Ru and Os complexes containing a P,N-donor heterotopic ligand: The effect of solvent on stereochemistry

Article abstract of DOI:10.1021/ic7019044

Ruthenium and osmium complexes of the general formula MCl ₂(PyP)₂ (where PyP is the P,N- donor ligand 1-(2-diphenylphosphinoethyl)pyrazole) were synthesized from MCl ₂(PPh₃)₃ (where M = Ru or Os). Three of the five possible stereoisomers of RuCl₂(PyP)₂ were synthesized and characterized in solution by multinuclear NMR spectroscopy, and the structure of these in the solid state was determined by X-ray crystallography. Two of the analogous Os isomers were also synthesized. It was found that different solvents induced isomerization between these stereoisomers, indicating either lability of the chloride anion or hemilability of the PyP ligand. Bimetallic complexes of the general formula [Ru(μ-Cl)(PyP) ₂]₂[X]₂ were synthesized from chloride abstraction from RuCl₂(PyP)₂ using either silver (X = OSO₂CF₃, BF₄) or sodium (X = BPh₄) salts. The osmium analogue of the Ru bimetallic complexes, [Os(μ-Cl)(PyP) ₂]₂[BPh₄]₂, was also synthesized. Solid-state structures were obtained using X-ray crystallography for the osmium bimetallic complex and the ruthenium bimetallic complex where X = OSO ₂CF₃. The hemilability of PyP was demonstrated through the synthesis of RuCl₂(CO)(κ¹-P-PyP) (κ²-P,N-PyP), which contains one pendant PyP ligand, bound through the P-donor atom.

Full text of DOI:10.1021/ic7019044

Inorg. Chem. 2008, 47, 3034-3044
Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand: The
Effect of Solvent on Stereochemistry
Serin L. Dabb,† Barbara A. Messerle,*,† Matthew K. Smith,‡ and Anthony C. Willis‡
School of Chemistry, The UniVersity of New South Wales, Sydney, New South Wales, Australia,
and Research School of Chemistry, The Australian National UniVersity, Canberra, ACT, Australia
Received September 25, 2007
Ruthenium and osmium complexes of the general formula MCl2(PyP)2 (where PyP is the P,N- donor ligand 1-(2-
diphenylphosphinoethyl)pyrazole) were synthesized from MCl2(PPh3)3 (where M ) Ru or Os). Three of the five
possible stereoisomers of RuCl2(PyP)2 were synthesized and characterized in solution by multinuclear NMR
spectroscopy, and the structure of these in the solid state was determined by X-ray crystallography. Two of the
analogous Os isomers were also synthesized. It was found that different solvents induced isomerization between
these stereoisomers, indicating either lability of the chloride anion or hemilability of the PyP ligand. Bimetallic
complexes of the general formula [Ru(µ-Cl)(PyP)2]2[X]2 were synthesized from chloride abstraction from RuCl2(PyP)2
using either silver (X ) OSO2CF3, BF4) or sodium (X ) BPh4) salts. The osmium analogue of the Ru bimetallic
complexes, [Os(µ-Cl)(PyP)2]2[BPh4]2, was also synthesized. Solid-state structures were obtained using X-ray
crystallography for the osmium bimetallic complex and the ruthenium bimetallic complex where X ) OSO2CF3.
The hemilability of PyP was demonstrated through the synthesis of RuCl2(CO)(κ1-P-PyP)(κ2-P,N-PyP), which contains
one pendant PyP ligand, bound through the P-donor atom.
Introduction
The majority of studies of metal complexes containing
phosphine-nitrogen hybrid ligands have focused on phos-
phine-pyridine,8,9 phosphine-oxazoline,10,11 and, to a lesser
extent, phosphine-imidazolyl12 ligand systems (Figure 1).
Only a limited number of phosphine-pyrazolyl bidentate
donor ligands are known,13–15 and the coordination chemistry
of phosphine-pyrazolyl ligands, and their possible hemila-
bility, has not been extensively studied. Pd,16 Ru,17,18 Fe19
and Rh20 metal complexes containing mixed phosphine-py-
razolyl ligands have been synthesized.
