1,8-Diphenylocta-1,3,5,7-tetraene complexes of ruthenium(II): Crystal structures of [μ-(s-cis-1,2,3,4-η:s-cis-5,6,7,8-η-PhCH=CHCH=CHCH=CH-CH=CHPh) (RuClCp*)2] and [μ-(s-trans-1,2,3,4-η:s-trans-5,6,7,8-η-PhCH=CHCH=CH-CH=CHCH=CHPh) {Ru(acac)2}2]

Article abstract of DOI:10.1021/om970534h

Reaction of 1,8-diphenyl-1,3,5,7-octatetraene with [Ru(μ-Cl)Cp*]₄ (1) (Cp* = η₅-pentamethylcyclopentadienyl) gave [μ-(s-cis-1,2,3,4-η:s-cis-5,6,7,8-η-PhCH=CHCH=CHCH=CH-CH=CHPh) (RuClCp*)₂] (2), whose crystal structure revealed that 2 has a planar tetraene backbone coordinated by two Cp*RuCl moieties in s-cis-η⁴-fashion; while the reaction with Ru(acac)₃/Zn system resulted in the formation of [μ-(s-trans-1,2,3,4-η:s-trans-5,6,7,8-η-PhCH=CHCH=CHCH=CHCH=CHPh) {Ru(acac)₂}₂] (3), where both of the two Ru(acac)₂ moieties prefer s-trans coordination and thus the plane of the octatetraene backbone of 3 is deformed into an S-shape. Electrochemical studies for complexes 2 and 3 revealed that they have a coupling between the two ruthenium centers and are conjugatively interacted dπ-pπ organometallic systems.

Full text of DOI:10.1021/om970534h

410
Organometallics 1998, 17, 410-414
1,8-Dip h en ylocta -1,3,5,7-tetr a en e Com p lexes of
Ru th en iu m (II): Cr ysta l Str u ctu r es of
[µ-(s-cis-1,2,3,4-η:s-cis-5,6,7,8-η-P h CHdCHCHdCHCHdCH-
CHdCHP h )(Ru ClCp *)2] a n d
[µ-(s-tr a n s-1,2,3,4-η:s-tr a n s-5,6,7,8-η-P h CHdCHCHdCH-
CHdCHCHdCHP h ){Ru (a ca c)2}2]
Kazushi Mashima,* Hiroki Fukumoto, and Kazuhide Tani
Department of Chemistry, Graduate School of Engineering Science, Osaka University,
Toyonaka, Osaka 560, J apan
Masa-aki Haga
Coordination Chemistry Laboratories, Institute for Molecular Science,
Myodaiji, Okazaki 444, J apan
Akira Nakamura
Department of Macromolecular Science, Graduate School of Science, Osaka University,
Toyonaka, Osaka 560, J apan
Received J une 25, 1997
Reaction of 1,8-diphenyl-1,3,5,7-octatetraene with [Ru(µ-Cl)Cp*]4 (1) (Cp* ) η5-penta-
methylcyclopentadienyl) gave [µ-(s-cis-1,2,3,4-η:s-cis-5,6,7,8-η-PhCHdCHCHdCHCHdCH-
CHdCHPh)(RuClCp*)2] (2), whose crystal structure revealed that 2 has a planar tetraene
backbone coordinated by two Cp*RuCl moieties in s-cis-η4-fashion; while the reaction with
Ru(acac)3/Zn system resulted in the formation of [µ-(s-trans-1,2,3,4-η:s-trans-5,6,7,8-η-
PhCHdCHCHdCHCHdCHCHdCHPh){Ru(acac)2}2] (3), where both of the two Ru(acac)2
moieties prefer s-trans coordination and thus the plane of the octatetraene backbone of 3 is
deformed into an S-shape. Electrochemical studies for complexes 2 and 3 revealed that
they have a coupling between the two ruthenium centers and are conjugatively interacted
dπ-pπ organometallic systems.
