Syntheses and structures of some coordinatively saturated and unsaturated diruthenium carbonyl complexes

Article abstract of DOI:10.1016/S0022-328X(02)01636-4

Reaction of [Ru₂(μ-CO)₂(μ-DPPM)₂(MeCN) ₄][BF₄]₂ (2). Upon addition of an excess amount of a uni-negative anion X^- to a solution of 2 in MeCN, a series of neutral, coordinatively unsaturated adducts [Ru₂(μ-CO)₂(μ-DPPM)₂X₂] (X^- = Cl^-, 3a; Br^-, 3b; I^-, 3c; SH^-, 3d; Stol , 3e; SⁱPr^-, 3f) were readily formed. The reaction of 3a with trimethylamine N-oxide dihydrate produced two isomeric products of [Ru₂(CO)₂ (μ-DPPM)₂Cl₂ (μ-H)(μ-OH)] at a ratio of 4a-4b = 2.25. Treatment of 3b and 3c with dimethyl acetylenedicarboxylate produced [Ru₂(μ-CO)(μ-DPPM)₂(μ-MeO₂ CCCCO₂Me)X₂] (X = Br, 5a; I, 5b), whereas treating of 3e and 3f with I₂ yielded [Ru₂(CO)₂(μ-DPPM)₂I₂ (μ-I)(μ-SR)] (R = tol, 6a; ⁱPr, 6b). The structures of 2, 3a, 3c, 3e, 4b, 5a and 6a were determined by X-ray crystallography. The observed Ru-Ru distances are compared and explained in terms of both electronic and steric effects by considering the multiple metal-ligand (M - X) bonding interactions and Alvarez's structural parameters including M M X pyramidal angles and the X-M-M-X torsional angles.

Full text of DOI:10.1016/S0022-328X(02)01636-4

Journal of Organometallic Chemistry 658 (2002) 117ꢃ125
/
www.elsevier.com/locate/jorganchem
Syntheses and structures of some coordinatively saturated and
unsaturated diruthenium carbonyl complexes
Kom-Bei Shiu a,*, Jiun-Yu Chen a, Gene-Hsiang Lee b, Fen-Ling Liao c, Bao-Tsan Ko d,
Yu Wang b, Sue-Lein Wang c, Chu-Chieh Lin d
a Department of Chemistry, National Cheng Kung University, 701 Tainan, Taiwan, ROC
b Instrument Center, National Taiwan University, 107 Taipei, Taiwan, ROC
c Instrument Center, National Tsing-Hua University, 300 Hsinchu, Taiwan, ROC
d Instrument Center, National Chung-Hsing University, 402 Taichung, Taiwan, ROC
Received 13 April 2002; received in revised form 13 May 2002; accepted 27 May 2002
Abstract
Reaction of [Ru2(CO)4(m-DPPM)2(m-OAc)][PF6] (1) with Et3OꢀBF4ꢁ in MeCN produced coordinatively saturated [Ru2(m-
CO)2(m-DPPM)2(MeCN)4][BF4]2 (2). Upon addition of an excess amount of a uni-negative anion Xꢁ to a solution of 2 in MeCN, a
series of neutral, coordinatively unsaturated adducts [Ru2(m-CO)2(m-DPPM)2X2] (Xꢁ ꢂ
/
Clꢁ, 3a; Brꢁ, 3b; Iꢁ, 3c; SHꢁ, 3d; Stolꢁ
,
3e; Si Prꢁ, 3f) were readily formed. The reaction of 3a with trimethylamine N-oxide dihydrate produced two isomeric products of
[Ru2(CO)2(m-DPPM)2Cl2(m-H)(m-OH)] at a ratio of 4aꢃ4bꢂ2.25. Treatment of 3b and 3c with dimethyl acetylenedicarboxylate
produced [Ru2(m-CO)(m-DPPM)2(m-MeO2CCCCO2Me)X2] (XꢂBr, 5a; I, 5b), whereas treating of 3e and 3f with I2 yielded
tol, 6a; Pr, 6b). The structures of 2, 3a, 3c, 3e, 4b, 5a and 6a were determined by X-ray
Ru distances are compared and explained in terms of both electronic and steric effects by
ligand (MꢀX) bonding interactions and Alvarez’s structural parameters including MꢀMꢀ
MꢀX torsional angles. # 2002 Elsevier Science B.V. All rights reserved.
/
/
/
i
[Ru2(CO)2(m-DPPM)2I2(m-I)(m-SR)] (Rꢂ
crystallography. The observed Ruꢀ
considering the multiple metalꢀ
pyramidal angles and the XꢀMꢀ
/
/
/
/
/
/X
/
/
/
Keywords: Ruthenium; Carbonyl; Coordinatively unsaturated adducts
1. Introduction
1ꢃ
compared and explained in terms of both electronic and
steric effects by considering the multiple metalꢀligand
(MꢀX) bonding interactions [2] and Alvarez’s structural
parameters including MꢀMꢀX pyramidal angles and
the XꢀMꢀMꢀX torsional angles [3].
/
3, vide infra). The Ruꢀ
/
Ru distances found will be
In a previous communication [1], we reported briefly
unusual transformations from [Ru2(CO)4(m-DPPM)2(m-
OAc)][PF6] (1) to [Ru2(m-CO)2(m-DPPM)2(MeCN)4]-
/
/
/
/
/
/
/
[BF4]2 (2), from
(Xꢁ ꢂ
2
to [Ru2(m-CO)2(m-DPPM)2X2]
/
Clꢁ, 3a; Brꢁ, 3b; Iꢁ, 3c; SHꢁ, 3d; Stolꢁ, 3e;
SiPrꢁ, 3f) and from 3a to [Ru2(CO)2(m-DPPM)2Cl2(m-
H)(m-OH)] in two isomers of 4a and 4b. Compounds
2. Experimental
3aꢃ
based on the 18-electron rule, but this assignment is not
supported by the observed RuꢀRu distance of 3c. In this
/
f appear to contain a formal Ruꢀ
/Ru triple bond,
All solvents were dried and purified by standard
methods and were freshly distilled under nitrogen
immediately before use. All reactions and manipulations
were carried out in standard Schlenk ware, connected to
a switchable double manifold providing vacuum and
nitrogen. Reagents were used as supplied by Aldrich,
Fluka, or Strem. 1H- and 31P-NMR spectra were
measured on a Brueker AMC-400 (1H, 400 MHz; 31P-
/
contribution, we wish to describe all these transforma-
tions in detail plus two solid-state structures for 3a and
3e, and two new reactions for 3b, 3c, 3e, and 3f (Schemes
* Corresponding author. Fax: ꢀ
E-mail address: kbshiu@mail.ncku.edu.tw (K.-B. Shiu).
/886-6-274-0552
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 6 3 6 - 4

118
K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ
/125
Scheme 1.
NMR, 162 MHz) NMR spectrometer. 1H chemical
shifts (d in ppm, J in Hz) are defined as positive
downfield relative to internal Me4Si (TMS) or the
deuterated solvent, while 31P chemical shifts are referred
to external 85% H3PO4. The IR spectra were recorded
on a BioRad FTS 175 instrument. Microanalyses were
carried out by the staff of the Microanalytical Service of
the Department of Chemistry, National Cheng Kung
University.
2.1. Synthesis of [Ru2(m-CO)2(m-
DPPM)2(MeCN)4][BF4]2 (2)
In a 100 ml Schlenk flask was added [Ru2(CO)4(m-
DPPM)2(m-OAc)][BF4] (1) [4] (1.753 g, 1.426 mmol), 20
ml of MeCN, and 4 ml of 1 M Et3OꢀBF4ꢁ solution in
CH2Cl2 at ambient temperature. The mixture was then
heated at 82 8C for 17 h and cooled to ambient
temperature. The volume of the solution was reduced
Scheme 2.

K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ
/125
119
Scheme 3.
to ca. 0.5 and 10 ml of MeOH was then added.
Filtration gave a pink solid 2, which was washed with
5 ml of MeOH and dried under vacuum. Yield 1.557 g
(80%). Compound 2: Anal. Calc. for C60H56B2F8N4O2-
P4Ru2: C, 52.80; H, 4.14; N, 4.11. Found: C, 52.77; H,
28.66 (s, 4 P). IR (CH2Cl2): n(CO), 1750w, 1702s cmꢁ1
.
