New complexes of the fac-{(CO)3Re+} fragment bearing a diaminediphosphine ligand

Article abstract of DOI:10.1016/j.poly.2010.04.013

The mono- and binuclear hydride compounds fac-[ReH(CO)₃L] (1a) and [{ReH(CO)₄}₂(μ-L)] (1b) have been prepared by reaction of [ReH(CO)₅] with Ph₂PN(CH₃)(CH ₂)₂N(CH₃)PPh₂ (L) under UV light. Protonation reactions of the hydride compound 1a with equimolar amounts of HSO₃CF₃ or HCl yielded the triflato or the chlorido compounds fac-[Re(OSO₂CF₃)(CO)₃L] (2) and fac-[ReCl(CO)₃L] (3), respectively. The compounds have been characterised by elemental analysis, IR and NMR spectroscopic data, and mass spectrometry. Their structures have been confirmed by X-ray crystallography.

Full text of DOI:10.1016/j.poly.2010.04.013

Polyhedron 29 (2010) 2171–2176
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
New complexes of the fac-{(CO)3Re+} fragment bearing
a diaminediphosphine ligand
a
*
**
Sandra Bolaño, Jorge Bravo , Jesús Castro, Soledad García-Fontán , M Carmen Marín
Departamento de Química Inorgánica, Universidade de Vigo, Lagoas-Marcosende, E-36310 Vigo, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
The mono- and binuclear hydride compounds fac-[ReH(CO)3L] (1a) and [{ReH(CO)4}2(l-L)] (1b) have
Received 6 January 2010
Accepted 13 April 2010
Available online 27 April 2010
been prepared by reaction of [ReH(CO)5] with Ph2PN(CH3)(CH2)2N(CH3)PPh2 (L) under UV light. Proton-
ation reactions of the hydride compound 1a with equimolar amounts of HSO3CF3 or HCl yielded the trif-
lato or the chlorido compounds fac-[Re(OSO2CF3)(CO)3L] (2) and fac-[ReCl(CO)3L] (3), respectively. The
compounds have been characterised by elemental analysis, IR and NMR spectroscopic data, and mass
spectrometry. Their structures have been confirmed by X-ray crystallography.
Keywords:
Rhenium(I)
Carbonyl complexes
Bis(phosphine) compounds
Binuclear complexes
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
stead of the oxygen atoms in the phosphinite ligands) influences
on the properties of the complexes.
Rhenium coordination chemistry is a well established field [1],
but a renewed interest has lately emerge due, particularly in the
case of the fac-{(CO)3Re+} fragment [2], to its photochemical prop-
erties [3] and to the introduction of the bꢀ emitting isotopes 188Re
and 186Re in the field of diagnostic and therapeutic radiopharma-
ceuticals [4], being the above mentioned fragment, one of the most
promising and developed organometallic cores for the labelling of
biomolecules [5]. The metal centre (in the low oxidation state +I) is
chemically highly inert and it permits the application of a broad
variety of donor and acceptor atoms [6]. Besides, the [Re(CO)3] core
is exceedingly compact, displaying an almost spherical shape. If the
octahedral coordination sphere is ‘‘closed” with an appropriate co-
ligand system, the metal centre will be efficiently protected against
further ligand attack or re-oxidation. On the other hand, such co-li-
gands are necessary to complete the coordination sphere of the
metal and allow the tuning of both steric and electronic properties
of the resulting labelled biomolecules. One of the areas we focus on
in the field of rhenium coordination chemistry is the study of the
influence of bidentate phosphinite co-ligands on the properties of
different rhenium-carbonyl complexes [7]. In this paper we report
on the synthesis and spectroscopic and diffractometric character-
isation of the hydrido, triflato and chlorido complexes of the
fac-{(CO)3Re+} fragment bearing a diaminediphosphine ligand,
with the aim of analysing how the presence of nitrogen atoms (in-
2. Experimental
2.1. General methods and instrumentation
All synthetic work was carried out under an inert atmosphere
using standard Schlenk techniques. All the solvents were purified
by conventional procedures [8] and distilled prior to use. The
ligand N,N0-dimethyl-bis(diphenylphosphine)ethylenediamine (L)
was prepared according to published methods [9]. Photoirradiation
was carried out with a 150 W medium-pressure Hg lamp. The 1H,
31P, 13C and 19F NMR (d in ppm) spectra were obtained on a Bruker
ARX-400 spectrometer operating at frequencies of 400, 161, 100,
and 376 MHz, respectively; the spectra were recorded in CDCl3 or
CD2Cl2 solutions, as indicated, using the solvent as internal lock.
