Coupling of alkynes promoted by Ru(CO)3(PPh3)2 and carbon dioxide: Syntheses and structures of (η4-C4R2R′ 2CO)Ru(CO)2(PPh3) (R = R′ = Ph; R = Ph, R′ = C≡CPh) and {Ph2C4(C≡CPh)2}Ru(CO)(PPh 3)2

Article abstract of DOI:10.1016/S0022-328X(98)01104-8

Dimerization of alkyne by Ru(CO)₃(PPh₃)₂ proceeded under carbon dioxide in refluxing toluene or C₆H₆ to afford a cyclopentadienone Ru(0) complex (R₂C₄R′₂CO)Ru(CO)₂(PPh ₃) (R = R′ = Ph; R = Ph, R′ = -C≡CPh) and cyclobutadiene Ru(0) complex (R₂C₄R′₂)Ru(CO)₂(PPh ₃) (R = Ph, R′ = -C≡CPh) in moderate yields, each compound being formed as mixtures of isomers, 2,4-and 3,4-diethynylated cyclobutadiene-1-one and 1,2-and 1,3-diethynylated cyclobutadiene, from MS, IR, ¹³C-, ³¹P-NMR and X-ray analyses. At higher temperatures, a carbonate Ru(II) complex Ru(CO₃)(CO)₂(PPh₃)₂ was also obtained in 85% yield from the reaction in presence of diphenylacetylene. A cationic Ru(II) species supplied by (CO+CO^2-₃) formed via a reductive disproportionation of CO₂ is proposed as an intermediate in an earlier stage of the coupling reactions of the alkyne molecules.

Full text of DOI:10.1016/S0022-328X(98)01104-8

Journal of Organometallic Chemistry 578 (1999) 61–67
Coupling of alkynes promoted by Ru(CO)3(PPh3)2 and carbon dioxide:
syntheses and structures of (h4-C4R2R%2CO)Ru(CO)2(PPh3)
(R=R%=Ph; R=Ph, R%=CꢀCPh) and
{Ph2C4(CꢀCPh)2}Ru(CO)(PPh3)2
Shinsaku Yamazaki a,*, Zenei Taira b
a Chemistry Laboratory, Kochi Gakuen College, 292 Asahi Tenjin-Cho, Kochi 780, Japan
b Faculty of Pharmaceutical Sciences, Tokushima Bunri Uni6ersity, 180 Nishihama Bouji, Yamashiro-Cho, Tokushima 770, Japan
Received 22 April 1998
Abstract
Dimerization of alkyne by Ru(CO)3(PPh3)2 proceeded under carbon dioxide in refluxing toluene or C6H6 to afford a
cyclopentadienone Ru(0) complex (R2C4R2%CO)Ru(CO)2(PPh3) (R=R%=Ph; R=Ph, R%= –CꢀCPh) and cyclobutadiene Ru(0)
complex (R2C4R2%)Ru(CO)2(PPh3) (R=Ph, R%= –CꢀCPh) in moderate yields, each compound being formed as mixtures of
isomers, 2,4-and 3,4-diethynylated cyclobutadiene-1-one and 1,2-and 1,3-diethynylated cyclobutadiene, from MS, IR, 13C-,
31P-NMR and X-ray analyses. At higher temperatures, a carbonate Ru(II) complex Ru(CO3)(CO)2(PPh3)2 was also obtained in
85% yield from the reaction in presence of diphenylacetylene. A cationic Ru(II) species supplied by (CO+CO23−) formed via a
reductive disproportionation of CO2 is proposed as an intermediate in an earlier stage of the coupling reactions of the alkyne
molecules. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Alkyne dimerization; Diethynylated cyclopentadienone; Diethynylated cyclobutadiene; Reductive disproportionation of
carbon dioxide; Synthesis; Crystal structures
Instead of potential problems of syntheses of M(CO)5
(M=Ru, Os), it is well known as a general reaction
1. Introduction
that carbon dioxide readily undergoes reductive dispro-
Dimerization of alkynes at a single metal center has
been observed for many complexes [1], most of which
portionation by the 18-electron complex M%[M(CO)4]
2
have been derived by photolysis and pyrolysis of metal-
carbonyls and cyclopentadienyl complexes with alkyne
molecules [2–4]. By an analogous procedure, unprece-
dented dimerization of bis(trimethylsilyl) butadiyne and
co-dimer ization of bis(trimethylsilyl) acetylene and
bis(trimethylsilyl)hexatriyne over CpCo(CO)2 have been
found by Vollhardt [5] (Fig. 1). Yet, dimerization of
alkyne molecules by 18-electron complexes using car-
bon dioxide is elusive.
* Corresponding author.
