Template synthesis of a macrocycle with a mixed NHC/phosphine donor set

Article abstract of DOI:10.1016/j.jorganchem.2011.07.010

Reaction of cis-[ReCl(NHC)(CO)₄] cis-[1] (NHC = NH,NH-substituted saturated cyclic diaminocarbene) with diphosphine (2-F-C ₆H₄)₂P-CH₂CH₂-P(C ₆H₄-2-F)₂ 2 yie

Full text of DOI:10.1016/j.jorganchem.2011.07.010

Journal of Organometallic Chemistry 696 (2011) 3337e3342
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Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Template synthesis of a macrocycle with a mixed NHC/phosphine donor set
*
Verena Blase, Tania Pape, F. Ekkehardt Hahn
Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Reaction of cis-[ReCl(NHC)(CO)4] cis-[1] (NHC ¼ NH,NH-substituted saturated cyclic diaminocarbene)
with diphosphine (2-FeC6H4)2PeCH2CH2eP(C6H4-2-F)2 2 yields complex fac-[Re(NHC)(2)(CO)3]Cl fac-[3]
Cl. Deprotonation of the NH,NH-NHC ligand in fac-[3]Cl with KOtBu leads to an intramolecular nucleo-
philic aromatic substitution of one fluorine atom from each eP(C6H4-2-F) group by the NHC ring
nitrogen atoms with formation of complex fac-[4]Cl bearing a facially coordinated [11]ane-P2CNHC ligand.
Reaction of cis-[MnBr(NHC)(CO)4] cis-[5] (NHC ¼ NH,NH-substituted saturated cyclic diaminocarbene)
with diphosphine 2 yields complex [MnBr(NHC)(2)(CO)2] [6] without substitution of the bromo ligand
and with the phosphine donors from the bidentate diphosphine occupying one cis and one trans position
to the NHC donor.
Received 8 June 2011
Received in revised form
7 July 2011
Accepted 7 July 2011
Keywords:
N-Heterocyclic carbene
Diphosphine
Macrocycle
Ó 2011 Elsevier B.V. All rights reserved.
Rhenium
Manganese
1. Introduction
all-syn isomer which, however, remains coordinated to the metal
center after its formation [7deo]. Originally, the metal template
Metal complexes bearing macrocyclic ligands have attracted
attention for many years [1]. Compared to complexes with acyclic
ligands, those with macrocyclic derivatives featuring otherwise an
identical donor set normally exhibit a higher stability due to the
macrocyclic effect [2]. This enhanced stability and robustness often
allows the use of complexes with macrocyclic ligands as catalysts
for selected transformations [3].
A large number of complexes used in homogeneous catalysis
contain phosphine [4] or N-heterocyclic carbene (NHC) ligands [5].
While many complexes bearing macrocyclic ligands with nitrogen
donor atoms are known [6], cyclic polyphosphine [7] or cyclic poly-
NHC ligands [8] are less common and macrocyclic ligands con-
taining both NHC and phosphine donor groups have only recently
been developed and are still quite rare [9]. This situation is most
likely caused by the synthetic problems encountered during the
ligand synthesis.
Triphosphine macrocycles have been generated in a purely
organic approach using high dilution methods [7a,b]. This synthesis
allows only few variations in the linkers between the phosphorus
atoms and the P3-macrocycles are always obtained as a mixture of
all possible diastereomers, whereas only the all-syn isomer can
coordinate to a metal center in a facial orientation. Alternatively,
a metal template controlled synthesis leads stereoselectively to the
controlled macrocyclization reaction was carried out via a radical
induced intramolecular hydrophosphination of allylphosphines
coordinated to a {M(CO)3} template center [7c,d]. Further devel-
opment of this approach using the versatile {CpFe}þ template
allowed the coupling of allyl [7eeh] or vinylphosphines via
hydrophosphinations [7i,j] and an example for a coordinated [12]
ane-P3 macrocycle is depicted as A in Fig. 1. Apart from the more
robustly coordinating 9-membered P3-ring system [7i,j], this
template methods gives access to a range of functionalized 9-, 10-,
and 11-and 12-membered P3-macrocycles [7].
Besides the radical induced intramolecular hydrophosphination
an alternative metal template approach utilizing the nucleophilic
attack of coordinated phosphides at coordinated o-fluorophenyl
diphosphines has also been developed [7o]. This method provides
a versatile and facile route to template controlled PeC bond
formation. In principle, this fluoride displacement should also be
feasible with nitrogen (amido) nucleophiles.
Complexes bearing macrocyclic poly-NHC ligands like B (Fig. 1)
are also accessible by a template synthesis [8a] or by metalation of
cyclic polyimidazolium salts. The latter reaction can lead to
mononuclear [8b], dinuclear [8b,c] or even polynuclear complexes
[8c,d].
Only template syntheses have so far given access to macrocyclic
ligands with a mixed phosphine/NHC donor set. We have described
the synthesis of rhenium(I) and manganese(I) complexes of type C
(Fig. 1) bearing the [11]ane-P2CNHC ligand [9a]. A similar synthetic
strategy can be employed for the generation of the [11]ane-P2CNHC
* Corresponding author. Tel.: þ49 251 8333111; fax: þ49 251 8333108.
