Transfer of hydrogen, oxygen, or both hydrogen and oxygen to unsaturated substrates from [ReH2(O)(Cyttp)]+ (Cyttp = PhP(CH2CH2CH2PCy2) 2)

Article abstract of DOI:10.1016/S0022-328X(03)00701-0

Reactions of the hydrido-oxo complex [ReH₂(O)(Cyttp)] SbF₆ (1(SbF₆): Cyttp=PhP(CH₂ CH₂CH₂PCy₂)₂) or [ReH₂(O)(Cyttp)]OTf (1(OTf): OTf=O₃SCF₃) with various unsaturated compounds proceed by transfer of hydrogen, oxygen, or both hydrogen and oxygen to the unsaturated substrate. Thus, 1(SbF₆) reacts with CO in acetone at 0 °C to afford the formate [ReH(η²-HCO₂)(CO)(Cyttp)] SbF₆ (2(SbF₆)), and in benzene at 25 °C to yield 2(SbF₆) and [Re(CO)₃(Cyttp)]SbF₆ (3(SbF₆)). Control experiments showed that the formation of 3(SbF₆) takes place by two pathways, viz., with or without 2(SbF₆) intermediate. Isocyanides react with 1(SbF₆) in benzene at 25 °C to produce [Re(CNR)₃(Cyttp)]SbF₆ (R=t-Bu, Cy); when R=t-Bu, RNCO was also observed. The reaction of 1(SbF₆) with SO₂ in benzene at 25 °C affords the sulfito-O, O′ complex [ReH₂(η²-SO₃)(Cyttp)] SbF₆ (6(SbF₆)) by oxide transfer. Heating 6(SbF₆) at 50 °C causes loss of SO₂ and regeneration of 1(SbF₆). The phosphite P(OMe)₃ behaves as an oxygen atom acceptor from 1(SbF₆) in benzene at 25 °C by furnishing OP(OMe)₃ and [ReH₂ (P(OMe)₃)₂(Cyttp)]SbF₆. The alkenes cyclohexene, norbornene, 3,3-dimethyl-1-butene, and diethyl fumarate require ca. 100 °C to react at a reasonable rate with 1(OTf) in THF or benzene under pressure by hydrogenation of the C-C bond. No oxygen-transfer products were detected. The alkyne PhC≡CH also reacts with 1(OTf) by hydrogenation to afford, at 100 °C, styrene, a small amount of ethylbenzene, and a mixture of inorganic products. Reactions of 1(OTf) with nitriles under anhydrous conditions are sensitive to the nature of the nitrile. Thus, ClCH₂CN reacts at ambient temperature in benzene solution to yield MeCN, ClCH₂C(O)NH₂, [Re(OH)(O)(Cl)(Cyttp)]OTf, ReCl₃(Cyttp), and uncharacterized minor products. In contrast, the aliphatic nitriles MeCN, EtCN, and Me₂CHCN require heating (75 °C) to undergo low-yield hydration to the appropriate amides. The aromatic nitriles also react differently to generate at 75 °C the amidato-O,N complexes [ReH(η²-ArC(O)NH)(NCAr)(Cyttp)]OTf (Ar=Ph, p-Tol, p-ClC₆H₄) and minor quantities of the appropriate aldehyde ArC(O)H. With added ca. one equivalent H₂O and in the presence of a small amount (ca. 0.01 equivalent) of 1(OTf), the nitriles MeCN, PhCN, and p-ClC₆H₄CN afford at 60 °C the corresponding amides; these catalytic reactions proceed through the appropriate η²-amidato-O,N complexes. All new compounds were characterized by a combination of elemental analysis, mass spectrometry, and IR and NMR spectroscopy. The structure of 6 (as 6 (SbF₆)·C₆H₆) was determined by single-crystal X-ray diffraction analysis.

Full text of DOI:10.1016/S0022-328X(03)00701-0

Journal of Organometallic Chemistry 682 (2003) 85Á101
/
www.elsevier.com/locate/jorganchem
Transfer of hydrogen, oxygen, or both hydrogen and oxygen to
unsaturated substrates from [ReH2(O)(Cyttp)]ꢀ (Cyttpꢁ
PhP(CH2CH2CH2PCy2)2)
/
Youhyuk Kim 1, Dean E. Rende 2, Judith C. Gallucci 3, Andrew Wojcicki *
Department of Chemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, OH 43210-1185, USA
Received 12 May 2003
Abstract
Reactions of the hydrido-oxo complex [ReH2(O)(Cyttp)]SbF6 (1(SbF6): Cyttpꢁ/PhP(CH2CH2CH2PCy2)2) or [ReH2(O)(Cytt-
p)]OTf (1(OTf): OTfꢁ
/
O3SCF3) with various unsaturated compounds proceed by transfer of hydrogen, oxygen, or both hydrogen
and oxygen to the unsaturated substrate. Thus, 1(SbF6) reacts with CO in acetone at 0 8C to afford the formate [ReH(h2-
HCO2)(CO)(Cyttp)]SbF6 (2(SbF6)), and in benzene at 25 8C to yield 2(SbF6) and [Re(CO)3(Cyttp)]SbF6 (3(SbF6)). Control
experiments showed that the formation of 3(SbF6) takes place by two pathways, viz., with or without 2(SbF6) intermediate.
Isocyanides react with 1(SbF6) in benzene at 25 8C to produce [Re(CNR)3(Cyttp)]SbF6 (Rꢁ
/
t-Bu, Cy); when Rꢁt-Bu, RNCO was
/
also observed. The reaction of 1(SbF6) with SO2 in benzene at 25 8C affords the sulfito-O,O? complex [ReH2(h2-SO3)(Cyttp)]SbF6
(6(SbF6)) by oxide transfer. Heating 6(SbF6) at 50 8C causes loss of SO2 and regeneration of 1(SbF6). The phosphite P(OMe)3
behaves as an oxygen atom acceptor from 1(SbF6) in benzene at 25 8C by furnishing OP(OMe)3 and [ReH2(P(OMe)3)2(Cyttp)]SbF6.
The alkenes cyclohexene, norbornene, 3,3-dimethyl-1-butene, and diethyl fumarate require ca. 100 8C to react at a reasonable rate
with 1(OTf) in THF or benzene under pressure by hydrogenation of the CÄ
/
C bond. No oxygen-transfer products were detected. The
alkyne PhCÅCH also reacts with 1(OTf) by hydrogenation to afford, at 100 8C, styrene, a small amount of ethylbenzene, and a
/
mixture of inorganic products. Reactions of 1(OTf) with nitriles under anhydrous conditions are sensitive to the nature of the nitrile.
Thus, ClCH2CN reacts at ambient temperature in benzene solution to yield MeCN, ClCH2C(O)NH2, [Re(OH)(O)(Cl)(Cyttp)]OTf,
ReCl3(Cyttp), and uncharacterized minor products. In contrast, the aliphatic nitriles MeCN, EtCN, and Me2CHCN require heating
(75 8C) to undergo low-yield hydration to the appropriate amides. The aromatic nitriles also react differently to generate at 75 8C the
amidato-O,N complexes [ReH(h2-ArC(O)NH)(NCAr)(Cyttp)]OTf (Arꢁ
/
Ph, p-Tol, p-ClC6H4) and minor quantities of the
appropriate aldehyde ArC(O)H. With added ca. one equivalent H2O and in the presence of a small amount (ca. 0.01 equivalent) of
1(OTf), the nitriles MeCN, PhCN, and p-ClC6H4CN afford at 60 8C the corresponding amides; these catalytic reactions proceed
through the appropriate h2-amidato-O,N complexes. All new compounds were characterized by a combination of elemental
analysis, mass spectrometry, and IR and NMR spectroscopy. The structure of 6 (as 6(SbF6)×/C6H6) was determined by single-crystal
X-ray diffraction analysis.
# 2003 Elsevier B.V. All rights reserved.
Keywords: Rhenium complexes; Hydrido-oxo complexes; Transfer of oxygen and hydrogen; Formate complex; Hydration of nitriles; Crystal
structure
* Corresponding author. Tel.: ꢀ
/
1-614-292-4750; fax: ꢀ1-614-292-1685.
/
E-mail addresses: gallucci.1@osu.edu (J.C. Gallucci), wojcicki@chemistry.ohio-state.edu (A. Wojcicki).
1
Present address: Department of Chemistry, School of Fundamental Sciences, Dankook University, Cheonan, Chungnam 330-714, South Korea.
Present address: UOP, 50 East Algonquin Road, P.O. Box 5016, Des Plaines, IL 60017-6016, USA.
2
3
To whom enquiries concerning the X-ray crystallographic study should be addressed. Fax: ꢀ1-614-292-1685.
/
0022-328X/03/$ - see front matter # 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00701-0

86
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
1. Introduction
Detector (IRD). Injections were usually accomplished
by using a 7673A Automatic Injector. The columns
leading to MSD and IRD were Altech RSL300 with the
stationary phase consisting of crosslinked 35% phenyl
and 50% methyl silicone. The IRD column was 30-m in
length with a 0.33-mm in ID. The MSD column was 15-
m in length with a 0.25-mm in ID linked to a 1-m in
length and 0.1-mm in ID deactivated fused silica tube.
FAB mass spectra were recorded on a Kratos VG70-
250S spectrometer by Mr. David C. Chang.
Transition-metal hydrides and oxides represent two
important and extensively investigated classes of com-
pounds with rich chemistry [1,2]. Their numerous
reactions include transfer of hydrogen and oxygen
ligands to various unsaturated substrates, e.g., carbon
monoxide, alkenes, and alkynes [1,2a,2b,3,4].
In contrast to the foregoing species, transition-metal
hydrido-oxo hybrid complexes are still relatively un-
common [5]. The binuclear and polynuclear metal
complexes [6], which generally predate their mono-
2.2. Materials
nuclear counterparts [5,7Á9], are more numerous than
/
the latter, but their chemistry has been little explored.
The mononuclear complexes have been studied with
respect to replacement of oxide ligand with hydride
[5,8d,8e] and of hydride with chloride or oxide [8a,8d],
Reagents were procured from various commercial
sources and used as received, except as noted below.
Sulfur dioxide was purified before use by passage
through concentrated H2SO4 and a column packed
with P4O10. The complexes [ReH2(O)(Cyttp)]SbF6
insertion of alkenes and acetaldehyde into MÃ
/H bond
[8d,8e], and protonation at oxygen [5,8b]. All these
reactions are known for metal hydrido and oxo com-
plexes in which the other ligand in point is absent.
An important type of reaction of a transition-metal
hydrido-oxo hybrid complex would be one in which
both hydrogen and oxygen are transferred to an
appropriate substrate, generally an unsaturated species.
Such reactions may be regarded as being analogous to
those occurring in low-valent transition-metal organo-
metallic chemistry, an example being transfer of both
hydrogen and CO from a metal hydrido-carbonyl to
alkene. They are the basis of important commercial
processes [10]. However, in metal hydrido-oxo chemis-
try, such double-transfer reactions are virtually un-
known. The only reported example concerns reaction
(1(SbF6):
Cyttpꢁ
/
PhP(CH2CH2CH2PCy2)2),
[Re-
O3SCF3), and [Re-
H2(O)(Cyttp)]OTf (1(OTf): OTfꢁ
/
H2(18O)(Cyttp)]SbF6 (1Ã
our previously published procedures [5].
/
18O(SbF6)) were prepared by
2.3. Reactions of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with CO
2.3.1. In acetone at 0 8C
Carbon monoxide was bubbled through a solution of
1(SbF6) (0.20 g, 0.19 mmol) in 40 ml of acetone at 0 8C
for 20 min to give a yellow solution. This solution was
concentrated to 2Á3 ml under reduced pressure, and
/
Et2O (20 ml) was added with stirring to afford a
yellowish white precipitate. The solid was collected by
filtration, washed with Et2O, and dried under vacuum
of
[ReH2(O)(Cyttp)]SbF6
(1(SbF6):
Cyttpꢁ
/
PhP(CH2CH2CH2PCy2)2) with CO, which was de-
scribed in a preliminary communication [9a]. We now
present our complete investigation on reactions of 1
with unsaturated substrates. Depending on the sub-
strate, transfer of hydrogen, oxygen, or both hydrogen
and oxygen was observed.
overnight.
The
yield
of
[ReH(h2-
HCO2)(CO)(Cyttp)]SbF6 (2(SbF6)) was 0.16 g (79%).
IR (Nujol): n(CO) 1904 (s), n(ReH) 1705 (vw),
nasym(OCO) 1546 (s) cmꢂ1; (KBr): n(CO) 1905 (s),
1
nasym(OCO) 1545 (s), nsym(OCO) 1364 (m) cmꢂ1. H-
NMR (acetone-d6, Cyttp signals not given): d 8.47 (q,
2
4JPH
(Pwꢁ
ꢁ
/
2.5 Hz, 1H, HCO2), ꢂ
/
5.03 (td, JP H
ꢁ51.6 Hz
/
w
2
wing P), JP H
/
ꢁ
/
12.4 Hz (Pcꢁcentral P), 1H,
/
c
2. Experimental
ReH) ppm. 31P{1H}-NMR (acetone-d6): d 23.93 (d,
2JP P
ppm. Anal. Found: C, 41.96; H, 5.90. Calc. for
ꢁ
/
15.5 Hz, Pw), ꢂ
/
17.21 (t, JP P
ꢁ15.5 Hz, Pc)
/
2
c
w
c
w
2.1. General procedures and measurements
C38H63F6O3P3ReSb: C, 42.15; H, 5.86%.
Reactions and manipulations of air-sensitive com-
pounds were conducted under an atmosphere of dry
argon by use of standard procedures [11]. Solvents were
dried [12], distilled under argon, and degassed before
use. Elemental analyses were carried out by M-H-W
Reaction was also conducted using 1(SbF6) and 13CO.
A 100-ml Schlenk flask containing a solution of 1(SbF6)
(0.10 g, 0.10 mmol) in 20 ml of acetone at 0 8C was
partially evacuated and filled with 13CO to ca. 1 atm.
The solution was stirred for 30 min, concentrated to 2Á3
/
2
Laboratories, Phoenix, AZ. IR and NMR (1H, H, 13C,
ml under reduced pressure, and treated with 20 ml of
Et2O to give a yellowish white precipitate. The solid was
filtered off, washed with Et2O, and dried under vacuum
overnight. Selected spectroscopic data for [ReH(h2-
19F, and 31P) spectra were obtained as previously
described [13,14]. GCÁ
/
MSÁIR were performed on a
/
HP5890A Series II GC connected to a HP5970B Mass
Selective Detector (MSD) and a HP5965A Infrared
H13CO2)(13CO)(Cyttp)]SbF6 (2Ã
/
13C2(SbF6)). IR (Nu-

