Solid state isomerisation reactions of some ruthenium complexes

Article abstract of DOI:10.1016/S0022-328X(03)00633-8

The isomerisation of ttt-RuCl₂(RNC)₂ (PPh₃)₂ (R=2,6-xylyl, ^tBu, ⁱPr, benzyl, 2-OMe-4-Clphenyl) to cct -RuCl₂ (RNC)₂(PPh₃)₂ has been carried out in the solid state. The reaction is first order and kinetic measurements have yielded activation energies of 210 kJ mol^-1 (R=^tBu) and 221 kJ mol^-1 (R=benzyl) for reactions performed between 160 and 180 °C. XRD analysis of the solid state reaction of ttt -RuCl₂ (^tBuNC)₂(PPh₃)₂ has revealed that the cct-isomer produced is a polymorph of that produced by recrystallisation of the pure cct-RuCl₂(^tBuNC) ₂(PPh₃)₂ isomer. A possible mechanism for the isomerisation reaction involving rotation of the two small groups (Cl, RNC) is proposed.

Full text of DOI:10.1016/S0022-328X(03)00633-8

Journal of Organometallic Chemistry 682 (2003) 2ꢂ7
/
www.elsevier.com/locate/jorganchem
Solid state isomerisation reactions of some ruthenium complexes
Florence M. Nareetsile, Owen P.M. Horwood, David G. Billing,
Demetrius C. Levendis, Neil J. Coville *
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, 1 Jan Smuts Ave, Johannesburg 2050, South Africa
Received 14 April 2003; received in revised form 27 June 2003; accepted 28 June 2003
Abstract
t
2,6-xylyl, Bu, Pr, benzyl, 2-OMe-4-Clphenyl) to cct-RuCl2(RNC)2(PPh3)2
i
The isomerisation of ttt-RuCl2(RNC)2(PPh3)2 (Rꢀ
/
has been carried out in the solid state. The reaction is first order and kinetic measurements have yielded activation energies of 210 kJ
molꢁ1 (Rꢀt
/
Bu) and 221 kJ molꢁ1 (Rꢀ
benzyl) for reactions performed between 160 and 180 8C. XRD analysis of the solid state
/
reaction of ttt-RuCl2(tBuNC)2(PPh3)2 has revealed that the cct-isomer produced is a polymorph of that produced by
recrystallisation of the pure cct-RuCl2(tBuNC)2(PPh3)2 isomer. A possible mechanism for the isomerisation reaction involving
rotation of the two small groups (Cl, RNC) is proposed.
# 2003 Elsevier B.V. All rights reserved.
Keywords: Ruthenium; Solid state; Isomerisation; DSC; Isonitrile
1. Introduction
classical coordination complexes has been summarised
by le May [2]. The summary reveals that in earlier work
the emphasis was on the study of 6-coordinate Cr and
Co complexes containing OH and H2O ligands, and
indicated the complexities associated with the presence
of the OH/H2O ligands. Thus simpler systems are
required to obtain more fundamental information on
the complex isomerisation and decomposition of 6-
coordinate complexes. Solid state rearrangements are
also well known for 4-coordinate Pt complexes of the
Reactions of inorganic coordination complexes in the
solid state have been little studied [1,2]. There are many
reasons for the limited exploration of this type of
reaction*lack of contact between reactants, decompo-
/
sition of reactants at the temperatures required for
reaction and analytical difficulties. By contrast, the area
of organic solid state chemistry has a rich and varied
history spanning many decades [3,4].
Some years ago we commenced a study of isomerisa-
tion reactions of a range of organometallic complexes in
the solid state. The reactions were focussed on pseudo 7-
type L2PtX2 (Lꢀ
In this study, we wish to report our investigation on
the solid state isomerisation reaction of a series of 6-
/
neutral donor, X halide) [2,6ꢂ11].
/
coordinate complexes of the type CpML4 (MꢀRe, Mo,
/
coordinate
Ru
complexes
of
Bu, 2,6-xylyl, benzyl, 2-
the
type
RuCl2(RNC)2(PPh3)2 (Rꢀt
/
W; L a range of ligands) [5]. The study revealed that
mechanistic pathways not available in a solution phase
could occur in the solid state. This led to synthetic
strategies to the synthesis of isomers that were not
favoured in solution studies.