E-mail address: fehahn@uni-muenster.de (F.E. Hahn).
0022-328X/$ e see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2011.07.010

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V. Blase et al. / Journal of Organometallic Chemistry 696 (2011) 3337e3342
carbene carbon atom at
d
¼ 186.6 ppm as a triplet due to coupling
(Cl)2
A
B
with the two cis-phosphorus atoms (2JCP ¼ 9.6 Hz). Two resonances
PF6
N
N
N
N
for the carbonyl carbon atoms were observed at
d
¼ 190.8 ppm (cis
N
N
N
N
P
Et
to NHC) and
d
¼ 189.5 ppm (trans to NHC). Only one resonance was
P
P
observed in the 31P{1H} NMR spectrum at
d
¼ 19.4 ppm for the two
N
N
N
N
Et
Et
Pt
Fe
chemically equivalent phosphorus atoms. Coordination of the
diphosphine to the metal center prevents inversion of the config-
uration at the phosphorus atoms leading to chemically non-
equivalent phenyl groups. Consequently, two slightly different
resonances were found in the 19F{1H} NMR spectrum at
d
¼ ꢀ100.9 ppm and
d
¼ ꢀ101.1 ppm.
C
D
Single crystals of fac-[3]Cl$0.5CH2Cl2 suitable for an X-ray
X
(PF6)2
Ph
N
N
diffraction study were obtained by slow diffusion of diethyl ether
into a saturated solution of complex fac-[3]Cl in dichloromethane.
The structure analysis confirms the expected facial arrangement of
the ligands in a distorted octahedral complex (Fig. 2). The asym-
metric unit contains two essentially identical molecules of fac-[3]Cl
and one molecule of dichloromethane.
P
Pt
P
P
OC
P
CO
N
N
M
F
F
N
N
C
O
Bond lengths and angles in the cation fac-[3]þ fall in the range
observed previously for related ReI NHC/diphosphine complexes
[9a,13]. Compared to the related complex with the 1,2-phenylene
bridged diphosphine ligand, which served as starting material for
the synthesis of complex C (Fig. 1), (ReeP 2.428(2) Å and
2.420(2) Å) [9a] the ReeP bond distances in cation fac-[3]þ are
slightly enlarged (range ReeP 2.4443(12) Å to 2.4516(13) Å). The
bond angles PeReeP measure 82.08(4)ꢁ and 82.70(4)ꢁ and thus
exhibit the largest deviation from octahedral geometry. These angle
are slightly larger than the PeReeP angle in the analogous complex
bearing the 1,2-phenylene bridged diphosphine ligand (80.11(5)ꢁ)
[9a]. This slight angle expansion is apparently caused by the slightly
larger bite of the ethylene bridged diphosphine in comparison to
the 1,2-phenylene bridged derivative. The plane of the carbene
Ph
M = Re, Mn
Fig. 1. Complexes bearing macrocyclic ligands with phosphine and/or NHC donors.
ligand at ruthenium(II) [9b] and iron(II) [9c] metal centers. In
addition, platinum(II) complex D with a tetradentate [16]ane-
P2CNHC has been obtained in a template controlled reaction [9d]
2
(Fig. 1).
We became interested in the template synthesis of [11]ane-
P2CNHC macrocycles featuring an aliphatic spacer between the
phosphorus atoms instead of the aromatic one in complexes of type
C. It was expected that macrocycles featuring alkylphosphine donor
groups are more basic than the [11]ane-P2CNHC macrocycle in
complex C which contains two triphenylphosphine donors. Here
we present the synthesis of a novel [11]ane-P2CNHC macrocycle at
the rhenium(I) template with an aliphatic spacer between the
phosphine donors. In addition, we describe our unsuccessful efforts
to generate an [11]ane-P2CNHC macrocycle with the aliphatic spacer
between the phosphine donors at the manganese(I) template.
2. Results and discussion
The macrocycle [11]ane-P2CNHC of complex fac-[4]Cl (Scheme 1)
has been generated at the ReI template by linkage of the NH,NH-
NHC ligand to an ethylene bridged diphosphine, all of which
were coordinated in facial geometry in complex fac-[3]Cl. Complex
fac-[3]Cl was synthesized from the known diphosphine 2 [10] and
complex cis-[1] bearing an NH,NH-substituted NHC ligand.
We have slightly modified the published procedure for the
synthesis of diphosphine 2 to obtain the ligand in an improved
yield of 80% (Scheme 1). Several methods for the generation of
complexes bearing NH,NH- or NH,O-substituted NHC ligands by
template controlled cyclization of
b-functionalized isocyanide
ligands have been reported [11] and saturated NH,NH-NHC ligands
are accessible by the cyclization reaction of 2-aminoethyl iso-
cyanide at suitable metal templates [11f,g]. For this study, however,
precursor complex cis-[1] was prepared according to the method
described by Liu et al. from [Re(Cl)(CO)5] and an amino-
phosphinimine leading to a phosphinimine substituted isocyanide
ligand which upon hydrolysis of the phosphinimine function reac-
ted via cyclization to give complex cis-[1] [12]. Complex fac-[3]Cl
was finally obtained by heatingof diphosphine 2 and complex cis-[1]
in acetonitrile for three days.