Fig. 1. Reactions of CpCo (CO)2 with silylalkynes.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)01104-8

62
S. Yamazaki, Z. Taira / Journal of Organometallic Chemistry 578 (1999) 61–67
Table 1
NMR data of {Ph4C4(CꢀCPh)2CO}Ru(CO)2(PPh3)} with isomers of 3,4- and 2,4-diethynyl substituted cyclopentadienones (1-a and 1-b),
(Ph4C4CO)Ru(CO)2(PPh3) with geometrical isomer-a and -b (2-a and 2-b), and {Ph2C4(CꢀCPh)2}Ru(CO)(PPh3)2 with isomers of 1,2- and
1,3-diethynyl substituted cyclobutadiene (3-a and 3-b)
Compound
31P-NMRa
13C-NMRb
CꢀCPh
95.8
Ring
83.0
CꢀO
200.1
CꢁO
1-a and 1-b
36.4
33.1
82.3
80.9
166.8
(12.7)
93.4
94.5
83.9
82.5
85.3
84.4
85.3
83.5
199.0c
175.0
166.3
2-a and 2-b
3-a and 3-b
26.5
32.7
105.31
105.27
81.59
81.57
201.8
ꢀ193
168.7
168.6
35.1
32.0
103.4
102.7
97.9
89.5
99.1
98.9
89.2
88.8
200.0
(14.1)
155.1
(12.7)
a Measured in CDCl3. Chemical shifts are in ppm relative to 85% H3PO4 at 0.00.
b Measured in CDCl3. Chemical shifts are in ppm relative to SiMe4 at 0.00. J (P, C) in Hz are in parentheses.
c J(P,C) not resolved.
(M=Fe, Ru, Os; M%=Li, Na) to afford M(CO)5 and
2. Results and discussion
carbonate, as Cooper et al. [6] found.
2.1. Isomers of diethynylated cyclopentadienone Ru(0)
compounds, {Ph2C4(CꢀCPh)2CO}Ru(CO)2(PPh3) 1-a,b
M2%[Ru(CO)4]+2CO2“Ru(CO)5+M%CO3
2
where M%=Li, Na.
In our goal of alkyne oligomerization at a single
metal center, we have accordingly utilized carbon diox-
ide and relatively stable and readily available
Ru(CO)3(PPh3)2 which is isoelectronic with M(CO)5
(M=Ru, Os). Ru(CO)3(PPh3)2 does not react with
alkyne alone by pyrolytic methods. However, under
carbon dioxide in refluxing C6H6 or toluene,
Ru(CO)3(PPh3)2 reacts with alkyne and also 1,3-diyne
to afford a sequence of alkyne dimerized complexes: the
By reacting Ru(CO)3(PPh3)2 with 1,4-diphenyl-1,3-
butadiyne(1,3-diyne) in refluxing toluene under CO2,
diethynylated cyclopentadienone complex {Ph2C4(CC-
Ph)2CO}Ru(CO)2(PPh3) was obtained in 31% yield
with two isomers with diethynyl-substutuents at the
3,4- and 2,4-positions on the cyclopentadienone
ring(CPDN), as their 13C- and 31P-NMR spectra shown
in Table 1. These two isomers could not be separated
by repeated TLC(Al2O3 or SiO2) methods. However, a
pale yellow crystal of one isomer was obtained from
C6H6-acetone and its X-ray structure analysis was per-
formed. The crystal structure of {Ph2C4(CꢀCPh)2-
CO}Ru(CO)2(PPh3) 1-a is shown in Fig. 2, and it
reveals that coupling of 1,3-diyne molecules and carbon
monoxide apparently occurred to form a 2,5-diphenyl-
3,4-bis(phenylethynyl)-2,4-cyclopentadiene-1-one now
coordinating to Ru(0) as a four electron donor ligand.
The geometry around Ru(0) may be described as a
tetragonal pyramid, in which the apical site is occupied
by carbon monoxide{C(6)–0(4)}. The bond lengths
cyclopentadienone
complex
(Ph4C4CO)Ru(CO)2-
(PPh3), the diethynylated complex {Ph2C4(CꢀCPh)2-
CO}Ru(CO)2(PPh3) and the diethynylated cyclobu-
tadiene complex {Ph2C4(CꢀCPh)2}Ru(CO)(PPh3)2 in
moderate yields, respectively. From the reactions of
Ru(CO)3(PPh3)2 with diphenylacetylene under CO2 in
refluxing toluene, a carbonate complex Ru(CO3)-
(CO)2(PPh3)2 was further obtained in high yield. This
paper deals an unique and simultaneous syntheses of
diethynylated cyclopentadienone and cyclobutadiene
Ru(0) complexes each with isomers by using carbon
dioxide. A crystal structure of one isomer of the cy-
˚
Ru–C(9) and Ru–C(12) 2.26(3) A are longer than
˚
˚
clopentadienone complex (Ph2C4R% –CO)Ru(CO)2-
Ru–C(10) 2.19(3) A and Ru–C(11) 2.18(3) A so that
the ketonic carbon C(8) is away from the ruthenium
2
(PPh3) (R%=Ph, –CꢀCPh) was determined to reveal
that the 3,4-disubstituted-cyclopentadienone is bonded
to Ru(0) as a four electron donor ligand. Reductive
disproportionation of carbon dioxide using Ru-
(CO)3(PPh3)2 to give cis- and trans-[Ru(CO)4(PPh3)2]-
[CO3] is proposed as a primary intermediate for the
present coupling reactions of alkynes.