Compound 3b: Anal. Calc. for C52H44Br2O2P4Ru2: C,
1
53.10; H, 3.70. Found: C, 53.02; H, 3.64%. H-NMR
(acetone-d6, 400 MHz): d 2.97 (quin, JP, Hꢂ4.4,
/
Ph2PCH2PPh2, 4 H), 7.28 (m, Ph, 24 H), 7.69 (m, Ph,
16 H). 31P{1H}-NMR (acetone-d6, 162 MHz): d 32.30
1
4.13; N, 4.08%. H-NMR (CD3CN, 400 MHz): d 1.97
(s, 4 P). IR (CH2Cl2): n(CO), 1750w, 1702s cmꢁ1
Compound 3c: Anal. Calc. for C52H44I2O2P4Ru2: C,
.
(s, CH3CN, 12 H), 3.03 (quin, JP, Hꢂ4.8,
/
Ph2PCH2PPh2, 4 H), 7.28 (m, Ph, 24 H), 7.46 (m, Ph,
16 H). 13C{1H}-NMR (acetone-d6, 100 MHz): d 0.83
1
48.77; H, 3.46. Found: C, 48.64; H, 3.45%. H-NMR
(quin, JP, C
Ph2PCH2PPh2, 2 C), 119.06 (br, CH3CN, 4 C), 258.53
(s, CO, 2 C), and the phenyl carbon atoms at 129.62 (br,
ꢂ
/
21, CH3CN, 4 C), 19.65 (quin, JP, C
ꢂ11,
/
(acetone-d6, 400 MHz): d 3.07 (quin, JP, Hꢂ4.4,
/
Ph2PCH2PPh2, 4 H), 7.26 (m, Ph, 24 H), 7.71 (m, Ph,
16 H). 31P{1H}-NMR (acetone-d6, 162 MHz): d 29.06
(s, 4 P). IR (CH2Cl2): n(CO), 1747w, 1702s cmꢁ1
Compound 3d: Anal. Calc. for C52H46O2P4Ru2S2: C,
.
16 C), 131.42 (quin, JP, C
ꢂ12.5, 8 C), 131.93 (br, 8 C),
/
133.74 (br, 16 C). 31P{1H}-NMR (CD3CN, 162 MHz):
d 28.52 (s, 4 P). IR (Nujol): n(CN), 2317w, 2309w,
2286w, 2280w; n(CO), 1683s, 1661sh cmꢁ1. IR: n(CO),
1736s cmꢁ1 in CH2Cl2 and 1700 cmꢁ1 in CH3CN.
1
57.14; H, 4.24. Found: C, 57.08; H, 4.17%. H-NMR
(acetone-d6, 400 MHz): d 2.98 (quin, JP, Hꢂ4.6,
/
Ph2PCH2PPh2, 4 H), 7.30 (m, Ph, 24 H), 7.70 (m, Ph,
16 H). 31P{1H}-NMR (acetone-d6, 162 MHz): d 33.93
(s, 4 P). IR (CH2Cl2): n(CO), 1704s cmꢁ1. Compound
3e: Anal. Calc. for C66H58O2P4Ru2S2: C, 62.26; H, 4.59.
Found: C, 62.21; H, 4.56%. 1H-NMR (CD2Cl2, 400
2.2. Synthesis of [Ru2(m-CO)2(m-DPPM)2X2] (Xꢁ ꢂ
/
Clꢁ, 3a; Brꢁ, 3b; Iꢁ, 3c; SHꢁ, 3d; Stolꢁ, 3e; SiPrꢁ,
3f)
MHz): d 1.90 (s, SC6H4CH3, 6 H), 2.73 (quin, JP, H
4.4, Ph2PCH2PPh2, 4 H), 5.96 (d, JH, H 7.9, 4 H) and
6.04 (d, JH, H 7.9, 4 H) for SC6H4CH3, 7.49 (m, Ph, 24
ꢂ
/
ꢂ
/
The preparation procedures for 3aꢃf are all similar,
/
ꢂ
/
and a typical procedure for 3c is described below. In a
100 ml Schlenk flask was added 2 (0.100 g, 0.073 mmol),
NaI (0.055 g, 0.367 mmol), and 10 ml of MeCN at
ambient temperature. The mixture was then stirred for 1
H), 7.85 (m, Ph, 16 H). 31P{1H}-NMR (CD2Cl2, 162
MHz): d 33.86 (s, 4 P). IR (CH2Cl2): n(CO), 1688s
cmꢁ1. Compound 3f: Anal. Calc. for C58H58O2-
P4Ru2S.2CH2Cl2: C, 56.12; H, 4.79. Found: C, 55.91;
h. Filtration gave the orangeꢃ/yellow product, which
1
H, 4.76%. H-NMR (acetone-d6, 400 MHz): d 0.24 (d,
was then recrystallized from CH2Cl2ꢃ/MeCN and dried
JH, H
CH(CH3)2, 2 H), 2.70 (quin, JP, H
ꢂ
/
6.6, CH(CH3)2, 12 H), 2.62 (hept, JH, H
ꢂ
/
6.6,
in vacuo to give 0.062 g (67%). Compound 3a: Anal.
Calc. for C52H44Cl2O2P4Ru2: C, 56.89; H, 4.04. Found:
C, 56.73; H, 4.15%. 1H-NMR (acetone-d6, 400 MHz): d
2.59 (br, Ph2PCH2PPh2, 4 H), 7.28 (m, Ph, 24 H), 7.60
(m, Ph, 16 H). 31P{1H}-NMR (CD2Cl2, 162 MHz): d
ꢂ
/
4.4, Ph2PCH2PPh2,
4 H), 7.25 (m, Ph, 24 H), 7.79 (m, Ph, 16 H). 31P{1H}-
NMR (CD2Cl2, 162 MHz): d 30.57 (s, 4 P). IR
(CH2Cl2): n(CO), 1682s cmꢁ1
.

120
K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ125
/
2.3. Reaction between [Ru2(m-CO)2(m-DPPM)2Cl2]
(3a) and trimethylamine N-oxide dihydrate
2.5. Reaction between [Ru2(m-CO)2(m-DPPM)2X2]
(Xꢂ
Stol, 3e; SiPr, 3f) and I2
/
The solution of 3e (0.512 g, 0.402 mmol) in 10 ml of
CH2Cl2 was added dropwise with 7.8 ml of an I2
solution prepared by dissolving 0.210 g of I2 (0.0827
mmol) in 10 ml of CH2Cl2. The solution was stirred for
1 h and the volatiles were pumped off. One major
The solution of 3a (0.158 g, 0.144 mmol) in 10 ml of
CH2Cl2 was added dropwise with 2.1 ml of the Me3NO
solution, prepared from Me3NO×/2H2O (0.100 g, 0.901
mmol) dissolved in 10 ml of MeOH. The solution was
stirred for 36 h and the volatiles were pumped off. Two
isomeric products of [Ru2(CO)2(m-DPPM)2Cl2(m-H)(m-
OH)] were separated as a major and a minor yellow
bands, respectively, by thin-layer chromatography
orangeꢃ
CH2Cl2ꢃ
(Kieselguhr 60 F254, E. Merk), and recrystallized from
CH2Cl2ꢃMeOH, producing 0.258 g (41% yield) of
/
red band was separated by TLC (silica gel,
/
hexaneꢂ1:1) in a glove box, using TLC plates
/
/
(TLC) (silica gel, CH2Cl2ꢃ
box, using TLC plates (Kieselguhr 60 F254, E. Merk),
and recrystallized from CH2Cl2ꢃhexane, producing 25
mg (16% yield) of 4a and 8 mg (5%) of 4b. Anal. Calc.