The diphosphine ligand in fac-[3]Cl coordinated to the ReI center
via substitution of one CO and the chloro ligand from cis-[1]. The
13C{1H} NMR spectrum of fac-[3]Cl exhibits the resonance for the
Scheme 1. Synthesis of the macrocyclic [11]ane-P2CNHC ligand at the rhenium(I)
template (the numbering refers to the assignment of the NMR resonances in the
Experimental section).

V. Blase et al. / Journal of Organometallic Chemistry 696 (2011) 3337e3342
3339
Fig. 3. Molecular structure of fac-[4]þ in fac-[4]Cl$CH2Cl2$0.5H2O (50% probability
ellipsoids). Hydrogen atoms have been omitted. Selected bond lengths (Å) and angles
(deg): ReeP1 2.3880(14), ReeP2 2.3968(12), ReeC1 2.157(5), ReeC30 1.970(6), ReeC31
1.952(6), ReeC32 1.962(6); P1eReeP2 82.44(5), P1eReeC1 77.84(15), P1eReeC30
93.3(2), P1eReeC31 95.3(2), P1eC1eC32 168.6(2), P2eReeC1 81.09(14), P2eReeC30
172.9(2), P2eReeC31 94.7(2), P2eReeC32 90.3(2), C1eReeC30 92.4(2), C1eReeC31
172.3(2), C1eReeC32 92.4(2), C30eReeC31 91.4(2), C30eReeC32 93.0(2),
C31eReeC32 94.0(3).
Fig. 2. Molecular structure of fac-[3]þ in fac-[3]Cl$0.5CH2Cl2 (50% probability ellip-
soids). Hydrogen atoms, except for the NeH hydrogen atoms, have been omitted.
Selected bond lengths (Å) and angles (deg) for molecule A [molecule B]: ReeP1
2.4443(12) [2.4516(13)], ReeP2 2.4450(12) [2.4500(14)], ReeC1 2.188(5) [2.204(5)],
ReeC4 1.965(6) [1.929(6)], ReeC5 1.961(6) [1.962(6)], ReeC6 1.954(5) [1.958(6)];
P1eReeP2 82.08(4) [82.70(4)], P1eReeC1 92.06(13) [89.04(13)], P1eReeC4 96.2(2)
[93.0(2)], P1eReeC5 86.43(15) [88.9(2)], P1eReeC6 172.6(2) [177.3(2)], P2eReeC1
88.47(13) [93.29(13)], P2eReeC4 175.9(2) [174.8(2)], P2eReeC5 93.2(2) [86.7(2)],
P2eReeC6 90.99(15) [95.0(2)], C1eReeC4 87.9(2) [89.6(2)], C1eReeC5 177.6(2)
[178.0(2)], C1eReeC6 90.4(2) [89.8(2)], C4eReeC5 90.4(2) [90.3(2)], C4eReeC6
90.8(2) [89.4(2)], C5eReeC6 91.4(2) [92.3(2)].
the CNHCeReeP angles in fac-[4]þ (77.84(15)ꢁ and 81.09(14)ꢁ) are
significantly smaller than the equivalent angles in fac-[3]þ (range
88.47(13)ꢁ to 93.29(13)ꢁ). For the macrocycle formation the NHC
ligand in fac-[3]þ must rotate by about 90ꢁ about the ReeCNHC
bond. In addition, the two phenyl groups linked to the NHC ligand
must rotate about the PeCphenyl bonds. After macrocycle formation,
the plane of the NHC ligand adopts an almost coplanar arrange-
ment with the two phenyl groups it is linked to.
ligand is oriented in a fashion which allows for a minimal inter-
action with the substituents of the coordinated diphosphine ligand.
The final step in the macrocycle synthesis is the linkage of the
dicarbene ligand to the phenyl groups of the coordinated diphos-
phine. Stirring of fac-[3]Cl together with KOtBu in THF for five days
causes deprotonation of the NeH functions followed by nucleo-
philic attack of the ring nitrogen atoms at the fluorine substituted
carbon atoms of the phenyl groups. This nucleophilic aromatic
substitution reaction leads to formation of fac-[4]Cl (Scheme 1).
The absence of the NeH signal in the 1H NMR spectrum of fac-
[4]Cl and the observation of only one resonance in the 19F{1H} NMR
spectrum indicate the formation of the [11]ane-P2CNHC macrocycle.
The 13C{1H} NMR spectrum exhibits the resonance of the carbene
To assess the general applicability of the synthesis protocol
described above, we tried to generate the [11]ane-P2CNHC using
diphosphine 2 at a MnI center. Manganese complexes bearing NHC
ligands are less common and most of these complexes bear
unsaturated imidazolin-2-ylidene ligands [14]. Complex cis-[5]
bearing a saturated NH,NH-substituted NHC ligand was synthe-
sized from [MnBr(CO)5] and 2-(triphenylphosphinimine)ethyl-
amine as previously described [9a]. Surprisingly, heating the
diphosphine 2 and complex cis-[5] in THF for two days did not yield
the expected MnI complex with a facial arrangement of the ligands
as was previously observed for the reaction of the 1,2-phenylene
bridged diphosphine ligand and complex cis-[5] [9a]. Instead,
complex [6] was obtained (Scheme 2) featuring a meridional
arrangement of the diphosphine and the NHC ligands. In contrast to
the reaction of rhenium(I) complex cis-[1] with 2, the halogenato
ligand in cis-[5] was not substituted by the diphosphine ligand 2
leading to the neutral MnI complex [6].