1H and 13C{1H} signals are referred to internal TMS, those of
19F{1H} to CFCl3 and those of 31P{1H} to 85% H3PO4, with downfield
shifts (d in ppm) considered positive. Low-temperature measure-
ments were made by cooling the probe with a stream of cold N2
(g) from a liquid N2 boil off evaporator. T1 relaxation times for
the hydridic resonances of complexes 1a and 1b were measured
in dichloromethane-d2 as a function of temperature at 400 MHz
using a standard inversion-recovery methodology. IR spectra (KBr
discs) were obtained on a Bruker VECTOR IFS 28 FT apparatus
and mass spectra were recorded on Micromass Autospec MLSIMS
(FAB+) system. Microanalyses were carried out on a Fisons Model
EA 1108 elemental analyzer.
* Corresponding author. Tel.: +34 986812275; fax: +34 986813798.
** Corresponding author. Tel.: +34 986812275; fax: +34 986813798.
E-mail addresses: jbravo@uvigo.es (J. Bravo), sgarcia@uvigo.es (S. García-Fontán).
0277-5387/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2010.04.013

2172
S. Bolaño et al. / Polyhedron 29 (2010) 2171–2176
2.2. Preparation of fac-[ReH(CO)3L] (1a) and [{ReH(CO)4}2(
l
-L)] (1b)
MS: m/z (referred to the most abundant isotopes): 1055 [M],
1053 [Mꢀ2H], 1025 [Mꢀ2HꢀCO], 997 [Mꢀ2Hꢀ2CO], 968
Ph2PN(CH3)(CH2)2N(CH3)PPh2 (L) (3 g, 6.72 mmol) was added to
a solution of [ReH(CO)5] (1 g, 3.06 mmol) in toluene (40 mL) and
the reaction mixture was irradiated with UV light at room temper-
ature for about 6 h. The solvent was then removed under reduced
pressure to give a yellow oil which was chromatographed on a sil-
ica gel column (length 70 cm, diameter 4 cm) using a 10:2 mixture
light petroleum (b.p. 40–60 °C) and diethyl ether as eluent. The
first fraction eluted (30 mL) was evaporated to dryness leaving
and oil which was treated with ethanol (3 mL). By cooling the
resulting solution to ꢀ25 °C white crystals of the mononuclear
compound 1a were obtained. The binuclear compound 1b was ob-
tained from the second fraction eluted (30 mL), after evaporation
of the solvent and treatment of the oily residue obtained with
ethanol.
[Mꢀ2Hꢀ3CO], 940 [Mꢀ2Hꢀ4CO], 912 [Mꢀ2Hꢀ5CO]. IR (cmꢀ1
)
m
CO: 2077 (s), 1962 (s), 1940 (s). 1H NMR (CD2Cl2, ppm): d ꢀ5.35
(d, 2H, JHP = 22 Hz, ReH), 2.49 (d, 6H, JHP = 11 Hz, –NCH3), 3.16
(m, 4H, –CH2], 7.19–7.73 (m, 20H, Ph). 31P{1H} NMR (CD2Cl2,
ppm): d 72.5 (s). 13C{1H} NMR (CDCl3, ppm): d 37.5 (s, –CH3),
51.4 (t, JCP = 6 Hz, –CH2), 127.9–136.9 (m, Ph), 188.2 (d, JCP = 46 Hz,
trans CO–P), 189.2 (d, JCP = 10 Hz, trans CO–H), 189.8 (d, JCP = 7 Hz,
trans CO–CO). Suitable crystals for X-ray structure analysis were
obtained by slow evaporation of the solvent from a solution of
1b in a 2:10 (v/v) CH2Cl2/EtOH mixture.
