Synthesis and characterization of the mer-[RuCl3(NO)(dppb)] isomer. X-ray structures of fac-[RuCl3(NO)(dppm)], cis-[RuCl2(dppm)2] and mer-[RuCl3(NO)(dppb)] [dppm=1,2-Bis(diphenylphosphino)methane and

Article abstract of DOI:10.1016/S0277-5387(99)00084-4

The fac-[RuCl₃(NO)(dppm)] (1) and cis-[RuCl₂(dppm)₂] (2) complexes were obtained with co-crystallization in the solid state from the reaction of RuCl₃(NO) with the diphosphine in dichloromethane. mer-[RuCl₃

Full text of DOI:10.1016/S0277-5387(99)00084-4

Polyhedron 18 (1999) 2079–2083
Synthesis and characterization of the mer-[RuCl (NO)(dppb)] isomer.
3
X-ray structures of fac-[RuCl (NO)(dppm)], cis-[RuCl (dppm) ]
3
2
2
and mer-[RuCl (NO)(dppb)] [dppm51,2-Bis(diphenylphosphino)methane
3
and dppb51,4-Bis(diphenylphosphino)butane]
a ,
a
b
c
c
*
Alzir A. Batista , Cid Pereira , Karen Wohnrath , Salete L. Queiroz , Regina H. de A. Santos ,
c
Maria Teresa do P. Gambardella
a
Departamento de Qu ´ı mica, UFSCar, CP 676, 13.565-905, S a˜ o Carlos, SP, Brazil
b
Instituto de Qu ´ı mica/UNESP-CP 355, 14800-900, Araraquara (SP), Brazil
c
Instituto de Qu ´ı mica de S a˜ o Carlos, USP, CP 780, 13560-250, S a˜ o Carlos, SP, Brazil
Received 22 October 1998; accepted 29 March 1999
Abstract
The fac-[RuCl (NO)(dppm)] (1) and cis-[RuCl (dppm) ] (2) complexes were obtained with co-crystallization in the solid state from
3
2
2
the reaction of RuCl (NO) with the diphosphine in dichloromethane. mer-[RuCl (NO)(dppb)] (3) was obtained from
3
3
[
RuCl (dppb)(H O)] by bubbling NO for 30 min in the same solvent. The crystal and molecular structures of these three compounds have
3 2
been determined from X-ray studies.
 1999 Elsevier Science Ltd. All rights reserved.
Keywords: Ruthenium; Nitrosyl; Complexes, Biphosphines; X-ray structure; Isomerism
1
. Introduction
2. Experimental
2
.1. General considerations
The chemistry of nitrosyl transition metal complexes is
of special interest because of the relevance of nitric oxide
in biological systems [1–4]. Nitrosyl–ruthenium complex-
es have been studied due to their importance as potential
catalysts in homogeneous processes, ambiental chemistry
or with bioinorganic purpose.
All manipulations involving solutions of the complexes
were performed under argon. Solvents were purified by
standard methods. All chemicals used were of reagent
grade or comparable purity. The RuCl ?3H O was pur-
3
2
chased from Degussa and the ligands dppm and dppb were
Recently, we published a paper on nitrosyl ruthenium
purchased from Aldrich. The RuCl (NO) was prepared
3
complexes with general formula [RuCl (NO)(P–P), where
3
according to the literature [5]. Yields are based on the
metal. Microanalyses were performed by Microanalytical
Laboratory of Universidade Federal de S a˜ o Carlos, S a˜ o
Carlos(SP) or of Universidade de S a˜ o Paulo, S a˜ o Paulo.
P–P5[PPh (CH ) PPh ] n51–3 and [PPh CH5CHPPh ]
2
2
n
2
2
2
including
RuCl (NO)
the
X-ray
structure
of
the
[
h
(PPh (CH ) PPh ] [5]. Now we are extend-
j
3
2
2
3
2
ing our studies to the mer-[RuCl (NO)(dppb)] complex
3
including its X-ray structure and of the fac-[Ru-
Cl (NO)(dppm)] isomer.
3
2
.2. Measurements
The infrared spectra of the complexes were measured
from powder samples diluted in CsI on an FTIR Bomem-
2
1
*
Corresponding author. Fax: 155-16-260-8350.