In tr od u ction
centers.9-14 On the other hand, the full complexation
of polyenes with transition metals has rarely been
reported so far.15 This is expected to provide a unique
pπ-dπ conjugated organometallic system; three catego-
ries (η2-complexation16 and two different η4-complex-
ations in s-cis- or s-trans-fashion17) being depicted in
Scheme 1. These distinctive structural features of the
diene complexes included in the polyene ligand prompted
π-Conjugated organic polymers have attracted much
interest in view of their unique physical properties
(conducting, photochemical, and nonlinear optical ma-
terials, etc.);1,2 however, less attention has been given
to π-conjugated polymers that incorporate transition
metal complex chromophores into the organic polymer
backbone.3-8 Polyene is one of the most interesting
π-conjugated compounds that bridge two metal
(9) Beck, W.; Niemer, B.; Wieser, M. Angew. Chem., Int. Ed. Engl.
1993, 32, 923.
(10) Ribou, A.-C.; Launay, J .-P.; Takahashi, K.; Nihira, T.; Tarutani,
S.; Spangler, C. W. Inorg. Chem. 1994, 33, 1325.
(11) Tolbert, L. M.; Zhao, X.; Ding, Y.; Bottomley, L. A. J . Am. Chem.
Soc. 1995, 117, 12891.
(12) Ribou, A.-C.; Launay, J .-P.; Sachtleben, M. L.; Li, H.; Spangler,
C. W. Inorg. Chem. 1996, 35, 3735.
(1) Salaneck, W. R.; Clark, D. L.; Samuelsen, E. J . E. Science and
Applications of Conducting Polymers; Adam Hilger: New York, 1990.
(2) Polymers for Second-Order Nonlinear Optics; Lindsay, G. A.;
Singer, K. D., Eds.; American Chemical Society: Washington, DC,
1995.
(3) Manners, I. Angew. Chem., Int. Ed. Engl. 1996, 35, 1602.
(4) Altmann, M.; Enkelmann, V.; Beer, F.; Bunz, U. H. F. Organo-
metallics 1996, 15, 394.
(5) Ley, K. D.; Whittle, C. E.; Bartberger, M. D.; Schanze, K. S. J .
Am. Chem. Soc. 1997, 119, 3423.
(6) Wang, B.; Wasielewski, M. R. J . Am. Chem. Soc. 1997, 119, 12.
(7) Peng, Z.; Gharavi, A. R.; Yu, L. J . Am. Chem. Soc. 1997, 119,
4622.
(8) Nishihara, H. In Handbook of Organic Conductive Molecules and
Polymers; Nalwa, H. S., Ed.; Wiley: New York, 1997; Vol. 2.
(13) Sponsler, M. B. Organometallics 1995, 14, 1920.
(14) Hradsky, A.; Bildstein, B.; Schuler, N.; Schottenberger, H.;
J aitner, P.; Ongania, K.-H.; Wurst, K.; Launay, J .-P. Organometallics
1997, 392.
(15) Adams, R. D.; Wu, W. Organometallics 1993, 12, 1243.
(16) Polymer-bound CpMn(CO)2(η2-CdC) complexes in polyethylene
film have been reported: Clarke, M. J .; Howdle, S. M.; J obling, M.;
Poliakoff, M. J . Am. Chem. Soc. 1994, 116, 8621.
(17) H. W. Whitlock, J .; Reich, C.; Woessner, W. D. J . Am. Chem.
Soc. 1971, 93, 2483.
S0276-7333(97)00534-7 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 01/07/1998

1,8-Diphenylocta-1,3,5,7-tetraene Complexes of Ru(II)
Organometallics, Vol. 17, No. 3, 1998 411
Sch em e 1. Differ en t Mod es of Meta l Coor d in a tion
π-conjugation of the tetraene backbone. In the absence
of metal coordination, this type of (s-cis)-trans-polyene
structure has not been found presumably due to the
unfavorable steric congestion at the inner hydrogens.
Bending back of these hydrogens on the Ru complex-
ation is primarily responsible for the observed extensive
planarity involving the two terminal phenyl groups.
When the reaction of 1 with an excess of the octa-
tetraene in THF was carried out, the complexation of
both diene units of the tetraene proceeded simulta-
neously and no predictable mononuclear complex was
observed in contrast to the previously reported mono-
nuclear Fe(CO)3(η4-1,8-diphenyl-1,3,5,7-octatetraene)
complex, which involved a mixture of monometallic
products.17 Introduction of the RuClCp* moiety to one
of the two diene parts of the tetraene would lower the
LUMO level of the remaining diene part and thereby
makes the adjacent diene moiety more reactive toward
the latter introduction of the RuClCp* fragment.