Studies on 4- and 6-coordinate inorganic systems have
also been published in the literature and much of the
early work on the study of solid state reactions of
i
OMe-4-Clphenyl and Pr), complexes that undergo an
isomerisation reaction from the ttt isomer to the cct-
isomer (Fig. 1).
A preliminary report on the solid state isomerisation
reaction of some related ttt-RuCl2(RNC)2(PPh3)2 com-
plexes [13] as well as related ttt-RuCl2(CO)2(PR3)2 have
been previously documented [14]. No kinetic data were
however reported.
Interestingly, we have also observed that the reaction
between RuCl2(PPh3)3 and RNC to produce ttt-
RuCl2(RNC)2(PPh3)2 can be carried out in the absence
* Corresponding author. Tel.:
7176749.
ꢃ
/
27-11-7176738; fax:
ꢃ27-11-
/
E-mail address: ncoville@aurum.chem.wits.ac.za (N.J. Coville).
0022-328X/03/$ - see front matter # 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00633-8

F.M. Nareetsile et al. / Journal of Organometallic Chemistry 682 (2003) 2ꢂ
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3
Table 1
IR spectral positions of the CN bands of ttt- and cct-
RuCl2(RNC)2(PPh3)2 complexes a
R
ttt-isomer/cmꢁ1
cct-isomer/cmꢁ1
t Bu
Xylyl
2126
2095
2112, 2154
2094, 2141
Fig. 1. Conversion of the ttt to the cct-isomer.
Benzyl
i Propyl
MeClPhNC b
2134
2131
2131, 2176
2119, 2166
2082, 2144, 2105(sh)
of solvents, and we also report our results on this
unexpected finding.
2082, 2105
a
Recorded in CH2Cl2.
Extra peaks may be associated with restricted rotation of the RNC
b
ligand.
2. Experimental
2.2. Solid state synthesis of ttt-
RuCl2(xylylNC)2(PPh3)2
The RNC ligands (RꢀtBu, 2,6-xylyl, benzyl, and iPr)
/
were obtained from Strem Chemicals. 2-OMe-4-Clphe-
nylNC (MeClPhNC) was obtained as a gift from Dr M
Layh of the School of Chemistry. The dichloromethane
and Et2O were distilled over LiAlH4 and Na/bezophe-
none, respectively. The known complexes ttt-
RuCl2(PPh3)2 (0.093 g, 0.097 mmol) and 2,6-xylylNC
(0.028 g, 0.21 mmol) were mixed together gently with a
spatula and placed in an NMR tube. The NMR tube
was evacuated and then purged with nitrogen. The
sample mixture was then heated at 100 8C for less than 1
min. The product was left to cool down to room
temperature (r.t.). It was then washed with Et2O to
remove the displaced triphenylphosphine ligand (yield:
0.080 g, 90%). Reaction with solid MeClPhNC gave a
similar result (55% yield).
RuCl2(RNC)2(PPh3)2 (Rꢀt
Bu, 2,6-xylyl) were pre-
/
pared by modification of the literature method [15].
The corresponding cct-isomers were prepared by heat-
ing the ttt isomers at high temperature in the solid state.
Thermal analysis was carried out on ꢀ10 mg samples
/
under flowing nitrogen at a constant heating rate of
10 8C minꢁ1 with a Du Pont Instruments 910 Differ-
ential Scanning Calorimeter. Solution IR spectra were
measured in CH2Cl2 on a Brucker VECTOR 22 FTIR
spectrometer. The 1H-NMR spectra were measured on a
Brucker AVANCE 300 NMR spectrometer in CDCl3
with Me4Si as the reference.
Similar reactions were performed (at 50 8C) with the
other liquid isonitriles, but here the reactions occurred
in the solution state. The liquid phase reaction also
occurred slowly at r.t. (colour change seen with time).
2.3. Kinetic studies
Kinetic studies were performed at constant tempera-
ture (in the range 160ꢂ180 8C) by heating ca. 10 mg of
/
2.1. Solution synthesis of ttt-RuCl2(tBuNC)2(PPh3)2
the solid sample in a sealed NMR tube for various time
intervals. The NMR tubes containing the solid samples
were evacuated and purged with nitrogen prior to
heating. After heating, the samples were cooled to r.t.
A mixture of RuCl2(PPh3)2 (1.0 g, 1.04 mmol) and
tBuNC (0.189 g, 2.28 mmol) was dissolved in 30 ml
freshly distilled CH2Cl2. The mixture was stirred for 1 h.