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
87
jol): n(13CO) 1858 (s), nasym(O13CO) 1504 (s),
and an additional one at d 1.36 ppm. The last resonance
was assigned to t-BuNCO by comparison with the
spectrum of an authentic sample obtained commercially.
Addition of t-BuNCO to the reaction solution increased
the intensity of this signal.
nsym(O13CO) 1342 (m) cmꢂ1
.
1H-NMR (CD2Cl2): d
5.28 (br t,
1
8.24 (d, J13
ꢁ
/
217.3 Hz, 1H, H13CO2), ꢂ
/
CH
2JP H
(CD2Cl2): d 190.26 (dt, JP C
ꢁ
51 Hz, 1H, ReH) ppm. 13C{1H}-NMR
/
w
2
2
65.8 Hz, JP C
ꢁ
/
ꢁ10.5
/
c
w
Hz, 13CO), 176.13 (s, H13CO2) ppm. 13C-NMR
1
(CD2Cl2): d 176.13 (d, JCH
ꢁ
/
217 Hz, H13CO2).
2.4.2. RNCꢁ
/
CyNC (CyꢁC6H11)
/
Reaction between 1(SbF6) (0.10 g, 0.10 mmol) and
CyNC (0.10 ml) was carried out similarly to that
between 1(SbF6) and t-BuNC. The yield of
[Re(CNCy)3(Cyttp)]SbF6 (5(SbF6)) was 0.090 g (69%).
Selected spectroscopic data. IR (Nujol): n(CN) 2110 (s,
2.3.2. In benzene at room temperature
Carbon monoxide was slowly bubbled through a
solution of 1(SbF6) (0.10 g, 0.10 mmol) in 30 ml of
benzene at room temperature for various lengths of time
from 1 to 15 h. Removal of the solvent under reduced
pressure yielded a yellowish white solid which was
1
sh), 2020 (s), 1990 (s, sh) cmꢂ1. H-NMR (acetone-d6):
d 4.10 (br, 2H, CH of NCy), 3.98 (br t, 1H, CH of NCy)
(CH of PCy at higher fields) ppm. 13C{1H}-NMR
(acetone-d6): d 55.98 (s, CH of NCy), 55.38 (s, CH of
NCy), 55.09 (s, CH of NCy) (CH of PCy at higher
shown to be
a
mixture of 2(SbF6) and
[Re(CO)3(Cyttp)]SbF6 (3(SbF6)) by 31P{1H}-NMR
spectroscopy. Washing with 3 ml of benzene gave
analytically pure 3(SbF6) as a white solid. The yield
varied depending on reaction time, the highest being
0.070 g (65%). Selected spectroscopic data. IR (Nujol):
fields) ppm. 31P{1H}-NMR (acetone-d6): d ꢂ
/
13.33 (d,
25.3 Hz, PC).
2
29.41 (t, JP P
2JP P
ꢁ
/
25.3 Hz, PW), ꢂ
/
ꢁ
/
c
w
c w
Anal. Found: C, 51.01; H, 7.01; N, 2.97; P, 6.77. Calc.
for C57H94F6N3P3ReSb: C, 51.23; H, 7.09; N, 3.14; P,
6.95%.
n(CO) 2030 (m), 1950 (s), 1915 (m, sh) cmꢂ1
2
NMR (acetone-d6): d 195.79 (q, JPC
.
13C{1H}-
ꢁ8.6 Hz, trans-
/
2
CO), 193.82 (q, JPC
ꢁ8.0 Hz, trans-CO), 192.96 (dt,
/
2
36.3 Hz, JP C
2JP C
ꢁ
/
ꢁ
/
7.3 Hz, cis-CO) ppm. 31P{1H}-
2.5. Reaction of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with SO2
c
w
2
12.89 (d, JP P
NMR (acetone-d6): d ꢂ
/
ꢁ
/
26.2 Hz, PW),
c
w
ꢂ
/
35.73 (t, 2JP P
H, 5.69; P, 8.61. Calc. for C39H61F6O3P3ReSb: C, 42.87;
H, 5.63; P, 8.50%.
ꢁ
/
26.2 Hz, PC). Anal. Found: C, 43.03;
c
w
Sulfur dioxide was passed through a solution of
1(SbF6) (0.10 g, 0.10 mmol) in 10 ml of benzene at
room temperature for ca. 1Á
violet solution was slowly concentrated to 2Á
/
2 min. The resulting bright
3 ml under
2.4. Reactions of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with RNC
/
reduced pressure and treated with 10 ml of Et2O to yield
a violet precipitate. The solid was collected on a filter
frit, washed with a small amount of Et2O, and dried
under vacuum overnight. The yield of [ReH2(h2-
SO3)(Cyttp)]SbF6 (6(SbF6)) was 0.090 g (82%). Crystals
of 6(SbF6) as a benzene solvate for X-ray diffraction and
elemental analysis were obtained by slow diffusion of
Et2O into a benzene solution of 6(SbF6). Selected
spectroscopic data. IR (CD2Cl2): n(ReH) 1827 (w),
2.4.1. RNCꢁt-BuNC
/
A solution of 1(SbF6) (0.10 g, 0.10 mmol) in 25 ml of
benzene was treated with an excess of t-BuNC (0.10 ml,
0.88 mmol), and the resulting mixture was stirred at
room temperature for 20 min. Removal of the volatiles
under reduced pressure and addition of 20 ml of Et2O
afforded a white powder, which was collected on a filter
frit, washed with a small amount of Et2O, and dried
under vacuum overnight. The yield of [Re(CNBu-
t)3(Cyttp)]SbF6 (4(SbF6)) was 0.12 g (98%). Selected
spectroscopic data. IR (Nujol): n(CN) 2050 (s, sh), 2020
(s), 1950 (m, sh) cmꢂ1. 1H-NMR (acetone-d6): d 1.60 (s,
9H, t-Bu), 1.57 (s, 9H, t-Bu), 1.53 (s, 9H, t-Bu) ppm.
1710 (w); n(SO) 1200 (m), 1190 (s) cmꢂ1
.
1H-NMR
34.1 Hz,
7.29 (qd,
2
0.74 (tdd, JP H
(CD2Cl2 sat. with SO2): d ꢂ
/
ꢁ
/
w
2
13.2 Hz, JHH
2JP H
ꢁ
/
ꢁ
/
6.5 Hz, 1H, ReH), ꢂ
/
c
2
2JPH
ꢁ
/
46.6 Hz, JHH
ꢁ6.5 Hz, 1H, ReH) ppm.
/
31P{1H}-NMR (CD2Cl2 sat. with SO2): d 23.66 (d,
2JP P
Anal. Found: C, 43.06; H, 6.04. Calc. for C42H69F6O3-
ꢁ
/
14.0 Hz, PW), ꢂ
/
4.13 (t, JP P
ꢁ14.0 Hz, PC).
/
2
c
w
c
w
13C{1H}-NMR (acetone-d6): d 151.60 (m, CN), 159.85
2
(m, CN), 148.77 (dm, JP C
ꢁ/45.0 Hz, CN), 56.83 (s,
P3ReSSb (6(SbF6)×C6H6): C, 43.16; H, 5.95%.
/
c
CMe3), 56.79 (s, CMe3), 56.62 (s, CMe3), 31.60 (s,
CMe3), 31.28 (s, CMe3), 30.90 (s, CMe3) ppm. 31P{1H}-
2.6. Reaction of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with P(OMe)3
2
15.19 (d, JP P
NMR (acetone-d6): d ꢂ
/
ꢁ
/
25.7 Hz, Pw),
c
w
2
29.71 (t, JP P
48.46; H, 6.95. Calc. for C51H88F6N3P3ReSb: C, 48.69;
ꢂ
/
ꢁ25.7 Hz, PC) ppm. Anal. Found: C,
/
c
w
A solution of 1(SbF6) (0.10 g, 0.10 mmol) in 25 ml of
benzene was treated with an excess of P(OMe)3 (0.050
ml, 0.42 mmol), and the resulting mixture was stirred at
room temperature for 30 min. The volatiles were
removed under reduced pressure, and hexane (20 ml)
H, 7.05%.
When the above reaction was monitored by 1H-NMR
spectroscopy in acetone-d6, five t-Bu resonances were
observed: three of 4(SbF6), one of unreacted t-BuNC,