for C52H44Cl2O3P4Ru2×2H2O: C, 54.32; H, 4.21. Found:
C, 54.36; H, 4.19%. For 4a: 1H-NMR (CD2Cl2, 400
MHz): d ꢁ26.36 (quin, JP, H 8.4, m-H, 1 H), 2.12 (br,
/
hexaneꢂ/6:1) in a glove
[Ru2(CO)2(m-DPPM)2I2(m-I)(m-Stol)] (6a). Compound
[Ru2(CO)2(m-DPPM)2I2(m-I)(m-SiPr)] (6b) was prepared
similarly from 3f. Yield 21%. Compound 6a: Anal. Calc.
for C61H51I3O2P4Ru2S: C, 47.12; H, 3.31. Found: C,
/
/
1
47.05; H, 3.32%. H-NMR (CD2Cl2, 400 MHz): d 2.38
(s, C6H4CH3, 3 H), 4.04 (m, Ph2PCH2PPh2, 2 H), 4.36
/
ꢂ
/
(m, Ph2PCH2PPh2, 2 H), 6.56 (d, JH, H
ꢂ/7.9, C6H4CH3,
m-OH, 1 H), 3.18 (m, Ph2PCH2PPh2, 2 H), 3.97 (m,
Ph2PCH2PPh2, 2 H), 7.20 (m, Ph, 40 H). 31P{1H}-NMR
(CD2Cl2, 162 MHz): d 6.16 (s, 4 P). IR (CH2Cl2):
n(OH), 3627w; n(CO), 1978s, 1964sh cmꢁ1. For 4b: 1H-
2 H), 6.85 (d, JH, H
ꢂ
/
7.9, C6H4CH3, 2 H), 7.20 (m, Ph,
40 H). 31P{1H}-NMR (CD2Cl2, 162 MHz): d 3.66 (s, 4
P). IR (CH2Cl2): n(CO), 1968s cmꢁ1. Compound 6b:
Anal. Calc. for C55H51I3O2P4Ru2S.CH2Cl2: C, 42.90; H,
1
NMR (CD2Cl2, 400 MHz): d ꢁ
/
25.06 (quin, JP, H
ꢂ8.4,
/
3.41. Found: C, 42.60; H, 3.36%. H-NMR (CD2Cl2,
6.6, CH(CH3)2, 3 H), 2.74
H), 4.02 (m,
m-H, 1 H), 2.12 (br, m-OH, 1 H), 3.12 (m, Ph2PCH2PPh2,
2 H), 3.67 (m, Ph2PCH2PPh2, 2 H), 7.32 (m, Ph, 40 H).
31P{1H}-NMR (CD2Cl2, 162 MHz): d 8.76 (s, 4 P). IR
400 MHz): d 0.69 (d, JH, H
ꢂ
/
(hept, JH, Hꢂ6.6, CH(CH3)2,
/
1
Ph2PCH2PPh2, 2 H), 4.41 (m, Ph2PCH2PPh2, 2 H),
7.24 (m, Ph, 24 H), 7.80 (m, Ph, 16 H). 31P{1H}-NMR
(CD2Cl2, 162 MHz): d 2.89 (s, 4 P). IR (CH2Cl2):
(CH2Cl2): n(OH), 3615w; n(CO), 1968s, 1954sh cmꢁ1
.
n(CO), 1968s cmꢁ1
.
2.4. Reaction between [Ru2(m-CO)2(m-DPPM)2X2]
2.6. X-ray data collection, solution, and refinement
(Xꢂ
/
Br, 3b; XꢂI, 3c) and dimethyl
/
acetylenedicarboxylate
Suitable single crystals of 2, 3a, 3c, 3e, 4b, 5a and 6a
were grown from CH2Cl2ꢃ
/
MeOH or CH2Cl2ꢃhexane at
/
The suspension of 3b (0.116 g, 0.098 mmol) and 0. 5
ml of dimethyl acetylenedicarboxylate (ca. 4.07 mmol)
in 18 ml of THF were heated under reflux for 16.5 h and
the volatiles were pumped off. Recrystallization from
room temperature and chosen for single crystal structure
determinations. All the X-ray diffraction data were
measured in frames with increasing v (width of 0.38
per frame) and with the scan speed at 20.00 s per frame
on a Siemens SMART-CCD instrument, equipped with
a normal focus and 3 kW sealed-tube X-ray source.
Empirical absorption corrections were carried out using
SHELXTL-PC program for 2 and 4b, and SADABS program
for 3a, 3c, 3e, 5a and 6a. The latter four structures were
solved by the heavy-atom method and refined by a full-
matrix least-squares procedure using NRCVAX [5].
Structures 2, 3a and 5b were solved by direct methods
and refined by a full-matrix least-squares procedure
CH2Cl2ꢃMeOH gave 77 mg (60% yield) of [Ru2(m-
/
CO)(m-DPPM)2(m-MeO2CCCCO2Me)Br2] (5a). Com-
pound [Ru2(m-CO)(m-DPPM)2(m-MeO2CCCCO2Me)I2]
(5b) were prepared similarly from 3c. Yield 69%.
Compound 5a: Anal. Calc. for C57H50Br2O5P4Ru2: C,
1
52.63; H, 3.87. Found: C, 52.37; H, 4.18%. H-NMR
(CD2Cl2, 400 MHz): d 2.08 (s, COOMe, 6 H), 2.19 (m,
Ph2PCH2PPh2, 2 H), 3.16 (m, Ph2PCH2PPh2, 2 H), 7.33
(m, Ph, 40 H). 31P{1H}-NMR (CD2Cl2, 162 MHz): d
12.88 (s, 4 P). IR (CH2Cl2): n(CO), 1731s (COOMe),
1704s (m-CO) cmꢁ1. Compound 5b: Anal. Calc. for
C57H50I2O5P4Ru2: C, 49.08; H, 3.61. Found: C, 48.85;
H, 3.39%. 1H-NMR (CD2Cl2, 400 MHz): d 2.08 (s,
COOMe, 6 H), 2.36 (m, Ph2PCH2PPh2, 2 H), 3.41 (m,
Ph2PCH2PPh2, 2 H), 7.25 (m, Ph, 40 H). 31P{1H}-NMR
(CD2Cl2, 162 MHz): d 14.33 (s, 4 P). IR (CH2Cl2):
using SHELXTL-PLUS [6]. Neutral atom scattering factors
for non-hydrogen atoms and the values for Df? and Dfƒ
described in each software were used [5,6]. The other
essential details of single-crystal data measurement and
refinement are listed in Table 1. In structure 3e, two
atomic positions with 0.5 occupancy were found for
atoms C(20) and C(21) of one phenyl group attached to
P(2).
n(CO), 1729s (COOMe), 1702s (m-CO) cmꢁ1
.

K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ
/125
121
Table 1
Crystal data
2
3a
3c×2CH2Cl2
3e
4b×2H2O
5a×2CH2Cl2
6a×CH3CN
Empirical formula
C
P2Ru
30H28BF4N2O- C26H22ClO2-
P2Ru
C54H48Cl4I2O2- C66H58O2-
C52H50Cl2O5-
P4Ru2
1151.84
Pna21
24.0411(9)
12.4778(5)
17.6573(7)
90
C59H54Br2Cl4- C61H54I3NO2-
P4Ru2
1450.62
Pna21
29.302(5)
15.541(2)
12.329(2)
90
P4Ru2S2
1273.26
P21/n
O5P4Ru2
1470.66
P21/c
P4Ru2S
1571.83
Pbca
Formula weight (fw)
Space group
682.36
P21/c
548.90
C2/c
˚
a (A)
11.3231(2)
17.6611(1)
16.0614(2)
90
18.4917(10)
13.4267(7)
20.7276(12)
90
11.4620(3)
13.0843(3)
19.8845(4)
90
12.7529(3)
15.8030(3)
28.8517(7)
90
18.637(4)
21.572(2)
30.292(4)
90
˚
b (A)
˚
c (A)
a (8)
b (8)
110.60(1)
90
111.439(1)
90
90
90
97.503(1)
90
90
90
97.951(1)
90
90
90
g (8)
3
V (A )
˚
3006.5(7)
4
1.508
4790.2(5)
8
1.522
5614(2)
4
1.716
2956.6(1)
2
1.430
5296.8(4)
4
1.444
5751.5(2)
4
1.698
12178(3)
8
1.715
Z
rcalc (g cmꢁ3
)
m (mmꢁ1
)
0.679
0.71073
293(2)
0.916
0.71073
293(2)
19.591
0.71073
298(1)
0.734
0.71073
295(2)
0.836
0.71073
295(2)
2.261
0.71073
120(1)
2.198
0.71073
293(2)
˚
l (A)
Temperature (K)
b
R
a, Rw
0.0556, 0.1431
1.110
0.0411, 0.0979 0.049, 0.040
0.719 1.37
0.0281, 0.0571 0.0442, 0.1155 0.0731, 0.2071 0.0628, 0.936
1.026 1.006 1.039 1.013
GOF
a
Rꢂ[ajjFojꢁjFcjj/ajFoj].
b
2 1/2
Rwꢂ[a v(jFojꢁjFcj)2/a vjFoj ]
.