2.3. Preparation of fac-[Re(OSO2CF3)(CO)3L] (2)
To a solution of [ReH(CO)3L] (1a) (50 mg, 0.07 mmol) in CH2Cl2
(15 mL), cooled to ꢀ80 °C, an equimolar amount of HSO3CF3 (7
lL,
2.2.1. fac-[ReH(CO)3L] (1a)
0.07 mmol) in CH2Cl2 was added. The mixture was allowed to
reach room temperature and was stirred for 1 h. The solvent was
evaporated to dryness leaving an oil which was triturated with
ethanol (2 mL) until a white solid separated off. This solid was fil-
tered out, washed with ethanol and dried under vacuum. Suitable
crystals for X-ray structure analysis were obtained by slow evapo-
ration of the solvent from a solution of 2 in a 2:10 (v/v) CH2Cl2/
Yield P 50%. Anal. Calc. for C31H31N2O3P2Re (727.72): C, 51.16;
H, 4.29; N, 3.85. Found: C, 51.12; H, 4.27; N, 3.84%. FAB MS: m/z
(referred to the most abundant isotopes): 727 [M], 671 [Mꢀ2CO],
669 [MꢀHꢀ2CO]. IR (cmꢀ1
) m
CO: 2004 (s), 1921 (s), 1908 (s). 1H
NMR (CD2Cl2, ppm): d ꢀ3.99 (t, 1H, JHP = 23 Hz, ReH), 2.43 (t, 6H,
JHP = 4 Hz, –NCH3), 3.10 (m, 2H, –CH2), 3.82 (m, 2H, –CH2), 7.14–
7.91 (m, 20H, Ph). 31P{1H} NMR (CD2Cl2, ppm): d 68.5 (s). 13C{1H}
NMR (CD2Cl2, ppm): d 39.4 (s, –CH3), 53.4 (s, –CH2), 126.3–139.4
(m, Ph), 194.2 (t, JCP = 6 Hz, COcis), 196.3 (m, COtrans). Suitable crys-
tals for X-ray structure analysis were obtained by slow evaporation
of the solvent from a solution of 1a in a 2:10 (v/v) CH2Cl2/EtOH
mixture.
EtOH mixture. Yield: 94%. Anal. Calc. for
C32H30SF3N2O6P2Re
(875.78): C, 43.89; H, 3.45; N, 3.20. Found: C, 43.79; H, 3.39; N,
3.27%. FAB MS: m/z (referred to the most abundant isotopes):
876 [M], 819 [Mꢀ2CO], 727 [MꢀSO3CF3]. IR (cmꢀ1
) mCO: 2038 (s),
1959 (s), 1929 (s). 1H NMR (CD2Cl2, ppm): d 2.52 (t, 6H, JHP = 4 Hz,
–NCH3), 3.15 (m, 2H, CH2), 3.67 (m, 2H, –CH2), 7.21–7.85 (m, 20H,
Ph). 31P{1H} NMR (CD2Cl2, ppm): d 62.4 (s); 19F{1H} NMR (CD2Cl2,
ppm): d ꢀ78.0 (s); 13C{1H} NMR (CDCl3, ppm): d 39.3 (t, JCP = 3 Hz,
–CH3), 51.7 (t, JCP = 7 Hz, –CH2), 125.3 (s, CF3), 127.2–135.6 (m, Ph),
188.3 (t, JCP = 6 Hz, COcis), 190.0 (m, COtrans).
2.2.2. [{ReH(CO)4}2(l-L)] (1b)
Yield P 10%. Anal. Calc. for C36H32N2O8P2Re2 (1054.98): C,
40.99; H, 3.06; N, 2.65. Found: C, 40.93; H, 3.10; N, 2.69%. FAB
Table 1
Crystal data and structure refinement for compounds 1a, 2, and 3.