Mechelson 102 spectrometer in the 4000–200 cm re-
31 1
E-mail address: alzir@dq.ufscar.br (A.A. Batista)
gion. The Ph Hj spectra were recorded in CH Cl on a
2
2
0
277-5387/99/$ – see front matter
 1999 Elsevier Science Ltd. All rights reserved.
PII: S0277-5387(99)00084-4

2
080
A.A. Batista et al. / Polyhedron 18 (1999) 2079–2083
3
˚
Bruker 400 MHz spectrometer, with H PO (85%) as
11 320(5) A ; Z58 [RuCl (NO)(dppm)] and
4
3
4
3
internal reference.
.3. Syntheses
The synthesis of the fac-[RuCl NO(dppm)] was de-
[RuCl (dppm) ]; crystal size 0.1030.0830.12 mm. In the
u range from 2.138C to 24.648C, 9664 unique reflections
2 2
were collected, with 3929 observed (I$3s(I)), R 50.026.
int
2
The structure was refined using F in two blocks of 340
parameters until R50.046; R 50.059 and R 50.21; max.
w
all
3
and min. residual density in the difference Fourier were 1.1
scribed in our previous paper [5]. The mer-[Ru-
3
˚
and 22.2 e/A respectively, with the hydrogen atoms
Cl NO(dppb)] was synthesized by bubbling NO [generated
3
˚
located in their ideal positions (d CH51.08A, Biso5
6
by reaction of dilute nitric acid (approx. 33%) over copper
metal and dried passing it through a column containing
2
˚
.0A ). The co-crystal structure showed that the molecules
(
1) and (2) have C symmetry with the Ru lying on the
2
anhydrous CaCl ] in a dichloromethane solution of the
2
two-fold axis.
[
RuCl (dppb)(H O)] (0.1 g) for 30 min after what the
3 2
The crystallographic parameters for compound (3) are:
volume of the solution was reduced and ether was added to
precipitate a yellow-greenish solid which was washed with
ether and dried under vacuum. The [RuCl (dppb)(H O)]
monoclinic system; s.g. P2 /c; a515.323(2), b59.690(1),
1
3
˚
˚
c519.083(2) A; b594.223(7)8C; V52819.8(5) A ; Z54,
crystal size 0.1030.1030.05 mm. In the u range from
3
2
was obtained and characterized in our laboratory from the
reaction of the [Ru Cl (dppb) ] [6] with chlorine. Yield:
2
.138C to 24.648C 5723 unique reflections were collected,
2
4
3
with 2168 observed (I$2s(I)), R 50.051. The structure
int
0
.087 g, 85.3%. Found C, 50.9; H, 4.3; N, 1.9%. Calcd. for
was refined using F in two blocks of 325 parameters until
R50.0501; R 50.0481 and R 50.259; max. and min.
C H Cl NORuP :. C, 50.7; H, 4.2; N 2.1%. n 1867
2
8
28
3
2.
NO
2
1
31
1
w
all
and n(Ru–Cl) 340 and 293 cm
and d 10.10(d), J(P–P)537.0 Hz.
;
Ph Hj NMR d 13.65(d)
residual density in the difference Fourier were 0.51 and
3
˚
0.21 e/A respectively, with the hydrogen atoms located
2
˚
in their ideal positions (d CH50.98A, Biso51.33B of
eq
2
.4. X-ray diffraction data
Suitable crystals of complexes were grown by slow
the attach atom).
evaporation of dichloromethane/diethyl ether solutions.
Single crystals were used for data collection and cell
parameter determination on an Enraf-Nonius CAD-4 dif-
fractometer, using Mo Ka radiation (graphite mono-
chromator) in the v-2u scan mode, at room temperature.
3. Results and discussion
The IR spectra of the [RuCl (NO)(dppb)] complex
3
2
1
shows n(NO) at 1867 cm indicating that it is indeed of
II
1
The fac-[RuCl (NO)(dppm)] (1) complex co-crys-
the
h
Ru — NO
j
[7,8]. The relevant interatomic bond
3
tallizes with cis-[RuCl (dppm) ] (2) compound. The crys-
lengths for complexes (1), (2) and (3) are listed in Table 1
and bond angles in Table 2.