3. Results and discussion
3.1. Synthesis of [Ru2(m-CO)2(m-
DPPM)2(MeCN)4]2ꢀ [2]2ꢀ
We previously described that the bridging acetate
ligands in [Ru2(CO)4L2(m-OAc)2] can be removed using
alkylating agents such as Et3OꢀBF4ꢁ in MeCN to form
the versatile cations [Ru2(CO)4(MeCN)4L2]2ꢀ [7]. How-
ever, when a similar treatment was applied to [Ru2(m-
CO)2(m-DPPM)2(m-OAc)]ꢀ [1]ꢀ, both the NMR and IR
spectra indicated that the presumed cation [Ru2(m-
CO)2(m-DPPM)2(MeCN)2]2ꢀ was indeed formed but
then transformed immediately even at the ambient
temperature into [Ru2(m-CO)2(m-DPPM)2(MeCN)4]2ꢀ
[2]2ꢀ (Scheme 1), isolated as BF4ꢁ or PF6ꢁ salts. The
structure of [2]2ꢀ (Fig. 1) was confirmed by X-ray
diffraction methods to adopt a geometry with idealized
D2h symmetry. It contains two bridging carbonyls, two
Fig. 1. ORTEP plot of [2]2ꢀ with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
have been retained for clarity). An inversion center is imposed
crystallographically at the center of the Ruꢀ
/
Ru bond. Selected bond
2.7703(7), Ru(1)ꢀP(1)ꢂ2.3875(12),
2.3951(12), Ru(1)ꢀC(26)ꢂ2.002(5), C(26)ꢀO(1)ꢂ
1.192(5), Ru(1)ꢀN(1)ꢂ2.156(4), N(1)ꢀC(27)ꢂ1.132(6), C(27)ꢀ
C(28)ꢂ1.454(8), Ru(1)ꢀN(2)ꢂ2.139(4), N(2)ꢀC(29)ꢂ1.115(6),
C(29)ꢀC(30)ꢂ1.465(8). Selected bond angles (8): Ru(1?)ꢀRu(1)ꢀ
P(1)ꢂ92.18(3), Ru(1?)ꢀRu(1)ꢀP(2)ꢂ93.37(3), C(26)ꢀRu(1)ꢀN(1)ꢂ
89.78(17), N(1)ꢀRu(1)ꢀN(2)ꢂ82.76(16), N(2)ꢀRu(1)ꢀC(26?)ꢂ
93.79(18), C(26?)ꢀRu(1)ꢀC(26)ꢂ93.71(18), Ru(1)ꢀC(26)ꢀO(1)ꢂ
135.3(4), Ru(1)ꢀC(26)ꢀRu(1?)ꢂ86.29(18), Ru(1)ꢀN(1)ꢀC(27)ꢂ
174.4(4), C(27)ꢀC(28)ꢂ177.4(6), Ru(1)ꢀN(2)ꢀC(29)ꢂ
N(1)ꢀ
178.6(5), N(2)ꢀC(29)ꢀC(30)ꢂ177.1(8).
˚
lengths (A): Ru(1)ꢀ
/
Ru(1?)ꢂ
/
/
/
Ru(1)ꢀP(2)ꢂ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
bridging DPPM ligands, and four terminal MeCN
˚
Ru distance of 2.7703(7) A in 2, a
/
/
/
/
/
/
/
/
/
/
/
/
ligands. The Ruꢀ
/
/
/
/
/
/
/
34-electron complex, is significantly shorter than that of
˚
/
/
/
2.841(1) A in [1]ꢀ [4], but still fall in the range of 2.558ꢃ
/
˚
3.020 A observed for typical Ruꢀ
/
Ru single bond
DPPM)2X4]2ꢁ, the neutral diamagnetic adducts [Ru2(m-
CO)2(m-DPPM)2X2] (Xꢁ ꢂClꢁ, 3a; Brꢁ, 3b; Iꢁ, 3c;
SHꢁ, 3d; Stolꢁ, 3e; SiPrꢁ, 3f) with a formal metalꢃ
distances [4,7,8].
/
/
3.2. Reaction of [Ru2(m-CO)2(m-
DPPM)2(CH3CN)4]2ꢀ [2]2ꢀ with uninegative anions
metal triple bond, assigned for the 30-electron products.
Three representative structures, 3a, 3c and 3e, were
determined using X-ray diffraction methods. The ‘triple’
˚
Ru distances are 2.7430(4) A in 3a (Fig. 2), 2.738(2)
˚ ˚
A in 3c (Fig. 3) and 2.8091(3) A in 3e (Fig. 4). To our
Upon the addition of an excess of the uninegative
anion Xꢁ to [2]2ꢀ, we obtained, instead of the expected
anionic substitution products such as [Ru2(m-CO)2(m-
Ruꢀ
/

122
K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ125
/
Fig. 4. ORTEP plot of 3e with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
attached to phosphorus atoms have been retained for clarity). An
Fig. 2. ORTEP plot of 3a with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
have been retained for clarity). An inversion center is imposed
inversion center is imposed crystallographically at the center of the
crystallographically at the center of the Ruꢀ
/
Ru bond. Selected bond
P(1)ꢂ2.3710(7), RuꢀP(2)ꢂ
Clꢂ2.3538(8), C(26)ꢀO(1)ꢂ
1.188(3). Selected bond angles (8): RuꢀRu?ꢀC(26)ꢂ45.65(8), Ru?ꢀ
RuꢀC(26)ꢂ46.32(8), RuꢀC(26)ꢀRu?ꢂ88.03(12), Ru?ꢀRuꢀP(1?)ꢂ
95.01(2), Ru?ꢀRuꢀP(2)ꢂ92.27(2), Ru?ꢀRuꢀClꢂ177.29(3), C(26)ꢀ
RuꢀC(26?)ꢂ91.97(12).
˚
Ruꢀ
Ru(1)ꢀ
1.998(2), Ru(1)ꢀ
S(1)ꢂ2.3282(6), S(1)ꢀ
Ru(1?)ꢀRu(1)ꢀP(1)ꢂ93.707(16),
Ru(1?)ꢀRu(1)ꢀS(1)ꢂ172.972(19),
Ru(1)ꢀC(1)ꢀRu(1?)ꢂ89.44(9),
Ru(1)ꢀS(1)ꢀC(2)ꢂ120.70(8).