The solvent was removed in vacuo and the orange
1
and then dissolved in CDCl3 and taken for H-NMR
measurement. The % ttt isomer versus time curves and
the Arrhenius plot for each individual isomerisation
process was constructed from the data. Typical data are
shown in Figs. 2 and 3.
residue was washed with 3ꢄ/25 ml portions of Et2O.
The solid was dried under vacuum overnight. Yieldꢀ
/
0.716 g (80%). The analogous procedure was followed
for the synthesis of ttt-RuCl2(2,6-xylylNC)2(PPh3)2
(85%), ttt-RuCl2(benzylNC)2(PPh3)2 (67%), ttt-
2.4. XRD data collection
RuCl2(MeClPhNC)2(PPh3)2
(20%)
and
ttt-Ru-
Cl2(iPrNC)2(PPh3)2 (78%). IR and NMR data for the
complexes are recorded in Tables 1 and 2, respectively
and the DSC data in Table 3. Elemental analysis data
(for the new complexes): RuCl2(MeClPhNC)2(PPh3)2
Anal. Found: C, 59.93; N, 2.99; H, 3.99. Calc.: C, 60.53;
N, 2.72; H, 4.10%. ttt-RuCl2(iPrNC)2(PPh3)2 Anal.
Found: C, 63.12; N, 3.33; H, 5.34. Calc.: C, 63.31; N,
3.36; H, 5.31%.
Samples were ground with an agate pestle and mortar
to a fine powder in preparation for powder X-ray
diffraction analysis. A Philips PW 1710 diffractometer
fitted with a Philips PW 1820 goniometer (with second-
ary beam monochromator and zero-background sample
holder) was used to collect the diffractograms. Copper
˚
K-alpha radiation (lꢀ1.5418 A) was employed, with
/
generator tension and current being 40 kV and 20 mA,

4
F.M. Nareetsile et al. / Journal of Organometallic Chemistry 682 (2003) 2ꢂ7
/
Table 2
1H-NMR data for RuCl2(RNC)2(PPh3)2 complexes
R
CHx region/ppm
Phenyl region/ppm
t Bu-ttt
t Bu-cct
1.0 (s)
0.72 (s)
7.26ꢂ
/
7.33 (m), 7.80ꢂ
/
7.87 (m)
7.31ꢂ
/
7.34 (m), 7.86ꢂ
/
7.90 (m)
2,6-Xylyl-ttt 2.05 (s)
2,6-Xylyl-cct 1.81 (s)
6.91 (d), 6.94 (t), 7.10ꢂ
6.81 (d), 6.92 (t), 7.05ꢂ
6.92ꢂ7.02 (m), 7.13ꢂ7.28 (m), 7.71ꢂ
6.60ꢂ6.63 (m), 7.13ꢂ7.30 (m), 7.90ꢂ
3.5 (CH, m) 7.30ꢂ7.32 (m), 7.79ꢂ
3.6 (CH, m) 7.26ꢂ7.34 (m), 7.90ꢂ
6.31ꢂ6.32 (d), 6.66ꢂ
6.28, 6.29 (d); 6.56, 6.60 (d); 7.02, 7.03 (d); 7.05, 7.06 (d); 7.13ꢂ
/
7.14 (m), 7.78ꢂ
/
7.85 (m)
/7.09 (m), 7.88ꢂ
/
7.94 (m)
Benzyl-ttt
Benzyl-cct
i Pr-ttt
4.32 (s)
3.76 (s)
/
/
/7.80 (m)
/
/
/8.00 (m)
0.92ꢂ
0.59ꢂ
3.49 (s)
/0.95 (CH3 d), 3.4ꢂ
/
/
/
7.82 (m)
i Pr-cct
/0.62 (CH3 d), 3.4ꢂ
/
/
/
8.00 (m)
MeClPh-ttt
/
/
6.69 (d), 7.10ꢂ
/7.149 (dd), 7.24ꢂ
/
7.26 (m), 7.84ꢂ
/
7.9 (m)
MeClPh-cct 3.48 (d)
/
7.32 (m), 7.97ꢂ8.03 (m)
/
Recorded in CDCl3.