88
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
was added with stirring to afford a white precipitate.
The solid was collected by filtration, washed with a
small amount of hexane, and dried under vacuum
overnight. The yield of [ReH2(P(OMe)3)2(Cyttp)]SbF6
(7(SbF6)) was 0.073 g (58%). Selected spectroscopic
0.0078 g, 0.093 mmol) in THF. The yield of 2,2-
dimethylbutane was 81% based on 1(OTf) (28% based
on 3,3-dimethyl-1-butene). MS: m/z 71 [Mꢀ Ã
43, 41.
/Me], 57,
data. IR (Nujol): n(ReH) 1960 (w), 1725 (w); n(PO)
1
2.7.4. Alkeneꢁ
/
diethyl fumarate
1100Á
/
1000 (s, br) cmꢂ1. H-NMR (acetone-d6): d 3.85
The reaction (100 8C, 48 h) and workup were
conducted as in Section 2.7.1 by using 1(OTf) (0.020 g,
0.021 mmol) and diethyl fumarate (0.010 ml, 0.010 g,
0.061 mmol) in THF. The yield of EtO2CCH2CH2-
3
3
(d, JPH
ꢁ
/
12.8 Hz, 9H, P(OMe)3), 3.81 (d, JPH
ꢁ
/
12.1
6.95 (d
67.5, 15.9 Hz, 1H, ReH) ppm. 31P{1H}-
NMR (acetone-d6): d 119.70 (m, P(OMe)3), 104.36 (ddt,
Hz, 9H, P(OMe)3), ꢂ
/
6.03 (m, 1H, ReH), ꢂ
/
2
quint, JPH
ꢁ
/
CO2Et was ꢁ80% based on 1(OTf) (28% based on
/
2JP P
ꢁ
/
231.2 Hz, 2JP
ꢁ
/
40.5 Hz, JP P
ꢁ
/
27.4
14.72 (br m, PW),
2
diethyl fumarate). MS: m/z 174 [Mꢀ], 147, 129, 101, 73,
55.
(O)P(O)
c
(O)
w (O)
Hz, P(OMe)3), 3.90 (br m, PW), ꢂ
/
2
30.23 (dq, JP P
2
231.2 Hz, JP P
ꢂ
/
ꢁ
/
ꢁ
/29.9 Hz,
c
(O)
c w
2JP P
P, 12.86. Calc. for C42H81F6O6P5ReSb: C, 42.51; H,
6.88; P, 13.05%.
ꢀ
/
30 Hz, PC). Anal. Found: C, 42.39; H, 6.77;
c
(O)
2.7.5. Alkeneꢁethylene
/
A solution of 1(OTf) (0.095 g, 0.10 mmol) in toluene
was maintained at reflux temperature in an atmosphere
of ethylene for 24 h. The volatiles were then removed,
and hexane (20 ml) was added. The solid was filtered off,
recrystallized from CH2Cl2/hexane, and washed with 10
ml of hexane containing two drops of CH2Cl2. The
recovery yield of 1(OTf) was 0.044 g.
When the above reaction was monitored by 1H-NMR
spectroscopy in acetone-d6, an additional Me resonance
3
was detected at d 3.38 ppm with a JPH
ꢁ11.1 Hz. The
/
resonance was assigned to OP(OMe)3 by comparison
with the spectrum of an authentic sample obtained
commercially. Addition of OP(OMe)3 to the reaction
solution enhanced the intensity of this signal. Similarly,
a singlet at d 1.17 ppm in the 31P{1H}-NMR spectrum
was shown to belong to OP(OMe)3 formed in the
reaction.
2.8. Reaction of [ReH2(O)(Cyttp)]OTf (1(OTf)) with
PhCÅ/CH
A solution of 1(OTf) (0.031 g, 0.033 mmol) and PhCÅ
/
CH (0.015 ml, 0.014 g, 0.14 mmol) in THF (0.60 ml) was
heated at 90 8C for 2 days in a pressure NMR tube. The
contents of the tube were then transferred to a distilla-
tion apparatus, and the volatiles were collected under
2.7. Reactions of [ReH2(O)(Cyttp)]OTf (1(OTf))
with alkenes
2.7.1. Alkeneꢁnorbornene
/
vacuum. The organic products were analyzed by GCÁ
MSÁIR. The yield of styrene was 36% based on 1(OTf)
(8% based on PhCÅCH). IR: n(CH) 3071 (s), 3010 (m);
/
A solution of 1(OTf) (0.030 g, 0.032 mmol) and
norbornene (0.016 g, 0.17 mmol) in 0.50 ml of THF was
heated at 100 8C for 48 h in a pressure NMR tube. The
solution was transferred to a distillation apparatus, and
the volatiles were collected. The organic products were
/
/
1595 (w), 1493 (m), 1189 (m), 986 (m), 919 (s), 772 (s),
1
683 (s) cmꢂ1. H-NMR: d 6.55 (dd), 5.58 (d), 5.05 (d).
MS: m/z 104 [Mꢀ], 103, 78, 63, 51.
analyzed by GCÁ
/
MSÁIR. The yield of C7H12, deter-
/
mined by GC analysis, was 91% based on 1(OTf) (17%
based on norbornene). IR: n(CH) 2968 (s), 2880 (m);
2.9. Stoichiometric reactions of [ReH2(O)(Cyttp)]OTf
(1(OTf)) with nitriles
1
1458 (w), 1319 (w), 834 (w) cmꢂ1. H-NMR: d 2.9 (s)
ppm. MS: m/z 96 [Mꢀ], 81, 67, 54, 39.
2.9.1. NitrileꢁClCH2CN
/
2.7.2. Alkeneꢁ
/
cyclohexene
Chloroacetonitrile (0.012 ml, 0.012 g, 0.l6 mmol) was
added to a solution of 1(OTf) (0.050 g, 0.053 mmol) in
0.60 ml of benzene, and the mixture was transferred to a
pressure NMR tube and capped under a flow of argon.
The tube was kept at room temperature for 24 h, and
then its contents were transferred to a distillation
apparatus. The volatiles were collected under vacuum
The reaction (100 8C, 24 h) and workup were
conducted as in Section 2.7.1 by using 1(OTf) (0.030 g,
0.032 mmol) and cyclohexene (0.030 ml, 0.024 g, 0.30
mmol) in THF. The yield of C6H12 was 76% based on
1(OTf) (8% based on cyclohexene). IR: n(CH) 2944 (s),
2869 (m); 1455 (w) cmꢂ1. 1H-NMR: d 1.3 (s) ppm. MS:
m/z 84 [Mꢀ], 69, 56, 55.
and
analyzed
by
GCÁ
/
MSÁ/IR.
Data
for
ClCH2C(O)NH2. IR: n(NH) 3550 (w), 3415 (w); n(CÄ
/
2.7.3. Alkeneꢁ
/
3,3-dimethyl-1-butene
O) 1755 (s); 1690 (m), 1382 (m) cmꢂ1. 1H-NMR (C6H6):
The reaction (100 8C, 72 h) and workup were
conducted as in Section 2.7.1 by using 1(OTf) (0.030 g,
0.032 mmol) and 3,3-dimethyl-1-butene (0.012 ml,
d 3.5 (s) ppm. MS: m/z (35Cl) 93 [Mꢀ], 44, 40. Data for
1
MeCN. H-NMR (C6H6): d 0.70 (s) ppm. MS: m/z 41
[Mꢀ], 40.

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
89
2
18.1 Hz, JP P
2
The residue was dissolved in a minimum amount of
benzene (B1 ml), and hexane was added slowly to the
solution resulting in the formation of a precipitate. The
solid was filtered off and washed with hexane. The
amount of isolated product, formulated as [Re(O-
H)(O)(Cl)(Cyttp)]OTf (8(OTf)), was sufficient only for
spectroscopic measurements. IR: n(OH) 3350 (w),
ꢁ
/
6.5 Hz, Pw), 12.0 (dd, JP P ꢁ
/
18.1
w
w?
c w?
2
Hz, JP P
2
/
ꢁ
/
6.5 Hz, Pw?), ꢂ
/
22.4 (t, JP P ꢁ2
18.1 Hz, Pc) ppm. The complex could not be isolated
in sufficient purity for satisfactory chemical analysis.
/
JP P ꢁ
/
w
w?
c
w
c w?
2.9.6. Nitrileꢁp-TolCN
/
The reaction (75 8C, 15 h) and workup were con-
ducted as in Section 2.9.5 by using 1(OTf) (0.050 g,
0.053 mmol) and p-TolCN (0.030 ml, 0.029 g, 0.25
mmol) in THF. Data for p-TolC(O)H. IR: n(CH) 2810
n(ReO) 957 (m) cmꢂ1
.
1H-NMR (C6D6): d 9.6 (br,
2
OH) ppm. 31P{1H}-NMR (C6D6): d 32.2 (t, JP P
ꢁ17
/
c
w
Hz, Pc), 16.1 (d, 2JP P
ꢁ17 Hz, Pw) ppm. FAB MS: m/z
OH], 806 [Mꢀ Ã35Cl], 758 [Mꢀ Ã
/
c
w
841 [Mꢀ], 824 [Mꢀ Ã
Cy].
/
/
/
(w), 2729 (w); n(CÄ
/
O) 1733; 1605 (m), 1173 (m), 809 (m)
cmꢂ1. MS: m/z 120 [Mꢀ], 119, 91, 65, 51.
By a procedure similar to that in Section 2.9.5,
[ReH(h2-p-TolC(O)NH)(NCTol-p)(Cyttp)]OTf
(10(OTf)) was isolated. H-NMR (C6D6): d 9.1 (br s,
2.9.2. NitrileꢁMeCN
/
1
A solution of 1(OTf) (0.043 g, 0.046 mmol) and
MeCN (0.012 ml, 0.0094 g, 0.23 mmol) in 0.70 ml of
benzene was heated at 75 8C for 15 h in a pressure NMR
tube. The solution was then transferred to a vacuum
distillation apparatus, and the volatiles were collected
1H, NH), 2.4 (s, 3H, Me), 2.0 (s, 3H, Me), ꢂ
/
6.8 (td,
2
61.7 Hz, JP H
2JP H
ꢁ
/
ꢁ
/
14.9 Hz, 1H, ReH) ppm.
w
c
31P{1H}-NMR (C6D6): d 16.6 (dd, JP P
ꢁ
/
20.3 Hz,
20.3 Hz,
JP P 20.3
2
c
w
2
2JP P
ꢁ
/
6.5 Hz, Pw), 12.2 (dd, JP P
2
ꢁ
/
w
c
w?
and analyzed by GCÁ
/
MSÁ
/
IR. The non-volatiles were
2JP Pw? ꢁ
/
6.5 Hz, Pw?), ꢂ
/
22.2 (t, JP P ꢁ2
/
ꢁ
/
w
w?
c
w
c w?
examined by NMR spectroscopy. Data for Me-
Hz, Pc) ppm. Satisfactory chemical analysis could not be
obtained.
C(O)NH2. IR: n(NH) 3551 (w), 3434 (w); n(CÄ
/
O)
1
1732 (s); 1598 (m), 1324, 911 (w), 742 (m) cmꢂ1. H-
NMR (C6H6): d 2.0 (s) ppm. MS: m/z 59 [Mꢀ], 44, 43.
2.9.7. Nitrileꢁp-ClC6H4CN
/
The reaction (75 8C, 15 h) and workup were con-
ducted as in Section 2.9.5 by using 1(OTf) (0.050 g,
0.053 mmol) and p-ClC6H4CN (0.020 g, 0.15 mmol) in
THF. Data for p-ClC6H4C(O)H. IR: n(CH) 3085 (w),
2.9.3. NitrileꢁEtCN
/
The reaction (75 8C, 15 h) and workup were con-
ducted as in Section 2.9.2 by using 1(OTf) (0.035 g,
0.037 mmol) and EtCN (0.011 ml, 0.0085 g, 0.15 mmol)
2810 (w), 2725 (w); n(CÄ
/
O) 1724 (s); 1594 (m), 1204 (m),
1099 (m), 891 (m) cmꢂ1. MS: m/z (35Cl) 140 [Mꢀ], 139,
111, 75, 50.
in benzene. Data for EtC(O)NH2. IR: n(CÄ
/
O) 1731 (s);
1595 (s) cmꢂ1. MS: m/z 73 [Mꢀ], 57, 44.
By a procedure similar to that in Section 2.9.5,
[ReH(h2-p-ClC6H4C(O)NH)(NCC6H4Cl-p)(Cyttp)]OTf
(11(OTf)) was isolated. H-NMR (C6D6): d 9.1 (br s,
2.9.4. NitrileꢁMe2CHCN
/
1
The reaction (75 8C, 15 h) in benzene and workup
were conducted as in Section 2.9.2 by using 1(OTf)
(0.050 g, 0.053 mmol) and Me2CHCN (0.010 ml, 0.0076
g, 0.011 mmol). Data for Me2CHC(O)NH2. MS: m/z 87
[Mꢀ], 72, 59, 44.
1H, NH), ꢂ
/
6.7 (td, 2JP H
ꢁ
/
55 Hz, 2JP H
ꢁ15.0 Hz, 1H,
/
w
c
ReH) ppm. 31P{1H}-NMR (C6D6): d 16.3 (dd, 2JP P
ꢁ
18.5
/
c
ꢁ
/
6.0 Hz, Pw), 11.9 (dd, JP P ꢁ w
/
2
18.5 Hz, JP P
2
w
w?
c w?
2
Hz, JP P
2
ꢁ
/
6.0 Hz, Pw?), ꢂ
/
21.8 (t, JP P ꢁ2
18.5 Hz, Pc) ppm. Satisfactory chemical analysis could
/
JP P
ꢁ
/
w
w?
c
w
c w?
2.9.5. NitrileꢁPhCN
/
not be obtained.
A solution of 1(OTf) (0.042 g, 0.046 mmol) and PhCN
(0.025 ml, 0.025 g, 0.24 mmol) in 0.60 ml of THF was
heated at 75 8C for 15 h in a pressure NMR tube. The
solution was then transferred to a vacuum distillation
apparatus, and the volatiles were collected and analyzed
2.10. Catalytic studies with [ReH2(O)(Cyttp)]OTf
(1(OTf))
2.10.1. Hydration of MeCN
by GCÁ
(w), 2805 (m), 2732 (m); n(CÄ
/
MSÁ
/
IR. Data for PhC(O)H. IR: n(CH) 3085
O) 1732 (s); 1198 (m), 829
A solution of 1(OTf) (0.030 g, 0.032 mmol), MeCN
(0.250 ml, 0.197 g, 4.79 mmol), and H2O (0.100 ml,
0.100 g, 5.56 mmol) in 0.60 ml of benzene was heated at
60 8C for 15 h in a pressure NMR tube. The solution
was then transferred to a vacuum distillation apparatus,
/
(m), 739 (m) cmꢂ1. MS: m/z 106 [Mꢀ], 105, 77, 51.
The residue was dissolved in a minimum amount of
benzene, and hexane was added slowly to the solution
resulting in the formation of a precipitate. The solid was
filtered off and washed with hexane. Selected spectro-
scopic data for [ReH(h2-PhC(O)NH)(NCPh)(Cytt-
p)]OTf (9(OTf)). 1H-NMR (C6D6): d 8.5 (br s, 1H,
and the volatiles were analyzed by GCÁ
/
MSÁIR whereas
/
the non-volatiles were examined by NMR spectroscopy.
The yield of MeC(O)NH2 was 0.125 g (6610% based on
1(OTf) and 44% based on MeCN). The IR and MS
spectra were identical with those given in Section 2.9.2.
1H-NMR: d 6.1 (br) ppm.
2
2
NH), ꢂ
/
6.8 (td, JP H
ꢁ
/
59.5 Hz, JP H
ꢁ17.0 Hz, 1H,
/
w
c
ReH) ppm. 31P{1H}-NMR (C6D6): d 16.5 (dd, 2JP P
ꢁ
/
c
w