Bidentate P∩N ligands, which contain both hard and soft
donor atoms, have been used extensively in the synthesis of
metal complexes. The differing electronic and structural proper-
ties of the donor atoms allow for tuning of the reactivity at the
metal center, and as such, these ligand systems have great
potential for use in catalysis. In particular, the potential
hemilability of such ligands, where one donor group is
substantially more labile than the other, is of interest in the
development of catalysts as these ligand allow for the formation
of reactive sites while maintaining the structure of the complex
and protecting ability of the ligand.1,2 Ruthenium complexes
of the formula RuCl2(P∩N)2 are effective catalysts for transfer
hydrogenation3–6 and also homocoupling of terminal alkynes.7
On binding of bidentate P∩N donor ligands with a range
of sp2 N-donors to Ru and Os, octahedral complexes of the
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* To whom correspondence should be addressed. E-mail: b.messerle@
unsw.edu.au.
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Winkler, B.; Stelzer, F. Monatsh. Chem. 1998, 129, 221–233.
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†
The University of New South Wales.
The Australian National University.
‡
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Dalton Trans. 1999, 1655–1661.
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3034 Inorganic Chemistry, Vol. 47, No. 8, 2008
10.1021/ic7019044 CCC: $40.75  2008 American Chemical Society
Published on Web 03/18/2008

Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand
Scheme 1
We have recently reported the synthesis of square planar
Figure 1
Rh and Ir complexes containing the P∩N ligand 1-(2-
diphenylphospinoethyl)pyrazole (PyP, 1, Scheme 1).28 In
order to provide insight into the coordination behavior of
this potentially hemilabile bidentate ligand, we have also
studied the reactivity of the PyP ligand with group 8 metals.
In this paper we report the first example of the synthesis of
three stereoisomers of the metal complex with general
formula RuCl2(P∩N)2, where P∩N ) PyP (1), along with
evidence of the hemilability of the PyP ligand. Crystal
structures have been obtained for trans,cis,cis- (2), cis,cis,cis-
(3), and cis,cis,trans-RuCl2(PyP)2 (4) and for the analogous
trans,cis,cis-OsCl2(PyP)2 (5). cis,cis,trans-OsCl2(PyP)2 (6)
was also synthesized. This is the first example of the
synthesis and X-ray structure of a phophino-pyrazolyl
complex of Os, and one of only a few29 examples of
complexes of the form OsCl2(P∩N)2. Bimetallic species of
the Ru and Os complexes were also synthesized through
chloride labilization and abstraction to yield a series of
complexes of the type [Ru(µ-Cl)(PyP)2]2[X]2 (X ) OSO2CF3
(7), BF4 (8), BPh4 (9)), and [Os(µ-Cl)(PyP)2]2[BPh4]2 (10).
The effects of solvent on the synthesis of the complexes,
and their subsequent isomerization, are also reported. Direct
comparisons between the isomerization of the Ru and Os
stereoisomers have been made, as well as their stabilities in
solution.
Figure 2
general formula MCl2(P∩N)2 have been reported. Five
possible stereoisomers of MCl2(P∩N)2 have been established
(Figure 2), with isomer A being the most common.5,6,17,21–24
There are far fewer known examples of isomers B25,26 and
E27 (Figure 2). Changes in metal precursor or ligand sub-
stituents can lead to the preferential formation of particular
isomers. For example, addition of P∩N ligands, where N is
a pyridine moiety, to RuCl2(PPh3)3 produced a mixture of
isomers A and B (in two diastereomers) where the ratio of
A:B was dependent on the nature of the substituents on the
phosphorus or pyridine.4 The addition of a (phosphinom-
ethyl)oxazoline ligand to RuCl2(PPh3)3 yielded isomer B
exclusively; however, when the Ru precursor was changed
to [RuCl2(COD)]n, a small percentage of isomer D was also
formed. Increasing the bulkiness of the substituents on the
oxazoline ring also led to the formation of isomers B
and D.3
Results and Discussion
Mononuclear Metal Complexes. Synthesis of trans,cis,cis-
RuCl2(PyP)2 (2). The addition of dichloromethane (DCM) to a
mixture of 1 equiv of RuCl2(PPh3)3 and 2 equiv of 1, with isolation
using n-hexanes to remove the free PPh3, gave trans,cis,cis-
RuCl2(PyP)2 (2) cleanly and in good yields (Scheme 1). The order
of addition of ligand and metal precursor in this reaction was
important, as addition of a solution of ligand in dichloromethane
to a solution of metal precursor in dichloromethane produced a
small percentage of the cis,cis,cis-isomer 3 in addition to isomer
2. The 31P{1H} NMR spectrum of isomer 2 exhibited the expected
singlet at 34.4 ppm, due to the C2 symmetry of the complex. In the
1H NMR spectrum the resonances due to the two methylene protons
on the ligand backbone (-NCH2CH2P-) appeared as broad singlets.