Treatment of Ru(acac)3 (acac ) acetylacetonate) in the
presence of zinc dust19,20 with the octatetraene gave rise
to another type of a dinuclear ruthenium tetraene
complex, [µ-(s-trans-1,2,3,4-η:s-trans-5,6,7,8-η-PhCHdCH-
CHdCHCHdCHCHdCHPh){Ru(acac)2}2] (3) in 74%
yield (eq 2). In good agreement to the case of 2, an
us to synthesize tetraene complexes of ruthenium. We
anticipated that this would be a model system leading
to the formation of the fully metal-complexed poly-
(acetylene) system. Herein we report synthesis and
characterization of the 1,8-diphenyl-1,3,5,7-octatetraene
complexes bearing two different kinds of ruthenium
fragments, RuCp*Cl (Cp* ) η5-pentamethylcyclopen-
tadienyl) and Ru(acac)2 (acac ) acetylacetonate); these
auxiliary ligands on the ruthenium atom controlling
coordination modes (s-cis and s-trans) as well as conju-
gative interactions between metal centers.
Resu lts a n d Discu ssion
Reaction of [RuClCp*]4 (1) with cyclic or acyclic diene
is known to give ruthenium-diene complexes of the type
of Cp*RuCl(diene).18 Thus the reaction of 1 with
(E,E,E,E)-1,8-diphenyl-1,3,5,7-octatetraene was inves-
tigated, hoping that this reaction would produce a
dinuclear ruthenium(II) complex [µ-(s-cis-1,2,3,4-η:s-cis-
5,6,7,8-η-P h CH dCH CH dCH CH dCH CH dCH P h )-
(RuClCp*)2] (2). Addition of 1 to 2 equiv of (E,E,E,E)-
1,8-diphenyl-1,3,5,7-octatetraene in THF led to the
precipitation of 2 as red solids in 74% yield (eq 1). The
analogous reaction with an excess of the tetraene ligand
resulted in the exclusive formation of 3. The cen-
trosymmetric dinuclear structure of 3 has been deter-
mined crystallographically (Figure 2). Most significant
feature is that both of the two octahedral Ru(acac)2
fragments prefer s-trans coordination and anti-position
each other. Thus the plane of the octatetraene backbone
of 3 is deformed, in contrast to 2, into an S-shape;
therefore the torsion angle of C(1)-C(2)-C(3)-C(4)
being 128(1)°. This deformation of the diene unit has
already been observed in mononuclear s-trans diene
complexes such as ZrCp2(s-trans-η4-PhCHdCH-
CHdCHPh),21 NbCp(s-cis-η4:s-trans-η4-2,4,7,9-C14H22),22
MoCp(NO)(s-trans-η4-2,4-C8H14),23 and Ru(acac)2(η4-1,3-
diene).19,20 The bond distances of Ru-O lie in the range
of 2.027(9)-2.051(10) Å as expected for s-trans-diene
complexes of Ru(acac)2(diene).19,20
dinuclear structure of 2 was determined by analytical
and spectroscopic data as well as X-ray crystallography;
an ORTEP is shown in Figure 1 along with representa-
tive bond distances and angles. In the complex 2, both
of the two RuClCp* fragments coordinate to the two
diene parts of the tetraene ligand in s-cis fashion. The
dihedral angle (179.2(7)°) of C(1)-C(2)-C(3)-C(4) shows
the planarity of the two diene units; which are related
by the centrosymmetry, and thus all eight carbons of
the tetraene ligand lie in a plane, indicating the longer
The cyclic voltammograms of the dinuclear tetraene
complexes 2 and 3 were measured together with those
(19) Ernst, R. D.; Melendez, E.; Stahl, L.; Ziegler, M. L. Organome-
tallics 1991, 10, 3635.
(20) Mele´ndez, E.; Ilarraza, R.; Yap, G. P. A.; Rheingold, A. L. J .
Organomet. Chem. 1996, 522, 1.
(21) Kai, Y.; Kanehisa, N.; Miki, K.; Kasai, N.; Mashima, K.; Yasuda,
H.; Nagasuna, K.; Nakamura, A. J . Chem. Soc., Chem. Commun. 1982,
191.
(22) Melendez, E.; Arif, A. M.; Rheingold, A. L.; Ernst, R. D. J . Am.
Chem. Soc. 1988, 110, 8703.