˚
atom (Ru–C(8) 2.55(3) A with a weak interaction). The
C–C distances in the dienone ring in the present case
are within normal ranges, but are longer than those of
(h4-C4Ph4CO)Os(CO)3 and (h4-C4Ph4CO)Ru(CO)3 and
length alternations are not regular: C(9)–C(10) 1.50(6)
˚
˚
˚
A C(10)–C(11) 1.50(6) A C(11)–C(12) 1.40(5) A (long-

S. Yamazaki, Z. Taira / Journal of Organometallic Chemistry 578 (1999) 61–67
63
long-short), while the diene carbon bond lengths of
(h4-C4Ph4CO)Os(CO)3 and (h4-C4Ph4CO)Ru(CO)3 are
˚
1.41–1.46 A (short-long-short alternation) [3] and
˚
1.42–1.48 A (long-short-long alternation), respectively.
The carbon–carbon triple bond distances of the
˚
alkynyls C(19)–C(20) 1.19 A and C(27)–C(28) 1.17(5)
˚
˚
A are both close to 1.20 A observed in the dangling
triple bond of [Pt(h2-diyne)(PPh3)2] and [Pt2Fe(m3-h2–,
h1,h1-(diyne) (CO)5(PPh3)2] [7]. These length alterna-
tions of the diene carbon bond lengths in {Ph2-
C4(CꢀCPh)2CO}Ru(CO)2(PPh3) may be affected by
Ru-ring p-back donation which may be strengthened by
the electron withdrawing substituent of ethynyl-groups
attached to C(10) and C(11) atoms approaching an
electron delocalized structure in the ring. The bond
Fig. 3. A proposed polarization and charge separated structure.
coupling. Carbon monoxide and the ketonic carbonyl
of the ring from 1-a appeared at 200.06 {J(P,C)=12.7
Hz} and 166.72, while the resonances at 199.6
{J(P,C)=12.0 Hz} and 175.0 ppm are due to 1-b,
respectively.
˚
distance of the ketonic carbonyl C(8)–0(3) 1.24(4) A is
2.2. Isomers of (Ph4C4CO)Ru(CO)2(PPh3).(C6H6) 2-a,b
longer than the (p4-C4Ph4CO)M(CO)3 type complexes
˚
˚
(1.224 A for M=Ru; 1.207(15) A for M=Os). In fact,
the IR stretching frequency of ketonic carbonyl was
1619.4 cm−1, which is in the lowest wavenumber in the
compounds found so far and are rather close to the
region to an enolic form. Therefore, the present com-
pound may largely be represented by a polarization and
charge-separated structure [2] as shown in Fig. 3.
31P-NMR and 13C-NMR of {Ph2C4(CꢀCPh)2-
CO}Ru(CO)2(PPh3) apparently show that another iso-
mer 1-b is contained with an approximate ratio of the
isomers a:b=4:1. In 12 resonances arising from the
(CꢀCPh)-group and ring carbons observed at 81–96
ppm (Table 1), eight resonances were assigned due to
the 2,4-diethynylated isomer 1-b (Fig. 4) given by the
head-to-tail coupling of the diyne, while the other four
intense resonances are due to the symmetrical 3,4-di-
substituted isomer 1-a produced by the head-to-head
The
tetraphenylcyclo-
pentadienone
complex
(Ph4C4CO)Ru(CO)2(PPh3)(C6H6) was prepared by an
analogous procedure to the corresponding diethyny-
lated complex. It unexpectedly contains mixtures of two
geometrical isomers as its 31P-NMR and 13C-NMR
show. These isomers could not be separated. 13C-NMR
resonances arising from cyclopentadienone ring were
observed at very similar chemical shifts as four signals
in which each two sets of resonances are magnetically
equivalent (Table 1). Resonances arising from the car-
bonyl ligands appeared at 201.84{d, Ru–CO,
2J(P,C)=12.45 Hz} and ca. 193{2J(P,C) not resolved},
which may correspond to two isomers each with a
symmetrical structure. From C6H6-acetone, a pale yel-
low crystal of one isomer 2-a was obtained and its
X-ray analysis was carried out (Fig. 5). Its crystal
structure reveals that 2,3,4,5-tetraphenyl-2,4-pentadi-
ene-1-one formed by a coupling of two diphenyl-
acetylene molecules now symmetrically bonds to the
Ru(PPh3)(CO)2-group as a four electron donor ligand.
The geometry around the ruthenium atom may also be
described as a tetragonal pyramid in which the apical
site is occupied by PPh3. The distances of the diene
˚
˚
carbons, C(11)–C(12) 1.42(2) A, C(11)–C(10) 1.42(3) A
˚
and C(9)–C(10) 1.47(3) A are shorter than those ob-
served in 1-a. The alternations are short-short-long.
Another isomer of (h4-Ph4C4CO) Ru(CO)2(PPh3) may
Fig. 2. Structure of {Ph4C4(CꢀCPh)2 CO}Ru(CO)2(PPh3) 1-a: Se-
˚
lected distances (A) and angles (°): Ru–P(2) 2.364(8), Ru–C(6)
1.88(4), Ru–C(7) 1.86(3), Ru–C(8) 2.55(3), Ru–C(9) 2.29(3), Ru–
C(10) 2.25(4), Ru–C(11) 2.17(4), Ru–C(12) 2.25(4), O(3)–C(8)–C(9)
127.9(27) C(8)–C(9)–C(10) 109.9(29), C(9)–C(10)–C(11) 102.0(27),
C(10)–C(11)–C(12) 111.3(30), C(11)–C(12)–C(8) 107.3(27), C(123)–
C(8)–C(9) 105.7(25), O(3)–C(8)–C(9) 127.9(27), O(3)–C(8)–C(9)
125.6(27).