/
Ru bond. Selected bond lengths (A): Ru(1)ꢀ
/
Ru(1?)ꢂ
2.3779(6),
Ru(1)ꢀ
1.995(2), C(1)ꢀO(1)ꢂ1.189(2), Ru(1)ꢀ
C(2)ꢂ1.785(2). Selected bond angles (8):
Ru(1?)ꢀRu(1)ꢀP(2)ꢂ92.466(15),
C(1)ꢀRu(1)ꢀC(1?)ꢂ90.56(9),
Ru(1)ꢀC(1)ꢀO(1)ꢂ135.55(16),
/
2.8091(3),
˚
lengths (A): Ruꢀ
/
Ru?ꢂ
/
2.7430(4), Ru?ꢀ
/
/
/
/
/
P(1)ꢂ
/2.3546(6),
Ru(1)ꢀ
/
P(2)ꢂ
/
/
C(1)ꢂ
/
2.3499(7), RuꢀC(26)ꢂ
/
/
1.962(3), Ruꢀ
/
/
/
/
/
C(1?)ꢂ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
surprise, all these values fall within the range for typical
RuꢀRu single bond distances vide supra. By comparing
the distances between the Ru atoms and the p-donor, X,
in 3a, 3c, and 3e with those in other similar compounds,
˚
tively shorter values of 2.660(2) and 2.679(2) A in 3c, in
/
comparison with the terminal Ruꢀ
/
I distance of 2.767(2)
I distances of 2.756(2) and
˚
A or with the bridging Ruꢀ
/
˚
2.825(2) A in [Ru2(m-I)(m-CO)(CO)2(m-DPPM)2I] [8g];
and also by the relatively shorter RuꢀS distance of
2.3282(6) A in 3e, in comparison with the bridging Ruꢀ
Ruꢀ
are believed to be present and lengthen the expected
RuꢀRu triple bond into a single bond in 3a, 3c and 3e
(Scheme 2). The multiple RuIꢀ
X bonding interactions in
these Ru22ꢀ complexes are reflected by the relatively
/X multiple, probably double, bonding interactions
/
˚
/
/
˚
A
S
distances of 2.4285(9) and 2.4358(11)
[Ru2(CO)4(m-SPh)2(PPh3)2] [8j]. Indeed, the direct evi-
dence for the presence of a double RuꢀStol bond, and
consequently a RuꢀRu single bond rather than a Ruꢀ
/
in
/
˚
Cl distance of 2.3538(8) A in 3a, in
/
shorter Ruꢀ
/
/
/
comparison with the terminal Ruꢀ
/
Cl distance of
5
Ru triple bond in 3e, is reflected in the angle, ꢁ
/
Ruꢀ
/
Sꢀ
˚
2.409(4) A in [(h -C5Me5)Ru(m-NO)2Cl]2 [9]; the rela-
C(tol), of 120.70(8)8, very close to the expected 1208 for
an sp2 hybridized sulfur atom. Furthermore, a rather
˚
C(tol) bond length of 1.785(2) A in 3e, relative
long Sꢀ
/
˚
to that of 1.52(2) A in 6a, described below (Fig. 7) was
observed and this elongation can be attributed to the
repulsion between the p-bonding electrons in the Ruꢀ
/
S
double bond and those in the benzene ring (truly, the
two p systems are not coplanar, as reflected in a torsion
angle, ꢁ
/
Ru(1)ꢀ
/
S(1)ꢀ
/
C(2)ꢀC(3), of 114.2(2)8).
/
3.3. Reactions of 3aꢃ
/
c and 3eꢃf
/
Fig. 3. ORTEP plot of 3c with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
Three typical reactions were carried out with three
representative structures determined (Scheme 3). The
˚
have been retained for clarity). Selected bond lengths (A): Ru(1)ꢀ
/
Ru(2)ꢂ
Ru(1)ꢀP(1)ꢂ
2.357(6), Ru(2)ꢀ
O(1)ꢂ1.18(2), Ru(2)ꢀ
O(2)ꢂ1.15(2), Ru(2)ꢀ
Ru(2)ꢀ
Ru(1)ꢀ
Ru(2)ꢀ
Ru(1)ꢀ
I(1)ꢂ117.9(5), I(2)ꢀ
90.9(7), C(2)ꢀRu(2)ꢀ
Ru(1)ꢀC(2)ꢀRu(2)ꢂ87.3(7).
/
2.738(2),
2.349(6),
P(4)ꢂ
C(1)ꢂ
C(2)ꢂ
Ru(1)ꢀ
Ru(1)ꢀ
2.349(6), Ru(1)ꢀ
1.99(2), Ru(1)ꢀ
2.013(16). Selected bond angles (8):
/
I(1)ꢂ
/
2.660(2),
P(3)ꢂ2.346(6),
C(1)ꢂ
C(2)ꢂ
Ru(2)ꢀ
/
I(2)ꢂ
Ru(2)ꢀ
1.954(16), C(1)ꢀ
1.95(2), C(2)ꢀ
/
2.679(2),
reaction of 3a with excess Me3NO×/2H2O afforded two
/
/
/
/
/
P(2)ꢂ
/
isomeric diamagnetic products 4a and 4b, with the
formula [Ru2(CO)2(m-DPPM)2Cl2(m-H)(m-OH)]. The ra-
/
/
/
/
/
/
/
/
/
/
/
tio 4aꢃ
4b is 2.25, based on the 1H-NMR evidence.
/
/
/
/
/
Ru(1)ꢀ
Ru(2)ꢀ
Ru(1)ꢀ
C(1)ꢂ148.3(6), C(1)ꢀ
Ru(2)ꢀC(1)ꢂ
I(2)ꢂ119.7(6), Ru(1)ꢀ
/
P(1)ꢂ
P(2)ꢂ
I(1)ꢂ
/
93.90(15),
Ru(2)ꢀ
Ru(1)ꢀ
Ru(2)ꢀ
C(2)ꢂ93.7(7), C(2)ꢀ
149.4(5), C(1)ꢀRu(2)ꢀ
C(1)ꢀRu(2)ꢂ88.0(7),
/
Ru(1)ꢀ
Ru(2)ꢀ
I(2)ꢂ
/
P(3)ꢂ
/
92.81(15),
These complexes appear to react with silica gel and only
part of the converted products survived after 4 h
separation. The yield obtained for 4a is 16% and that
for 4b is 5%. Although the relevant formation mechan-
ism is not known, a similar report concerning the
formation of [Os3(CO)10(NMe3)(m3-S)(m-OH)(m-H)]
/
/
/93.19(15),
/
/
P(4)ꢂ
/
92.83(15),
/
/
/
165.15(8), Ru(1)ꢀ
/
/
/
165.15(9), I(1)ꢀ
Ru(1)ꢀ
C(2)ꢂ
/
/
/
/
Ru(1)ꢀ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/

K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ
/125
123
from the reaction of [Os3(CO)10(m3-S)] and trimethyla-
mine N-oxide dihydrate was described in the literature
[10]. However, it is not clear at the moment about the
source of the hydroxyl oxygen atom in the Os com-
pound or our Ru complex, probably either from
trimethylamine N-oxide or the hydrated water. How-
ever, good single crystals of the minor product 4b were
grown successfully, and the solid-state structure was
determined. Importantly, this structure helps us to
distinguish the two isomeric structures. The structure
(Fig. 5) confirms the presence of two terminal carbonyls,
a bridging hydride, and a bridging hydroxide rather
Alvarez and his co-workers [3f] showed that a variation
I
RuI distances of
[Ru2(bridge)2(CO)4Ln] complexes can be attributed to
different pyramidal and torsional angles (the average
˚
as large as 0.255 A in the Ru ꢀ
/
pyramidal angle, a, in a range of 84.5ꢃ
average torsional angle, t, in a range of 0.0ꢃ
observed for the RuꢀRu distances, d(RuꢀRu), in a
2.885 A [3f]. After a multilinear regres-
/
89.98 and the
/
28.58 are
/
/
˚
range of 2.630ꢃ
/
sion analysis, they obtained an equation that showed a
fair correlation with a regression coefficient of 0.945:
d(Ruꢀ
/
Ru)ꢂ
/
2.296ꢀ
/
3.148 cos aꢀ
/
0.353 cos 2t. In other
words, the Ruꢀ
/
Ru distance decreases more sensitively
1
with increasing pyramidality than with increasing tor-
sional angles). Their results prompted us to calculate the
angles for our singly bonded diruthenium compounds
than a bridging oxide or aqua based on solution H-
NMR and IR data. Clearly, the bridging hydride shows
1
a virtual H-NMR quintet at d ꢁ
/
26.36 for 4a and d ꢁ
/
and found (a, t)ꢂ
and (89.18, 8.58) in 4b. Clearly, their conclusion is
applicable to our compounds, the smallest d(RuꢀRu)
value of 2.7703(7) A was observed for the largest a value
of 92.78 in 2, while the longest d(RuꢀRu) value of
/
(92.78, 1.78) in 2, (89.98, 1.28) in 3e,
25.04 for 4b. The bridging hydroxide displays only one
weak IR Oꢀ
/
H stretching band at 3627 cmꢁ1 for 4a and
3615 cmꢁ1 for 4b. The two terminal carbonyls are trans
to the bridging hydroxide in 4b (Fig. 5). Apparently the
structure of the other isomer 4a contains a different
orientation with the stronger s-donor, the m-hydrido
bridging ligand, trans to the carbonyls. This would
/
˚
/
˚
2.8620(7) A was observed for the shortest a value of
89.18 in 4b.