carbon atom at
d
¼ 190.9 ppm as a triplet (2JCP ¼ 3.0 Hz). Arylation
of the nitrogen atoms of the NHC ligand leads only to a slight
downfield shift of the CNHC resonance compared to fac-[3]Cl
(
d
(CNHC) ¼ 186.6 ppm). Contrary to complex fac-[3]Cl, the NHC
ligand in fac-[4]Cl cannot rotate about the ReeCNHC bond and
consequently the protons of the imidazolidin-2-ylidene ligand
become diastereotopic giving rise to two multiplets at
d
¼ 4.84e4.79 ppm and
d
¼ 4.47e4.43 ppm in the 1H NMR
spectrum.
Crystals of fac-[4]Cl$CH2Cl2$0.5H2O were obtained by diffusion
of diethyl ether into a saturated solution of [4]Cl in dichloro-
methane. An X-ray diffraction study with these crystals confirmed
the formation of the P2CNHC macrocycle in fac-[4]Cl (Fig. 3). The
asymmetric unit contains one molecule of fac-[4]Cl together with
one disordered molecule of CH2Cl2 and 0.5 molecules of H2O. Upon
formation of the macrocycle in fac-[4]þ the ReeCNHC and ReeP
bond distances become significantly shorter than the equivalent
bonds in fac-[3]þ, while the ReeCO bond distances remain essen-
tially unchanged. Due to the steric constraints introduced by the
formation of the macrocycle, all bond angles involving the rhenium
atom and atoms from the macrocycle are now smaller than 90ꢁ.
While the PeReeP angles in fac-[3]þ (82.08(4)ꢁ and 82.70(4)ꢁ) and
fac-[4]þ (82.44(5)ꢁ) assume almost identical values in both cations,
Complex [6] was characterized by 31P{1H} NMR spectroscopy
showing two resonances for the two chemically different phos-
phorus atoms at
d
¼ 72.2 ppm and
d
¼ 58.9 ppm. The 19F NMR
spectrum features four resonances for the four chemically different
AreF atoms and the 13C{1H} NMR spectrum shows the resonance
for the CNHC atom at
resonances for the phenyl substituents.
d
¼ 227.9 ppm in addition to four sets of
Composition and coordination geometry of complex [6] have
been confirmed by an X-ray diffraction analysis carried out with
crystals of [6]$CH2Cl2$H2O which were obtained by slow diffusion
of diethyl ether into a saturated dichloromethane solution of [6].
The structure analysis (Fig. 4) confirms that the phosphine donors
are located in trans (P1) and cis (P2) positions relative to the NHC in
a slightly distorted octahedral complex. The asymmetric unit

3340
V. Blase et al. / Journal of Organometallic Chemistry 696 (2011) 3337e3342
of the phosphine donors. In previous studies with NHC/PPh3
complexes of palladium(II) and platinum(II), it has been noticed
that the NHC ligand normally avoids the trans position to the PPh3
ligand and that the cis-[M(NHC)(PPh3)L2] complexes are the ther-
modynamically most stable reaction products [16]. The MneP
distances differ significantly in lengths with the shorter distance
observed for the phosphine donor located in trans position to the
NHC ligand. Owing to the generally shorter MeP distances in the
MnI complex [6] compared to the ReI complexes fac-[3]Cl and fac-
[4]Cl the bite angle of the diphosphine increases to 85.68(4)ꢁ.
3. Conclusions
We present the synthesis of a new macrocyclic [11]ane-P2CNHC
ligand obtained in a template synthesis from an NH,NH-NHC ligand
and the ethylene bridged diphosphine (2-FeC6H4)2PeCH2CH2e
P(C6H4-2-F)2 2 coordinated facially to the ReI template center.
Attempts to extend this synthesis to MnI as template metal were
unsuccessful as the NH,NH-NHC and the diphosphine ligands could
not be coordinated in the required facial geometry but instead the
MnI complex with the meridional arrangement of these ligands was
formed. The reasons for the formation of complex [6]Cl are not
obvious at this time. We can only conclude that even a slight
modification in the spacer of the diphosphine from phenylene to
ethylene can cause a significant change in the coordination mode of
the diphosphine.
Scheme 2. Reaction of cis-[5] with
numbering refers to the assignment of the NMR resonances in the Experimental
section).
2 yielding manganese(I) complex [6] (the
contains one molecule each of [6], CH2Cl2 and water, the water
molecule being disordered.
4. Experimental section
The MneCNHC bond length (2.013(4) Å) is shorter than previ-
ously reported values for MnI complexes bearing saturated [9] or
unsaturated [14] NHC ligands. It falls in the range described for
MnIV or MnIII NHC complexes [15]. The short MnIeCNHC bond may
be attributed to the unusual position of the NHC ligand trans to one
4.1. General methods
All manipulations were carried out under an argon atmosphere
using standard Schlenk or glove-box techniques. Solvents were
dried by standard methods under argon and were freshly distilled
prior to use. 1H, 13C, 31P and 19F NMR spectra were measured on
a Bruker AVANCE I 400 or a Bruker AVANCE III 400 spectrometer.