The resonances due to the phenyl and pyrazolyl protons of the
product have similar, but distinguishable, chemical shifts to those
of the protons of the free ligand (Figure 6).
(14) Abbenhuis, H. C. L.; Burckhardt, U.; Gramlich, V.; Togni, A.; Albinati,
A.; Mueller, B. Organometallics 1994, 13, 4481–4493.
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(16) Grotjahn, D. B.; Combs, D.; Van, S.; Aguirre, G.; Ortega, F. Inorg.
Chem. 2000, 39, 2080–2086.
(17) Esquius, G.; Pons, J.; Yanez, R.; Ros, J.; Mathieu, R.; Lugan, N.;
Donnadieu, B. J. Organomet. Chem. 2003, 667, 126–134.
(18) Espino, G.; Jalon, F. A.; Maestro, M.; Manzano, B. R.; Perez-
Manrique, M.; Bacigalupe, A. C. Eur. J. Inorg. Chem. 2004, 2542–
2552.
(19) Tribo, R.-M.; Ros, J.; Pons, J.; Yanez, R.; Alvarez-Larena, A.; Piniella,
J.-F. J. Organomet. Chem. 2003, 676, 38–42.
(20) Esquius, G.; Pons, J.; Yanez, R.; Ros, J.; Mathieu, R.; Donnadieu,
B.; Lugan, N. Eur. J. Inorg. Chem. 2002, 2999–3006.
(21) Crochet, P.; Gimeno, J.; Borge, J.; Garcia-Granda, S. New J. Chem.
2003, 27, 414–420.
(22) Abdur-Rashid, K.; Guo, R.; Lough, A. J.; Morris, R. H.; Song, D.
AdV. Synth. Catal. 2005, 347, 571–579.
(23) Guo, Z.; Habtemariam, A.; Sadler, P. J.; James, B. R. Inorg. Chim.
Acta 1998, 273, 1–7.
2 was also synthesized in a much lower yield on refluxing 1
mol equiv of RuCl2(PPh3)3 with 2 mol equiv of PyP (1) in toluene.
(24) Morris, R.; Habtemariam, A.; Guo, Z.; Parsons, S.; Sadler, P. J. Inorg.
Chim. Acta 2002, 339, 551–559.
(25) Caballero, A.; Jalon, F. A.; Manzano, B. R.; Sauthier, M.; Toupet,
L.; Reau, R. J. Organomet. Chem. 2002, 663, 118–126.
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R. Inorg. Chim. Acta 1994, 221, 109–116.
(28) Burling, S.; Field, L. D.; Messerle, B. A.; Vuong, K. Q.; Turner, P.
Dalton Trans. 2003, 4181–4191.
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1994, 2257–2264.
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56, 775–780.
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J. Chem. Soc., Dalton Trans. 1993, 3001–3008.
Inorganic Chemistry, Vol. 47, No. 8, 2008 3035

Dabb et al.
Figure 5. ORTEP depiction of 4 at 30% probability levels. H atoms have
been omitted for clarity.
Figure 3. ORTEP depiction of 2 at 30% probability levels. H atoms have
been omitted for clarity.
Table 2. Selected Bond Angles and Bond Lengths for the Solid-State
Structure of 3
Bond Lengths (Å)
Ru(1)-Cl(1)
Ru(1)-P(1)
Ru(1)-N(111)
2.4314(11) Ru(1)-Cl(2)
2.2742(12) Ru(1)-P(2)
2.4989(12)
2.2871(11)
2.079(3)
2.181(3)
Ru(1)-N(211)
Bond Angles (deg)
N(111)-Ru(1)-P(2) 173.40(10)
N(211)-Ru(1)-Cl(1) 175.66(9)
P(1)-Ru(1)-N(111) 89.23(10)
P(2)-Ru(1)-N(211) 92.06(9)
Cl(1)-Ru(1)-Cl(2) 90.41(4)
P(1)-Ru(1)-Cl(2)
170.98(4)
and angles are given in Table 2. The formation of isomer 3 was
also observed during the synthesis of isomer 2. Isomer 3 is only
sparingly soluble in tetrahydrofuran, acetone, and chloroform, unlike
isomers 2 and 4, which showed much higher solubilities in these
solvents. As 3 readily isomerizes in solution, it could not be isolated
as a pure sample. Microanalysis was performed on a clean mixture
of 3 and 2 and NMR and mass spectroscopic data were acquired
on a mixture of isomer 2 and 4.