2
2
tallographic parameters for the co-crystal compound (1)
and (2) are: monoclinic system; s.g. I2/a; a520.632(5),
The molecular structure of the compounds (1) and (2)
are showed in Fig. 1a and b, respectively, with labeled
˚
b515.207(3), c536.096(7) A; b591.71(1)8C; V5
Table 1
˚
Selected bond distances (A) for fac-[RuCl NO(dppm)], mer-[RuCl NO(dppb)] and cis-[RuCl (dppm)]
3
3
2
fac-[RuCl NO(dppm)]
mer-[RuCl NO(dppb)]
cis-[RuCl (dppm)]
3
3
2
Ru(2)-Cl(1B)
Ru(2)-Cl(2B)
Ru(2)-Cl(3B)
Ru(2)-N
Ru(2)-P(1B)
Ru(2)-P(2B)
N-O
2.439(3)
2.430(3)
2.345(3)
1.716(8)
2.338(3)
2.336(3)
1.14(1)
Ru-Cl(1)
Ru-Cl(2)
Ru-Cl(3)
Ru-N
Ru-P(1)
Ru-P(2)
N-O
2.383(2)
2.374(3)
2.395(2)
1.748(8)
2.412(2)
2.498(3)
1.18(2)
Ru(1)-Cl(1A)
2.437(3)
Ru(1)-P(1A)
Ru(1)-P(2A)
2.342(3)
2.312(3)
N-O9
1.15(2)
O-O9
0.86(2)
P(1B)-C
P(2B)-C
P(1B)-C(1B)
P(1B)-C(7B)
P(2B)-C(13B)
P(2B)-C(19B)
1.84(1)
1.84(1)
1.78(1)
1.80(1)
1.800(9)
1.808(9)
P(1)-C(1)
P(2)-C(4)
P(1)-C(1A)
P(1)-C(7A)
P(2)-C(1B)
P(2)-C(7B)
C(1)-C(2)
C(3)-C(4)
1.825(9)
1.826(9)
1.82(1)
1.814(9)
1.825(9)
1.831(9)
1.52(2)
P(1A)-C9
P(2A)-C9
P(1A)-C(13A)
P(1A)-C(19A)
P(2A)-C(1A)
P(2A)-C(7A)
1.85(1)
1.84(1)
1.81(1)
1.76(1)
1.83(1)
1.81(1)
1.55(1)

A.A. Batista et al. / Polyhedron 18 (1999) 2079–2083
2081
Table 2
Selected bond angles (8) for fac-[RuCl NO(dppm)], mer-[RuCl NO(dppb)] and cis-[RuCl (dppm)]
3
3
2
fac-[RuCl NO(dppm)]
mer-[RuCl NO(dppb)]
cis-[RuCl (dppm)]
3
3
2
Cl(1B)-Ru(2)-Cl(2B)
Cl(1B)-Ru(2)-Cl(3B)
Cl(2B)-Ru(2)-Cl(3B)
Cl(1B)-Ru(2)-N
Cl(2B)-Ru(2)-N
Cl(3B)-Ru(2)-N
Cl(1B)-Ru(2)-P(1B)
Cl(1B)-Ru(2)-P(2B)
Cl(2B)-Ru(2)-P(1B)
Cl(2B)-Ru(2)-P(2B)
Cl(3B)-Ru(2)-P(1B)
Cl(3B)-Ru(2)-P(2B)
91.27(9)
91.07(9)
91.20(9)
91.4(3)
Cl(1)-Ru-Cl(2)
Cl(1)-Ru-Cl(3)
Cl(2)-Ru-Cl(3)
Cl(1)-Ru-N
Cl(2)-Ru-N
Cl(3)-Ru-N
Cl(1)-Ru-P(1)
Cl(1)-Ru-P(2)
Cl(2)-Ru-P(1)
Cl(2)-Ru-P(2)
Cl(3)-Ru-P(1)
Cl(3)-Ru-P(2)
177.8(1)
90.25(9)
88.14(9)
86.6(3)
92.0(4)
93.2(3)
92.53(9)
89.92(9)
89.19(9)
91.4(1)
175.1(1)
84.4(1)
Cl(1A)-Ru(1)-Cl(1A)*
85.5(1)
92.2(3)
175.8(3)
169.5(1)
97.71(9)
98.39(9)
169.8(1)
84.70(9)
83.73(9)
Cl(1A)-Ru(1)-P(1A)
Cl(1A)-Ru(1)-P(2A)
Cl(1A)-Ru(1)-P(1A)*
Cl(1A)-Ru(1)-P(2A)*
92.6(1)
163.1(1)
92.4(1)
88.4(1)
P(1A)-Ru(1)-P(1A)*
P(1A)-Ru(1)-P(2A)
P(2A)-Ru(1)-P(2A)*
P(1A)-Ru(1)-P(2A)*
173.2(1)
72.0(1)
101.6(1)
103.6(1)
P(1B)-Ru(2)-P(2B)
72.34(9)
P(1)-Ru-P(2)
91.61(9)
P(1B)-Ru(2)-N
P(2B)-Ru(2)-N
Ru(2)-N-O
92.3(3)
92.5(3)
176.8(8)
P(1)-Ru-N
P(2)-Ru-N
Ru-N-O
91.0(3)
175.7(3)
157.(1)
Ru-N-O9
160.(1)
O-N-O9
43.(1)
Ru(2)-P(1B)-C
94.7(3)
111.2(3)
122.1(3)
94.6(3)
113.5(3)
121.6(3)
Ru-P(1)-C(1)
Ru-P(1)-C(1A)
Ru-P(1)-C(7A)
Ru-P(2)-C(4)
Ru-P(2)-C(1B)
Ru-P(2)-C(7B)
114.9(3)