Fig. 4. 3,4- and 2,4-diethynylated cyclobutadienone isomers coordi-
nating to Ru(CO)2(PPh3)-group as four electron donor ligand.

64
S. Yamazaki, Z. Taira / Journal of Organometallic Chemistry 578 (1999) 61–67
resonances were assigned to 1,2-diethynylated cyclobu-
tadiene structure 3-a, and the other 4 resonances to
another isomer 1,3-diethynylated cyclobutadiene 3-b
also symmetrical as shown in Fig. 6. All resonances
were singlets and the other conceivable metalla-cy-
clopentadienone structure has been excluded since such
structure should have shown doublets or triplet pat-
2
terns caused by J(P,C), but not so in the present case.
13C-NMR resonances arising from CO of one isomer
appeared at 200.0 with J(P,C)=14.1 Hz, while the
other isomer was in the higher field region at 155.08
with J(P,C)=12.7 Hz.
Ru(CO)3(PPh3)2 did not react with the alkyne by the
pyrolysis method. When carbon monoxide was intro-
duced, complete dissociation of CO from the complex
occurred(IR). However, under carbon dioxide, dimer-
ization of alkyne and 1,3-diyne molecules readily oc-
curred to afford two isomers of a diethylynated
cyclopenta- dienone complex with 2,4- and 3,4-di-
ethynyl substituents on the ring and two isomers of
diethylynated cyclobutadiene complex with 1,2- and
1,3-diethynyl substituents on the cyclobutadiene ring,
respectively. From the reaction of Ru(CO)3(PPh3)2 un-
der CO2 in refluxing toluene, a carbonate Ru(II) com-
plex Ru(CO3)(CO)2(PPh3)2 was obtained in 85% yield.
However, from an analogous reaction in absence of
diphenyl- acetylene, no carbonate compound was ob-
tained (IR). Accordingly, it seems most probable that
the present alkyne dimerization reaction proceeded first
via a reductive disproportionation of carbon dioxide
affording (CO+CO23−). A transient intermediate with
a stoichiometry of cis- and trans-[Ru(CO)4(PPh3)2]-
(CO3) may be supposed. And, it is indicative that the
carbonate Ru(II) compound may be formed via a p-
alkyne complex of Ru(II)3 given by subsequent ligand
substitution reactions of the equatorial sites of cis-,
trans- [Ru(CO)4(PPh3)2](CO3). It should be noticed
when the present reactions were carried by using
diphenylacetylene, any cyclo-butadiene compound
analogous to 3-a,b could not be obtained. These may
indicate that the cyclobutadiene compound and cy-
clopentadienone compound are afforded by different
processes. On the bases of these intermediates, succeed-
ing dimerization reactions of 1,3-diyne and diphenyl-
acetylene may be described in which cyclobutadiene
compounds 3-a,b may be formed through trans-
Fig. 5. Structure of (Ph4C4CO)Ru(CO)2(PPh3) · (C6H6) 2-a. Selected
bond distances (A) and angles (deg.): Ru–P(2) 2.372(6), Ru–C(6)
˚
1.87(3), Ru–C(7) 1.86(3), Ru–C(8) 2.546(10), Ru–C(9) 2.26(3), Ru–
C(10) 2.19(3), Ru–C(11) 2.18(3), Ru–C(12) 2.26(3), C(8)–O(3),
C(8)–C(9) 1.48(3), C(9)–C(10) 1.47(3), C(10)–C(11) 1.42(3), C(11)–
C(12) 1.42(4), O(3)–C(8)–C(9) 129.1(18) C(8)–C(9)–C(10) 108.5
(17), C(9)–C(10)–C(11) 106.6(18), C(10)–C(11)–C(12) 110.2(19),
C(11)–C(12)-C(8) 108.0(18), C(12)–C(8)-C(9) 103.5(17), O(3)–C(8)–
C(9) 129.1(18), O(3)–C(8)–C(9) 129.1(18), O(3)–C(8)–C(12)
127.1(19).
be visualized in crystal structures of (h4-Ph4C4CO)Ru-
(CO)2(PPh3) and {h4-Ph2C4(CꢀCPh)2CO}Ru(CO)2-
(PPh3), where the former appears to be formed by
rotating the cyclopentadienone ring ca. 90° from that of
the latter.
2.3. Isomers of diethynylated cyclobutadiene Ru(0)
compounds 3-a,b
The reaction of Ru(CO)3(PPh3)2 with the 1,3-diyne
under CO2, also gave diethynylated cyclobutadiene
compound, {Ph2C4(CCPh)2} Ru(CO) (PPh3)2 3-a,b, in
36% yield as a mixture of two inseparable isomers by
tlc. methods. 31P-NMR(CDCl3) of the isomers shows
two independent singlet resonances at 35.1 and 32.0
ppm with equal intensities (Table 1). This indicates that
the phosphines in two isomers are not magnetically
equivalent. They have similar chemical shifts, suggest-
ing that they are in similar environments. The IR
spectrum is consistent with this, and two stretching
bands due to the carbonyl ligands were observed with
equal intensities at 2013.6 and 1955.8 cm−1. A total 8
13C-NMR resonances arising from the (CꢀCPh)-groups
and the ring carbons were observed at d88–104 ppm,
the chemical shifts which are in region close to those of
the corresponding cyclopentadienone compounds. Four
Fig. 6. 1,2- and 1,3-diethynylated cyclobutadiene isomers coordinat-
ing to Ru(CO)(PPh3)2-group as a four electron donor ligand.