(18) Fagan, P. J .; Mahoney, W. S.; Calabrese, J . C.; Williams, I. D.
Organometallics 1990, 9, 1843.
(23) Hunter, A. D.; Legzdins, P.; Nurse, C. R.; Eisenstein, F. W. B.;
Willis, A. C. J . Am. Chem. Soc. 1985, 107, 1791.

412 Organometallics, Vol. 17, No. 3, 1998
Mashima et al.
F igu r e 1. ORTEP drawing of complex 2 with the atom numbering scheme. Selected bond lengths (Å), angles (deg), and
torsion angles (deg): Ru-Cl ) 2.445(1), Ru-C(1) ) 2.270(4), Ru-C(2) ) 2.167(4), Ru-C(3) ) 2.163(4), Ru-C(4) )
2.275(4), C(1)-C(2) ) 1.399(5), C(2)-C(3) ) 1.436(5), C(3)-C(4) ) 1.381(6), C(4)-C(4)* ) 1.453(7); Cl-Ru-C(1) )
84.7(1), Cl-Ru-C(4) ) 82.0(1), C(1)-Ru-C(4) ) 78.7(1), Ru-C(1)-C(2) ) 67.6(2), Ru-C(4)-C(3) ) 67.5(2), C(1)-C(2)-
C(3) ) 121.1(4), C(2)-C(3)-C(4) ) 121.5(4); C(1)-C(2)-C(3)-C(4) ) 179.2(7), C(3)-C(4)-C(4)*-C(3)* ) 180.
F igu r e 2. ORTEP drawing of complex 3 with the atom numbering scheme. Selected bond lengths (Å), angles (deg), and
torsion angles (deg): Ru-O(1) ) 2.040(8), Ru-O(2) ) 2.027(9), Ru-O(3) ) 2.043(8), Ru-O(4) ) 2.051(10), Ru-C(1) )
2.29(1), Ru-C(2) ) 2.10(1), Ru-C(3) ) 2.11(1), Ru-C(4) ) 2.27(1), C(1)-C(2) ) 1.38(2), C(2)-C(3) ) 1.44(2), C(3)-C(4)
) 1.37(2), C(4)-C(4)* ) 1.45(2); O(1)-Ru-O(2) ) 92.9(4), O(1)-Ru-O(3) ) 84.2(4), O(1)-Ru-O(4) ) 82.8(4), O(2)-Ru-
O(3) ) 84.3(4), O(2)-Ru-O(4) ) 175.0(4), O(3)-Ru-O(4) ) 92.6(4), C(1)-Ru-C(4) ) 100.7(5), C(1)-C(2)-C(3) ) 119(1),
C(2)-C(3)-C(4) ) 119(1); C(1)-C(2)-C(3)-C(4) ) 128(1), C(2)-C(3)-C(4)-C(4)* ) -167(1), C(3)-C(4)-C(4)*-C(3)* )
180.
of mononuclear 1,4-diphenyl-1,3-butadiene complexes,
Cp*RuCl(s-cis-η4-PhCHdCHCHdCHPh) (4) and Ru-
(acac)2(s-trans-η4-PhCHdCHCHdCHPh) (5) in different
solvents. A reversible or quasireversible oxidation was
observed at E1/2 ) + 0.33 V for complex 4 and E1/2 ) +
0.40 V vs Fc+/Fc for 5. On the other hand, dinuclear
complexes 2 and 3 showed a strong solvent dependence
on the cyclic voltammogram. The cyclic voltammogram
of 2 in 1,2-dichloroethane showed an irreversible two-
electron oxidation wave with an Ep value of + 0.16 V at
100 mV/s. However, at faster scan rate (>10 V/s)
another quasi-reversible wave at +0.25 V was observed
in addition to the reversible first wave at +0.09 V,
indicating the successive one-electron processes followed
by fast chemical reactions. This observation allows us
to evaluate approximate potential separation between
the first and the second processes. On the other hand,
complex 3 showed two quasireversible one-electron
oxidation waves at E1/2 ) +0.29 and +0.46 V at -50
°C. Since the differences in potential between the half-
reactions of the successive electron transfers can depend
upon the extent of interaction between the sites, the
potential separation for complex 3 (∆E1/2 ) 170 mV) is
comparable to that for complex 2 (∆E1/2 ) ca. 160 mV),
indicating a coupling between the metal centers (con-
jugated dπ-pπ organometallic systems). When the CV

1,8-Diphenylocta-1,3,5,7-tetraene Complexes of Ru(II)
Organometallics, Vol. 17, No. 3, 1998 413
Ta ble 1. Cr ysta l a n d Refin em en t Da ta for 2 a n d 3
measurement was performed in polar solvent such as
acetone or THF, the cyclic voltammograms of 2 and 3
showed only irreversible oxidation wave(s) (Ep ) + 0.06
V for complex 2; +0.31 and +0.50 V for 3 in acetone,
and Ep ) +0.15 V for 2; +0.35 V vs Fc+/Fc for 3 in THF,
both at 100 mv/s, respectively), indicating that solvent
plays an important role for the oxidation processes of
these complexes.