122.8(3)
107.8(3)
114.3(3)
111.4(3)
120.7(3)
Ru(1)-P(1A)-C9
95.4(3)
122.9(4)
122.7(4)
96.5(4)
122.3(4)
127.0(4)
Ru(2)-P(1B)-C(1B)
Ru(2)-P(1B)-C(7B)
Ru(2)-P(2B)-C
Ru(2)-P(2B)-C(13B)
Ru(2)P(2B)C(19B)
Ru(1)-P(1A)-C(13A)
Ru(1)-P(1A)-C(19A)
Ru(1)-P(2A)-C9
Ru(1)-P(2A)-C(1A)
Ru(1)-P(2A)-C(7A)
˚
scheme and Fig.
2
is drawing of the mer-[Ru-
same molecule, Ru–Cl(1) and Ru–Cl(2), 2.439(3) A and
˚
Cl (NO)(dppb)] complex.
2.430(3) A, respectively. This is expected due to the trans
3
In the [RuCl (NO)(dppb)] complex the NO is essential-
strengthening effect of the NO group [10,12].
3
ly linear with the ruthenium atom (/ Ru–N–O5157(1)8)
The observed Ru–N–O bond angle for the mer-[Ru-
and the Ru–Cl, Ru–N and Ru–P bond lengths in this
nitrosyl complex, close to 2.4, 1.7 and 2.5 A, respectively,
Cl (NO)(dppb)] complex (approx. 1608) is smaller than the
3
˚
angle [172.0(6)8] found for same isomer with the 1,3-
bis(diphenilphosphine)propane (dppp) ligand [8]. This
effect can be attributed to the bigger repulsion between the
extensive molecular orbital of the NO ligand and the
phenyl rings bonded to the P(2) atom of the dppb ligand
compared to the same repulsion with the P(2) atom of the
dppp ligand. This is probably to due the larger carbon
chain between the two phosphorus atoms P(1) and P(2) in
the dppb ligand what makes the phosphorus orbital [P(2)]
to move towards the NO orbital easily and consequently
promotes a stronger repulsion with this orbital making the
Ru–N–O angle smaller in this case The length of the chain
between the two phosphorus atoms in the biphosphines
also is reflected in the angles P(1)–Ru–N, which is
169.8(2)8 for the complex with the dppp and 175.7(3)8 for
the P(2)–Ru–N dppb complex. The silent EPR of the
fac-[RuCl (NO)(dppm)] and mer-[RuCl (NO)(dppb)]
are comparable to those found for similar complexes as
can be seen in Table 3 [5,9–13]. It is interesting to point
˚
out that in this complex the distance Ru–P(2) [2.498(3) A]
which has the NO group in trans position is shorter than
˚
the distance Ru–P(1) [2.412(2) A] where the chlorine is in
trans position. Here, like in our [RuCl (NO)(dppp)]
3
complex the trans strengthening effect of the NO group
was not observed [5]. This can be explained taking in
consideration that probably the NO group does not present
strong bonding when trans a bad donor atom like phos-
phorus [15,16]. The high thermal parameter of the oxygen
atom of the NO group in the [RuCl (dppb)(NO)] molecule
3
confirms the flexibility for the orientation of the nitrosyl
with respect to the Ru–N bond in this class of complexes
[5].