S. Yamazaki, Z. Taira / Journal of Organometallic Chemistry 578 (1999) 61–67
65
Table 2
[Ru(CO)4(PPh3)2](CO3), while cyclopentadienone Ru(0)
compounds 1-a,b and 2 via cis-[Ru(CO)4(PPh3)2](CO3).
Each products of 1,3-diyne molecules with isomers may
be visualized by their head-to -head and head-to-tail
coupling. Detailed studies of reactions of the carbonate
Ru(II) compound with alkyne molecules are in progress
(Tables 2 and 3).
Atomic positional parameters of an isomer of {Ph2C4(Cꢁ
CPh)2CO}Ru(CO)2(PPh3) 1-a and U(iso)a [8]
Atom x/a
y/b
z/c
U(iso)
Ru(1)
P(2)
O(3)
O(4)
O(5)
C(6)
C(7)
C(8)
C(9)
0.13040(11) 0.34140(17)
0.19060(19) 0.051(2)
0.0796(3)
0.1342(10)
0.0340(13)
0.1841(10)
0.0703(13)
0.1626(14)
0.1524(11)
0.1305(14)
0.1709(18)
0.2106(14)
0.1959(15)
0.0870(12)
0.0386(14)
-0.0015(13)
0.0015(14)
0.0490(14)
0.0917(15)
0.1748(12)
0.1796(16)
0.1984(6)
0.1156(6)
0.3838(17)
0.1064(21)
−0.0019(17)
0.1374(23)
0.0704(23)
0.3598(20)
0.3712(20)
0.3502(30)
0.3014(22)
0.2955(22)
0.4334(22)
0.4132(22)
0.4732(22)
0.5507(32)
0.5708(20)
0.5132(26)
0.3755(22)
0.3922(23)
0.4131(26)
0.4543(25)
0.4658(26)
0.4399(29)
0.4015(32)
0.3883(25)
0.2774(24)
0.2572(22)
0.2367(30)
0.1437(29)
0.1176(19)
0.183(3)
0.051(5)
0.05(1)
0.05(2)
0.05(2)
0.06(2)
0.06(2)
0.05(2)
0.05(2)
0.06(3)
0.07(2)
0.06(2)
0.06(2)
0.07(2)
0.08(2)
0.09(2)
0.09(2)
0.06(2)
0.07(2)
0.06(2)
0.07(2)
0.09(2)
0.11(3)
0.15(3)
0.11(3)
0.11(2)
0.06(2)
0.07(2)
0.07(3)
0.10(2)
0.10(2)
0.12(3)
0.12(2)
0.09(3)
0.06(3)
0.07(2)
0.10(3)
0.10(3)
0.09(3)
0.08(3)
0.06(2)
0.08(3)
0.08(2)
0.09(3)
0.09(3)
0.07(4)
0.06(3)
0.07(2)
0.09(2)
0.10(2)
0.08(3)
0.07(3)
0.06(3)
0.07(3)
0.08(3)
0.08(3)
0.07(3)
0.08(3)
0.5316(15)
0.4814(21)
0.3565(20)
0.4272(24)
0.3484(27)
0.4500(22)
0.3520(24)
0.2737(26)
0.3347(23)
0.4362(23)
0.3305(20)
0.3879(19)
0.3741(20)
0.3006(23)
0.2476(21)
0.2565(24)
0.1732(22)
0.0850(22)
3. Experimental
3.1. Isomers of (Ph4C4–CO)Ru(CO)2(PPh3) 2-a,b
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
C(41)
C(42)
Ru(CO)3(PPh3)2(0.22 g: 0.31 mmol) in C6H6(ca. 20
cm3) was added with diphenylacetylene(0.055 g: 0.3
mmol) in a two necked flask with condenser. Nitrogen
was bubbled through the solution for 5 min, and then
replaced with a flow of carbon dioxide. The solution
was refluxed for 4 h, cooled and evaporated. The
residue was developed by TLC(Al2O3) using C6H6. A
canary yellow band was collected and rechro-
matographed as above to give
a canary yellow
0.1836(16) −0.0212(24)
0.1452(14) −0.0742(22)
0.1496(14) −0.1741(31)
0.1903(17) −0.2307(28)
0.2296(18) −0.1768(23)
0.2260(18) −0.0781(26)
solid(0.018–0.13g: 7–40%). Anal. Found: 74.03; H,
4.87%. (Ph4C4CO)–Ru(CO)2 (PPh3) (C6H6) Calc. C,
73.80; H, 4.74%. FABMS(m-nitrobenzyl alcohol as a
matrix) 805.2(M) 776.1(M–CO) 749.1(M–2CO).