Treatment of 3b and 3c with dimethyl acetylenedi-
explain why 4a were formed in a larger quantity than 4b.
The RuIIꢀ
carboxylate
MeO2CCCCO2Me)X2] (Xꢂ
afforded
[Ru2(m-CO)(m-DPPM)2(m-
Br, 5a; I, 5b) as the only
/
RuII distance of 2.8620(7) A in this com-
˚
/
pound, though much longer than the RuIꢀRuI distance
of 2.7703(7) A in 2 but comparable to that of 2.8091(3)
/
product. The structure of 5a was also determined using
X-ray diffraction methods (Fig. 6). The alkyne molecule
is bound to the metals as a cis-dimetalated olefin (i.e. in
an m-II mode [11]); therefore, all angles about C(2) and
C(3) are close to 1208 as expected for sp2-hybridization
of these atoms. The distortion from idealized sp2-
hybridization results from the strain imposed by the
˚
˚
A in 3e, may still indicate the presence of a single bond
in spite of the maximum change in the metalꢀ
/
metal
˚
distances as large as 0.09 A. The results achieved by
Ruꢀ
C(2)ꢀ
110.1(6)8, respectively. Similar distortions were observed
in other metalꢀmetal bonded species with analogously
bound acetylene ligands [11a]. When no metalꢀmetal
/
Ru bond vide infra which compresses the Ru(1)ꢀ
/
/
C(3) and Ru(2)ꢀC(3)ꢀC(2) angles to 114.6(2) and
/
/
/
/
bond is present, the acetylene ligands are found to
approach more closely the olefin geometry
[11b,11c,11d]. In spite of the strain in the acetylene
molecule, the ruthenium atoms and the carbon atom
framework of the acetylene ligand are quite planar with
Fig. 5. ORTEP plot of 4b with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
the torsional angle,
0.8(8)8. On the basis of the observed strain in the
molecule, one might expect that the resulting metalꢃ
ꢁ
/
Ru(1)ꢀ
/
C(2)ꢀ
/
C(3)ꢀ
/
Ru(2)ꢂ
/
˚
have been retained for clarity). Selected bond lengths (A): Ru(1)ꢀ
/
Ru(2)ꢂ
Ru(1)ꢀP(3)ꢂ
2.3751(19), Ru(2)ꢀ
O(1)ꢂ1.152(9),
C(2)ꢀO(2)ꢂ1.168(11),
2.182(5), O(3)ꢀH(3)ꢂ
H(1)ꢂ1.748(10). Selected bond angles (8): Ru(2)ꢀ
P(4)ꢂ91.68(5),
Ru(2)ꢀP(2)ꢂ91.73(5),
Ru(1)ꢀP(4)ꢂ176.02(6),
Ru(1)ꢀRu(2)ꢂ49.09(13),
Ru(1)ꢀC(1)ꢀO(1)ꢂ178.4(7),
Cl(2)ꢀRu(2)ꢀO(3)ꢂ97.79(13),
C(2)ꢀRu(2)ꢀCl(1)ꢂ177.7(8),
/
2.8620(7), Ru(1)ꢀ
2.3829(18), Ru(1)ꢀ
P(2)ꢂ2.3646(19), Ru(1)ꢀ
C(1)ꢀO(1)ꢂ1.152(9), Ru(2)ꢀ
Ru(1)ꢀO(3)ꢂ2.161(4),
0.804(10), Ru(1)ꢀH(1)ꢂ1.797(10), Ru(2)ꢀ
Ru(1)ꢀP(3)ꢂ
Ru(2)ꢀP(1)ꢂ
Ru(2)ꢀP(2)ꢂ
Ru(1)ꢀO(3)ꢂ
Ru(1)ꢀCl(1)ꢂ
Ru(1)ꢀO(3)ꢀRu(2)ꢂ
O(3)ꢀRu(2)ꢀRu(1)ꢂ
Ru(1)ꢀH(1)ꢀRu(2)ꢂ
/
Cl(1)ꢂ
/
2.438(2), Ru(2)ꢀ
P(4)ꢂ2.3719(19), Ru(2)ꢀ
C(1)ꢂ1.821(8), C(1)ꢀ
C(2)ꢂ1.816(10),
Ru(2)ꢀO(3)ꢂ
/
Cl(2)ꢂ
/
2.4169(17),
/
/
/
/
/
/
P(1)ꢂ
/
/
/
/
/
/
acetylene orbital overlap would be less than in un-
strained cases, resulting in less acetylene activation.
However, the other structural parameters in the ligand
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
do not confirm this expectation. The rutheniumꢀ
lene bonds (d(Ru(1)ꢀC(2))ꢂ2.039(8) and d(Ru(2)ꢀ
2.034(8) A) are among the shortest observed
for diruthenium acetylene-bridged complexes, and the
/acety-
/
/
/
/
/
/
/
91.28(4),
91.90(5),
175.97(7),
97.60(14),
93.1(2),
Ru(2)ꢀ
Ru(1)ꢀ
P(3)ꢀ
O(3)ꢀ
/
Ru(1)ꢀ
/
/
Ru(1)ꢀ
P(1)ꢀ
Cl(1)ꢀ
C(1)ꢀ
/
/
/
˚
/
/
/
/
/
/
C(3))ꢂ
/
/
/
/
/
/
/
/
/
/
/
/
/
˚
C(3), 1.336(11) A) is
acetylene Cꢀ
/
C bond (i.e. C(2)ꢀ
/
/
/
/
/
/
/
consistently among the longest observed [12]. The
distances between Ru and acetate oxygen atoms are
˚
82.44(17),
48.47(11),
35.6(1).
/
/
/
/
/
/
/
/
/
/
/
/
d(Ru(1)ꢀ
/
O(3))ꢂ/2.624(6)
A
and d(Ru(2)ꢀ
/
O(5))ꢂ
/

124
K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ125
/
i
tol, 6a; Pr, 6b) was iso-
DPPM)2I2(m-I)(m-SR)] (Rꢂ
/
lated. The solid-state structure of 6a (Fig. 7) was
determined using X-ray diffraction methods to reveal
the loss of one doubly bonded RS group, isomerization
of the remaining RS group from the terminal to the
bridging position, coordination of three I atoms in one
bridging and two terminal positions, and the cleavage of
the Ruꢀ
Ru(2) separation of 3.687(2) A. The singly bonded
RuIIꢀ
I distances in either terminal (d(Ru(1)ꢀI(1))ꢂ
2.746(2) and d(Ru(2)ꢀ 2.765(2) A) or bridging
positions (d(Ru(1)ꢀI(2))ꢂ
2.752(2) A) are longer as expected in 6a (Fig. 7)
than the partially doubly bonded RuIꢀ
I distances
(d(Ru(1)ꢀI(1))ꢂ2.660(2) and d(Ru(2)ꢀI(2))ꢂ2.679(2)
/
Ru single bond, as reflected in the long Ru(1)ꢀ
/
˚
Fig. 6. ORTEP plot of 5a with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
/
/
/
˚
/
I(3))ꢂ
/
˚
have been retained for clarity). Selected bond lengths (A): Ru(1)ꢀ
/
˚
/
/
2.759(2) A and d(Ru(2)ꢀ
/
Ru(2)ꢂ
2.5246(10), Ru(1)ꢀ
P(2)ꢂ2.366(2), Ru(2)ꢀ
Ru(2)ꢀC(1)ꢂ1.996(7), C(1)ꢀ
Ru(2)ꢀC(3)ꢂ2.034(8), C(2)ꢀ
1.485(12), C(3)ꢀC(6)ꢂ1.466(11), C(4)ꢀ
O(4)ꢂ1.197(11), C(4)ꢀO(3)ꢂ1.334(11), C(6)ꢀ
O(3)ꢀC(5)ꢂ1.462(11), O(5)ꢀC(7)ꢂ1.449(12). Selected bond angles
(8): Ru(2)ꢀRu(1)ꢀP(1)ꢂ91.87(5), Ru(2)ꢀRu(1)ꢀP(3)ꢂ92.24(5),
Ru(1)ꢀRu(2)ꢀP(2)ꢂ91.99(5), Ru(1)ꢀRu(2)ꢀP(4)ꢂ92.07(5), Ru(2)ꢀ
Ru(1)ꢀBr(1)ꢂ147.75(4), Ru(1)ꢀRu(2)ꢀBr(2)ꢂ152.51(4), Br(1)ꢀ
Ru(1)ꢀC(1)ꢂ103.8(2), C(1)ꢀRu(1)ꢀC(2)ꢂ110.8(3), Ru(1)ꢀC(2)ꢀ
C(3)ꢂ114.2(6), C(2)ꢀC(3)ꢀRu(2)ꢂ110.1(6), C(3)ꢀRu(2)ꢀC(1)ꢂ
112.2(3), Ru(2)ꢀC(1)ꢀO(1)ꢂ129.8(6), Ru(2)ꢀC(1)ꢀRu(1)ꢂ92.7(3),
Ru(1)ꢀC(1)ꢀO(1)ꢂ137.5(6), Br(1)ꢀRu(1)ꢀC(2)ꢂ145.4(2), Br(2)ꢀ
Ru(2)ꢀC(1)ꢂ109.2(2), Br(2)ꢀRu(2)ꢀC(3)ꢂ138.6(2).