1a
2
3
Empirical formula
Formula weight
Crystal size (mm)
T (K)
C
31H31N2O3P2Re
C32H30F3N2O6P2ReS
875.78
C31H30ClN2O3P2Re
762.16
727.72
0.39 ꢁ 0.38 ꢁ 0.25
0.22 ꢁ 0.14 ꢁ 0.08
0.22 ꢁ 0.13 ꢁ 0.11
293(2)
293(2)
293(2)
Wavelength (Å)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
0.71073
Monoclinic
P21/n
10.5523(7)
9.6130(6)
30.210(2)
0.71073
Monoclinic
C2/c
0.71073
Monoclinic
C2/c
25.5482(16)
15.7749(10)
17.2456(11)
117.894(1)
6142.8(7)
37.306(3)
10.3552(7)
18.8577(13)
105.070(1)
7034.4(9)
b (°)
94.6020(10)
3054.6(3)
V (Å3)
Z
4
8
8
Dcalc (Mg mꢀ3
)
1.582
4.116
1440
1.654
3.665
3456
1.648
4.182
3008
l
(mmꢀ1
F(0 0 0)
)
h Range for data collection (°)
Index ranges
2.10–28.04
ꢀ11 6 h 6 13
ꢀ12 6 k 6 12
ꢀ39 6 l 6 37
18 423
2.05–28.02
ꢀ48 6 h 6 48
ꢀ13 6 k 6 11
ꢀ24 6 l 6 24
19 103
1.57–28.05
ꢀ16 6 h 6 33
ꢀ19 6 k 6 20
ꢀ22 6 l 6 22
17 537
Reflections collected
Independent reflections (Rint
)
7161(0.0510)
5429
7884(0.0878)
3389
6955(0.0744)
3284
Reflections observed (>2
r)
Data completeness
0.968
0.927
0.933
Maximum and minimum transmission
Data/restraints/parameters
1.000 and 0.708
7161/0/358
0.911
1.000 and 0.710
7884/0/426
0.689
1.000 and 0.816
6955/17/353
0.812
Goodness-of-fit (GOF) on F2
Final R indices [I > 2
R indices (all data)
r
(I)]
R1 = 0.0311, wR2 = 0.0530
R1 = 0.0503, wR2 = 0.0564
0.922 and ꢀ1.212
R1 = 0.0481, wR2 = 0.0538
R1 = 0.1626, wR2 = 0.0708
1.036 and ꢀ0.932
R1 = 0.0499, wR2 = 0.0618
R1 = 0.1409, wR2 = 0.0724
1.531 and ꢀ0.776
Largest diff. peak and hole (e Åꢀ3
)

S. Bolaño et al. / Polyhedron 29 (2010) 2171–2176
2173
Table 2
ppm): d 2.52 (t, 6H, JHP = 4 Hz, –NCH3), 3.15 (m, 2H, –CH2), 4.27
(m, 2H, –CH2), 7.25–8.13 (m, 20H, Ph); 31P{1H} NMR (CD2Cl2,
ppm): d 56.2 (s); 13C{1H} NMR (CDCl3, ppm): d 39.3 (t, JCP = 3 Hz,
–CH3), 52.5 (t, JCP = 7 Hz, –CH2), 127.1–136.6 (m, Ph), 187.2
(t, JCP = 6 Hz, cis CO), 190.5 (m, trans CO). Suitable crystals for X-
ray structure analysis were obtained by slow evaporation of the
solvent from a solution of 3 in a 2:10 (v/v) CH2Cl2/EtOH mixture.
Crystal data and structure refinement for 1b.
1b
Empirical formula
Formula weight
Crystal size (mm)
T (K)
Wavelength (Å)
Crystal system
Space group
a (Å)
C
36H32N2O8P2Re2
1054.98
0.28 ꢁ 0.25 ꢁ 0.16
293(2)
0.71073
Monoclinic
P21/c
8.6370(6)
16.4673(12)
13.7691(10)
104.5110(10)
1895.9(2)
2
2.5. X-ray crystallographic analysis
b (Å)
c (Å)
Crystallographic data were collected on a Bruker Smart 1000
CCD diffractometer at CACTI (Universidade de Vigo) using graphite
b (°)
V (Å3)
monochromated Mo K
a radiation (k = 0.71073 Å), and were cor-
rected for Lorentz and polarisation effects. The software SMART
[10] was used for collecting frames of data, indexing reflections,
and the determination of lattice parameters, SAINT [11] for integra-
tion of intensity of reflections and scaling, and SADABS [12] for
empirical absorption correction. The structures were solved and
refined with the Oscail program [13] by direct methods (1a, 1b,
and 2) or by Patterson methods (3) and refined by a full-matrix
least-squares based on F2 [14]. Non-hydrogen atoms were refined
with anisotropic displacement parameters. Hydrogen atoms were
included in idealised positions and refined with isotropic displace-
ment parameters except in the case of those bonded to the metal
(1a and 1b). In the case of compound 3 one of the phenyl groups
is disordered over two positions with occupancy factor of
54:46%. Details of crystal data and structural refinement are given
in Tables 1 and 2.
