (C52H42NO3PRu requires:
C, 72.54; H, 4.92; N, 1.63. Found: C, 72.85; H, 5.17;
4.7.2. Crystal data for [Ru{(Z)-HC@CHPh}(CO)2(g5-
C5Ph5)] (1)
Formula: C46H34Cl2O2Ru, molecular weight: 790.70,
1
N, 1.78%.). H NMR (CD2Cl2, 200.13 MHz): d 9.02
(1H, dd, J(HH) = 16.1 Hz, J(PH) = 4.6 Hz, RuCH), 8.05–
6.79 (35H, m, C5Ph5 + Ph + C6H4 + @CHC6H4NO2),
1.69 (3H, d, J(HP) = 2.5 Hz, Me), 1.65 (3H, d,
J(HP) = 2.5 Hz, Me) ppm. IR (KBr) mmax 3081 (sh),
3056 w, 3037 (sh), 2973 vw, 2956 vw, 2916 vw, 2869 vw,
2863 vw, 1923 vs, 1594 (sh), 1587 m, 1558 w, 1540 m,
1535 m, 1506 s, 1456 vw, 1444 w, 1436 w, 1419 w,
1406 w, 1331 vs, 1283 w, 1208 vw, 1176 w, 1157 vw,
1108 m, 1075 w, 1028 w, 967 w, 944 w, 909 m, 858 w,
841 w, 801 w, 781 w, 767 vw, 740 m, 704 (sh), 700 vs,
688 w, 620 vw, 584 m, 565 m, 558 w, 547 w, 531 w,
517 w, 491 w, 426 w cmꢀ1. IR (CH2Cl2): m(CO) 1924
˚
orthorhombic, space group Pbca (#61), a = 19.323(2) A,
3
˚
˚
˚
b = 15.940(2) A, c = 26.801(3) A, V = 8254.9(16) A ,
Dcalc = 1.272 g cmꢀ3, Z = 8, crystal size 0.482 ·
0.356 · 0.246 mm, colour colourless, habit prism, tem-
˚
perature = 223(2) K, k(Mo Ka) = 0.71073 A, l(Mo
Ka) 0.544 mmꢀ1, T(SADABS
)
0.84, 1.00, 2hmax
min,max
56.04, hkl range: ꢀ25–25, ꢀ21–21, ꢀ35–35, N = 86477,
Nind = 9871 (Rmerge = 0.0302), Nobs = 8113 (I > 2r(I)),
Nvar = 487, residuals R1(F) = 0.0622, wR2(F2, all
data) = 0.1661, GoF(all) = 1.225, Dqmin,max = ꢀ0.897,
ꢀ3
˚
A .
0.929 eꢀ
vs cmꢀ1
.
4.7.3. [Ru{(Z)-HC@CHC6H4NO2}(CO)2(g5-C5Ph5)]
(2)
4.7. Structure determinations
A suitable crystal was obtained by slow diffusion of n-
hexane into a dichloromethane solution of 2. A yellow
oblate like crystal was inserted in a glass capillary, and
mounted on a Rigaku AFC7R diffractometer employing
graphite monochromated Cu Ka radiation generated
from a rotating anode. Cell constants were obtained
from a least squares refinement against 21 reflections lo-
cated between 41ꢁ and 54ꢁ 2h. Data were collected at
294(2) K with x–2h scans to 130ꢁ 2h. The data process-
ing was undertaken with TEXSAN [27], and subsequent
computations were carried out with the TEXSAN [27]
and XTAL [28] graphical user interfaces. The intensities
of 3 standard reflections measured every 150 reflections
changed by ꢀ5.39 during the data collection, and a cor-
rection was accordingly applied to the data. An empiri-
cal absorption correction based on azimuthal scans of
three suitable reflections was also applied to the data.
The structure was solved in the space group P21/n
(#14) by direct methods with SIR-92 [34], and extended
and refined with SHELXL-97 [32]. In general the non-
hydrogen atoms were modelled anisotropically, and
the hydrogen atoms were included in the model at calcu-
lated positions with group thermal parameters. Three
sites were treated as partially occupied water sites and
no hydrogens were included in the model for these sites.
The water oxygen occupancies were refined and then
fixed, with the total occupancy being 0.5, and these sites
were modelled with isotropic displacement parameters.
A riding atom model with group displacement parame-
ters was used for the hydrogen atoms. Although the
crystals decomposed unless mounted in a capillary, there
was no direct evidence of solvent molecules in the lattice;
presumably the bulk of the solvent had been lost from
the crystal before the completion of the data collection.
An ORTEP [33] depiction of the molecule with 20% dis-
placement ellipsoids is provided in Fig. 2.