Table 3
DSC of the ttt- and cct-RuCl2(RNC)2(PPh3)2 complexes
R
Exothermic peak/8C
Endothermic peak/8C
ttt-t Bu
210
253
254
317
318
266
254
288
290
cct-isomer
ttt-Xylyl
ꢂ/
230
cct-isomer
ttt-Benzyl
cct-isomer
ttt-i Propyl
cct-isomer
ttt-MeClPhNC
cct-isomer
ꢂ/
211
258ꢂ
/
ꢂ/
228
ꢂ/
208
240, 257 a
240, 261 a
ꢂ/
a
Peak associated with decomposition; confirmed by TGA analysis.
Fig. 3. Typical plot of ln a versus time plot for RuCl2(ben-
zylNC)2(PPh3)2 (160 8C).
to be essentially unchanged*
significant evidence of degradation within the X-ray
beam. Diffractograms for RNCꢀt
BuNC are presented
/hence samples showed no
/
in Fig. 4.
3. Results and discussion
3.1. Synthesis and characterisation of
RuCl2(RNC)2(PPh3)2
RuCl2(PPh3)3 and an appropriate amount of RNC
were stirred together in CH2Cl2 at room temperature to
give the yellow complexes of ttt-RuCl2(RNC)2(PPh3)2
with yields between 67 and 85%. Attempts to prepare
these complexes in refluxing solvent, as described in the
literature [15], yielded a mixture of a black and yellow
solid. Separation of the mixture by column chromato-
graphy led to the disappearance of much of the yellow
complex on the column resulting in a very low yield of
the product. The Ru complexes are soluble in most of
the polar organic solvents and insoluble in non-polar
solvents.
Fig. 2. Typical plot of % ttt isomer versus time plot for ttt-
RuCl2(benzylNC)2(PPh3)3 (160 8C).
respectively. Samples were run as powders on rotating
silicon wafers using silicone grease. Diffractograms were
recorded in step-scan mode, from start angle (2u) 3.0008
to end angle (2u) 70.0008, with a step size of (2u) 0.0208
and time per step of 25 s. Diffraction data was
recollected after the initial X-ray exposure and found

F.M. Nareetsile et al. / Journal of Organometallic Chemistry 682 (2003) 2ꢂ
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5
Fig. 4. XRD plots. (A) ttt-RuCl2(t BuNC)2(PPh3)2; (B) cct-RuCl2(t BuNC)2(PPh3)2 (obtained after complete solid state conversion from the ttt
isomer); (C) cct-RuCl2(t BuNC)2(PPh3)2 (obtained after recrystallisation from dichloromethane solution).
Heating a mixture of RuCl2(PPh3)3 and 2,6-xylyliso-
cyanide in the solid state between room temperature and
60 8C did not reveal any visual reaction (10 min) but at
100 8C rapid formation of a yellow complex occurred
3.1.1. IR studies
Solution IR spectra of the ttt-isomers display one
strong n(CN) band. Two bands were noted for the
MeClPh complex; this could arise from two different
arrangements of the bulky OMe groups attached to the
ligand. Analogous ttt-RuCl2(EtNC)2(EPh3)2 ( where
(B1 min). A white deposit also formed on the complex
/
that was identified as the triphenylphosphine ligand.
Washing the solid with diethyl ether left behind a bright
yellow solid. Since the melting point of the isonitrile is
ca. 175 8C this suggests that the reaction occurred in the
solid phase or between a solid and a vapour (xylylisoni-
trile has a high vapour pressure at room temperature).
Either way, the Ru complex remained in the solid state
throughout the reaction. A similar result was obtained
with solid 2-OMe-4-ClphenylNC, showing the general-
ity of the reaction.
Eꢀ
/
P, As or Sb and XꢀCl or Br) complexes were
/
also reported to show one absorption band, both in the
solid state and in solution [12]. The n(CN) band position
increases in the order 2,6-xylylB
/
MeClPhBt
benzyl, suggestive of a correlation with the electron
/
BuBi
/
Pr5
/
donating capacity of the RNC ligand.
When the complexes ttt-RuCl2(RNC)2(PPh3)2 are
heated in the solid state two n(CN) IR bands, with
positions different from that of the original samples,
were detected. These are associated with the cis arrange-
ment of the isonitrile ligands and the band positions
again vary with the electron donating capacity of the
RNC ligand.
Reaction between RuCl2(PPh3)3 and the liquid iso-
nitriles occurred without the addition of solvent at room
temperature to slowly (or more rapidly at 50 8C) give the
required complexes in ꢁ85% yield. Thus very clean
/
reactions are possible in the absence of solvent [16,17].