Chemical shifts (d) are expressed in ppm using the residual
protonated solvent signal as internal standard. Coupling constants
are expressed in Hertz. Mass spectra were obtained with an Orbi-
trap LTQ XL (Thermo Scientific) or a MicroTof (Bruker Daltonics)
spectrometer. IR spectra were measured with a Bruker Vector 22
spectrometer. The preparation of cis-[ReCl(CO)4(NHC)] cis-[1] [9a]
and cis-[MnBr(CO)4(NHC)] cis-[5] [9a] was carried out as
described. Consistent microanalytical data were difficult to obtain
due to the presence of fluorine in all complexes. ESI HRMS data and
1H, 13C{1H}, 19F, and 31P NMR spectroscopic data for all complexes
are provided instead.
4.2. Synthesis of diphosphine 2
The published procedure for the synthesis of 2 [10] has been
modified leading to a higher yield. The reaction has to be carried
out at ꢀ78 ꢁC. All reactants have to be cooled to this temperature
prior to use.
A solution of o-bromofluorobenzene (1.3 mL,
11.9 mmol) in diethyl ether (15 mL) was added dropwise to
a solution of n-buthyllithium (1.6 M in hexane, 7.1 mL,11.4 mmol) in
diethyl ether (30 mL). Caution: this reaction can lead to a higly
reactive benzyne at reaction temperatures above ꢀ78 ꢁC [17]. After
stirring for 30 min a solution of 1,2-bis(dichlorophosphino)ethane
(0.4 mL, 2.7 mmol) in diethyl ether (15 mL) was added dropwise
over a period of 2 h. The reaction mixture was stirred for 4 h
at ꢀ78 ꢁC and then for 12 h at ambient temperature. A saturated
aqueous ammonium chloride solution (100 mL) was added and the
mixture was extracted with diethyl ether (3 ꢂ 60 mL). The
combined organic phases were dried over magnesium sulfate and
Fig. 4. Molecular structure of [6] in [6]Cl$CH2Cl2$H2O (50% probability ellipsoids).
Hydrogen atoms, except for the NeH atom, have been omitted. Selected bond lengths
(Å) and angles (deg): MneBr 2.5639(8), MneP1 2.2812(12), MneP2 2.3287(12),
MneC1 2.013(4), MneC30 1.807(5), MneC311.833(7); BreMneP1 88.13(4), BreMneP2
87.32(4), BreMneC1 88.91(13), BreMneC30 92.6(2), BreMneC31 177.72(14),
P1eMneP2 85.68(4), P1eMneC1 176.21(14), P1eMneC30 94.70(14), P1eMneC31
89.65(14), P2eMneC1 91.82(13), P2eMneC30 179.60(15), P2eMneC31 92.01(14),
C1eMneC30 87.8(2), C1eMneC31 93.3(2), C30eMneC31 88.1(2).

V. Blase et al. / Journal of Organometallic Chemistry 696 (2011) 3337e3342
3341
the solvent was removed in vacuo. The residue was recrystallized
from methanol giving compound 2 as a colorless solid. Yield: 1.01 g
(dd, 2JCF ¼ 23.0 Hz, 3JCP ¼ 3.8 Hz, C-14), 114.2 (br, C-10), 52.5 (C-2),
29.4 (br, C-3). 31P{1H} NMR (162.0 MHz, CD2Cl2):
d
n
15.8 (br). 19F{1H}
(cmꢀ1): 2033 (s,
(2.1 mmol, 81%). 1H NMR (400.1 MHz, CDCl3):
d
7.37e7.31 (m, 4H,
NMR (376.4 MHz, CD2Cl2):
d
¼ ꢀ97.1. IR (KBr):
AreH), 7.26e7.21 (m, 4H, AreH), 7.11e7.08 (m, 4H, AreH),
CO), 1944 (s, CO), 1871 (m, CO). HRMS (ESI, positive ions) m/z (%):
3
7.03e6.99 (m, 4H, AreH), 2.28 (t, JHP ¼ 4.8 Hz, 4H, H-1). 13C{1H}
771.07854 (100) [4]þ (calcd for [4]þ 771.07822).
NMR (100.6 MHz, CDCl3):
d
164.6 (dd, 1JCF ¼ 246.0 Hz, 2JCP ¼ 11.1 Hz,
C-7), 133.6, 131.2 (m, C-3, C5), 124.4 (m, C4), 123.4 (m, C-2), 115.5 (d,
4.5. Synthesis of [6]
2JCF ¼ 23.9 Hz, C-6), 21.2 (m, C-1). 31P{1H} NMR (162.0 MHz, CDCl3):
d
ꢀ32.9 (m). 19F{1H} NMR (376.4 MHz, CDCl3):
d
ꢀ103.9 (m). HRMS
A solution of cis-[5] (110.0 mg, 0.35 mmol) and diphosphine 2
(180.0 mg, 0.38 mmol) in THF (3 mL) was heated under reflux for
2 d. After cooling to ambient temperature diethyl ether (10 mL) was
added. A precipitate formed which was isolated by filtration,
washed with diethyl ether (20 mL) and dried in vacuo. Yield:
149 mg (0.20 mmol, 59%) of an orange solid. 1H NMR (400.1 MHz,
(ESI, positive ions) m/z (%): 493.0876 (100) [2 þ Na]þ (calcd for
[2 þ Na]þ 493.0869), 471.1055 (8) [2 þ H]þ (calcd for [2 þ H]þ
471.1049).