Due to the inequivalence of the two PyP ligands on the metal
center of isomer 3 (one P is trans to N and one is trans to Cl), we
would expect at least four separate resonances for the methylene
protons (-NCH2CH2P-) on the ethyl backbone. The geminal
protons on each carbon are also pairwise inequivalent and therefore
the resonances due to the methylene protons of isomer 3 appear as
eight distinct resonances all integrating to one proton (Figure 6c).
Synthesis of cis,cis,trans-RuCl2(PyP)2 (4). Heating the Ru
isomer 2 to reflux in EtOH for 1.5 h yielded 4. The product 4 was
also obtained by stirring isomer 2 in EtOH for 48 h at room
temperature. As expected the 31P{1H} NMR spectrum exhibited a
singlet, with only a slight difference in chemical shift from the
equivalent resonance observed for the trans,cis,cis-isomer 2. The
1H NMR spectrum of 4 is similar to that of the trans,cis,cis-isomer
2 as the two ligands are chemically and magnetically equivalent.
However, the protons of the phenyl groups and -NCH2- protons
within the ligand are magnetically inequivalent, as indicated by
two-dimensional 1H NMR spectroscopy and observed in the spectra
of the cis,cis,cis-isomer 3. The resonances due to the protons of
the two phenyl rings of PPh2 exhibit two sets of chemical shifts.
The chemical shifts of the resonances due to the protons of the
-PCH2 groups appear at one chemical shift, but the resonances
due to the -NCH2 protons appear as two multiplets, each with an
integration of one proton (Figure 6b).
Figure 4. ORTEP depiction of 3 at 30% probability levels. H atoms have
been omitted for clarity.
Table 1. Selected Bond Angles and Bond Lengths for the Solid-State
Structures of 2
Bond Lengths (Å)
Ru(1)-Cl(1)
Ru(1)-P(1)
Ru(1)-N(11)
2.4170(9) Ru(1)-Cl(2)
2.2861(2) Ru(1)-P(2)
2.4245(9)
2.3103(9)
2.161(3)
2.157(3)
Ru(1)-N(21)
Bond Angles (deg)
Cl(1)-Ru(1)-Cl(2) 171.38(3)
P(1)-Ru(1)-N(21) 170.55(8)
P(2)-Ru(1)-N(11) 169.54(8)
P(1)-Ru(1)-N(11) 88.31(8)
P(2)-Ru(1)-N(21) 87.41(8)
On addition of PyP (1) to RuCl2(DMSO)4 in dichloromethane at
room temperature, an inseparable mixture of products was formed.
A view of the structure of 2, as determined by X-ray crystal-
lography, is shown in Figure 3, together with the atomic numbering
system; selected bond distances and angles are given in Table 1.
Synthesis of cis,cis,cis-RuCl2(PyP)2 (3). 3 was synthesized by
stirring a suspension of 2 in EtOH overnight. The product exhibited
a pair of doublets in an AB splitting pattern in the 31P{1H} spectrum,
2
with a JPP coupling of 37 Hz. The only isomer matching this
splitting pattern is 3, which was confirmed as the product by X-ray
crystallography. A view of the structure of 3 is shown in Figure 4,
together with the atomic numbering system; selected bond lengths
3036 Inorganic Chemistry, Vol. 47, No. 8, 2008

Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand
Figure 6. 1H NMR spectra of (a) trans,cis,cis-isomer 2 in CD2Cl2, (b) cis,cis,trans-isomer 4 in CD2Cl2, and (c) cis,cis,cis-isomer 3 in CDCl3 at 298 K, 300
MHz.