1
Characterisation of the isonitrile complexes by H-
1
3.1.2. Characterization by H-NMR spectroscopy
1H-NMR spectral data for the samples are given in
Table 2. The NMR data are consistent with the
proposed molecular structures.
NMR and IR spectroscopy gave data consistent with
the structure of ttt-RuCl2(RNC)2(PPh3)2. When ttt-
RuCl2(RNC)2(PPh3)2 was heated in the solid state pale
The ttt-RuCl2(tBuNC)2(PPh3)2 isomer undergoes
100% conversion to the cct complex on heating. Similar
results were found for the other complexes. The CH3/
CH2 resonance of the RNC ligand of the ttt isomer
always shifted downfield as the cct-isomer formed.
These NMR absorptions were thus chosen to monitor
the extent of the isomerisation reaction as a function of
time (see below).
yellow
RuCl2(RNC)2(PPh3)2 (Rꢀt
MeClPh) were produced in quantitative yield. The
complexes with Rꢀt
Bu, benzyl and 2,6-xylyl have
to
near
white
complexes
of
cct-
i
/
Bu, 2,6-xylyl, Pr, benzyl,
/
been prepared before while the other complexes are
new. The solid state isomerisation reaction of the
complexes RuCl2(RNC)2(PPh3)2 was monitored by IR,
1
DSC, H-NMR and XRD techniques.

6
F.M. Nareetsile et al. / Journal of Organometallic Chemistry 682 (2003) 2ꢂ7
/
3.1.3. DSC studies
the ttt isomer. The conversion of this ttt isomer to the
cct-isomer was established by powder XRD. The XRD
pattern of the fully isomerised material produced in the
solid state reaction i.e. cct-RuCl2(tBuNC)2(PPh3)2 (de-
gree of reaction established by solution NMR spectro-
scopy) is shown in Fig. 4B. The two isomers have quite
distinctive XRD patterns. The cct-isomer was then
The results of a DSC study for the different RNC
complexes are shown in Table 3. The DSC profiles of all
the ttt complexes exhibit the same pattern, with an
exotherm (isomerisation peak) appearing before the
endotherm (melting peak). The endotherm corresponds
to the melting point of the cct-isomer and ranges
between 250 and 320 8C. The exothermic peaks range
between 210 and 230 8C. A DSC profile for a typical
isomer pair viz. ttt- and cct-RuCl2(iPrNC)2(PPh3)2 is
shown in Fig. 5.
recrystallised (CH2Cl2ꢂhexane) and the XRD powder
/
pattern recorded (Fig. 4C). The patterns of the two cct
samples are quite different, suggesting that the cct-
isomer can exist as a number of polymorphs. This issue
is currently under investigation.
It will be noted that the profiles for the two isomers
differ. Both isomers exhibit the same endotherm (melt-
ing peak; 288 8C) but only the ttt isomer exhibits an
exotherm (isomerisation peak; 228 8C) (Fig. 2). The
DSC profile reveals that the isomerisation of the ttt
complexes takes place in the solid state. This was
confirmed by heating the ttt isomer to above the
exotherm and then cooling the sample. Part of the
sample was then used to record a NMR spectrum that
revealed only the cct-isomer while the second part was
used to re-record the DSC that indicated no exotherm in
the rerun.
3.2. Kinetic studies
The kinetic studies of the isomerisation reactions were
followed by heating solid samples for periods of time
and then dissolving the material and evaluating the
degree of reaction by 1H-NMR spectroscopy. The peaks
that appeared in the CH3/CH2 region of the NMR
spectrum were used to monitor these reactions. For
t
example, in the Bu complex, the methyl peak at 1.00
ppm gradually disappears and is replaced by the peak at
0.70 ppm corresponding to the newly formed cct-
isomer. By measuring the disappearance of the ttt
complex, as a function of time, it is therefore possible
to evaluate the advance of the solid state isomerisation
reaction.
The DSC profiles of Rꢀ
2,6-xylyl, and tBu have been
/
reported previously [13] and minor changes in the
positions of the endothermic/exothermic peaks between
our data and the literature data were noted. The
differences are associated with different operating con-
ditions and the different instruments used.
The DSC studies on the ttt complexes show that the
complexes undergo similar rearrangement processes
irrespective of the RNC ligand used.