IR(nujol mull) 2037.2w 2011.2m 1981.5w 1955.9vs(Ru–
CO) 1605.8 cm−1s {w(CꢁO}.
0.2576(15)
0.2933(14)
0.3368(15)
0.35B2(14)
0.3942(12)
0.409(2)
0.3876(14)
0.3519(17)
0.228(2)
0.2859(15)
0.3142(16)
0.2905(11)
0.236(2)
0.2034(19)
0.0243(16)
0.0351(18)
0.2832(24)
0.2334(22)
0.1642(28)
0.1783(21)
0.1072(24)
0.026(3)
0.0147(26)
0.0824(34)
0.519(3)
0.5185(25)
0.6005(29)
0.6746(31)
0.674(3)
0.5962(31)
0.2263(22)
3.2. Isomers of {(Ph2C4(CꢀCPh)2CO}Ru(CO)2(PPh3)
1-a,b
0.2732(23)
0.3017(29)
0.256(4)
0.2911(28)
0.2596(33)
0.1964(26)
0.164(3)
Ru(CO)3(PPh3)2 (0.30 g: 0.42 mmol) in toluene(ca. 20
cm3) was added with 1,4-diphenyl-1,3-butadiyne (0.17
g: 0.84 mmol) in a two necked flask with condenser.
Nitrogen was bubbled through the solution for 5 min
and then replaced with a flow of carbon dioxide. The
solution was refluxed for 4 h, cooled and evaporated.
The residue was separated by TLC (SiO2) using C6H6 to
give a yellow green solid (0.11 g: 0.13 mmol: 31%).
Anal. Found: C, 74.38; H, 3.97; P, 5.50%.
Ru(CO)2(PPh3){CO(diyne)2} Calc: C, 74.72; H, 4.14; P,
3.64%. FABMS(m-nitrobenzylalcohol as a matrix).
852.1(M). 824.1(M–CO) 797.1(M–2CO: base peak).
IR(nujol mull). 2017.9vs 1965.9vs 1928.2vs 1928.2w
1619.4 cm−1 m(CꢁO).
0.1938(28)
−0.0013(29)
0.2796X24) −0.0873(27)
C(43) −0.0049(16)
C(44) −0.0589(19)
C(45) −0.0684(16)
C(46) −0.029(3)
C(47)
C(48)
C(49)
0.3017(24)
0.2703(27)
0.2138(28)
0.194(3)
0.129(3)
0.0266(24)
−0.1746(26)
−0.1839(26)
−0.0965(27)
−0.012(4)
0.207(3)
0.2234(26)
0.2929(23)
0.3339(24)
0.3156(32)
0.2504(34)
0.064(3)
0.1116(32)
0.0705(32)
−0.0141(32)
−0.0629(30)
−0.0280(43)
0.042(2)
0.0458(16)
0.0157(13) −0.0152(20)
C(50) −0.0222(17)
C(51) −0.0268(17)
0.0410(24)
0.1415(30)
0.1900(36)
0.100(3)
0.0867(28)
0.0179(30)
3.3. Isomers of (Ph2C4(CꢀCPh)2Ru(CO)(PPh3)2 3-a,b
C(52)
C(53)
C(54)
C(55)
C(56)
C(57)
C(58)
0.0056(17)
0.121(2)
0.1774(15)
0.2092(18)
Another orange band developed on the same
TLC(SiO2) plate yielding {Ph2C4(CCPh)2CO}Ru-
(CO)2(PPh3), orange solid was obtained (36%). Anal.
Found: C, 78.56; H, 4.52%.{Ph2C4(CꢀCPh)2}- Ru(CO)
(PPh3)2 calcd. C, 78.32; H, 4.76%. FABMS(m-nitroben-
zylalcohol as a matrix). 1030.2(M–CO: base peak).
IR(nujol) 2146.0w 2011.5vs 1955.6 cm−1 vs.
0.1840(17) −0.0385(31)
0.1302(15) −0.0279(29)
0.0979(18)
0.0412(36)
a Temperature factor of the form: T=exp[2y2U], U=Uiso or Ueqv
eqv=1/3S3i=1Sj3=1Uijaiajaiaj.
;
U

66
S. Yamazaki, Z. Taira / Journal of Organometallic Chemistry 578 (1999) 61–67
Table 3
3.4. Ru(CO)2(PPh3)2(CO3) 4
Atomic positional parameters of an isomer of (Ph4C4CO)Ru(CO)2–
(CO)2(PPh3) · (C6H6) 2-a and Uiso [9]
a
Ru(CO)3(PPh3)2 (0.25 g: 0.35 mmol) in toluene (ca.
15cm3) was added with diphenylacetylene (0.13 g: 0.73
mmol) in two necked flask with condenser. Nitrogen
was bubbled through the solution for 5 min, and then
replaced with a flow of carbon dioxide. The solution
was refluxed for 4 h, cooled and then evaporated. The
residue was separated by TLC(Al2O3) in CH2Cl2. A
yellow band gave pale yellow solid (0.22 g: 0.3 mmol:
85%). Anal: Found: C, 63.65; H, 4.37%.
Ru(CO3)(CO)2(PPh3)2 Calc. C, 63.95; H, 4.24%.
FABMS(m-nitrobenzyl alcohol as a matrix) 743(M).