Table 3. Selected Bond Angles and Bond Lengths for the Solid-State
Structure of 4
molecule a
molecule b
Bond Lengths (Å)
Ru(1)-Cl(1)
Ru(1)-P(1)
Ru(1)-N(11)
Ru(1)-Cl(2)
Ru(1)-P(2)
Ru(1)-N(21)
2.4883(5) Ru(2)-Cl(3)
2.2915(5) Ru(2)-P(3)
2.1016(15) Ru(2)-N(31)
2.4907(5) Ru(2)-Cl(4)
2.2808(5) Ru(2)-P(4)
2.1042(15) Ru(2)-N(41)
2.4815(5)
2.2934(5)
2.1035(16)
2.4752(5)
2.2794(6)
2.1053(17)
Bond Angles (deg)
Cl(2)-Ru(1)-P(1) 177.22(18)
Cl(1)-Ru(1)-P(2) 170.54(19)
N(11)-Ru(1)-N(21) 174.36(6)
Cl(3)-Ru(2)-P(4) 174.21(19)
Cl(4)-Ru(2)-P(3) 174.98(2)
N(31)-Ru(2)-N(41) 173.33(6)
P(1)-Ru(1)-N(11)
P(2)-Ru(1)-N(21)
Cl(1)-Ru(1)-Cl(2)
P(1)-Ru(1)-P(2)
93.31(5)
92.93(5)
82.84(17)
94.74(19)
P(3)-Ru(2)-N(31)
P(4)-Ru(2)-N(41)
Cl(3)-Ru(2)-Cl(4)
P(3)-Ru(2)-P(4)
93.40(5)
93.20(5)
86.76(19)
96.43(19)
The solid-state structure of 4 was also determined using X-ray
crystallography. The crystals consisted of two crystallographically
independent but almost identical molecules (a and b). A view of
the structure of one of the molecules (a) is shown in Figure 5,
together with the atomic numbering system; selected bond lengths
and angles are give in Table 3.
Figure 7. ORTEP depiction of trans,cis,cis-OsCl2(PyP)2 (5) at 30%
probability levels. H atoms have been omitted for clarity.
on the ethyl backbone appearing at 5.29 and 2.67 ppm for the
-NCH2 and -PCH2 groups, respectively, and was similar to the
spectrum of the analogous Ru compound 2. The 31P NMR spectrum
showed the expected singlet but with a significantly different
chemical shift at -28.2 ppm to those of the equivalent ruthenium
compounds.
The solid-state structure of 5 was characterized by X-ray
crystallography. The crystals consisted of two crystallographically
independent but almost identical molecules (a and b). A view of
the structure of molecule a of 5 is shown in Figure 7, together
with the atomic numbering system; selected bond lengths and angles
are given in Table 4.
Synthesis of trans,cis,cis-OsCl2(PyP)2 (5) and cis,cis,trans-
OsCl2(PyP)2 (6). The trans,cis,cis-isomer of 5 was synthesized in
the same manner as the analogous Ru compound 2 by addition of
dichloromethane to a mixture of 1 mol equiv of OsCl2(PPh3)3 and
2 mol equiv of PyP with stirring at room temperature for 5 h. The
order of addition of ligand and metal precursor in this case was
not important, with clean product being formed in high yields
whether solvent was added to a mixture of the starting materials
or a solution of the ligand was added slowly to OsCl2(PPh3)3.
1
The H NMR spectrum exhibited the expected peaks attributed
to the protons of the 1 ligand, with the resonances due to the protons
Inorganic Chemistry, Vol. 47, No. 8, 2008 3037

Dabb et al.
Table 4. Selected Bond Angles and Bond Lengths for the Solid-State
Structure of 5
Scheme 3
molecule a
molecule b
Bond Lengths (Å)
Os(1)-Cl(1)
2.431(3) Os(2)-Cl(3)
2.276(3) Os(2)-P(3)
2.150(8) Os(2)-N(311)
2.435(3) Os(2)-Cl(4)
2.289(3) Os(2)-P(4)
2.179(9) Os(2)-N(411)
2.436(3)
2.289(3)
2.149(9)
2.432(3)
2.294(3)
2.155(9)
Os(1)-P(1)
Os(1)-N(111)
Os(1)-Cl(2)
Os(1)-P(2)
Os(1)-N(211)
Bond Angles (deg)
N(211)-Os(1)-P(1) 171.9(3)
N(111)-Os(1)-P(2) 171.1(2)
N(411)-Os(2)-P(3) 171.8(3)
N(311)-Os(2)-P(4) 170.6(3)
Cl(1)-Os(1)-Cl(2)
P(1)-Os(1)-N(111)
P(2)-Os(1)-N(211)
165.79(10) Cl(3)-Os(2)-Cl(4)
168.43(10)
88.9(3)
87.4(3)
were monitored for conversion to isomer 2 and 4, respectively, with
and without the addition of excess [n-Bu4N]Cl. The formation of
isomer 2 from isomer 4 in dichloromethane was significantly slower
in the presence of [n-BuN4]Cl, as isomer 4 was still present in the
solution after 7 days whereas isomer 4 was fully converted to isomer
2 after only 5 days when no tetrabutylammonium chloride was
added. Similar suppression of isomerization was seen for the
complex 2, where a mixture of isomers 3 and 4 was formed in a
ratio of 2:5, respectively, after leaving a mixture of [n-Bu4N]Cl
and isomer 2 in EtOH after 22 h, and isomer 2 was converted fully
to isomer 4 in the absence of [n-BuN4]Cl after the same time.