Z
Dcalc (Mg mꢀ3
)
1.848
6.514
1012
l
(mmꢀ1
F(0 0 0)
)
h Range for data collection (°)
Index ranges
1.97–28.04
ꢀ9 6 h 6 11
ꢀ21 6 k 6 21
ꢀ16 6 l 6 18
11 563
4455(0.0623)
3309
0.967
1.000 and 0.549
4455/0/231
0.895
R1 = 0.0319, wR2 = 0.0583
R1 = 0.0509, wR2 = 0.0616
1.515 and ꢀ0.746
Reflections collected
Independent reflections (Rint
Reflections observed (>2
Data completeness
)
r)
Maximum and minimum transmission
Data/restraints/parameters
Goodness-of-fit (GOF) on F2
Final R indices [I > 2
R indices (all data)
r
(I)]
Largest difference peak and hole (e Åꢀ3
)
3. Results and discussion
2.4. Preparation of fac-[ReCl(CO)3L] (3)
3.1. Synthesis and spectroscopic characterisation of fac-[ReH(CO)3L]
(1a) and [{ReH(CO)4}2(l-L)] (1b)
To a solution of [ReH(CO)3L] (1a) (0.15 mg, 0.2 mmol) in CH2Cl2
(5 mL) cooled to ꢀ80 °C an equimolar amount of HCl was added
and the reaction mixture, brought to room temperature, was stir-
red for 2 h. The solvent was evaporated to dryness leaving an oil
which was triturated with ethanol (2 mL). The white solid obtained
was filtered out and recrystallised from a mixture CH2Cl2/EtOH by
slow evaporation of the solvent. Yield: 86%. Anal. Calc. for
Reaction of [ReH(CO)5] with Ph2PN(CH3)(CH2)2N(CH3)PPh2 (L)
in 1:2 mole ratio gave a 2:1 mixture of two products that were sub-
sequently separated by column chromatography. The mayor
component was identified as the mononuclear compound fac-[Re-
H(CO)3L] (1a) and the minor component as the binuclear com-
pound [{ReH(CO)4}2(
At 298 K, the 31P{1H} NMR spectrum of 1a displays a singlet at d
68.5 ppm and the 1H NMR spectrum displays
triplet at
l-L)] (1b).
C31H30ClO3P2N2Re (762.16): C, 48.85; H, 3.99; N, 3.67. Found: C,
48.80; H, 3.92; N, 3.52%. FAB MS: m/z (referred to the most abun-
dant isotopes): 762, [M]; 734, [MꢀCO]; 699, [MꢀClꢀCO]. IR
a
ꢀ3.99 ppm (JHP = 23 Hz). The signals corresponding to the methy-
(cmꢀ1 CO: 2030 (vs), 1966 (m), 1932 (vs). 1H NMR (CD2Cl2,
) m
lene protons of the bidentate ligand L appear as two multiplets
Fig. 1. Molecular structure of compound 1a.

2174
S. Bolaño et al. / Polyhedron 29 (2010) 2171–2176
(at 3.10 and 3.82 ppm) indicating their diastereotopic nature, as it
was already observed for similar systems [9b]. The 13C{1H} spec-
trum shows, at low field, a triplet (194.2 ppm, JCP = 6 Hz) assign-
able to the CO group located cis to both phosphorous nuclei, and
a multiplet (196.3 ppm) corresponding to the other two CO groups,
supporting the formulation of compound 1a as the fac isomer of
[ReH(CO)3L]. The value of T1 (min) found for the hydrido signal
was 207 ms (227 K) at 400 MHz.
one at 189.2 ppm (JCP = 10 Hz) that is assignable to CO trans to
the H atom and one at 189.8 ppm (JCP = 7 Hz) corresponding to
the mutually trans CO groups (this signal integrates to approxi-
mately double than the previous one). Determination of the mini-
mum spin-lattice relaxation time [T1 (min)] for the hydrido
nucleus at 400 MHz by the standard inversion-recovery method
gave a value of 372 ms at 230 K. This value is significantly higher
than that obtained for compound 1a, possibly due to their having
different numbers of P nuclei in the vicinity of the hydrido ligand
[15]. This fact was already observed for similar rheniumhydrido-
carbonyl compounds bearing diphosphinites as supporting ligands
[7c].