/
2.8717(9),
Ru(1)ꢀ
P(1)ꢂ2.363(2), Ru(1)ꢀ
P(4)ꢂ2.374(2),
O(1)ꢂ1.161(9), Ru(1)ꢀ
C(3)ꢂ1.336(11),
O(2)ꢂ1.192(12), C(6)ꢀ
O(5)ꢂ1.364(10),
/
Br(1)ꢂ
/
2.5350(10),
P(3)ꢂ
Ru(1)ꢀ
Ru(2)ꢀ
2.374(2), Ru(2)ꢀ
C(1)ꢂ1.972(7),
C(2)ꢂ2.039(8),
C(2)ꢀC(4)ꢂ
/
Br(2)ꢂ
/
˚
/
/
/
/
/
I(2))ꢂ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
ꢁ
˚
A) in 3c (Fig. 3). The bridging SR group is not
/
/
/
/
/
/
/
/
/
/
coplanar with two Ru atoms, as reflected in the
/
/
/
/
torsional
angle,
ꢁ
/
Ru(1)ꢀ
/
Ru(2)ꢀ
/
S(1)ꢀ
/
C(3),
of
/
/
/
/
/
/
136.7(9)8. The S atom is apparently in sp3-hybridization
and the SRꢁ group acts as a four-electron donor,
donating two electrons to each Ru atom. The similarity
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
in the Ruꢀ
/
I distances (i.e. Ruꢀ
/
I(terminal) and Ruꢀ
/
/
/
/
/
/
/
I(bridging)) indicates that the bridging Iꢁ atom may
also act as a four-electron donor, donating two electrons
to each Ru atom in the complex. The electron count for
each Ru atom thus reaches 18, explaining the observed
diamagnetic property for 6a and 6b.
/
/
/
/
/
/
/
/
/
/
/
/
˚
2.829(6) A, far beyond the expected single-bond distance
˚
of 2.12 A, calculated based on the reported distance of
˚
2.16 A found in [Re2(CO)9(m-HCCCO2Me)] [13] and the
smaller covalent radius for Ru [14]. The Ruꢀ
/
Ru
˚
˚
distance is 2.8717(9) A, similar to that of 2.8620(7) A
in 4b. Apparently it is a single bond distance, although a
‘triple’ Ruꢀ
the 18-electron rule with both Br atoms as the two-
electron donors. The shorter terminal RuIIꢀ
Br distances
and d(Ru(2)ꢀ
2.525(1) A in 5a, compared with that of
/Ru bond is expected again in 5a, based on
/
˚
with d(Ru(1)ꢀ
/
Br(1))ꢂ
/2.535(1)
A
/
˚
Br(2))ꢂ
/
˚
2.543(4) A in [Ru2Br2(m-Br)2(CO)6] [15] may indicate
the presence of multiple (probably double) RuꢀBr
bonding interactions, which then lengthen the ‘triple’
RuꢀRu distance to the single-bond value. Further, the
observed Ruꢀ
considered as ‘expected’, by considering the pyramidal
and torsional effects on the metalꢀmetal single bond
/
/
˚
Ru distance of 2.8717(9) A can be
/
Fig. 7. ORTEP plot of 6a with 50% thermal ellipsoids and the
numbering scheme (only the ipso carbon atoms of each phenyl group
/
˚
have been retained for clarity). Selected bond lengths (A): Ru(1)ꢀ
/
length vide supra. This value co-exists with the averaged
pyramidal angle, a, of 89.18 and with the averaged
torsion angle, t, of 1.08 in 5a. Since the pyramidal angle
I(1)ꢂ
I(3)ꢂ
P(2)ꢂ
O(1)ꢂ
S(1)ꢂ2.407(4), Ru(2)ꢀ
bond angles (8): P(1)ꢀ
169.3(2), I(1)ꢀRu(1)ꢀI(2)ꢂ
S(1)ꢀRu(1)ꢀC(1)ꢂ92.4(6), C(1)ꢀ
Ru(2)ꢂ83.99(6), Ru(1)ꢀS(1)ꢀRu(2)ꢂ
121.0(8), Ru(2)ꢀS(1)ꢀC(3)ꢂ121.9(7), I(2)ꢀ
I(2)ꢀRu(2)ꢀS(1)ꢂ88.04(12), S(1)ꢀRu(2)ꢀC(2)ꢂ
Ru(2)ꢀI(3)ꢂ81.2(6), Ru(1)ꢀC(1)ꢀO(1)ꢂ174(2),
O(2)ꢂ174(2).
/
2.746(2), Ru(1)ꢀ
2.765(2), Ru(1)ꢀP(1)ꢂ
2.374(5), Ru(2)ꢀP(4)ꢂ
1.10(2), Ru(2)ꢀC(2)ꢂ
S(1)ꢂ2.396(5), S(1)ꢀ
Ru(1)ꢀP(3)ꢂ170.1(2), P(2)ꢀ
94.05(6), I(2)ꢀRu(1)ꢀS(1)ꢂ
Ru(1)ꢀI(1)ꢂ85.7(5), Ru(1)ꢀ
100.3(2), Ru(1)ꢀS(1)ꢀC(3)ꢂ
Ru(2)ꢀI(3)ꢂ96.21(7),
94.7(6),
C(2)ꢀ
Ru(2)ꢀC(2)ꢀ
/
I(2)ꢂ
/
2.759(2), Ru(2)ꢀ
2.398(5), Ru(1)ꢀ
2.418(5), Ru(1)ꢀ
1.93(2), C(2)ꢀO(2)ꢂ
C(3)ꢂ
/
I(2)ꢂ
P(3)ꢂ
C(1)ꢂ
1.04(2), Ru(1)ꢀ
1.52(2). Selected
Ru(2)ꢀP(4)ꢂ
87.66(12),
I(2)ꢀ
/
2.752(2), Ru(2)ꢀ
2.402(5), Ru(2)ꢀ
1.84(2), C(1)ꢀ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
is identical to that in 4b, the significantly longer Ruꢀ
/
Ru
bond length of 2.8717(9) A in 5a, relative to that of
/
/
/
/
/
˚
/
/
/
/
/
/
˚
2.8620(7) A in 4b, is probably caused by the smaller
/
/
/
/
/
/
/
/
/
/
/
/
/
/
torsion angle of 1.08 in 5a, compared with that of 8.58 in
4b.