Binuclear Complexes of Ru and Os. A series of complexes
with the general formula [Ru(µ-Cl)](PyP)2]2[X]2 (where X )
OSO2CF3, BF4, or BPh4) was synthesized by three different methods
(Scheme 3).
Upon addition of 1 equiv of either AgOSO2CF3 or AgBF4 to a
solution of 2 in dichloromethane and after removal of AgCl by
filtration, the complexes [Ru(µ-Cl)(PyP)2]2[X]2 (where X )
OSO2CF3 (7) or BF4 (8)) were isolated in good yields (Scheme 3).
The product 7 was fully characterized, with X-ray crystallography
confirming the dimeric structure of the complex. Addition of
AgOSO2CF3 to the cis,cis,trans-isomer (4) yielded the same product
(7) as the addition of AgOSO2CF3 to the trans,cis,cis-isomer (2).
TlOSO2CF3 was also used instead of AgOSO2CF3 to yield 7 under
the same reaction conditions.
It was established that silver salts were not necessary for chloride
abstraction. When trans,cis,cis-RuCl2(PyP)2 (2) was refluxed in
EtOH with 1 equiv of NaBPh4, the dimeric complex [Ru(µ-
Cl)(PyP)2]2[BPh4]2 (9) was formed in good yield. Performing the
reaction in dichloromethane at room temperature yielded only
starting material. The BPh4- analogue was also synthesized through
counterion displacement, where NaBPh4 was added to [Ru(µ-
Cl)(PyP)2]2[OSO2CF3]2 (7) in dichloromethane to produce [Ru(µ-
Cl)(PyP)2]2[BPh4]2 (9).
The NMR spectra of all of the binuclear complexes were similar
(not including differences due to the resonances due to the
counterions). The bimetallic species has a similar geometry to the
monomeric cis,cis,trans-isomer 4, with both P nuclei trans to a Cl-,
and the N-donor atoms of the ligand both trans to each other.
31P{1H} spectra contained one singlet at a similar chemical shift to
that of the Ru starting material 2. The inequivalence of the
resonances due to the protons of the two Ph rings of -PPh2 in the
1H NMR spectrum indicated that the rings are unable to rotate
freely, most likely due to significant steric hindrance. The rigidity
of the ethyl backbone of the ligand seen in the cis,cis,cis- and
cis,cis,trans-isomers is not apparent in the dimer, with the
resonances due to the pairs of geminal protons of each methylene
group of the complexes 7, 8, and 9 being magnetically equivalent.
The m/z peak due to the cationic species [RuCl(PyP)2]+ (or
[Ru(µ-Cl)(PyP)2]22+) was observed by mass spectrometry for
complexes 7 and 9.
89.5(2)
88.4(3)
N(311)-Os(2)-P(3)
P(4)-Os(2)-N(41)
Scheme 2
6 was synthesized in a similar manner to the analogous Ru isomer
4, with refluxing in EtOH for 2 h. Complex 6 was characterized
fully by NMR spectroscopy, mass spectroscopy, and microanalysis.
The 1H NMR spectrum of 6 mimics that of ruthenium complex 4,
with the protons of the phenyl groups and the geminal -NCH2-
protons within the ligand being magnetically inequivalent. The 31
P
NMR spectrum exhibits a singlet at -22.4 ppm, which shows the
same upfield trend as the osmium isomer 5.
Exchange between Isomers of RuCl2(PyP)2 and OsCl2(PyP)2.
It was found that isomerization of RuCl2(PyP)2 can be induced
through changes in the reaction conditions, such as solvent and
temperature (Scheme 2), as observed by NMR spectroscopy.