IR(nujol mull) 2045.6vs (Ru–CO) 1982.0vs(Ru–CO)
w(CꢁO) 1626.1vs(br). 13C-NMR (CDCl3) 163.275(s;
CO3) 197.912(t, Ru–CO). This compound was also
obtained in 24% yield as a by-product in obtaining
(Ph4C4CO) Ru(CO)2(PPh3)(C6H6), when the reaction
was carried out in refluxing C6H6.
Atom x/a
y/b
z/c
U(iso)
Ru(1) 0.45360(10)
0.23940(8)
0.59480(12)
0.4553(4)
0.3682(11)
0.7283(16)
0.6901(15)
0.6771(17)
0.6489(17)
0.4630(15)
0.5476(14)
0.6459(16)
0.6239(17)
0.5171(19)
0.5313(17)
0.6059(19)
0.5898(17)
0.5008(19)
0.4263(16)
0.4405(22)
0.7401(19)
0.7323(16)
0.8181(18)
0.9104(21)
0.9200(19)
0.8356(17)
0.7008(20)
0.6753(17)
0.7402(19)
0.8323(21)
0.8584(20)
0.7927(24)
0.4608(20)
0.3775(24)
0.3268(21)
0.3569(21)
0.438(3)
0.0527(8)
0.053(2)
0.053(8)
0.05(1)
0.05(1)
0.05(1)
0.05(1)
0.041(9)
0.05(1)
0.04(1)
0.05(1)
0.05(1)
0.05(1)
0.06(1)
0.07(1)
0.09(1)
0.08(1)
0.06(1)
0.05(1)
0.05(1)
0.06(1)
0.08(1)
0.08(1)
0.06(1)
0.05(1)
0.07(1)
0.10(1)
0.09(1)
0.08(1)
0.06(1)
0.06(1)
0.06(2)
0.09(1)
0.09(1)
0.10(2)
0.07(2)
0.05(2)
0.05(2)
0.07(1)
0.08(2)
0.08(2)
0.07(2)
0.05(2)
0.06(2)
0.07(2)
0.07(2)
0.06(1)
0.06(2)
0.05(2)
0.07(2)
0.08(2)
0.10(2)
0.11(2)
0.09(3)
0.10(2)
0.10(3)
0.10(2)
0.09(2)
0.12(2)
0.092(2)
P(2)
O(3)
O(4)
O(5)
C(6)
C(7)
C(8)
C(9)
0.5094(3)
0.3002(9)
0.5569(12)
0.5592(11)
0.5190(12)
0.5185(13)
0.3231(11)
0.3114(12)
0.2514(3)
0.2610(8)
0.3458(10)
0.1224(11)
0.3044(10)
0.1665(10)
0.2512(10)
0.3021(11)
0.2664(10)
0.1949(10)
0.1842(11)
0.3770(11)
0.4249(13)
0.4952(12)
0.5184(12)
0.4730(12)
0.4020(15)
0.3000(14)
0.3314(10)
0.3619(12)
0.3614(15)
0.3274(11)
0.2974(10)
0.1397(12)
0.0989(11)
0.0490(12)
0.0379(13)
0.0764(13)
0.1275(13)
0.1181(14)
0.1120(17)
0.0506(13)
−0.0062(14)
−0.001(2)
0.061(2)
0.2655(13)
0.2903(17)
0.3004(14)
0.2883(19)
0.264(1)
0.2533(17)
0.177(2)
0.1332(13)
0.074(2)
0.059(1)
0.1028(12)
0.162(2)
0.3250(25)
0.3880(13)
0.447(2)
C(10) 0.3522(12)
C(11) 0.3507(13)
C(12) 0.3432(14)
C(13) 0.3332(12)
C(14) 0.3711(14)
C(15) 0.3589(12)
C(16) 0.3084(14)
C(17) 0.2713(12)
C(18) 0.2824(15)
C(19) 0.3405(16)
C(20) 0.2709(13)
C(21) 0.2563(13)
C(22) 0.3096(17)
C(23) 0.3797(15)
C(24) 0.3948(13)
C(25) 0.3439(17)
C(26) 0.2761(14)
C(27) 0.2661(15)
C(28) 0.3208(15)
C(29) 0.3862(15)
C(30) 0.3980(15)
C(31) 0.3258(16)
C(32) 0.2611(16)
C(33) 0.2428(15)
C(34) 0.2907(15)
C(35) 0.355(2)
C(36) 0.375(2)
C(37) 0.6137(17)
C(38) 0.6468(17)
C(39) 0.7246(15)
C(40) 0.7709(19)
C(41) 0.742(2)
C(42) 0.6602(18)
C(43) 0.497(2)
C(44) 0.5580(18)
C(45) 0.546(2)
C(46) 0.472(2)
C(47) 0.4129(17)
C(48) 0.425(2)
C(49) 0.4726(19)
C(50) 0.4743(19)
C(51) 0.449(2)
C(52) 0.428(2)
C(53) 0.4250(18)
C(54) 0.446(3)
C(55) 0.121(3)
C(56) 0.096(3)
C(57) 0.068(2)
C(58) 0.059(2)
C(59) 0.082(2)
C(60) 0.113(2)
3.5. X-ray crystal structure determination of an isomer
of {Ph2C4(CꢀCPh)2CO}Ru(CO)2(PPh3) 1-a and an
isomer of {(Ph4C4CO}Ru(CO)2(PPh3) · (C6H6) 2-a;
crystal data for {Ph2C4(CꢀCPh)2CO}Ru(CO)2(PPh3)
Intensity data collected by q/2q scans at 298 K on a
Mac Science MXC18 diffractometer using CuKa radia-
tion (u=1.54178) were corrected for Lorentz and po-
larization effects, but not for absorption. Structure
solutions were by direct methods using CRYSTAN SIR
92 with refinement by full-matrix least-squares methods
with anisotropic thermal parameters for non-hydrogen
atoms and isotropic for hydrogen atoms.