The NO bond lengths for complexes (1) and (3) are
3
3
1
˚
˚
close to 1.14 A, practically the same distance 1.06 A of the
complexes confirm that the
diamagnetics, maintaining the linear structures of the Ru–
NO bonds.
h
Ru–NO
j
species are
1
free N–O group [14] showing almost absence of bac-
kbonding in the bonding between the ruthenium and
nitrogen atoms. In the fac-[RuCl (NO)(dppm)] complex
the distance Ru–Cl(3) 2.345(3) A is shorter than the bond
The crystallographic data found in this work for the
3
˚
cis-[RuCl (dppm) ] co-crystallized with compound (1) are
2 2
lengths of the others two chlorine atoms present in the
essentially the same found previously for this compound

2
082
A.A. Batista et al. / Polyhedron 18 (1999) 2079–2083
Fig. 2. ORTEP view of mer-[RuCl NO(dppb)] with 50% probability
3
thermal ellipsoids.
Table 3
˚
Comparison of Ru–Cl distances (A) trans to NO in ruthenium com-
pounds
Compound
Ru–Cl
Ru–NO
N–O
Ref.
2
1
[
[
[
[
[
[
[
RuCl(py) (NO)]
2,315(3)
2.357(1)
2.357(2)
2.353(2)
2.346(2)
2.345(3)
2.384(2)
1.766(8)
1.738(2)
1.744(6)
1.737(7)
1.729(7)
1.716(8)
1.748(8)
1.123(1)
1.131(3)
1.132(6)
1.142(8)
1.151(9)
1.14(1)
[9]
4
2
2
RuCl (NO)]
[10]
[11]
[12]
a[13]
5
RuCl (PMePh ) (NO)
3
2 2
RuCl (PPh ) (NO)]
RuCl (AsPh ) (NO)]
RuCl (dppm)(NO)
RuCl (dppb)(NO)
3
3 2
3
3 2
3
a
1.15(2)
3
a
This work
P(2A) is 95.7(5)8 and P(1A)–Ru–P(2A) is 72.0(1)8 (Fig.
b).
It is interesting also to mention that the isomerization
process from the mer to the fac-[RuCl (NO)(dppb)]
1
3
3
1
isomer was also observed through
h1 j
P H experiments. In
this case the doublets at d 13.65(d) and d 10.10(d) of a
fresh CH Cl solution do not totally disappear in an
2
2
interval of time of 48 h and only 10 h after running the
first spectra the intensity of these doublets is reasonably
decreased and the singlet at d 22.86 of the fac isomer is
really observed. Thus the isomerization process of the
Fig. 1. ORTEP view of fac-[RuCl NO(dppm)] (a) and cis-[RuCl (dppm)]
3
2
mer-[RuCl (NO)(dppb)] is much slower than the observed
3
(
b) with 50% probability thermal ellipsoids.
for the mer-[RuCl (NO)(dppp)] [5]. This probably is due
3
the stronger strain caused by the shorter carbon chain
between the phosphorus atoms in the dppp ligand when
compared with the dppb molecule.
crystallized as cis-[RuCl (dppm) ]?CHCl in the space
2
2
3
group P2 /n [16]. In this complex (2) the Cl–Ru–Cl angle
1
is 85.5(1)8 which is less than the ideal value of 908. In this
work was also observed that angles between cis phosphor-
us atoms from different dppm ligands are considerably
higher than 908. The chelate ring is very much distorted as
is shown by the P–Ru–P angles in the complexes. The
steric strain is also imposed on the C9 and phosphorus
atoms of the dppm ligand where the angle P(1A)–C9–
Supplementary data
The supplementary material of fac-[RuCl (NO)(dppm)]
(1) co-crystallized with cis-[RuCl (dppm) ] (2) was de-
posited in the CCDC with the number 102519 and the
number 102520 is for the mer-[RuCl (NO)(dppb)] (3).
3
2
2
3

A.A. Batista et al. / Polyhedron 18 (1999) 2079–2083
2083
[
[
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We thank CNPq, CAPES, FINEP and FAPESP for
financial support.
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