In solution both 3 and 4 are less stable toward isomerization
than isomer 2, with both species isomerizing completely into 2 in
chlorinated solvents (such as dichloromethane and chloroform). In
ethanol complex 2 isomerizes to complex 3 at room temperature
overnight; complex 3 then further isomerizes to complex 4 after
another 24 h at room temperature in ethanol. In both chloroform
and dichloromethane, complex 3 converts back to a mixture of
isomers 2 and 3, with full conversion of 3 to 2 after 2 days. The
trans,cis,cis-isomer 2 converts fully to the cis,cis,trans-isomer 4
upon refluxing in ethanol for a few hours. Isomer 4 is stable in
chlorinated solvents for 2 days but converts almost entirely back
to the trans,cis,cis-isomer 2 after a week at room temperature in
dichloromethane. The three isomers 2, 3, and 4 exhibit no
isomerization in tetrahydrofuran or acetone.
5 converts to 6 upon refluxing in ethanol, in a similar fashion to
the ruthenium analogue 2. cis,cis,cis-OsCl2(PyP)2 was observed by
NMR spectroscopy upon allowing 6 to stand in a CDCl3 solution
over 1 week, but attempts to isolate this complex led only to
recovery of the original isomer 6. The cis,cis,trans-isomer 6 was
synthesized cleanly, and was stable toward isomerization in CD2Cl2
solutions, unlike the analogous ruthenium complex 4.
The isomerization of the Ru complexes in solution was also
investigated in the presence of excess tetrabutylammonium chloride,
which is a source of chloride ions. The presence of [n-Bu4N]Cl is
expected to suppress isomerization of the ruthenium complexes if
the isomerization process is due to labilization of the Cl- coligand.
Solutions of isomer 4 in dichloromethane and isomer 2 in ethanol
3038 Inorganic Chemistry, Vol. 47, No. 8, 2008

Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand
Figure 9. ORTEP depiction of the cation of [Os(µ-Cl)(PyP)2]2[BPh4]2 (10)
at 30% probability levels. H atoms have been omitted for clarity.
Figure 8. ORTEP depiction of [Ru(µ-Cl)(PyP)2]22+, the cation of 7. H
atoms have been omitted for clarity. Atom Ru1_2 was generated by
symmetry.
Table 6. Selected Bond Angles and Bond Lengths for the Solid-State
Structure of [Os(µ-Cl)(PyP)2]2[BPh4]2 (10)a
Table 5. Selected Bond Angles and Bond Lengths for the Solid-State
Structure of [Ru(µ-Cl)(PyP)2]2 [OSO2CF3]2 (7)a
Bond Lengths (Å)
Os(1)-Cl(1)
Os(1)-P(1)
Os(1)-N(11)
2.4875(8) Os(1)-Cl(2)
2.2805(8) Os(1)-P(2)
2.5066(7)
2.2757(8)
2.118(3)
Bond Lengths (Å)
2.114(3)
Os(1)-N(21)
Ru(1)-Cl(1)
Ru(1)-P(1)
Ru(1)-N(111)
2.4774(14) Ru(1)-P(2)
2.2859(14) Ru(1)-N(211)
2.110(2)
2.2915(8)
2.111(2)
Bond Angles (deg)
Cl(1)-Os(1)-P(1)
Cl(1)-Os(1)-P(2)
92.37(3)
171.41(3)
N(11)-Os(1)-N(21) 174.09(10)
P(1)-Os(1)-N(11) 93.27(8)
a Only one-half of the atoms of the dimer are represented due to sym-
metry of the molecule.
Os(1)-Cl(1)-Os(2) 101.46(3)
P(1)-Os(1)-P(2)
P(2)-Os(1)-N(21)
Cl(1)-Os(1)-Cl(2)
96.22(3)
92.86(8)
78.51(2)
Bond Angles (deg)
Cl(1)-Ru(1)-P(1)
Cl(1)-Ru(1)-P(2)
92.40(13) Ru(1)#1-Cl(1)-Ru(1) 99.68(3)
171.73(2) P(1)-Ru(1)-P(2) 95.59(3)
N(111)-Ru(1)-N(211) 174.72(8)
93.54(6)
P(2)-Ru(1)-N(211) 93.71(6)
Cl(1)-Ru(1)-Cl(1)#1 80.32(3)
P(1)-Ru(1)-N(111)
a Atoms labeled with #1 were generated by symmetry.