The room temperature 31P{1H} NMR spectrum of the binuclear
compound 1b shows a singlet at 72.5 ppm, indicating the magnetic
equivalence of the two phosphorous nuclei of the bridging ligand.
The 1H NMR spectrum of 1b displays a doublet at high field
(ꢀ5.35 ppm, JHP = 22 Hz). The appearance of the methylene protons
signal as a single narrow multiplet at 3.16 ppm suggests that in 1b
the environment of these nuclei is more uniform than in 1a, prob-
ably due to the presence of the more restrictive chelating ligand in
1a. In agreement with these results, the 13C{1H} spectrum shows,
at low field, three doublets attributable to the CO groups: one at
188.2 ppm (JCP = 46 Hz) corresponding to the CO trans to P atom,
3.2. Synthesis and spectroscopic characterisation of fac-[Re(OSO2CF3)
(CO)3L] (2)
Protonation of the hydride [ReH(CO)3L] (1a) with HSO3CF3 in
1:1 mole ratio leads to the formation of the triflate complex [Re(-
OSO2CF3)(CO)3L] (2), with releasing of H2(g). Compound 2 was sta-
ble in solid state at room temperature. The IR spectrum shows
three strong bands at 2038, 1959 and 1929 cmꢀ1 that can be as-
signed to the CO stretching vibrations. The 31P{1H} NMR spectrum
shows a single resonance indicating the magnetic equivalence of
the two phosphorus nuclei. In keeping with the fac arrangement
of the CO ligands, the 13C{1H} spectrum shows two low-field sig-
nals assignable to the CO groups: a triplet corresponding to the
CO group located cis to both phosphorous nuclei (189 ppm,
JCP = 6 Hz), and a multiplet (190 ppm) corresponding to the other
two CO ligands.
3.3. Synthesis and spectroscopic characterisation of fac-[ReCl(CO)3L]
(3)
Reaction of fac-[ReH(CO)3L] (1a) with an equimolar amount of
HCl afforded fac-[ReCl(CO)3L]. The new complex is stable in the so-
lid state and in solution at room temperature, and was character-
ised by the usual spectroscopic techniques. The IR spectrum
shows three strong m
(CO) bands characteristic of the fac-ReI(CO)3
fragment [16] at 2030, 1966 and 1932 cmꢀ1. The 1H NMR spectrum
of 3 shows two multiplets located at 3.15 ppm and 4.27 ppm cor-
responding to the methylene protons of the bidentate ligand. The
13C{1H} NMR spectrum shows two low field signals assignable to
the CO groups: a triplet corresponding to the CO group located
Fig. 2. Molecular structure of compound 2.
Fig. 3. Molecular structure of compound 3.

S. Bolaño et al. / Polyhedron 29 (2010) 2171–2176
2175
Table 3
Selected bond lengths (Å) and angles (°) for complexes 1a, 2, and 3.
3.4. Description of the structures
Figs. 1–3 show ORTEP drawings of compounds 1a, 2, and 3 with
the numbering scheme. Selected bond lengths and bond angles are
listed in Table 3. All the compounds consist of a rhenium(I) atom in
an octahedral environment, coordinated by three carbonyl ligands
facially disposed and two phosphorous atoms from the bidentate
1a
2
3
Re–Aa
Re–C(1)
Re–C(2)
Re–C(3)
Re–P(1)
Re–P(2)
C(1)–O(1)
C(2)–O(2)
C(3)–O(3)
P(1)–N(1)
P(2)–N(2)
S(1)–O(13)
S(1)–O(12)
S(1)–O(11)
1.89(3)
2.230(4)
1.829(9)
1.902(8)
1.920(8)
2.486(2)
2.514(2)
1.201(8)
1.167(8)
1.164(8)
1.640(6)
1.697(6)
1.401(6)
1.415(5)
1.468(4)
2.537(2)
1.858(9)
1.890(9)
1.897(8)
2.457(2)
2.498(2)
1.187(8)
1.168(8)
1.170(8)
1.6534
1.955(4)
1.918(4)
1.927(4)
2.4532(9)
2.4595(9)
1.145(4)
1.150(4)
1.139(4)
1.663(3)
1.705(3)
N,N0-dimethyl-bis(diphenylphosphino)ethylenediamine
ligand.