4.3. Synthesis of fac-[3]Cl
CD2Cl2, for assignment of the resonances see Scheme 2):
d 8.18 (br,
A solution of cis-[1] (100.0 mg, 0.25 mmol) and diphosphine 2
(151.0 mg, 0.32 mmol) in acetonitrile (10 mL) was heated under
reflux for 3 d. After cooling to ambient temperature the solution
was concentrated and diethyl ether (25 mL) was added. The
precipitate which formed upon addition of the diethyl ether was
isolated by filtration, washed with diethyl ether (20 mL) and dried
in vacuo giving complex fac-[3]Cl as a colorless solid. Yield: 48 mg
(0.06 mmol, 23% of the solvent free compound). 1H NMR (400 MHz,
DMSO-d6, for assignment of the resonances see Scheme 1):
1H, AreH), 7.91 (br, 1H, AreH), 7.66 (br, 1H, AreH), 7.35e6.93 (m,
13H, AreH), 6.81 (s, br, 2H, NH), 3.63 (s, 4H, H-2), 2.80e3.33 (m, 4H,
H-3). 13C{1H} NMR (100.6 MHz, CD2Cl2, for assignment of the
resonances see Scheme 2):
d
228.8 (CO), 227.9 (d, 2JCP-trans ¼ 17.6 Hz,
1
C-1), 226.2 (CO), 164.1 (d, JCF ¼ 246.8 Hz, C-9), 163.6 (d,
1JCF ¼ 246.6 Hz, C-9), 163.4 (d, JCF ¼ 247.3 Hz, C-9), 163.4 (d,
1
1JCF ¼ 247.3 Hz, C-9), 136.7 (dd, JCP ¼ 12.7 Hz, JCF ¼ 4.1 Hz, C-5),
135.7 (dd, 2JCP ¼ 15.8 Hz, 3JCF ¼ 2.8 Hz, C-5), 135.2 (dd, 2JCP ¼ 7.8 Hz,
3JCF ¼ 4.8 Hz, C-5), 133.0 (d, 3JCF ¼ 9.7 Hz, C-7), 132.9 (C-5), 132.4 (d,
3JCF ¼ 8.3 Hz, C-7),132.3 (d, 3JCF ¼ 8.6 Hz, C-7),132.0 (d, 3JCF ¼ 8.1 Hz,
C-7), 124.2 (d, 3JCP ¼ 10.9 Hz, C-6), 124.2 (d, 3JCP ¼ 9.8 Hz, C-6), 123.7
2
3
d
7.76e7.69 (m, 2H, H-5a), 7.61e7.56 (m, 8H, H-5, H-7, H-7a, NH),
7.40e7.33 (m, 4H, H-6, H-6a), 7.30e7.20 (m, 4H, H-8, H-8a),
3.69e3.61 (m, 2H, H-3), 3.12e3.04 (m, 2H, H-3), 2.86 (s, 4H, H-2).
13C{1H} NMR (100.6 MHz, DMSO-d6, for assignment of the reso-
3
4
3
(dd, JCP ¼ 10.6 Hz, JCF ¼ 1.9 Hz, C-6), 123.2 (dd, JCP ¼ 8.2 Hz,
4JCF ¼ 2.8 Hz, C-6),116.5e115.4 (m, 4ꢂ C-8), 45.9 (C-2), 27.6 (m, C-3),
26.2 (m, C-3). The resonance for the C-4 atoms was not detected. 31P
nances see Scheme 1):
d
190.8 (d, 2JCP-trans ¼ 53.4 Hz, COcis-C1), 189.5
(t, 2JCP-cis ¼ 6.6 Hz, COtrans-C1), 186.6 (t, 2JCP ¼ 9.6 Hz, C-1), 163.0 (d,
1JCF ¼ 247.5 Hz, C-9), 162.5 (d, 1JCF ¼ 247.9 Hz, C-9a), 134.3 (C-5, C-7,
{1H} NMR (162.0 MHz, CD2Cl2): 72.2, 58.9. 19F{1H} NMR
d
(376.4 MHz, CD2Cl2):
d
ꢀ100.0, ꢀ101.1, ꢀ101.6, ꢀ102.0. IR (KBr):
n
2
3
C-7a), 132.4 (dd, JCP ¼ 9.1 Hz, JCF ¼ 1.6 Hz, C-5a), 125.0 (dd,
(cmꢀ1): 3397 (m, NH), 2027 (m, CO), 1940 (s, CO), 1850 (s, CO).
HRMS (ESI, positive ions) m/z (%): 651.07807 (100) [6eBr]þ (calcd
for [6eBr]þ 651.07806).