90
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
A similar reaction with D2O in place of H2O afforded
2
MeC(O)ND2. H-NMR: d 6.1 (br) ppm.
atoms with partial occupancy factors were used to
model this ring of disordered fluorine atoms in the
plane perpendicular to the F(1)Á
/
SbÁF(2) axis. It was
/
2.10.2. Hydration of PhCN
also necessary to refine the benzene solvent molecule as
a rigid group. After the model converged at the isotropic
level with an R factor of 0.081, a DIFABS absorption
correction [17] was applied and the R factor decreased
to 0.055. Hydrogen atoms were included in the model as
The reaction (60 8C, 15 h) and workup were con-
ducted as in Section 2.10.1 by using 1(OTf) (0.030 g,
0.032 mmol), PhCN (0.250 ml, 0.250 g, 2.45 mmol), and
H2O (0.050 ml, 0.050 g, 2.78 mmol) in benzene. The
yield of PhC(O)NH2 was 0.263 g (6780% based on
1(OTf) and 89% based on PhCN). IR: n(NH) 3550 (w),
fixed contributions in calculated positions with CÃ
/
Hꢁ
/
˚
0.98 A and B(H)ꢁ
/
1.2Beq(attached carbon atom). The
3434 (w); n(CÄ
/
O) 1731 (s); 1587 (m), 1348 (s), 708 (m)
two hydrogen atoms bonded to Re could not be located
on any electron density maps. The final refinement cycle
cmꢂ1. H-NMR: d 7.0 (br) ppm. MS: m/z 121 [Mꢀ],
105, 77, 51.
1
resulted in agreement indices of Rꢁ
/
0.044 and RWꢁ
/
0.052 for the 5523 intensities with F2oꢁ
/
3s(F2o) and the
2.10.3. Hydration of p-ClC6H4CN
476 variables (Re complex anisotropic, all hydrogen
atoms fixed, benzene molecule as rigid group, Sb, F(1)
and F(2) anisotropic, with rest of fluorine atoms
isotropic). The final difference electron density map
The reaction (60 8C, 14 h) and workup were con-
ducted as in Section 2.10.1 by using 1(OTf) (0.030 g,
0.032 mmol), p-ClC6H4CN (0.250 g, 1.82 mmol), and
H2O (0.050 ml, 0.050 g, 2.78 mmol) in benzene. The
yield of p-ClC6H4C(O)NH2 was 0.238 g (4780% based
has maximum and minimum peak heights of 2.2 and ꢂ
/
ꢂ3
1.5 e A , with the top four peaks (1.0 to 2.2 e Aꢂ3) in
the immediate vicinity of either the Re atom or the
benzene solvent molecule. Scattering factors for neutral
atoms, including terms for anomalous dispersion, are
from the literature [18]. All least-squares refinements are
˚
˚
on 1(OTf) and 84% based on p-ClC6H4CN). IR: n(CÄ
/
O) 1732 (s); 1701 (m), 1605 (m), 1395 (m), 1095 (m)
1
cmꢂ1. H-NMR: d 7.0 (br) ppm. MS: m/z (35Cl) 155
[Mꢀ], 137, 111, 85, 75, 50.
full-matrix, where the function minimized is aw(jFojꢂ
/
2.11. Crystallographic analysis of [ReH2(h2-
jFcj)2 with wꢁ
/
1/s(Fo). A summary of the crystal data
and the details of the intensity data collection and
refinement are provided in Table 1.
SO3)(Cyttp)]SbF6×
/
C6H6 (6(SbF6)×/C6H6)
Examination of the diffraction pattern on an Enraf-
Nonius CAD4 diffractometer at ꢂ50 8C indicated a
triclinic crystal system so that the space group possibi-
/
Table 1
Summary of crystal data, data collection, and structure refinement
¯
lities are restricted to P1 or P1: The cell constants were
determined by a least-squares fit of the diffractometer
parameters for 6(SbF6)×C6H6
/
Empirical formula
Formula weight
Temperature (8C)
Crystal system
Space group
C36H63F6O3P3ReSSb×
1168.93
50
triclinic
/
C6H6
setting angles for 25 reflections in the 2u range 24Á298
/
˚
with MoÁ
Intensities were measured by the v Á
/
Ka radiation (
/
l(Ka¯)ꢁ0:71073 A):
/
ꢂ/
/
2u scan method.
¯
P1
/
Three standard reflections were measured after every 3 h
of X-ray exposure and indicated a small amount of
crystal decay during the course of data collection. The
average decrease in the intensities of the standards was
8.1%. Data reduction, which included a linear decay
correction, and all additional calculations were done
with the TEXSAN package of crystallographic programs
[15].
˚
a (A)
12.329(5)
13.451(4)
15.060(5)
72.71(3)
83.72(3)
86.26(3)
2369
˚
b (A)
˚
c (A)
a (8)
b (8)
g (8)
3
V (A )
˚
Z
2
1.64
Dcalc (g cmꢂ3
)
Solution and refinement of the structure were per-
¯
formed in a space group P1: The position of the Re
atom was located on a Patterson map and used as a
phasing model in the direct methods DIRDIF procedure
[16]. Most of the atoms of the Re complex were located
on the resulting electron density map along with an
Crystal size (mm)
0.15ꢃ
33.61
0.80Á
452u 5
h, 9k, 9
8302
5523
476
/
0.23ꢃ
/
0.23
Absorption coefficient (cmꢂ1
Transmission factors
2u limits (8)
)
/
1.21
/
/50
Data collected
No. of unique data
No. of unique data with F2oꢁ3s(Fo2)
Final no. of variables
R(F) a
Rw(F) b
Error in obsn. of unit wt. (e)
ꢀ/
/
/
l
/
F(1)Á
/
SbÁF(2) fragment. Standard Fourier methods
/
0.044
0.052
1.80
revealed the four missing carbon atoms of the Re
complex along with many peaks in the plane perpendi-
cular to the F(1)Á
of benzene. The SbF6ꢂ ion is disordered with respect to
rotation about the F(1)ÁSbÁF(2) axis. Ten fluorine
/
SbÁ/F(2) axis, and a solvent molecule
a
R(F)ꢁ
Rw(F)ꢁ
/
ajjFojꢂ
/
jFcj/ajFoj.
b
/
[aw(jFojꢂ
/
jFcj)2/awjFoj ] with w ꢁ
2 1/2
/
1/s2(Fo).
/
/

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
91
3. Results and discussion
each of the three phosphorus atoms of Cyttp. Finally,
the triplet of doublets splitting pattern of the hydride
signal at d ꢂ
5.03 ppm is compatible with Hꢂ occupy-
ing the other position cis to CO and Cyttp.
/
3.1. Carbonylation of [ReH2(O)(Cyttp)]SbF6
(1(SbF6))
When 1(SbF6) and CO reacted in benzene at 25 8C for
various lengths of time from 1 to 15 h, a mixture of
2(SbF6) and [Re(CO)3(Cyttp)]SbF6 (3(SbF6)) was iso-
Passage of carbon monoxide through a solution of
1(SbF6) in acetone at 0 8C for 20 min affords after
workup a yellowish white solid which is formulated as
lated (Eq. (2)). Gaseous products were not analyzed, but
1
MS and by H-
formic acid was not detected by GCÁ
/
the
(Cyttp)]SbF6 (2(SbF6)) (Eq. (1)). The corresponding
isotopomers
[ReH(h2-HCO18O)(CO)(Cyttp)]SbF6
(2Ã
18O(SbF6)) and ReH(h2-H13CO2)(13CO)(Cyttp)]-
SbF6 (2Ã
13C2(SbF6)) were prepared similarly from
18O(SbF6)) and CO and
h2-formato
complex
[ReH(h2-HCO2)(CO)-
NMR spectroscopy when the reaction was conducted in
benzene-d6. Complex 3(SbF6) was freed of 2(SbF6) by
washing with benzene and characterized by IR and
NMR spectroscopy as well as elemental analysis. The
1H-NMR spectrum shows the absence of hydride
ligands, and the IR n(CO) absorption band pattern
indicates meridional stereochemistry around the metal.
Interestingly, three 13C{1H} resonances are observed for
the carbonyl ligands: at d 195.75 and 193.82 ppm as
quartets (2JPC of trans COs) and at d 192.96 ppm as a
/
/
[ReH2(18O)(Cyttp)]SbF6 (1Ã
/
from 1(SbF6) and 13CO, respectively, to assist in the
characterization of 2(SbF6) by IR and NMR spectro-
scopy.
2
doublet of triplets (2JP C and JP C, respectively, of cis
c
w
CO). The appearance of two signals for the trans COs is
most likely due to the orientation of the Ph ring on the
central phosphorus atom of Cyttp toward one of these
carbonyls (cf. structure 3 in (Eq. (2)). Studies on the
preparation and structure of two isomers of mer, cis-
IrH2Cl(Cyttp) [22] support this proposal.
ð1Þ
1
The presence of formate in 2 is supported by a H-
NMR signal of its isotopomer 2Ã
ppm with 1J13 217.3 Hz [8a,19,20]. In the 13C-NMR
13C2(SbF6), the signal of HCO2 is
observed at d 176.13 ppm (1J13
217 Hz). For
Re(h2-HCO2)(dppe)2
Ph2PCH2CH2PPh2) exhibits the corresponding
/
13C2(SbF6) at d 8.24
ꢁ
/
CH
spectrum of 2Ã
/
ꢁ
/
CH
comparison,
(dppeꢁ
13C resonance at d 171.9 ppm with JCH
The IR spectrum of 2(SbF6) shows the nasym(HCO2) and
nsym(HCO2) bands at 1545 (s) and 1364 (m) cmꢂ1
respectively. Upon replacement of 12C with 13C (i.e., in
2Ã
13C2(SbF6)), they shift to 1500 (s) and 1340 (m)
cmꢂ1, respectively, and upon substitution of 16O with
18O(SbF6)), to 1535 (s) and 1346 (m)
the
complex
/
1
ꢁ202 Hz [19].
/
ð2Þ
,
/
18O (i.e., in 2Ã
/
cmꢂ1, respectively, as expected. These changes on going
from 12C to 13C are similar to those observed for Re(h2-
HCO2)(dppe)2 [19]. The magnitude of separation be-
tween nasym(HCO2) and nsym(HCO2) indicates that the
formate coordinates in a bidentate rather than mono-
dentate fashion [21].
The assigned gross stereochemistry of 2 was also
inferred from IR and NMR data. Accordingly, the
31P{1H}-NMR spectrum shows a typical AX2 splitting
pattern, indicating the presence of a plane of symmetry
13C2 is observed at
65.8 Hz,
10.5 Hz), consistent with the carbonyl ligand
being trans to the central phosphorus atom. The
When the reaction in (Eq. (2)) was conducted to
completion in benzene solution for 45 min at 25 8C, a 1:1
mixture of 2(SbF6) and 3(SbF6) was obtained. Longer
allowed reaction times increase the ratio 3/2 to suggest
that 2(SbF6) gradually decomposes to 3(SbF6) under
CO in solution. This was confirmed by monitoring the
behavior of a benzene solution of 2(SbF6) under CO at
25 8C by 31P{1H}-NMR spectroscopy. After 15 h, an
approximately 1:1 mixture of 2(SbF6) and 3(SbF6) was
observed. These experiments show that the rate of the
conversion of 2(SbF6) to 3(SbF6) is slower than the
formation of 3(SbF6) from 1(SbF6) and CO under
similar conditions. Accordingly, we conclude that
in the complex. The CO carbon of 2Ã
/
d 190.26 ppm as a doublet of triplets (2JP C
ꢁ
/
c
2JP C
ꢁ
/
w
1
4
formate H-NMR signal, a quartet with JPH
supports approximate cis orientation of the ligand to
ꢁ
/
2.5 Hz,