The remaining coordination position is occupied by a hydrido
(compound 1a), triflato (compound 2) or chlorido (compound 3) li-
gand. The Re–P bond lengths range from 2.4532(9) to 2.514(2) Å.
For each compound the two distances are similar, with differences
lower than 0.05 Å, being the average of these distances shorter for
the hydrido compound (1a) and longer for the triflato compound
(2). The Re–C bond lengths trans to the phosphorus atoms range
from 1.891(9) to 1.927(4) Å. All these values are similar to those re-
ported for the bromo derivative [ReBr(CO)3{Ph2PN(Me)CH2CH2(Me)-
NPPh2}] [9b] but, in contrast with what was observed in the bromo
analogue, the shorter Re–P bond has, as expected, the longer Re–C
bond trans to it.
1.7015
C(1)–Re–Aa
C(2)–Re–A
C(3)–Re–A
A–Re–P(1)
175.0(9)
82.6(9)
87.4(9)
89.4(9)
90.4(9)
93.7(1)
93.5(1)
93.0(1)
172.4(1)
175.9(1)
87.4(1)
93.3(2)
89.6(2)
89.1(2)
90.08(3)
173.9(4)
174.7(4)
178.5(4)
121.0(3)
123.1(2)
115.8(3)
120.3(2)
117.7(2)
107.4(3)
176.9(3)
91.7(3)
92.0(3)
89.8(1)
94.1(1)
91.9(2)
88.4(3)
90.9(2)
173.9(3)
177.8(2)
88.0(2)
85.7(3)
86.3(3)
90.1(3)
90.83(7)
173.4(7)
175.9(8)
176.6(8)
121.8(5)
123.7(5)
114.2(6)
122.7(4)
117.8(5)
108.0(6)
175.0(2)
84.8(2)
90.0(2)
90.18(7)
96.21(7)
90.1(2)
88.8(2)
90.3(2)
175.2(2)
179.7(3)
85.5(2)
90.2(3)
89.8(3)
89.9(3)
94.36(6)
176.9(8)
176.4(7)
178.3(8)
115.2
A–Re–P(2)
C(1)–Re–P(1)
C(1)–Re–P(2)
C(2)–Re–P(1)
C(2)–Re–P(2)
C(3)–Re–P(1)
C(3)–Re–P(2)
C(1)–Re–C(2)
C(1)–Re–C(3)
C(2)–Re–C(3)
P(1)–Re–P(2)
O(1)–C(1)–Re(1)
O(2)–C(2)–Re(1)
O(3)–C(3)–Re(1)
P(1)–N(1)–C(51)
P(1)–N(1)–C(52)
C(51)–N(1)–C(52)
P(2)–N(2)–C(53)
P(2)–N(2)–C(54)
C(53)–N(2)–C(54)
The remaining Re–C bond lengths have values of 1.955(4) Å (for
compound 1a), 1.829(9) Å (for compound 2), and 1.855(9) Å (for
compound 3), reflecting the p-donor ability of the anionic ligands
trans to them (triflato > chlorido > hydrido).
The seven-membered chelate ring adopts, in all cases, a boat
shape with P–Re–P angles ranging from 90.08(3)° to 94.32(6)°.
Considering the equatorial plane as that described by the Re(1)–
P(1)–P(2)–C(2)–C(3) atoms the chelate ring is twisted towards
the anionic ligand in all cases. That plane is more regular in the
case of the chlorido complex (3) [Rms deviation of 0.008 Å vs
0.034 and 0.037 Å for compounds 1a and 2, respectively]. The rhe-
nium atom is located below this plane by 0.096(2) Å, for compound
1a, and above this plane by 0.012(3) and 0.072(3) Å, for com-
pounds 2 and 3, respectively. This fact is probably due to the lower
steric requirements of the hydride ligand. Remarkably, and in a
similar way with what was reported for the related bromo complex
[9b], each of the three complexes presents one of the nitrogen
atoms, N(1), virtually planar [sum of angles of 359.9(3)°, 359.6°
and 359.7(6)° respectively], while the other one, N(2), is pyramidal
[sum of angles: 345.4(3)°, 348.2° and 348.5(6)° respectively]. Also
this is accompanied by a slight shortening of the P(1)–N(1) dis-
122.4
122.0
124.6
118.8
104.8
a
A represents the hydride atom (compound 1a), the donor oxygen O(11) atom
(compound 2), or the chloride atom (compound 3).
cis to both phosphorus nuclei (ꢂ187 ppm; JCP ꢂ 7 Hz), and a multi-
plet (ꢂ190 ppm) corresponding to the other two CO ligands.