4.7.1. [Ru{(Z)-HC@CHPh}(CO)2(g5-C5Ph5)] (1)
A suitable crystal was obtained by slow diffusion of n-
hexane into a dichloromethane solution of 1. A colour-
less prismatic crystal was attached with Exxon Paratone
N to a short length of fibre supported on a thin piece of
copper wire inserted in a copper mounting pin. The crys-
tal was quenched in a cold nitrogen gas stream from an
Oxford Cryosystems Cryostream. A Bruker SMART
1000 CCD diffractometer employing graphite mono-
chromated Mo Ka radiation generated from a sealed
tube was used for the data collection. Cell constants
were obtained from a least squares refinement against
7512 reflections located between 5ꢁ and 56ꢁ 2h. Data
were collected at 223(2) K with x scans to 56ꢁ 2h. The
data integration and reduction were undertaken with
SAINT and XPREP [26], and subsequent computations
were carried out with the TEXSAN [27] and XTAL [28]
graphical user interfaces. The intensities of 75 standard
reflections recollected at the end of the experiment did
not change significantly during the data collection.
An empirical absorption correction determined with
SADABS [29,30] was applied to the data.
The structure was solved in the space group Pbca
(#61) by direct methods with SIR-97 [31], and extended
and refined with SHELXL-97 [32]. In addition to the com-
plex molecule, the asymmetric unit was found to contain
two disordered dichloromethane solvate sites. Rigid
bodies were used to model the disordered solvate sites,
with three groups being used for one site and four for
the second. The solvate pupations were refined and then
fixed, giving a total occupancy of one. The non-hydro-
gen atoms of the complex molecule were modelled with
anisotropic thermal parameters, whereas the solvate
molecules were modelled with isotropic thermal param-
eters. A riding atom model was used for the hydrogen

P.A. Humphrey et al. / Inorganica Chimica Acta 358 (2005) 1663–1672
1671
4.7.4. Crystal data for [Ru{(Z)-HC@CHC6H4NO2}-
5. Supplementary material
(CO)2(g5-C5Ph5)] (2)
Formula: C45H31NO4.50Ru, molecular weight:
Final atomic positional coordinates, with estimated
standard deviations, bond lengths and angles and aniso-
tropic thermal parameters have been deposited at the
Cambridge Crystallographic Data Centre and allocated
the deposition Nos. CCDC 246351 for 1 and CCDC
246352 for 2. Copies of this information may be ob-
tained free of charge from The Director, CCDC, 12 Un-
ion Road, Cambridge, CB2 1E2, UK (fax: +44 1223 336
033; email: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
758.78, monoclinic, space group P21/n (#14),
˚
˚
˚
a = 10.409(2) A, b = 22.806(3) A, c = 16.790(4) A, b =
3
91.64(2)ꢁ, V = 3984.1(13) A , Dcalc = 1.265 g cmꢀ3
,
˚
Z = 4, crystal size 0.47 · 0.11 · 0.10 mm, colour yellow,
habit oblate, temperature = 294(2) K, k(Cu Ka) =
1.54178 A, l(Cu Ka) 3.525 mmꢀ1, T(Psi Scan)min,max
˚
0.646, 0.998, 2hmax 130.18, hkl range: 0–12, 0–26,
ꢀ19–19, N = 7204, Nind = 6773 (Rmerge = 0.0659),
Nobs = 2290
(I > 2r(I)),
Nvar = 473,
residuals
R1(F) = 0.0808, wR2(F2, all data) = 0.2472, GoF(all) =
ꢀ3
˚
1.208, Dqmin,max = ꢀ0.771, 1.013 e A
.
Acknowledgements
4.8. Hyper-Rayleigh scattering measurements
We thank the Australian Research Council (A.F.M.,
L.D.F., M.G.H., and M.P.C.), the Fund for Scientific
Research-Flanders (G.0297.04) (A.P.), the Belgian Gov-
ernment (IUAP/5/3) (A.P.) and the K.U.Leuven (GOA/
2000/03) (A.P.) for financial support. M.G.H. is an
ARC Australian Professorial Fellow, and M.P.C. is an
ARC Australian Research Fellow and I.A. is a Postdoc-
toral Fellow of FWO-Vlaanderen.
The beam from an injection-seeded Nd:YAG laser
(Q-switched Nd:YAG Quanta Ray GCR5, 1064 nm, 8
ns pulses, 10 Hz) was focussed into a cylindrical cell (7
ml) containing the sample. The intensity of the incident
beam was varied by rotation of a half-wave plate placed
between crossed polarizers. Part of the laser pulse was
sampled by a photodiode to measure the vertically
polarized incident light intensity. The frequency-
doubled light was collected by an efficient condenser sys-
tem and detected by a photomultiplier. The harmonic
scattering and linear scattering were distinguished by
appropriate filters; gated integrators were used to obtain
intensities of the incident and harmonic scattered light.
Further details of the experimental procedure have been
reported elsewhere [35].
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