92
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
Scheme 1.
1(SbF6) reacts with CO by two pathways as depicted in
Scheme 1.
The proposed mechanism involves addition of CO to
min [Re(CNR)3(Cyttp)]SbF6 (Rꢁ
/
t-Bu (4(SbF6)), Cy
(5(SbF6)) as a white solid in 98Á
/
69% yield (Eq. (3)).
When the reaction between 1(SbF6) and t-BuNC was
conducted in acetone-d6, t-BuNCO was observed in
1
solution by H-NMR spectroscopy.
the rheniumÃ/oxygen bond to form a CO2 intermediate
I. Dissociation of CO2 leads to the direct formation of 3
(path b), whereas migration of cis hydride to h2-CO2
[23] generates the formate ligand in 2 (path a). Alter-
natively, however, the entering CO first reacts with
hydride to give a formyl, which then combines with the
oxide to yield formate. Although the latter mechanistic
possibility cannot be ruled out, it is considered less likely
than that in Scheme 1 since hydride migration to CO is
not very common [3] and formyl coupling with coordi-
nated oxide is unprecedented. The decarboxylation of 2
to 3 represents a well-established reaction in metal
formate chemistry [8a,23]. The reason why reaction of
1(SbF6) with CO in acetone produces exclusively
2(SbF6) whereas that in benzene generates both
2(SbF6) and 3(SbF6) may be ascribed to coordinating
ability of the solvent in effecting migration of hydride
onto h2-CO2 (cf. Scheme 1). Similar solvent effects have
been noted for migratory insertion of CO [24].
ð3Þ
The trisisocyanide products 4(SbF6) and 5(SbF6) were
characterized by IR and NMR spectroscopy and
elemental analysis. Their meridional structures can be
inferred from the IR spectra in the n(CN) region [27]
and from a close similarity of the 31P{1H}-NMR d and
Although reactions of metal oxo complexes with free
or coordinated CO to yield free or ligated CO2 have
been reported [2a,2b,25,26], participation of both oxo
and hydride ligands in converting CO to an organic
group is unprecedented. It is also to be noted that the
conversion of 1 to 2 represents a two-electron redox
reaction, with the oxo ligand being transferred as an
oxygen atom to CO. The resultant CO2 then combines
with hydride to give formate.
2JP P data to those of 3(SbF6). The H-NMR spectra
1
c
w
show no hydride resonances, but display three signals of
the t-Bu methyl groups of 4(SbF6) at d 1.60, 1.57, and
1.50 ppm, and two signals of the cyclohexyl NCH
protons of 5(SbF6) at d 4.10 and 3.98 ppm (2:1 intensity
ratio). The aforementioned data for 4(SbF6) are con-
sistent with the presence of inequivalent trans t-BuNC
ligands owing to the orientation of the Ph group of
Cyttp, as proposed for the tricarbonyl complex 3(SbF6).
This is further supported by the appearance of three
resonances for each of the CN, CMe3, and Me carbon-
3.2. Reactions of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with organic isocyanides
Complex 1(SbF6) reacts with an excess of t-BuNC or
CyNC in benzene solution at 25 8C to afford within 20

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
93
13 nuclei of 4(SbF6), and for the cyclohexyl NCH
carbon of 5(SbF6).
The mechanism of formation of 4(SbF6) and 5(SbF6)
by the reaction in 3 is probably analogous to that of the
formation of 3(SbF6) represented by path b in Scheme 1,
with h2-RNCO intermediate II replacing h2-CO2 inter-
mediate I. An alternative route, corresponding to path a
in Scheme 1, viz., formation of a h2-N-alkylformami-
dato-O,N complex III and its transformation to 4 or 5,
cannot be dismissed, but appears less probable. This is
because decomposition of III, by analogy with the
decomposition of 2, might be expected to proceed
relatively slowly in benzene at 25 8C.
Fig. 1. Molecular structure of [ReH2(h2-SO3)(Cyttp)]ꢀ (6). Non-
hydrogen atoms are drawn with 50% probability displacement
ellipsoids. The two hydrogen atoms bonded to rhenium were not
located. The other hydrogen atoms and the phenyl and cyclohexyl
carbon atoms not bonded to phosphorus are omitted for clarity.
3.3. Reaction of [ReH2(O)(Cyttp)]SbF6 (1(SbF6) with
sulfur dioxide
The ligand SO3 is attached to rhenium in a bidentate
mode, with the two ReÃ
/
O bond distances being equal
˚
˚
(ReÃ
geometry around the sulfur atom is approximately
pyramidal*the angles O(1)ÃSÃO(2), O(1)ÃSÃO(3),
and O(2)ÃSÃO(3) are 92.0(3)8, 109.0(5)8, and
107.1(4)8, respectively*to reflect a sulfite rather than
sulfur trioxide nature of the SO3. Of the three SÃO bond
distances that involving the unattached oxygen is
/
O(1)ꢁ
/
2.026(6) A, ReÃ
/
O(2)ꢁ
/
2.024(6) A). The
A colorless solution of 1(SbF6) in benzene at 25 8C
turns violet on passage of SO2 for 1Á
affords the bright violet h2-sulfinato-O,O? complex
[ReH2(h2-SO3)(Cyttp)]SbF6×
C6H6 (6(SbF6×C6H6)) in
/
2 min. Workup
/
/
/
/
/
/
/
/
/
/
good yield (Eq. (4)). The product was characterized by
IR and NMR spectroscopy and elemental analysis, and
its structure was determined by single-crystal X-ray
diffraction techniques.
/
˚
significantly shorter (SÃ
/
O(3)ꢁ1.445(9) A) than those
/
with the oxygen atoms coordinated to rhenium, which
˚
are not equal (SÃ
/
O(1)ꢁ
/
1.582(6) A, SÃ
/
O(2)ꢁ1.629(7)
/
˚
A).
The observed coordination environment around the
rhenium center contains, in addition to the sulfite, the
ð4Þ
triphosphine Cyttp. Its ReÃ
/
P bond distances ReÃ
/
˚
˚
P(1)ꢁ
/
2.396(3) A, ReÃ
/
P(2)ꢁ
/
2.362(3) A, and ReÃ
/
˚
2.390(3) A (mean: 2.383 A) compare well with
˚
P(3)ꢁ
/
3
˚
/4MeOH (mean: 2.395 A [5]) and
The 1H-NMR spectrum of 6(SbF6) exhibits two metal
hydride resonances with the chemical shifts and cou-
those of 1(SbF6)×
ReH5(Cyttp) (mean: 2.380 A [29]). The triphosphine
/
˚
2
2
pling constants JHH and JPH similar to those of
1(SbF6) (cf. Section 2.5). Likewise, the 31P{1H}-NMR
signals resemble those of the parent hydrido-oxo
compound with their AX2 pattern. In the IR spectrum,
two n(ReH) absorption bands and bands due to n(SO)
[28] are observed.
adopts a severely distorted meridional geometry, with
P(1)Ã
and P(2)Ã
ReÃP(3) is, in fact, smaller than the angles P(1)Ã
O(2) (145.0(2)8) and P(2)ÃReÃO(1) (135.3(2)8), and
similar to the angle P(3)ÃReÃO(1) (124.7(2)8). These
/
ReÃ
/
P(2)ꢁ
/
87.46(9)8, P(1)Ã
89.6(1)8. The bond angle P(1)Ã
ReÃ
/
ReÃ
/
P(3)ꢁ
/
128.47(8)8,
/
ReÃP(3)ꢁ
/
/
/
/
/
/
/
/
/
/
The structure of 6(SbF6) (as 6(SbF6)×
/
C6H6) consists
values further reflect a highly distorted environment of
ligands around the metal in 6, which most likely results
from the presence of two small hydrides. These hydrides
were not located; however, their presence in inequivalent
of the complex cation 6 and the anion SbF6ꢂ. An ORTEP
drawing of 6 is presented in Fig. 1, and selected bond
distances, bond angles, and torsion angles are given in
Table 2.
1
positions is unambiguously demonstrated by H-NMR

94
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
Table 2
3.4. Reaction of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with trimethylphosphite
˚
Selected bond distances (A), bond angles (8), and torsion angles (8) of
6(SbF6)×C6H6
/
Stirring a benzene solution of 1(SbF6) and an excess
of P(OMe)3 at room temperature for 30 min followed by
workup resulted in the isolation of [ReH2(P(O-
Me)3)2(Cyttp)]SbF6 (7(SbF6)) as a white solid (Eq.
(5)). When this reaction was monitored by 1H- and
31P{1H}-NMR spectroscopy in acetone-d6, formation of
OP(OMe)3 was also observed. The chemical composi-
tion of 7(SbF6) is supported by elemental analysis, and
the suggested structure is based on IR and 1H- and
31P{1H}-NMR spectroscopic data. Interestingly,
7(SbF6) exhibits no fluxional behavior at ambient
temperature, unlike most rhenium hydrido-Cyttp com-
plexes of high coordination number [29,30].
ReÃ
ReÃ
ReÃ
ReÃ
/
P(1)
2.396(3)
2.362(3)
2.390(3)
2.026(6)
ReÃ
/
O(2)
2.024(6)
1.582(6)
1.629(7)
1.445(9)
/
P(2)
P(3)
O(1)
SÃ
SÃ
SÃ
/
O(1)
O(2)
O(3)
/
/
/
/
P(1)Ã
P(1)Ã
P(2)Ã
P(1)Ã
P(1)Ã
P(2)Ã
P(2)Ã
/
ReÃ
ReÃ
ReÃ
ReÃ
ReÃ
ReÃ
ReÃ
/
P(2)
P(3)
P(3)
O(1)
O(2)
O(1)
O(2)
87.46(9)
128.47(8)
89.6(1)
P(3)Ã
P(3)Ã
ReÃO(1)Ã
ReÃO(2)Ã
O(1)Ã
O(1)Ã
O(2)Ã
/
ReÃ
/
O(1)
124.7(2)
86.1(2)
99.2(4)
97.7(3)
92.0(3)
109.0(5)
107.1(4)
/
/
/
ReÃ
/O(2)
/
/
/
/
S
S
/
/
90.5(2)
/
/
/
/
145.0(2)
135.3(2)
87.5(2)
/
SÃ
SÃ
SÃ
/
O(2)
O(3)
O(3)
/
/
/
/
/
/
/
/
ReÃO(1)Ã
ReÃO(1)Ã
ReÃO(2)Ã
ReÃO(2)Ã
SÃO(1)ÃReÃ
SÃO(1)ÃReÃ
SÃO(1)ÃReÃ
SÃO(1)ÃReÃ
SÃO(2)ÃReÃ
SÃO(2)ÃReÃ
SÃO(2)ÃReÃ
SÃO(2)ÃReÃ
/
/
SÃ
SÃ
SÃ
SÃ
/
O(2)
O(3)
O(1)
O(3)
P(1)
P(2)
P(3)
O(2)
P(1)
P(2)
P(3)
O(1)
10.5(4)
119.4(4)
/
/
/
/
/
/
ꢂ
/
10.5(4)
121.0(4)
159.6(3)
/
/
/
ꢂ
ꢂ/
/
/
/
/
/
/
/
ꢂ
/
72.6(4)
/
/
/
60.7(4)
/
/
/
ꢂ9.0(3)
/
/
/
/
67.7(4)
149.6(3)
120.7(3)
8.7(3)
/
/
/
/
/
/
ꢂ/
/
/
/
ð5Þ
spectroscopy (vide supra). The idealized geometry of 6
appears to be a capped octahedron and is related to the
octahedral structure of 1 by replacement of the oxo
ligand in the latter with one oxygen atom (O(2)) of
SO23ꢂ. The other ligated oxygen atom of SO23ꢂ (O(1))
caps the P(1)O(2)H(trans to P(2)) face.
The reaction of 1(SbF6) with SO2 proceeds by transfer
of the rhenium-bonded oxygen as oxide to sulfur, in
contrast to the reaction of 1(SbF6) with CO (and
probably with RNC), which takes place by transfer of
that oxygen as an atom. The former is therefore an
The presence of two hydride ligands is indicated by
the IR n(ReH) absorption at 1960 (w) and 1725 (w)
cmꢂ1 and by equal intensity proton resonances at d
1
6.95 ppm. The H-NMR spectrum also
ꢂ
/
6.03 and ꢂ
/
shows two Me signals of comparable intensity to reveal
presence of two inequivalent P(OMe)3 ligands. One of
the phosphites appears to be positioned trans to the
hydride resonating at d ꢂ6.95 ppm, since the signal of
/
2
that hydride shows a large JPH (67.5 Hz) [31].
There are five 31P{1H} resonances of approximately
equal intensity. Two occur at d 119.70 and 104.36 ppm,
close to the signal of free P(OMe)3 [32], and three are
acidÁbase interaction, whereas the latter is a redox
/
process involving reduction of rhenium(V) in 1 to
rhenium(III) in I and 2. This difference in reactivity
may arise from the higher Lewis acidity of SO2
compared with CO.
Complex 6(SbF6) is stable in the solid under vacuum
at ambient temperatures; however, heating its solution
in benzene at 50 8C results in elimination of SO2 and
regeneration of 1(SbF6). In acetone or CH2Cl2 solution
at 25 8C, equilibrium is attained between 6(SbF6) and
1(SbF6)/SO2. Similar behavior has been reported for
observed at d 3.90, ꢂ
region typical of
/
14.72, and ꢂ
rhenium-coordinated
/
30.23 ppm, in the
Cyttp
[5,9,14,29,30]. It is noteworthy that the wing phosphorus
atoms (PW) are inequivalent.
Structures that best-fit these and other NMR data
given in Section 2.6 are based on an octahedral
arrangement of Cyttp, two P(OMe)3, and one Hꢂ
ligands, with one triangular face being capped by the
other Hꢂ. Such capping would account for the observed
magnetic inequivalence of the PW atoms. However,
available NMR data do not implicate any of the four
ꢄ
Cp2Re2(m-O)2(O)2, which undergoes reversible reaction
2
ꢄ
with SO2 to afford Cp2Re2(m-O)2(O)(h -SO3) and
2
2
ꢄ
Cp2Re2(m-O)2(h -SO3)2 [28]. The desulfination of these
different triangular sites for the capping. The large JPP
(231.2 Hz) between a phosphorus atom of Cyttp (d
sulfito complexes suggests (a) relatively weak OS(Á
/
O)2Re bond(s).
ꢂ30.23 ppm) and that of one phosphite (d 104.36 ppm)
/