/
/
/
/
/
/
/
/
/
/
/
/
/
Iodination of the singly Ruꢀ
/
Ru and doubly Ruꢀ
/
S
/
/
/
/
/
/
/
bonded complexes, 3e and 3f is a complicated reaction,
/
/
/
/
/
/
/
from which a diamagnetic compound [Ru2(CO)2(m-
/

K.-B. Shiu et al. / Journal of Organometallic Chemistry 658 (2002) 117ꢃ
/125
125
[2] W.A. Nugent, J.M. Mayer, Metalꢃ
/
Ligand Multiple Bonds,
4. Conclusions
Wiley, New York, 1988.
[3] (a) J. Losada, S. Alvarez, J.J. Novoa, F. Mota, J. Am. Chem. Soc.
112 (1990) 8998;
Our investigation into the acetate-removal of
[Ru2(CO)4(m-DPPM)2(m-OAc)]ꢀ [1]ꢀ with Et3OꢀBF4ꢁ
in MeCN resulted in the formation of versatile products
[Ru2(m-CO)2(m-DPPM)2(MeCN)4]2ꢀ [2]2ꢀ (Scheme 1).
Upon addition of an excess amount of a uninegative
anion Xꢁ to a solution of 2 in MeCN, a series of
neutral, coordinatively unsaturated adducts [Ru2(m-
(b) F. Mota, J.J. Novoa, J. Losda, S. Alvarez, R. Hoffman, J.
Sivestre, J. Am. Chem. Soc. 115 (1993) 6216;
(c) G. Aullon, S. Alvarez, Inorg. Chem. 32 (1993) 3712;
(d) J.J. Novoa, G. Aullon, P. Alemany, S. Alvarez, J. Am. Chem.
Soc. 117 (1995) 7169;
(e) G. Aullon, P. Alemany, S. Alvarez, Inorg. Chem. 35 (1996)
5061;
CO)2(m-DPPM)2X2] (Xꢁ ꢂ
/
Clꢁ, 3a; Brꢁ, 3b; Iꢁ, 3c;
(f) G. Aullon, S. Alvarez, J. Chem. Soc. Dalton Trans. (1997)
2681;
SHꢁ, 3d; Stolꢁ, 3e; SiPrꢁ, 3f) were readily formed
(Scheme 2). The reaction of 3a with Me3NO×2H2O
afforded two isomeric products of [Ru2(CO)2(m-
(g) X.-Y. Liu, S. Alvarez, Inorg. Chem. 36 (1997) 1055;
(h) G. Aullon, S. Alvarez, Chem. Eur. J. 3 (1997) 655.
[4] S.J. Sherlock, M. Cowie, E. Singleton, M.M. de, V. Steyn,
Organometallics 7 (1988) 1663.
DPPM)2Cl2(m-H)(m-OH)] at a ratio of 4aꢃ
/
4bꢂ/2.25.
Treatment of 3b and 3c with dimethyl acetylenedicar-
[Ru2(m-CO)(m-DPPM)2X2(m-
Br, 5a; I, 5b), whereas treat-
[5] E.J. Gabe, Y. Le Page, J.-P. Charland, F.L. Lee, P.S. White, J.
Appl. Crystallogr. 22 (1989) 384.
boxylate
produced
MeO2CCCCO2Me)] (Xꢂ
/
[6] G.M. Sheldrick, SHELXTL-PLUS Crystallographic System, Release
4.21, Siemens Analytical X-ray Instruments, Madison, WI, 1991.
[7] K.-B. Shiu, C.-H. Li, T.-J. Chan, S.-M. Peng, M.-C. Cheng, S.-L.
Wang, F.-L. Liao, M.-Y. Chiang, Organometallics 14 (1995) 524.
[8] (a) S.J. Sherlock, M. Cowie, E. Singleton, M.M. de Steyn, J.
Organomet. Chem. 361 (1989) 353;
ment of 3e and 3f with I2 yielded [Ru2(CO)2(m-
DPPM)2I2(m-I)(m-SR)] (Rꢂ
tol, 6a; iPr, 6b) (Scheme
3). Structures 2, 3a, 3c, 3e, 4b, 5a and 6a in Figs. 1ꢃ7,
respectively, were described. The observed RuꢀRu
distances are compared and explained in terms of both
electronic and steric effects by considering the multiple
/
/
/
(b) P.L. Andren, J.A. Cabeza, V. Riera, F. Jennin, J. Organomet.
Chem. 372 (1989) C15;
metalꢀ
ez’s structural parameters including Mꢀ
dal angles and the XꢀMꢀMꢀX torsional angles.
/
ligand (Mꢀ
/
X) bonding interactions and Alvar-
(c) S. Garcia-Granda, R. Obeso-Rosete, J.M.R. Gonzalez, A.
Anillo, Acta Crystallogr. Sect. C 46 (1990) 2043;
(d) G. Rheinwald, H. Stoeckli-Evans, G. Suss-Fink, J. Organo-
met. Chem. 441 (1992) 295;
/
MꢀX pyrami-
/
/
/
/
(e) K.-B. Shiu, S.-M. Peng, M.-C. Cheng, J. Organomet. Chem.
452 (1993) 143;
5. Supplementary material
(f) W.G. Klemperer, Z. Bianxia, Inorg. Chem. 32 (1993) 5821;
(g) K.-B. Shiu, W.-N. Guo, T.-J. Chan, J.-C. Wang, L.-S. Liou,
S.-M. Peng, M.-C. Cheng, Organometallics 14 (1995) 1732;
(h) K.-B. Shiu, L.-T. Yang, S.-W. Jean, C.-H. Li, R.-R. Wu, J.-C.
Wang, L.-S. Liou, M.-Y. Chiang, Inorg. Chem. 35 (1996) 7845;
(i) K.-B. Shiu, S.-W. Jean, H.-J. Wang, S.-L. Wang, F.-L. Liao,
J.-C. Wang, L.-S. Liou, Organometallics 16 (1997) 114;
(j) K.-B. Shiu, S.-L. Wang, F.-L. Liao, M.-Y. Chiang, S.-M. Peng,
G.-H. Lee, J.-C. Wang, L.-S. Liou, Organometallics 17 (1998)
1790.
Crystallographic data for the structural analysis has
been deposited with the Cambridge Crystallographic
Data Centre, CCDC Nos. 187200ꢃ187206 for com-
pounds 2, 3a, 3c, 3e, 4b, 5a, and 6a respectively. Copies
of this information may be obtained free of charge from:
The Director, CCDC, 12 Union Road, Cambridge, CB2
/
1EZ, UK (Fax: ꢀ44-1223-336033; e-mail: deposit@
/
[9] J.L. Hubbard, A. Morneau, R.M. Burns, C.R. Zoch, J. Am.
Chem. Soc. 113 (1991) 9176.
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
[10] R.D. Adams, J.E. Babin, H.S. Kim, Inorg. Chem. 25 (1986) 1122.
[11] (a) C.-L. Lee, C.T. Hunt, A.L. Balch, Inorg. Chem. 20 (1981)
2489;
Acknowledgements
(b) M. Cowie, R.S. Dickson, Inorg. Chem. 20 (1981) 2682;
(c) B.L. Shaw, S.J. Higgins, J. Chem. Soc. Dalton Trans. (1988)
457;
Financial support for this work by the National
Science Council of Republic of China (Contracts
NSC89-2113-M006-019 and NSC90-2113-M-006-021)
is gratefully acknowledged.
(d) J.T. Mague, Polyhedron 11 (1992) 677.
[12] (a) J.S. Field, R.J. Haines, J. Sundermeyer, S.F. Woollam, J.
Chem. Soc. Dalton Trans. (1993) 3749;
(b) J. Kuncheria, H.A. Mirza, R.J. Puddephatt, J. Organomet.
Chem. 593ꢃ594 (2000) 77.
[13] R.D. Adams, L. Chen, W. Wu, Organometallics 12 (1993) 1257.
[14] J. Emsley, The Elements, Oxford University Press, New York,
/
References
1989.
[15] S. Merlino, G. Montagnoli, Acta Crystallogr. Sect. B 24 (1968)
424.
[1] K.-B. Shiu, S.-S. Yang, S.-I. Chen, J.-Y. Chen, H.-J. Wang, S.-L.
Wang, F.-L. Liao, S.-M. Peng, Y.-H. Liu, Organometallics 18
(1999) 4244.