In summary, we have demonstrated that it is possible
to control the coordination mode of the diene units in
the tetraene ligand by varying the auxiliary ligand on
the ruthenium metal. We found that the complexation
of the tetraene with two ruthenium moieties occurred
concurrently, and thus the complete complexation of
much longer π-conjugated polyene system with the
ruthenium fragments would be expected instead of
partial ones. We are presently engaged in attempts to
prepare fully coordinated multinuclear ruthenium com-
plexes of polyenes as well as poly(alkyne)s, both of which
are expected to be new dπ-pπ bonded electronic materi-
als.
complex
formula
fw
2
C
3
40H48Cl2Ru2
C41H48O8Cl2Ru2
941.87
801.87
cryst system
space group
a, Å
b, Å
c, Å
monoclinic
P21/n (#14)
8.342(3)
18.412(2)
11.687(2)
92.69(2)
2
monoclinic
P21/c (#14)
12.140(3)
15.367(2)
13.122(3)
106.70(1)
2
â, deg
Z
V, Å3
1792.9(6)
1.485
2344.8(7)
1.334
d
calcd, g cm-3
radiation
Mo KR
Mo KR
(λ ) 0.710 69 Å)
+h, +k, (l
0.2 × 0.2 × 0.3
10.18
(λ ) 0.710 69 Å)
+h, +k, (l
0.2 × 0.2 × 0.3
6.85
no. of reflcns measd
no. of crystal size, mm
abs coeff, cm-1
scan mode
ω-2θ
20
ω-2θ
20
temp, °C
2θmax, deg
55.0
4535
4254 (Rint ) 0.015)
3233
55.0
5840
5585 (Rint ) 0.030)
2522
no. of data colcd
no. of unique data
no. of observns
(I > 1.50σ(I))
199
0.036
(I > 3.00σ(I))
243
0.074
no. of variables
Ra
b
Rw
0.028
0.065
GOF
2.39
0.48 (max)
-0.47 (min)
4.13
1.80 (max)
-1.05 (min)
Exp er im en ta l Section
∆, e Å-3
Gen er a l P r oced u r es. All manipulations involving air-
and moisture-sensitive organometallic compounds were carried
out by using the standard Schlenk techniques under an argon
atmosphere. THF, hexane, toluene, and ether were dried over
sodium benzophenone ketyl. Dichloromethane was purified
by distillation after drying over CaH2. Ethanol was distilled
from magnesium ethoxide. 1,4-Diphenyl-1,3-butadiene and
1,8-diphenyl-1,3,5,7-octatetraene were purchased from Aldrich
Chemical Co., Inc. Complexes [Ru(µ3-Cl)(η5-C5Me5)]4 (1) and
Ru(acac)3 were prepared according to the literature proce-
dure.1,2
Nuclear magnetic resonance [1H(400 and 270 MHz) and 13C
(400 MHz) NMR] spectra were measured on a J EOL J NM-
GSK400 or a J EOL J NM-EX270 spectrometer. Other spectra
were recorded by the use of the following instruments: IR,
Hitachi 295; low- and high-resolution mass spectra, J EOL SX-
102; UV/vis spectra, J asco Ubest-30 and Shimadzu UV-265FS.
X-ray crystallographic studies were performed on a Rigaku
AFC-7 diffractometer interfaced with the TEXSAN computer
system. Elemental analyses were performed at Elemental
Analysis Center, Faculty of Science, Osaka University. All
melting points were measured in sealed tubes and were not
corrected.