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
95
indicates that the two atoms are trans and that the
former must be PC. The signal of PC appears further
observed, viz., cyclohexane, norbornane, 2,2-dimethyl-
butane, and EtO2CCH2CH2CO2Et, respectively. For
ethylene, no attempt was made to confirm the formation
of gaseous ethane; however, ethanol could not be
detected. The reaction of 1(OTf) with cyclohexene
took approximately 24 h for completion (i.e., disap-
pearance of 1(OTf) by 31P{1H}-NMR spectroscopy).
The corresponding reactions with norbornene, 3,3-
dimethyl-1-butene, and diethyl fumarate required ca.
48, 72, and 48 h, respectively, to consume all 1(OTf).
The yields of the hydrogenated products, obtained by
GC analysis, were 76% cyclohexane, 91% norbornane,
split into a quartet (2JPP
ꢀ30 Hz) by the combined effect
/
of two PW atoms and the phosphorus atom of the
P(OMe)3 resonating at d 119.70 ppm. This phosphite
ligand is positioned trans to the Hꢂ that shows a large
2JPH of 67.5 Hz (vide supra). The proposed arrangement
of ligands around the Re center is depicted in (Eq. (5)).
The P(Cy)2P(OMe)3H face was selected for capping for
steric reasons.
The conversion of 1(SbF6) by P(OMe)3 to 7(SbF6)
with formation of OP(OMe)3 proceeds by oxygen atom
transfer. It is therefore a redox reaction and resembles
the reactions of 1(SbF6) with CO and RNC. Signifi-
cantly, PMe3 in excess does not react with 1(SbF6) under
comparable conditions. A similar difference in behavior
toward P(OMe)3 and PMe3 was noted for WO2(pipdtc)2
86% 2,2-dimethylbutane, and ꢁ80% EtO2CCH2CH2-
/
CO2Et. However, the difference in the yields was
probably due more to the efficiency of separation of
the volatiles from the resultant inorganic complex than
to the reaction itself. At equal temperatures, solvent
(THF, benzene) had little influence on the reaction rate,
and addition of water to the reacting 1(OTf) and
norbornene produced no noticeable effect either.
(pipdtcꢁS2CNC5H10) [33]. It appears that a certain
/
degree of acidity of the reacting unsaturated species
(CO, RNC, P(OMe)3) is necessary for binding to 1 and
abstraction of oxygen.
3.5. Reactions of [ReH2(O)(Cyttp)]OTf (1(OTf))
with alkenes and alkynes
3.5.1. Reactions with alkenes
ð6Þ
Hydration of alkenes to alcohols mediated by metal
complexes is a research area of considerable interest and
activity [34]. In this general context, we endeavored to
explore reactions of 1 with alkenes to ascertain possible
transfer of both hydrogen and oxygen to CÄ
/
C.
Initial studies showed that 1(SbF6) does not react with
alkenes at ambient temperatures. Since at higher tem-
peratures 1(SbF6) undergoes conversion to [Re-
H(O)(F)(Cyttp)]ꢀ [9], our investigations under more
forcing conditions were conducted with the thermally
stable 1(OTf). At ca. 100 8C, reactions between 1(OTf)
and the alkenes cyclohexene, norbornene, 3,3-dimethyl-
1-butene, and diethyl fumarate were found to proceed
over a reasonable time frame. They were carried out in
pressure tubes using THF or benzene solvent. The
reaction between 1(OTf) and ethylene was run in toluene
at reflux temperature. All reactions were monitored by
31P{1H}-NMR spectroscopy, and after completion,
Whereas the organic products have been fully char-
acterized, the nature of the resultant rhenium complex
remains undetermined. Regardless of the alkene em-
ployed, the same metal complex appears to be formed as
reflected by 31P{1H}-NMR spectroscopy. The spectra in
toluene solution show broad signals centered around d
7.1 and ꢂ
/
5.8 ppm, with the signal at d ꢂ5.8 (PW) being
/
approximately twice as intense as that at d 7.1 ppm (PC).
However, in CH2Cl2 solution the signals appear as a
broad doublet at d 2.1 ppm (PW) and a broad triplet at
1
d 16.2 ppm (PC). The H-NMR spectra consist only of
the resonances of the Cyttp ligand. Neither metal
hydride nor alkene ligand signals were observed. The
complex contains ionic OTfꢂ, as evidenced by a
volatile liquids were analyzed by GCÁ
/
MSÁIR. The
/
IR, NMR, and/or mass spectra of the organic products
are summarized in the appropriate parts of Section 2.7;
these products were characterized by comparison of
their spectroscopic properties with those obtained on
authentic samples. Non-volatile, inorganic products
resonance at d ꢂ
77.3 ppm in the 19F{1H}-NMR
/
spectrum [35]. Little additional information could be
derived from the IR spectra, which show only weak,
unassignable bands. Absorption bands characteristic of
n(ReO) of a terminal oxo ligand [2b,8] were not present.
The foregoing spectroscopic data suggest that the
inorganic product of the reaction is a [Re(O)(Cyttp)]nnꢀ
complex possibly containing coordinated solvent. It may
be a dimer or a more highly aggregated species involving
1
were investigated by H- and 31P{1H}-NMR spectro-
scopy.
The reactions of 1(OTf) with alkenes proceed as
shown in (Eq. (6)). For cyclohexene, norbornene, 3,3-
dimethyl-1-butene, and diethyl fumarate, only the
product of hydrogenation of the CÄ/C bond was
oxo bridges and/or metalÃ
/
metal bonds.

96
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
Hydrogen transfer from 1 to alkenes represents a well-
organic compounds had formed, viz., MeCN and
ClCH2C(O)NH2. The GCÁMS confirmed the identity
of these products by showing the parent ion peaks at m/
known reaction in organometallic chemistry. Numerous
metal hydride complexes participate in such processes,
and the mechanism has been extensively investigated
[36].
/
z 41 and 93 and 95 (35Cl and 37Cl) with the fragmenta-
tion
patterns
appropriate
for
MeCN
and
ClCH2C(O)NH2, respectively. The IR spectrum showed
a n(CO) band at 1755 cmꢂ1, consistent with the
presence of C(O)NH2.
3.5.2. Reaction with phenylacetylene
Since alkenes accept only hydrogen from 1 to yield
corresponding alkanes, it was of interest to ascertain
whether the more unsaturated alkynes would add both
hydrogen and oxygen. Reaction of 1(OTf) with PhCÅ
CH was carried out with this objective.
Treatment of 1(OTf) with an excess of PhCÅ
/
/CH in
THF or benzene in a pressure tube at ca. 100 8C for 48
h, followed by a workup similar to that for the
corresponding reactions with alkenes, enabled detection
ð8Þ
of styrene as the major organic product (36% by GCÁ
/
MS) and ethylbenzene as a minor product (B5%) (Eq.
/
(7)). No organooxygen products were found among the
volatiles. The low yield of styrene may be reflected in the
formation of multiple products observed in the 31P{1H}-
NMR spectrum of the crude reaction mixture. The
numerous phosphorus resonances suggest that the
reaction does not proceed in the same fashion as that
with alkenes. Coordination of alkyne to rhenium may be
occurring, although no evidence could be obtained by
examining the product mixture. Since hydrogenation by
metal complexes of alkynes in general [37], and of
phenylacetylene in particular [38], represents known
reactions, no further studies were pursued with alkynes.
Elucidation of the nature of the Re-containing
products was attempted by use of IR and NMR
spectroscopic and FAB mass spectrometric techniques.
Whereas the 31P{1H}-NMR spectrum showed only one
major Re-containing compound, the 1H-NMR spectrum
consisted of numerous signals indicative of multiple
products. It is, however, not uncommon for paramag-
netic rhenium(III) compounds to display sharp 1H-
NMR signals and be 31P{1H}-NMR silent [30]. The
lone diamagnetic species was isolated in trace amounts
and formulated from spectroscopic data (Section 2.9.1)
as [Re(OH)(O)(Cl)(Cyttp)]OTf (8(OTf)). The relative
orientation of the ligands in the set mer-(OH,O,Cl) was
not determined. The only other major product in the
mixture was characterized as the paramagnetic Re-
Cl3(Cyttp) by comparison of its 1H-NMR spectrum
with that reported by us earlier [30].
ð7Þ
Whereas ClCH2CN underwent reaction at room
temperature, the other aliphatic nitriles studied required
much more vigorous conditions to react with 1(OTf).
Each of MeCN, EtCN, and Me2CHCN (RCN) was
heated with 1(OTf) in benzene solution at 75 8C for 15 h
in a pressure tube, and the volatiles were analyzed by
3.6. Reactions of [ReH2(O)(Cyttp)]OTf (1(OTf))
with nitriles
3.6.1. Stoichiometric reactions
Rections of 1(OTf) with nitriles were investigated to
explore the possibility of double transfer of hydrogen
GCÁ
/
MSÁIR. The IR, NMR, and/or mass spectra (cf.
/
Sections 2.9.1, 2.9.2 and 2.9.3) indicated that the
corresponding amide RC(O)NH2 was formed in each
case (Eq. (9)), albeit in a relatively low yield. The
observation of the molecular ion peaks and of the
appropriate fragmentation patterns in the mass spectra
was especially helpful in the characterization. No other
organic products were detected. The 31P{1H}-NMR
spectra of the non-volatile reaction mixtures showed
multiple signals associated with products containing
and oxygen to the CÅ
/
N bond. Nitriles are known to
undergo partial hydration under a variety of conditions
to afford amide products [39].
Initial studies were conducted with ClCH2CN, typi-
cally by using 1(OTf) and an excess of the nitrile in
benzene at room temperature. Monitoring the reaction
by 31P{1H}-NMR spectroscopy revealed complete dis-
appearance of 1(OTf) after 24 h (Eq. (8)). The 1H-NMR
spectrum of the volatile products indicated that two

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
97
2
Cyttp. These mixtures could not be separated, and
therefore further characterization was not pursued.
nuclei (d 16.6Á
/
16.3 and 12.2Á
6.5 Hz, JP P ꢁ2
JP P 18.1Á
coupling constants 2JP P are indicative of a meridional
/
11.9 ppm; JP P
ꢁ
/
6.0Á
/
w
w?
2
/
ꢁ
/
/
20.3 Hz). The small
c
w
c
w?
w
w?
arrangement of Cyttp in these complexes, and the
absence of an AX2 splitting pattern in the spectra shows
that the complexes lack a plane of symmetry and
therefore may contain a bidentate amidate ligand. The
1H-NMR spectrum of each of 9(OTf), 10(OTf), and
11(OTf) revealed equal intensity signals of ReH as a
ð9Þ
Based on the intensity of the signals in the GCÁ
IR, it appears that the amount of the amide formed
decreases in the order ClCH2CNꢁMeCN]EtCN]
/
MSÁ
/
triplet of doublets at d ꢂ
a broad singlet at d 9.1Á8.5 ppm [39e,40]. The values of
2JPH (2JP H
14.9Á17.0 Hz, JP H
/
6.7 to ꢂ
/
6.8 ppm and of NH as
/
2
/
/
/
ꢁ
/
/
ꢁ
/
55Á61.7 Hz) indi-
/
c
w
Me2CHCN. This trend parallels the increasing elec-
tron-releasing ability of R in RCN and is expected for
reactions involving addition of nucleophile to ligated
nitrile. However, steric effects associated with R may
also contribute to this order. The observed chlorination
of 1 by ClCH2CN eventually to yield ReCl3(Cyttp) and
MeCN finds analogy in the reactions of metal hydrido
complexes with alkyl chlorides [1].
cate that the hydride is located out of the plane of the
1
phosphorus atoms. The H-NMR spectrum of 10(OTf)
contained also two equal intensity Me signals at d 2.4
and 2.0 ppm, consistent with the presence of two
different tolyl groups in the complex. This would seem
to suggest that two inequivalent nitriles are attached to
the Re center, or that one of the nitriles was chemically
modified, e.g., to an amidate ligand (vide supra).
Unfortunately, however, the complexes could not be
isolated in sufficient purity for satisfactory chemical
analysis or for X-ray diffraction.
Aromatic nitriles react differently from the aliphatic
ones, although the experimental conditions required are
similar in both cases. The reaction of each of ArCN
The suggested structures would appear similar to the
structure of the h2-formato complex 2(SbF6), prepared
in this study by reaction of 1(SbF6) with CO. In both
cases, transfer of the oxo and one hydrido ligand
occurred from 1 to the unsaturated substrate (CO and
nitrile). A number of transition-metal amidato com-
plexes have been prepared, and some were structurally
(ArꢁPh, p-Tol, p-ClC6H4) with 1(OTf) in benzene at
/
75 8C for 15 h in a pressure tube proceeds as shown in
(Eq. (10)). In each case, the organic product was
characterized as the appropriate aldehyde ArC(O)H by
GCÁ
/
MSÁIR (Sections 2.9.5, 2.9.6 and 2.9.7). For
/
example, for PhC(O)H, the mass spectrum showed the
molecular ion at m/z 106, and the fragmentation pattern
was consistent with that of an authentic benzaldehyde
rather than with that of benzamide. Likewise, the IR
spectra matched well those of authentic ArC(O)H.
characterized [39Á42]. Known modes of attachment of
/
the ligand in point to metal include h1-amidato-O, h1-
amidato-N, and h2-amidato-O,N in mononuclear metal
complexes, and m-amidato-O,N in binuclear metal
complexes.
The formation of aldehydes in the reactions of 1(OTf)
with aromatic nitriles probably results from minor
decomposition of the metal complex. Aldehydes can be
synthesized by hydrogenation of a nitrile, which pro-
duces the corresponding imine, RCHÄ/NH [43]. Hydro-
lysis of the imine affords the appropriate aldehyde. Since
alkenes have been shown in this study to undergo
hydrogenation by 1(OTf), it is possible that some of
the nitrile became hydrogenated. The resultant imine
may have been converted to the corresponding aldehyde
during workup or during the injection of the solution on
column, as a rigorously anhydrous treatment of the
organic volatiles was not maintained.
ð10Þ
The 31P{1H}-NMR spectra of the reaction mixtures
showed the formation of only one major product in each
case. These products were isolated and characterized by
1H- and 31P{1H}-NMR spectroscopy as the amidato-
O,N complexes [ReH(h2-ArC(O)NH)(NCAr)(Cytt-
3.6.2. Catalysis of hydration of nitriles
The reactions of 1(OTf) with aliphatic nitriles af-
forded low yields of the appropriate amides and resulted
in the formation of multiple Re-containing products. It
was therefore of interest to ascertain whether added
water would lead to a cleaner hydration reaction. In that
vein, MeCN (4.8 mmol), H2O (5.6 mmol), and 1(OTf)
p)]OTf (ArꢁPh (9(OTf)), p-Tol (10(OTf)), and p-
/
ClC6H4 (11(OTf))). A salient feature in their 31P{1H}-
NMR spectra is the magnetic inequivalence of the Pw