0.491(3)
0.4890(23)
0.4127(28)
0.4320(21)
0.5307(22)
0.611(2)
0.5864(26)
0.371(3)
0.3722(22)
0.313(2)
0.248(3)
0.2442(22)
0.307(3)
0.3726(29)
0.4223(20)
0.368(3)
0.261(2)
0.2128(24)
0.267(2)
0.446(3)
0.469(4)
0.554(3)
0.606(3)
0.576(3)
0.498(3)
4. Supplementary material
Tables of structural data, anisotropic thermal
parameters, bond lengths and angles, and hydrogen
atom coordinates for 1-a and 2-a. Ordering information
is given on any current masthead page.
Acknowledgements
An author (S.Y.) thanks Professor Anthony J.
Deeming(UCL) for his generous support to this work
and Professor N. Yamasaki and M. Ochi for provision
of JEOL Lambda 400 NMR spectrometer (Kochi
University).
0.445(2)
0.3827(13)
0.322(2)
0.284(1)
0.349(2)
0.354(2)
0.295(2)
0.232(2)
0.226(2)
References
a Temperature factor of the form: T=exp[2y2U], U=Uiso or Ueqv
eqv=1/3S3i=1Sj3=1Uijaiajaiaj.
;
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J. Chem. Soc. (1962) 3488; (d) F. Canziani, O. Chini, A. Guarta,
A.D. Martino, J. Organometal. Chem. 26 (1971) 285; (e) M.
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Chem. Commun. (1984) 1141; (f) M. Crocker, M. Green, A.G.
Orpen, H.P. Neumann, C.J. Schaverien, J. Chem. Soc. Chem.
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K.R. Nagle, A.G. Orpen, D.M. Thomas, J. Chem. Soc. Dalton
Trans. (1987) 2803; (h) M. Crocker, M. Green, K.R. Nagle, A.G.
Orpen, H.P. Newmann, C.E. Morton, C.J. Schaverien,
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B.F.G. Johnson, J.E. McGrady, J. Chem. Soc. Dalton Trans.
(1995) 2749; R.B. King; M.N. Ackermann, J. Organomet. Chem.,
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Chem. Soc. 42 (1964) 182; (l) See for review of cyclotrimerization;
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(Ed.) Transition metal Organometallics in Organic Syntheses: 7.3;
D.B. Grotjahn, Transition metal alkyne complexes: Transition
metal catalyzed cyclo- rimerization, Pergamon, Oxford.
[4] M.R. Burke, T. Funk, J. Takats, V.W. Day, Oraganometallics 13
(1994) 2109.
[5] J.R. Fritch, K.P.C. Vollhardt, J. Am. Chem. Soc. 100 (1978)
3643; J.R. Fritch; K.P.C. Vollhardt, Organometallics 1 (1982)
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(1987) 2956.
[7] S. Yamazaki, A.J. Deeming, D.M. Speel, Organometallics 17
(1998) 775.
[8] Crystal data for {Ph2C4(CꢀCPh)2CO}Ru(CO)2(PPh3) 1-a: color-
less crystal, 0.35×0.3×0.2 mm3, monoclinic, space group P21/a,
˚
˚
˚
a=24.55(1) A, b=13.303(5) A, c=12.658(4) A, i=101.91(3)°,
V=4044.2(3) A , Z=4, Dc=1.352 g cm−3, R=5.6%, wR=
3
˚
6.7%, goof=2.879 for 3470 independent reflections in the range
15q525° with I\3.00|(I0) refining 523 parameters. Its frac-
tional atomic coordinates and Ua(iso) are in Table 2.
[9] Crystal data for (Ph4C4CO)Ru(CO)2(PPh3)-(C6H6) 2-a: mono-
˚
˚
clinic, space group P21/n, a=18.094(7) A, b=19.470(6) A, c=
3
˚
˚
13.446(5) A, i=105.87(3)°, V=4556.4(2) A , Z=4, Dc=1.243 g
cm−3, R=6.4%, wR=9.2%, goof=1.927 for 3977 independent
reflections in the range 15q525° with I\3.00|(I0) refining 583
parameters. Its fractional atomic coordinates and Ua(iso) are in
Table 3.
[2] M. Abed, Z. Goldbeg, Y. Shvo, Organometallics 7 (1988) 2054.
[3] J. Washington, R. McDonald, J. Takats, N. Menashe, Y. Shvo,
Organometallics 14 (1995) 3996; K.A. Johnson; W.L. Gladfelter,
.