Fig. 4. Molecular structure of compound 1b.

2176
S. Bolaño et al. / Polyhedron 29 (2010) 2171–2176
Table 4
pared to similar compounds bearing diphosphinite ligands [7] in-
Selected bond lengths (Å) and angles (°) for 1b.
stead of the diaminodiphosphine ligand L. Interestingly, the two
nitrogen atoms in each of the mononuclear complexes 1a, 2, and
3 exhibit different geometries (planar or pyramidal). In the case
of the binuclear compound 1b, both nitrogen atoms are pyramidal.
Re–C(1)
Re–C(3)
Re–H(1)
C(1)–O(1)
C(3)–O(3)
N(1)–P(1)
H(1)–Re–C(1)
H(1)–Re–C(3)
H(1)–Re–P(1)
C(2)–Re–P(1)
C(4)–Re–P(1)
C(1)–Re–C(3)
C(2)–Re–C(3)
C(3)–Re–C(4)
Re–C(2)–O(2)
Re–C(4)–O(4)
C(31)–N(1)–P(1)
1.960(6)
1.955(6)
1.61(6)
1.150(6)
1.150(6)
1.705(4)
83(2)
Re–C(2)
Re–C(4)
Re–P(1)
C(2)–O(2)
C(4)–O(4)
1.962(6)
1.948(5)
2.443(1)
1.137(6)
1.143(6)
Supplementary data
H(1)–Re–C(2)
H(1)–Re–C(4)
C(1)–Re–P(1)
C(3)–Re–P(1)
C(1)–Re–C(2)
C(1)–Re–C(4)
C(2)–Re–C(4)
Re–C(1)–O(1)
Re–C(3)–O(3)
C(31)–N(1)–C(32)
C(32)–N(1)–P(1)
174(2)
93(2)
87(2)
83.8(2)
89.2(1)
90.6(1)
92.3(2)
89.6(2)
92.4(2)
177.8(4)
177.7(5)
112.0(3)
114.7(3)
CCDC 760590–760593 contain the supplementary crystallo-
graphic data for compounds 1a, 3, 2, and 1b, respectively. These
data can be obtained free of charge via http://www.ccdc.cam.a-
c.uk/conts/retrieving.html, or from the Cambridge Crystallographic
Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44)
1223-336-033; or e-mail: deposit@ccdc.cam.ac.uk.
96.6(1)
170.9(2)
175.7(2)
92.0(2)
89.9(2)
177.8(5)
178.1(6)
114.3(3)
Acknowledgements
Financial support from the Xunta de Galicia (Project PGIDT04P-
XIC31401PN) and the Ministerio de Educación y Ciencia (Project
BQU2003-06783) is gratefully acknowledged. We thank the Uni-
versity of Vigo CACTI services for collecting X-ray data and record-
ing NMR spectra.
tances [1.663(3), 1.6534 and 1.640(6) Å] as compared to the P(2)–
N(2) distances [1.705(3), 1.7015 and 1.697(6) Å]. This feature con-
trasts with what was observed for Pt(II) [17] or Pd(II) [18]
complexes with a similar bidentate aminophosphine ligands where
both nitrogen atoms are planar.
Fig. 4 shows the ORTEP drawing of the binuclear compound 1b,
with the numbering scheme. Selected bond lengths and bond an-
gles are listed in Table 4.
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4. Conclusions
The mononuclear complexes fac-[ReA(CO)3L] [A = H (1a), OTf
(2), Cl (3); L = N,N0-dimethyl-bis(diphenylphosphino)ethylenedia-
mine] and the binuclear compound [{ReH(CO)4}2(L)] (1b) have
been synthesised and characterised. The spectroscopic parameters
of the compounds do not exhibit significant differences when com-
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