98
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
(0.03 mmol) in benzene were allowed to react at ca.
25 8C. No reaction was observed at this temperature;
however, heating at 60 8C led to the formation of one
major species, [ReH(h2-MeC(O)NH)(NCMe)(Cytt-
p)]OTf (12(OTf)), as revealed by 31P{1H}-NMR spec-
troscopy. Complex 12(OTf) showed a spectrum that was
very similar to that of the h2-amidate 9(OTf), 10(OTf),
cycle. Noteworthily, intermediate V is identical with that
obtained in the stoichiometric reaction of 1(OTf) with
aromatic nitriles (RꢁPh (9), p-ClC6H4 (11)). It is
/
strictly analogous to the cobalt h2-amidato complex
prepared by Chin and coworkers [39e], also from an
aromatic nitrile. With the aliphatic nitriles, such com-
plexes proved to be generally unstable [39e]. This
instability appears to be in accord with the observed
decomposition in the absence of water of aliphatic nitrile
complexes to multiple Re-containing products (Section
3.6.1).
or 11(OTf), with signals at d 16.0 (dd, PW), 12.3 (dd,
2
P
W?), and ꢂ
/
22.6 (t, PC) ppm, and JP P ꢁ2
/
JP P
ꢁ19
/
c
w
c w?
2
Hz and JP P
ꢁ
/
5.3 Hz. The in situ 1H-NMR spectrum
w
w?
exhibited signals at d 8.1 (br s, 1H, NH), 6.1 (br), and ꢂ
/
7.7 (td, 1H, ReH) ppm. The first resonance corresponds
to that assigned to the amidate NH in 9(OTf), 10(OTf),
and 11(OTf). The signal at d 6.1 ppm, which continued
to grow after all the 1(OTf) had been consumed and
until the resonance of H2O had almost entirely dis-
appeared, was assigned to the NH2 of free acetamide.
Confirmation of the product as MeC(O)NH2 was
Our suggested mechanism, depicted in Scheme 2, is an
adaptation of the mechanisms proposed for other
catalytic systems involving hydration of nitriles
[39e,42a]. Minor variations in the catalytic cycle cannot,
however, be dismissed on the basis of the evidence
presented. Interestingly, use of D2O instead of H2O in
the catalytic hydration of MeCN yields the h2-amidato
complex V (12-d1) and free amide containing ND and
ND2, respectively, while the lone metal hydride ligand in
V (12-d1) retains its isotopic integrity. This result
suggests that the trans (to the oxo ligand) hydride in
1(OTf) remains on the metal at all times, but the cis
hydride equilibrates with the deuterium from D2O,
presumably after migration to the oxo ligand in IV.
realized by GCÁ
/
MSÁIR. The overall turnover number
/
based on 1(OTf) was calculated to be 66 after 15 h of
reaction time. There appeared to be a 3-h induction
period during which no MeC(O)NH2 could be detected
by 1H-NMR spectroscopy; this induction period ap-
proximately coincided with the disappearance of 1(OTf).
Reaction with water in the presence of ca. 100-fold
molar deficiency of 1(OTf) was also examined for the
aromatic nitriles PhCN and p-ClC6H4CN. As with
MeCN, no amide was observed at room temperature;
however, by heating each reaction mixture at 60 8C for 3
h, essentially complete disappearance of 1(OTf) was
noted. The 31P{1H}-NMR spectra showed the forma-
tion of the appropriate amidato complex, 9(OTf) or
11(OTf), which occurred much faster than in the
corresponding anhydrous reactions. No free amide
could be detected by 1H-NMR spectroscopy in the
initial stages of the reaction; on prolonged heating,
however, ArC(O)NH2 was observed, and its concentra-
tion increased as for MeC(O)NH2. The identity of
ArC(O)NH2 was established by GCÁ
/
MSÁIR. The
/
turnover numbers for PhC(O)NH2 and p-
ClC6H4C(O)NH2 were 68 h (after 15 h) and 48 h (after
14 h) based on 1(OTf).
The hydration of nitriles to amides catalyzed by
numerous metal complexes, including those of rhenium
[39a], has been a topic of considerable current research
activity [39Á42]. Metal amidato intermediates have been
/
detected in some cases. We suggest that, in the present
study, nucleophilic attack of RCN at the Re center in 1
promotes migration of H to the oxo ligand [8c] to afford
a hydroxo complex, IV. Complex IV then undergoes
intramolecular coupling of coordinated RCN and OH
[39e,42a], with a proton shift from oxygen to nitrogen,
to produce the h2-amidate V, which is in equilibrium
with a h1-amidate, VI. The latter binds H2O and, upon
proton transfer therefrom to the amidate NH, releases
RC(O)NH2 and regenerates IV for another catalytic
Scheme 2.

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
99
Relevant to this finding is the observation of the absence
of HÁD exchange between ReH and D2O in 1(SbF6) [5].
lication CCDC No. 194129. Copies of the data can be
obtained free of charge from The Director, CCDC, 12
/
Union Road, Cambridge CB2 1EZ, UK (Fax: ꢀ44-
/
3.7. Reactions of [ReH2(O)(Cyttp)]SbF6 (1(SbF6))
with other unsaturated compounds
1223-336-033; e-mail: deposit@ccdc.cam.ac.uk or http://
www.ccdc.cam.ac.uk).
No reaction was observed between 1(SbF6) and
gaseous CO2 in benzene at 25 8C overnight. In contrast,
treatment of a benzene solution of 1(SbF6) with NO at
room temperature generated a brown gas, presumably
NO2, and uncharacterized solid products.
Acknowledgements
The authors acknowledge the donors of The Petro-
leum Research Fund, administered by the ACS, for
partial support of this research. We thank Dr. Gordon
Renkes for help with GCÁ
/
MSÁIR analyses and H.
/
4. Concluding remarks
Deng and A. Blackburn for assistance with the X-ray
diffraction study. This paper was written in part during
A.W.’s tenure as Visiting Professor at the Institute of
Chemistry, Academia Sinica, Taipei, Taiwan.
Reactions of the cationic oxo-hydrido complex 1 were
found to fall into three classes with regard to transfer of
one or both hydrogen and oxygen to various unsatu-
rated substrates.
References
4.1. Transfer of both hydrogen and oxygen
[1] Selected reviews of metal hydrido complexes: (a) M.Y. Darens-
bourg, Adv. Organomet. Chem. 27 (1987) 1Selected reviews of
metal hydrido complexes:;
Such a double transfer occurs with CO, RCN, and,
possibly (since no reaction intermediate was character-
ized), RNC. With CO and RNC, these reactions would
be best described as oxygen atom plus hydride ion
transfers. With RCN, the reaction may be regarded as
oxide plus proton donation to the nitrile. In all cases,
rhenium(V) is reduced to rhenium(III). (With RNC,
further reduction occurs to rhenium(I) by elimination of
H2.)
(b) R.H. Crabtree, in: G. Wilkinson, R.D. Gillard, J.A. McClev-
2
erty (Eds.), Comprehensive Coordination Chemistry, vol.
(Chapter 19), Pergamon Press, Oxford, 1987 (Chapter 19);
(c) A. Dedieu, Transition Metal Hydrides, VCH, New York,
1992;
(d) P.G. Jessop, R.H. Morris, Coord. Chem. Rev. 121 (1992) 155;
(e) D.M. Heinekey, W.J.J. Oldham, Chem. Rev. 93 (1993) 913;
(f) M. Peruzzini, R. Poli (Eds.), Recent Advances in Hydride
Chemistry, Elsevier, Amsterdam, 2001.
[2] Selected reviews of metal oxo complexes: (a) R.A. Sheldon, J.K.
Kochi, Metal-catalyzed Oxidations of Organic Compounds
(Chapter 6), Academic Press, New York, 1981 (Chapter 6);
4.2. Transfer of hydrogen only
(b) W.A. Nugent, J.M. Mayer, MetalÃ
/
Ligand Multiple Bonds,
Transfer of both hydrogen atoms (i.e., hydrogena-
tion) occurs with alkenes and alkyne. This process
should be accompanied by reduction of rhenium(V),
but reduction was not confirmed.
Wiley, New York, 1988;
(c) F. Bottomley, L. Sutin, Adv. Organomet. Chem. 28 (1988)
399;
(d) G. Parkin, Progr. Inorg. Chem. 47 (1998) 1.
[3] (a) J.A. Gladysz, Adv. Organomet. Chem. 20 (1982) 1;
(b) C.E.L. Hedford, W.R. Roper, in: P.S. Braterman (Ed.),
Reactions of Coordinated Ligands, vol. 1 (Chapter 8), Plenum
Press, New York, 1986 (Chapter 8).
4.3. Transfer of oxygen only
[4] G. Parkin, J.E. Bercaw, Polyhedron 7 (1988) 2053.
[5] Y. Kim, D.E. Rende, J.C. Gallucci, A. Wojcicki, Inorg. Chim.
Acta 352 (2003) 171.
Oxygen transfer from 1 has been shown to occur as
oxide to SO2 and as oxygen atom to P(OMe)3 and CO,
the former in competition with oxygen atom plus
hydride ion transfer (vide supra). With RNC, oxygen
atom is probably transferred. Transfer of oxygen atom
results in the reduction of rhenium(V) to rhenium(III)
(and, with CO and RNC, further to rhenium(I)),
whereas transfer of oxide leaves rhenium(V) unaffected.
[6] Ta2: (a) P. Belmonte, R.R. Schrock, M.R. Churchill, W.J.
Youngs, J. Am. Chem. Soc. 102 (1980) 2858;
(b) M.R. Churchill, W.J. Youngs, Inorg. Chem. 20 (1981) 382;
W2: (c) T.A. Budzichowski, M.H. Chisholm, W.E. Strieb, J. Am.
Chem. Soc. 116 (1994) 389;
Re3: (d) A. Bertolucci, M. Freni, P. Romiti, G. Ciani, A. Sironi,
V.G. Albano, J. Organomet. Chem. 113 (1976) C61;
(e) G. Ciani, A. Sironi, V.G. Albano, J. Chem. Soc. Dalton Trans.
(1977) 1667;
Ru3: (f) S.A. Fouda, B.C.Y. Hui, G.L. Rempel, Inorg. Chem. 17
(1978) 3213;
5. Supplementary material
(g) X.D. He, B. Chaudret, F. Lahoz, J.A. Lopez, J. Chem. Soc.
Chem. Commun. (1990) 958;
(h) G. Meister, G. Rheinwald, H. Stoeckli-Evans, G. Suss-Fink, J.
Crystallographic data for the structural analysis of
6(SbF6)×
/
C6H6 have been deposited with the Cambridge
¨
Crystallographic Data Centre as supplementary pub-
Chem. Soc. Dalton Trans. (1994) 3215;