Kinetic studies were performed on ruthenium com-
plexes with Rꢀt
Bu and benzyl. When complexes with
/
i
Rꢀ2,6-xylyl or Pr were used, the reaction progression
/
was difficult to follow as the corresponding cct-isomers
were poorly soluble in the solvents used, and hence
precipitate out of, CDCl3 or C6D6.
The percent conversion (a) at a given time t was
calculated from the expression
3.1.4. XRD studies
A preliminary XRD study of the complexes was
attempted and data for RuCl2(tBuNC)2(PPh3)2 are
shown in Fig. 4. Fig. 4A gives the XRD pattern for
a(ttt) ꢀfI(ttt)=[(I(ttt) ꢃI(cct)]gꢄ100
where I(ttt) is the intensity of the ttt-isomer and I(cct) is
the intensity of the cct-isomer, the intensity data being
obtained from the solution NMR spectra of the samples
after reaction. The a versus time curves for the
isomerisation process for the two ttt complexes show a
similar sigmoid shape (see Fig. 3). The plots of ln a
versus time yielded a straight line that is expected of a
first order reaction (see Fig. 4).
t
From these plots, the rate constant values for Bu
10ꢁ4
,
complexes were found to be 0.00449
/
6.2ꢄ
/
0.002593.2ꢄ 4.3ꢄ
/
/
10ꢁ4, 8.58ꢄ10ꢁ49 10ꢁ4 at 185,
/
/
/
180 and 175 8C, respectively. The activation energy,
Ea, derived from the least-squares analysis of the best fit
from the ln K versus 1/T plot was found to be 210 kJ
molꢁ1
.
For the benzyl complex, the samples were heated at
Fig. 5. DSC profile of (a) ttt- and (b) cct-RuCl2(i PrNC)2(PPh3)2
160, 170 and 180 8C and the rate constants were found
recorded at a scan rate of 10 8C minꢁ1
.
to be 0.00419
/
3ꢄ
/
10ꢁ4
,
0.00579
/
4.0ꢄ
10ꢁ4 and
/

F.M. Nareetsile et al. / Journal of Organometallic Chemistry 682 (2003) 2ꢂ
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7
0.0299
/
0.004 sꢁ1, respectively. The activation energy Ea
Acknowledgements
was found to be 221 kJ molꢁ1
.
We would like to thank the THRIP, the NRF (project
#2053379) and the Universities of Botswana and the
Witwatersrand for financial aid. Sigi Heiss and Richard
Mampa are thanked for recording the NMR spectra.
3.2.1. Mechanism
The conversion of the ttt isomer to the cct-isomer in
the solid state is unidirectional, and no ccc isomer was
detected [18]. The reaction is unimolecular and first
order. It is assumed that the isomerisation reaction is an
intramolecular process involving no loss of ligands from
the Ru during the ligand exchange.
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6-coordinate metal complexes have been proposed and
these involve rotation of two or three ligands relative to
the other ligands [19]. A consideration of the complexes
synthesised in this study (see Fig. 1) suggests that only
one pair of ligands (Cl, RNC) needs to exchange to
bring about the isomerisation reaction. These are the
small ligands. Movement of the large PPh3 ligands in the
solid state is less likely although flexing of these and the
other ligands to assist with the process is expected. The
reaction could thus entail a direct Cl/RNC exchange via
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/
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via a bicapped tetrahedral intermediate followed by a
1808 rotation around the tetrahedral edge [20]. This
would be a high-energy process, consistent with the
activation energy data generated (ꢁ
200 kJ molꢁ1).
/
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4. Conclusion
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Inorg. Chim. 27 (1988) 4307.
The isomerisation reaction of
RuCl2(RNC)2(PPh3)2 (Rꢀ
2,6-xylyl, tBu, Pr, benzyl,
a series of ttt-
i
/
[15] Y. Yamamoto, T. Tanase, T. Date, Y. Koide, J. Organomet.
Chem. 386 (1990) 365.
MeClPh) complexes to their cct-RuCl2(RNC)2(PPh3)2
isomers has been studied in the solid state. Kinetic data
for the unidirectional reaction were obtained and are
consistent with a first order reaction. A mechanism in
which only two groups (Cl, RNC) interchange was
proposed, similar to that proposed recently for some 7-
coordinate Re complexes [5].
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(2001) 620.
[20] A.A. Ismail, F. Sauriol, I.S. Butler, Inorg. Chem. 28 (1989) 1007.