Electrochemical measurements were made at room temper-
ature as well as -50 °C with a BAS 100 B/W electrochemical
workstation. The working electrode was a platinum disk
electrode and the auxiliary electrode was a platinum wire. The
reference electrode was Ag/AgNO3 (0.01 M in 0.1 M TBABF4-
CH3CN), abbreviated as Ag/Ag+. The E1/2 value for the
ferrocenium/ferrocene (Fc+/Fc) couple is +0.23 V vs Ag/Ag+.
All potential values are reported vs Fc+/Fc.
P r ep a r a tion of 2. To a suspension of [Ru(µ3-Cl)(η5-C5-
Me5)]4 (1) (1.084 g, 1.00 mmol) in THF (50 mL) was added 1,8-
diphenyl-1,3,5,7-octatetraene (0.513 g, 1.99 mmol) at 25 °C.
The color of the mixture turned to bright red, and then red
solid was precipitated. After 3 h, the red precipitation was
collected and then washed with hexane. Recrystallization from
dichloromethane afforded 2 (1.18 g, 74% yield) as red micro-
crystals, mp 220-230 °C (dec). 1H NMR (CDCl3, 35 °C): δ
1.36 (s, 30H, C5Me5), 2.97 (dd, 2H, H4, J ) 6.5 and 2.6 Hz),
3.57 (d, 2H, H1, J ) 10.1 Hz), 5.10-5.30 (m, 4H, H2 and H3),
7.17-7.52 (m, 10H, C6H5). FAB MS (NBA matrix): m/z 802
(M+). UV/vis (CH2Cl2): λmax 518 nm (ꢀ ) 1.14 × 104 M-1 cm-1).
Anal. Calcd for C40H48Cl2Ru2: C, 59.90, H, 6.03. Found: C,
59.64, H, 5.74.
a
b
2
R ) ∑||Fo| - |Fc||/|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑wFo
]
1/2. w )
1/σ2(Fo); function minimized: ∑w(|Fo| - |Fc|)2.
P r ep a r a tion of 3. To Ru(acac)3 (0.400 g, 1.00 mmol) in
ethanol (30 mL) was added 1,8-diphenyl-1,3,5,7-octatetraene
(0.129 g, 0.500 mmol) and zinc dust (activated by HCl, 0.13
g). The reaction mixture was refluxed for 12 h until the color
turned to orange. The solvent was removed in vacuo, and then
the residue was extracted with toluene (40 mL). The remained
zinc dust and Zn(acac)2 were removed by centrifugation. The
supernatant was concentrated and then cooled at -20 °C,
affording 3 (0.32 g, 74% yield) as yellow-orange solids, mp
165-170 °C (dec). 1H NMR (CD2Cl2, 35 °C): δ 1.61 (s, 6H,
acac methyl), 1.90 (s, 6H, acac methyl), 1.97 (s, 6H, acac
methyl), 2.31 (s, 6H, acac methyl), 3.72 (m, 2H, H3), 4.06 (m,
2H, H4), 4.47 (m, 4H, H1 and H2), 5.40 (s, 2H, acac methine),
5.57 (s, 2H, acac methine), 7.13-7.23 (m, 10H, C6H5). FAB
MS (NBA matrix): m/z 858 (M+). IR (Nujol): ν (CO)/cm-1 1560
(m), 1545 (w), 1520 (s). UV/vis (CH2Cl2): λmax 340 nm (ꢀ )
0.26 × 104 M-1 cm-1). Anal. Calcd for C40H46O8Ru2: C, 56.05,
H, 5.41. Found: C, 55.70, H, 5.54.
P r ep a r a tion of 4. To a suspension of [Ru(µ3-Cl)(η5-C5-
Me5)]4 (1) (0.544 g, 0.500 mmol) was added 1,4-diphenyl-1,3-
butadiene (0.413 g, 2.00 mmol) at room temperature. The
reaction mixture was stirred for 3 h. The color of the solution
turned to bright red. After the solvent was removed under
reduced pressure, the resulting residue was extracted with
dichloromethane (40 mL). The extract was concentrated to
ca 5 mL and cooled at -20 °C for 12 h, affording 4 as red
crystals (0.75 g, 78% yield), mp 175-180 °C (dec). 1H NMR
(CDCl3, 35 °C): δ 1.16 (s, 15H, C5Me5), 3.81 (dd, 2H, J ) 14.6
and 4.7 Hz), 5.33 (dd, 2H), 7.18-7.57 (m, 10H, C6H5). FAB
MS (NBA matrix): m/z 478 (M+). UV/vis (CH2Cl2): λmax 481
nm (ꢀ ) 0.59 × 104 M-1cm-1). Anal. Calcd for C26H29ClRu:
C, 65.31, H, 6.11. Found: C, 65.18, H, 5.99.