100
Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á101
/
(i) M. Faure, M. Jahncke, A. Neels, H. Stoeckli-Evans, G. Suss-
¨
Fink, Polyhedron 18 (1999) 2679;
(b) R.F. Stewart, E.R. Davidson, W.T. Simpson, J. Chem. Phys.
42 (1965) 3175.
(j) M. Faure, A. Tesouro Vallina, H. Stoeckli-Evans, G. Suss-
¨
Fink, J. Organomet. Chem. 621 (2001) 103;
[19] M.G. Bradley, D.A. Roberts, G.L. Geoffroy, J. Am. Chem. Soc.
103 (1981) 379.
(k) G. Suss-Fink, M. Faure, T.R. Ward, Angew. Chem. Int. Ed.
¨
Engl. 41 (2002) 99;
[20] G. Jia, D.W. Meek, Inorg. Chem. 30 (1991) 1953.
[21] K. Nakamoto, Infrared and Raman Spectra of Inorganic and
Coordination Compounds, 3rd ed., Wiley, New York, 1978, pp.
Re : (l) U. Florke, H.-J. Haupt, Z. Kristallogr. 192 (1990) 286;
¨
4
WRe, W2Re2: (m) H.-L. Wu, G.-L. Lu, Y. Chi, L.J. Farrugia, S.-
M. Peng, G.-H. Lee, Inorg. Chem. 35 (1996) 6015;
WRe: (n) Y. Chi, H.-L. Wu, S.-M. Peng, G.-H. Lee, J. Chem. Soc.
Dalton Trans. (1997) 1931;
230Á233.
/
[22] C. Yang, S.M. Sokol, D.J. Kountz, D.W. Meek, R. Glaser, Inorg.
Chim. Acta 114 (1986) 119.
[23] (a) D.J. Darensbourg, R.A. Kudaroski, Adv. Organomet. Chem.
22 (1983) 129;
WRe2: (o) Y. Chi, P.-S. Cheng, H.-L. Wu, D.-K. Hwang, P.-C.
Su, S.-M. Peng, G.-H. Lee, J. Chem. Soc. Chem. Commun. (1994)
1839;
(b) J.D. Miller, in: P.S. Braterman (Ed.), Reactions of Coordi-
nated Ligands, vol. 2 (Chapter 1), Plenum Press, New York, 1989
(Chapter 1).
MnFe3: (p) C.K. Schauer, E.J. Voss, M. Sabat, D.F. Shriver,
Inorg. Chim. Acta 300Á302 (2000) 7;
MoOs3: (q) J.T. Park, M.-K. Chung, K.M. Chun, M. Kang, S.S.
Yun, S. Kim, Organometallics 11 (1992) 3313;
/
[24] A. Wojcicki, Adv. Organomet. Chem. 11 (1973) 87.
[25] W.A. Herrmann, U. Kusthardt, A. Schafer, E. Herdtweck,
¨
¨
Angew. Chem. Int. Ed. Engl. 25 (1986) 817.
[26] R.S. Pilato, G.L. Geoffroy, A.L. Rheingold, J. Chem. Soc. Chem.
Commun. (1989) 1287.
WOs3: (r) M.R. Churchill, Y.-J. Li, J. Organomet. Chem. 291
(1985) 61;
(s) M.R. Churchill, Y.-J. Li, J. Organomet. Chem. 294 (1985) 367;
(t) J.T. Park, Y. Chi, J.R. Shapley, M.R. Churchill, J.W. Ziller,
Organometallics 13 (1994) 813;
[27] (a) P.M. Treichel, G.E. Dirreen, H.J. Mueh, J. Organomet. Chem.
44 (1972) 339;
(b) P.M. Treichel, D.W. Firsich, G.P. Essenmacher, Inorg. Chem.
18 (1979) 2405.
(u) J.T. Park, J.-H. Chung, H. Song, K. Lee, J.-H. Lee, J.-R. Park,
I.-H. Suh, J. Organomet. Chem. 526 (1996) 215.
[28] W.A. Herrmann, K.A. Jung, E. Herdtweck, Chem. Ber. 122
(1989) 2041.
[7] Ta: (a) A. van Asselt, B.J. Burger, V.C. Gibson, J.E. Bercaw, J.
Am. Chem. Soc. 108 (1986) 5347;
[29] Y. Kim, H. Deng, J.C. Gallucci, A. Wojcicki, Inorg. Chem. 35
(1996) 7166.
(b) G. Parkin, A. van Asselt, D.J. Leahy, L. Winnery, N.G. Hua,
R.W. Quan, L.M. Henling, W.P. Schaefer, B.D. Santarsiero, J.E.
Bercaw, Inorg. Chem. 31 (1992) 82;
[30] Y. Kim, J. Gallucci, A. Wojcicki, Organometallics 11 (1992) 1963.
[31] R.H. Crabtree, The Organometallic Chemistry of the Transition
Metals, 2nd ed., Wiley, New York, 1994, p. 237.
[32] M.M. Crutchfield, C.H. Dungan, J.H. Letcher, V. Mark, J.R.
Van Wazer, Top. Phosphorus Chem. 5 (1967) 1.
[33] R.H. Holm, S.-B. Yu, Inorg. Chem. 28 (1989) 4385.
[34] (a) R. Kolodziej, S. Dutt, Hydrocarbon Process. 80 (2001) 103;
(b) C.M. Jensen, W.C. Trogler, Science 233 (1986) 1069;
(c) K. Kato, T. Yamada, T. Takai, S. Inoki, S. Isayama, Bull.
Chem. Soc. Jpn. 63 (1990) 179.
(c) H. Brunner, M.M. Kubicki, J.-C. Leblanc, C. Moıse, F.
¨
Volpato, J. Chem. Soc. Chem. Commun. (1993) 851.;
(d) P. Sauvageot, A. Sadorge, B. Nuber, M.M. Kubicki, J.-C.
Leblanc, C. Moıse, Organometallics 18 (1999) 2133.
¨
[8] Re: (a) E. Spaltenstein, T.K.G. Erikson, S.C. Crichlow, J.M.
Mayer, J. Am. Chem. Soc. 111 (1989) 617;
(b) R.R. Conry, J.M. Mayer, Organometallics 10 (1991) 3160;
(c) S.H. Tahmassebi, R.R. Conry, J.M. Mayer, J. Am. Chem. Soc.
115 (1993) 7553;
[35] G.A. Lawrance, Chem. Rev. 86 (1986) 17.
[36] (a) B.R. James, Adv. Organomet. Chem. 17 (1979) 319;
(b) D.P. Riley, S.J. Tremont, in: M.V. Twigg (Ed.), Mechanisms
of Inorganic and Organometallic Reactions, vol. 5 (Chapter 14),
Plenum Press, New York, 1988 (Chapter 14);
(d) Y. Matano, S.N. Brown, T.O. Northcutt, J.M. Mayer,
Organometallics 17 (1998) 2939;
(e) Y. Matano, T.O. Northcutt, J. Brugman, B.K. Bennett, S.
Lovell, J.M. Mayer, Organometallics 19 (2000) 2781.
[9] Re: (a) Y. Kim, J. Gallucci, A. Wojcicki, J. Am. Chem. Soc. 112
(1990) 8600;
(c) F.P. Pruchnik, Organometallic Chemistry of the Transition
Elements (Chapter 13), Plenum Press, New York, 1990 (Chapter
13);
(b) D.E. Rende, Y. Kim, C.M. Beck, A. Wojcicki, Inorg. Chim.
Acta 240 (1995) 435.
(d) H. Werner, M. Schultz, M.A. Esteruelas, L.A. Oro, J.
Organomet. Chem. 445 (1993) 261;
[10] (a) I. Ojima, M. Eguchi, M. Tzamarioudaki, in: E.W. Abel,
F.G.A. Stone, G. Wilkinson (Eds.), Comprehensive Organome-
tallic Chemistry II, vol. 12 (Chapter 2), Pergamon Press, Oxford,
1995 (Chapter 2);
(e) S.T. Lo, Z. Xu, T.B. Wen, W.S. Ng, S.H. Liu, Z.Y. Zhou, Z.
Lin, C.P. Lau, G. Jia, Organometallics 19 (2000) 4523.
[37] J.J. Zuckerman (Ed.), Inorganic Reactions and Methods, Vol. 16,
VCH, New York, 1991.
(b) H.-W. Bohnen, B. Cornils, Adv. Catal. 47 (2002) 1.
[11] D.F. Shriver, M.A. Drezdzon, The Manipulation of Air-sensitive
Compounds, 2nd ed., Wiley, New York, 1986.
[38] (a) S. Gopinathan, S.S. Deshpande, C. Gopinathan, Transition
Met. Chem. 18 (1993) 406;
[12] D.D. Perrin, W.L.F. Armarego, D.R. Perrin, Purification of
Laboratory Chemicals, Pergamon Press, Oxford, 1991.
[13] R.R. Willis, M. Calligaris, P. Faleschini, J.C. Gallucci, A.
(b) C. Bianchini, P. Barbaro, A. Meli, M. Peruzzini, A. Vacca, F.
Vizza, Organometallics 12 (1993) 2505.
[39] (a) J.L. Eglin, Comments Inorg. Chem. 23 (2002) 23;
(b) F. Matsuda, Chemtech 7 (1977) 306;
Wojcicki, J. Organomet. Chem. 193Á194 (2000) 465.
[14] M.W. Baize, J.C. Gallucci, A. Wojcicki, Inorg. Chim. Acta 259
/
(c) C.M. Jensen, W.C. Trogler, J. Am. Chem. Soc. 108 (1986) 723;
(d) D.P. Fairlie, W.G. Jackson, G.M. McLaughlin, Inorg. Chem.
28 (1989) 1983;
(1997) 339.
[15] TEXSAN, Single Crystal Structure Analysis Software, Version 5.0,
Molecular Structure Corp., The Woodlands, TX, 1989.
[16] V. Parthasarathi, P.T. Beurskens, H.J.B. Slot, Acta Crystallogr.
Sect. A 39 (1983) 860.
(e) J.H. Kim, J. Britten, J. Chin, J. Am. Chem. Soc. 115 (1993)
3618.
[40] (a) D.A. Buckingham, P. Morris, A.M. Sargeson, A. Zanella,
Inorg. Chem. 16 (1977) 1977;
[17] N. Walker, D. Stuart, Acta Crystallogr. Sect. A 39 (1983) 158.
[18] (a) International Tables for X-ray Crystallography, Vol. IV,
Kynoch Press, Birmingham, UK, 1974, pp. 71 and 148.;
(b) J. Chin, J.H. Kim, Angew. Chem. Int. Ed. Engl. 29 (1990) 523;

Y. Kim et al. / Journal of Organometallic Chemistry 682 (2003) 85Á
/101
101
(c) R. Cini, F.P. Intini, L. Maresca, C. Pacifico, G. Natile, Eur. J.
Inorg. Chem. (1998) 1305.
113 (1991) 7805;
(h) R.L. Angel, D.P. Fairlie, W.G. Jackson, Inorg. Chem. 29
(1990) 20;
[41] Selected references: (a) V.Y. Kukushkin, A.J.L. Pombeiro, Chem.
Rev. 102 (2002) 1771;
(b) B. Lippert, Prog. Inorg. Chem. 37 (1989) 1;
(i) N.J. Curtis, N.E. Dixon, A.M. Sargeson, J. Am. Chem. Soc.
105 (1983) 5347.
(c) H. Sigel, R.B. Martin, Chem. Rev. 82 (1982) 385;
(d) C.B. Bauer, T.E. Concolino, J.L. Eglin, R.D. Rogers, R.J.
Staples, J. Chem. Soc. Dalton Trans. (1998) 2813.;
(e) D.P. Fairlie, Y. Ilan, H. Taube, Inorg. Chem. 38 (1997) 1029;
(f) R. Cini, F.P. Intini, G. Natile, C. Pacifico, J. Chem. Soc.
Dalton Trans. (1994) 3753.;
[42] (a) K.L. Breno, M.D. Pluth, D.R. Taylor, Organometallics 22
(2003) 1203;
(b) S.I. Murahashi, H. Takaya, Acc. Chem. Res. 33 (2000) 225;
(c) A.W. Parkins, Platinum Met. Rev. 40 (1996) 169.
[43] R.O. Hutchins, M.G.K. Hutchins, in: S. Patai, Z. Rappaport
(Eds.), Supplement C: The Chemistry of Triple-bonded Func-
tional Groups, Part 1, Wiley, New York, 1983, p. 587.
(g) R. Cini, F.P. Fanizzi, F.P. Intini, G. Natile, J. Am. Chem. Soc.