4
3
3JCP ¼ 9.9 Hz, JCF ¼ 2.1 Hz, C-6a), 124.5 (dd, JCP ¼ 9.9 Hz,
4JCF ¼ 2.3 Hz, C-6), 119.9 (dd, 1JCP ¼ 48.9 Hz, JCF ¼ 16.9 Hz, C-4a),
2
117.0 (dd, 1JCP ¼ 44.4 Hz, 2JCF ¼ 17.6 Hz, C-4), 116.6 (d, 2JCF ¼ 23.7 Hz,
2
C-8a), 116.0 (d, JCF
¼
22.2 Hz, C-8), 44.1 (C-2), 26.5 (dd,
4.6. Crystal structure determinations
1JCP ¼ 33.5 Hz, 2JCP ¼ 9.6 Hz, C-3). 31P{1H} NMR (162.0 MHz, DMSO-
d6):
d
(ppm) ¼ 19.4. 19F{1H} NMR (376.4 MHz, DMSO-d6):
d
ꢀ101.1
X-ray diffraction data for all compounds were collected for all at
(C9eF), ꢀ100.9 (C9aeF). IR (KBr):
n
(cmꢀ1): 2036 (s, CO), 1971 (s,
T ¼ 153(2) K with a Bruker AXS APEX CCD diffractometer equipped
CO), 1923 (s, CO), the NH vibration could not be identified. HRMS
(ESI, positive ions) m/z (%): 811.09001 (100) [3]þ (calcd for [3]þ
811.09083).
with a rotation anode using graphite-monochromated Mo-Ka
radiation (
Cl$CH2Cl2$0.5H2O or Cu-K
l
¼ 0.71073 Å) for fac-[3]Cl$0.5CH2Cl2 and fac-[4]
a
radiation (
l
¼ 1.54178 Å) for [6]
Cl$CH2Cl2$H2O. Diffraction data were collected over the full sphere
and were corrected for absorption. Structure solutions were found
with the SHELXS-97 [18] package using direct methods and were
refined with SHELXL-97 [18] against all jF2j using first isotropic and
later anisotropic thermal parameters. Hydrogen atoms were added
to the structure models in calculated positions (for exceptions see
description of the individual molecular structures).
4.4. Synthesis of fac-[4]Cl
Complex fac-[3]Cl (20.0 mg, 0.024 mmol) was suspended in THF
(10 mL) and KOtBu (6.0 mg, 0.047 mmol) was added. The colorless
solution was stirred for 5 d at ambient temperature during which
time the solution turned yellow. The solvent was removed in vacuo
and the remaining residue was dissolved in dichloromethane. After
filtration the solution was concentrated and diethyl ether (20 mL)
was added. A precipitate formed which was isolated by filtration
and dried in vacuo. Complex fac-[4]Cl was isolated as a pale yellow
solid. Yield: 15.0 mg (0.019 mmol, 79%). 1H NMR (400.1 MHz,
CD2Cl2, for assignment of the resonances see Scheme 1):
4.6.1. Crystal data for fac-[3]Cl$0.5CH2Cl2
C32.5H27N2Cl2F4O3P2Re, M ¼ 888.60, triclinic, P1, a ¼ 12.3472(6),
b ¼ 14.8272(7), c ¼ 19.5326(9) Å,
a
¼ 91.1340(10),
b
¼ 90.8400(10),
g
m
¼ 111.7320(10)ꢁ, V ¼ 3320.2(3) Å3, Z ¼ 4, Dcalc ¼ 1.778 g cmꢀ3
,
¼ 3.977 mmꢀ1, 39258 measured intensities (3.0ꢁ ꢃ 2
q
ꢃ 60.0ꢁ),
d
7.69e7.52 (m, 8H, H-7, H-8, H-11, H-13), 7.42e7.38 (m, 2H, H-12),
19234 independent (Rint ¼ 0.0312) diffractions data, refinement of
838 parameters, R ¼ 0.0453, wR ¼ 0.1106 for 14874 observed
7.32e7.27 (m, 2H, H-14), 7.20e7.17 (m, 2H, H-6), 6.91e6.86 (m, 2H,
H-5), 4.84e4.79 (m, 2H, H-2), 4.47e4.43 (m, 2H, H-2), 3.20 (m, 2H,
H-3), 2.99 (m, 2H, H-3). 13C{1H} NMR (100.6 MHz, CD2Cl2, for
intensities (I ꢄ 2
s(I)). The asymmetric unit contains two formula
units.