P r ep a r a tion of 5. To a suspension of Ru(acac)3 (0.200 g,
0.502 mmol) in ethanol (30 mL) was added 1,4-diphenyl-1,3-
butadiene (0.103 g, 0.499 mmol) and zinc dust (activated by
HCl, 0.13 g). The reaction mixture was refluxed for 12 h until
the color turned to orange. The solvent was removed in vacuo,
and the residue was extracted with toluene (40 mL). After
the extraction was concentrated to ca. 5 mL, crystallization
from toluene at -20 °C afforded 5 (0.15 g, 58% yield) as orange
microcrystals, mp 191-197 °C (dec). 1H NMR (C6D6, 35 °C):

414 Organometallics, Vol. 17, No. 3, 1998
Mashima et al.
δ 1.56 (s, 6H, acac methyl), 1.77 (s, 6H, acac methyl), 4.52 (dd,
2H, J ) 8.7 and 2.2 Hz), 4.70 (dd, 2H), 5.30 (s, 2H, acac
methine), 7.01-7.42 (m, 10H, C6H5). FAB MS (NBA matrix):
m/z 506 (M+). IR (Nujol): ν (CO)/cm-1 1568 (s), 1515 (s). UV/
vis (CH2Cl2): λmax 325 nm (ꢀ ) 0.13 × 104 M-1 cm-1). Anal.
Calcd for C26H28O4Ru: C, 61.76, H, 5.58. Found: C, 61.49,
H, 5.54.
indices are defined as R ) ∑||Fo| - |Fc||/∑|Fo| and Rw ) [∑w(|Fo|
- |Fc|)2/∑w(|Fo|)2]1/2, where w-1 ) σ2(Fo) ) σ2(Fo2)/(4Fo2). The
positions of all non-hydrogen atoms for all complexes were
found from a difference Fourier electron density map and
refined anisotropically. All hydrogen atoms for each complex
were placed in calculated positions (C-H ) 0.95 Å) and kept
fixed. All calculations were performed using the TEXSAN
crystallographic software package, and illustrations were
drawn with ORTEP.
Cr ysta llogr a p h ic Da ta Collection a n d Str u ctu r e De-
ter m in a tion of 2 a n d 3. Da ta Collection . Crystals of 2
and 3 (Table 1) suitable for X-ray diffraction studies were
sealed in glass capillaries under argon atmosphere, and then
each crystal of complexes was mounted on a Rigaku AFC-7R
four-circle data collection using Mo KR radiation. The unit
cell parameters at 23 °C were determined by a least-squares
fit to 2θ values of 25 strong higher reflections for all complexes.
Three standard reflections were chosen and monitored every
150 reflections. Empirical absorption correction was carried
out based on an azimuthal scan. Every sample showed no
significant intensity decay during the data collection.
Str u ctu r e Deter m in a tion a n d Refin em en t. The struc-
tures of all complexes were solved by direct method (SHELXS
86)24 and refined by the full-matrix least-squares method. In
the subsequent refinement, the function ∑w(|Fo| - |Fc|)2 was
minimized, where |Fo| and |Fc| are the observed and calculated
structure factors amplitudes, respectively. The agreement
Ack n ow led gm en t. This work was financially sup-
ported by a Grant-in-Aid for Scientific Research on
Priority Area from the Ministry of Education, Science
and Culture, J apanese government. K.M. appreciates
the financial support from the Asahi Glass Foundation.
Su p p or tin g In for m a tion Ava ila ble: Final positional
parameters, final thermal parameters, bond distances, angles,
and torsion angles for the complexes 2 and 3 (30 pages).
Ordering information is given on any current masthead page.
OM970534H
(24) Shedrick, G. M. In Crystallographic Computing 3; Sheldrick,
G. M., Kru¨ger, C., Goddard, R., Eds.; Oxford University Press: Oxford,
U.K., 1985; p 179.