assignment of the resonances see Scheme 1): d 193.7 (br, COtrans-C1),
2
2
190.9 (t, JCP ¼ 3.0 Hz, C-1), 190.1 (d, JCP-trans ¼ 48.8 Hz, COcis-C1),
164.3 (d, 1JCF ¼ 251.0 Hz, C-15), 145.7 (d, 2JCP ¼ 11.6 Hz, C-9), 135.8
(C-11, C-13), 133.6 (d, 4JCP ¼ 2.1 Hz, C-7), 131.2 (d, 2JCP ¼ 2.6 Hz, C-5),
126.7 (d, 3JCP ¼ 7.9 Hz, C-6), 126.3 (dd, 3JCP ¼ 10.0 Hz, 4JCF ¼ 3.2 Hz,
C-12),124.0 (d, 3JCP ¼ 6.9 Hz, C-8),123.3 (d, 1JCP ¼ 49.2 Hz, C-4),117.5
4.6.2. Crystal data for fac-[4]Cl$CH2Cl2$0.5H2O
C33H27N2Cl3F2O3.5P2Re, 900.06, monoclinic, C2/c,
M
¼
a
b
m
¼
30.1945(11),
b
¼
12.3444(4),
c
¼
20.7168(7) Å,
¼ 104.1940(10)ꢁ, V ¼ 7486.1(4) Å3, Z ¼ 8, Dcalc ¼ 1.597 g cmꢀ3
,
¼ 3.591 mmꢀ1, 43287 measured intensities (2.8ꢁ ꢃ 2
q
ꢃ 60.0ꢁ),

3342
V. Blase et al. / Journal of Organometallic Chemistry 696 (2011) 3337e3342
(g) P.G. Edwards, J.S. Fleming, S.S. Liyanage, S.J. Coles, M.B. Hursthouse,
J. Chem. Soc. Dalton Trans. (1996) 1801e1807;
(h) P.G. Edwards, P.D. Newman, D.E. Hibbs, Angew. Chem. Int. Ed. 39 (2000)
2722e2724;
(i) P.G. Edwards, P.D. Newman, K.M.A. Malik, Angew. Chem. Int. Ed. 39 (2000)
2922e2924;
(j) P.G. Edwards, M.L. Whatton, R. Heigh, Organometallics 19 (2000)
2652e2654;
10903 independent (Rint ¼ 0.0319) diffraction data, refinement of
457 parameters, R ¼ 0.0444, wR ¼ 0.1392 for 8797 observed
intensities (I ꢄ 2
s(I)). The asymmetric unit contains one formula
unit. The CH2Cl2 molecule is disordered. Non-hydrogen atoms of
solvent molecules were refined with isotropic thermal parameters,
no hydrogen atoms of solvent molecules were added to the struc-
ture model.
(k) P.G. Edwards, R. Haigh, D. Li, P.D. Newman, J. Am. Chem. Soc. 128 (2006)
3818e3830;
(l) P.G. Edwards, K.M.A. Malik, L.-l. Ooi, A.J. Price, Dalton Trans. (2006)
433e441;
4.6.3. Crystal data for [6]$CH2Cl2$H2O
C32H30N2BrCl2F4MnO3P2,
M
¼
834.27,
triclinic,
P1,
(m) P.G. Edwards, M.L. Whatton, Dalton Trans. (2006) 442e450;
(n) A.R. Battle, P.G. Edwards, R. Haigh, D.E. Hibbs, D. Li, S.M. Liddiard,
P.D. Newman, Organometallics 26 (2007) 377e386;
(o) T. Albers, P.G. Edwards, Chem. Commun. (2007) 858e860.
[8] (a) F.E. Hahn, V. Langenhahn, T. Lügger, T. Pape, D. Le Van, Angew. Chem. Int.
Ed. 44 (2005) 3759e3763;
a ¼ 11.2319(4), b ¼ 12.1710(4), c ¼ 13.3111(4) Å,
a
¼ 85.396(2),
b
¼ 87.881(2),
g
¼ 78.617(2)ꢁ, V ¼ 1777.71(10) Å3, Z ¼ 2,
Dcalc ¼ 1.559 g cmꢀ3
,
m
¼ 7.064 mmꢀ1, 10041 measured intensities
(6.7ꢁ ꢃ 2
q
ꢃ 143ꢁ), 5942 independent (Rint ¼ 0.0484) diffraction
(b) R. McKie, J.A. Murphy, S.R. Park, M.D. Spicer, S.-Z. Zhou, Angew. Chem. Int.
Ed. 46 (2007) 6525e6528;
(c) F.E. Hahn, C. Radloff, T. Pape, A. Hepp, Chem.e Eur. J. 14 (2008)
10900e10904;
data, refinement of 427 parameters, R ¼ 0.0599, wR ¼ 0.1835 for
5206 observed intensities (I ꢄ 2
s(I)). The asymmetric unit contains
one formula unit. The H2O molecule is disordered. The water
molecule is disordered. Positional parameters of the water oxygen
atom were refined with isotropic thermal parameters. No hydrogen
atoms for the water molecule were added to the structure model.
(d) C. Radloff, H.-Y. Gong, C. Schulte to Brinke, T. Pape, V.M. Lynch, J.L. Sessler,
F.E. Hahn, Chem.e Eur. J. 16 (2010) 13077e13081.
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F.E. Hahn, J. Am. Chem. Soc. 131 (2009) 306e317;
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metallics 28 (2009) 6362e6369;
Appendix A. Supplementary material
(c) A. Flores-Figueroa, T. Pape, J.J. Weigand, F.E. Hahn, Eur. J. Inorg. Chem.
(2010) 2907e2910;
(d) A. Flores-Figueroa, T. Pape, K.-O. Feldmann, F.E. Hahn, Chem. Commun. 46
(2010) 324e326.
[10] C.K. Mirabelli, D.T. Hill, L.F. Faucette, F.L. McCabe, G.R. Girard, D.B. Bryan,
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1356e1359;
CCDC-829156 (fac-[3]Cl$0.5CH2Cl2), CCDC-829157 (fac-[4]
Cl$CH2Cl2$0.5H2O), and CCDC-829158 ([6]$CH2Cl2$H2O) contain
the supplementary crystallographic data for this paper. These date
can be obtained free of charge from The Cambridge Crystallo-
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