RuCl2(PyP)2 (2, 3, and 4), and also for trans,cis,cis-OsCl2(PyP)2
(5), [Ru(µ-Cl)(PyP)2]2[OSO2CF3]2 (7), and [Os(µ-Cl)(PyP)2]2-
[BPh4]2 (10). Suitable crystals were grown by slow diffusion of a
nonpolar solvent (either n-pentane or n-hexanes) into a concentrated
dichloromethane or acetone solution of the compound. Crystal-
lographic data for all six compounds are given in Table 7.
The crystallographic asymmetric unit of each complex contained
at least one molecule of solvent: dichloromethane and/or water,
n-pentane, or acetone. These are specified in the crystallographic
table (Table 7). The crystallographic asymmetric unit of isomer 3
consists of one molecule of RuCl2(PyP)2 and one highly disordered
molecule of n-pentane. (The displacement parameters of the
n-pentane molecule have been left isotropic since the disorder could
not be modeled well). The trans,cis,cis-isomers for Ru (2) and Os
(5) have a pseudo C2 symmetry axis that bisects the N-M-N angle
and P-M-P angles. Although Ru isomer 4 has no crystallographi-
cally imposed symmetry in the solid-state, it shows an approximate
C2 symmetry with the pseudo-2-fold axis bisecting the Cl-Ru-Cl
and P-Ru-P angles.
The Ru-Cl, Ru-P, and Ru-N bond lengths in the isomers 2,
3, and 4 of RuCl2(PyP)2 are typical for complexes of the type
RuCl2(P∩N)2 with values between 2.42 and 2.50, 2.26 and 2.31,
and 2.08 and 2.18 Å, respectively. Complexes of this general
formula also typically have a distorted octahedral geometry, as
indicated by axial bond angles less than the ideal 180°.3,4,17,21,24,26
Axial bond angles as low as 158.4(1)° have been observed for
cis,cis,cis-RuCl2(P∩N)2 (isomer C), where P∩N was the ligand
2-(diphenylphosphino)pyridine with a short P∩N bridge.26 All three
isomers presented here, however, exhibit average axial bond angles
with values between 169.54 and 177.22°. This general lack of high
distortion from the ideal angle of 180° seen across all three isomers
indicates there is no reason (due to steric strain) why one isomer
should be formed preferentially over another.
The solid-state structure of [Ru(µ-Cl)(PyP)2]2[OSO2CF3]2 (7) was
determined using X-ray crystallography. A view of the structure
of the cation is shown in Figure 8, together with the atomic
numbering system; selected bond distances and angles are given
in Table 5.
The synthesis of the Os bimetallic species, [Os(µ-Cl)(PyP)2]2[X]2,
could only be achieved via addition of a sodium salt to 5. Reaction
of trans,cis,cis-OsCl2(PyP)2 (5) with AgOSO2CF3 gave a paramag-
netic Os(III) species as indicated by a very broad 1H NMR
spectrum, and mass spectroscopy confirmed that the product
contained the [OsCl2(PyP)2]+ ion. It was concluded that Ag+ had
oxidized the Os(II) starting material; however, reaction with
TlOSO2CF3, which is not regarded as an oxidizing reagent, yielded
the same result. [Os(µ-Cl)(PyP)2]2[BPh4]2 (10) was synthesized by
refluxing 5 and NaBPh4 in EtOH to give a product with comparable
spectroscopic and structural properties to the Ru analogue 9. The
difference in chemical shift of the phosphorus resonance in the 31
P
NMR spectra of the Ru and Os monomeric species 2 and 5 was
mirrored in the bimetallic species, as the Os dimer 10 exhibited a
singlet at a far higher field (-20.5 ppm) than that of the Ru analogue
9 (35.1 ppm).
The solid-state structure of [Os(µ-Cl)(PyP)2]2[BPh4]2 (10) was
determined using X-ray crystallography. A view of the structure is
shown in Figure 9, together with the atomic numbering system;
selected bond distances and angles are given in Table 6.
The complex RuCl(OSO2CF3)(PyP)2 could not be synthesized
through chloride substitution in 2, nor did we see dissociation of
the bimetallic species of either Ru or Os into the five-coordinate
complex [MCl(PyP)2][X]. Low-temperature (<210 K) NMR studies
yielded no evidence of an equilibrium existing between the dimeric
and monomeric complexes in solution.
Structural Information. Solid-state structures determined by
X-ray crystallography were obtained for the three isomers of
Inorganic Chemistry, Vol. 47, No. 8, 2008 3039

Dabb et al.
Table 7. Crystallographic Data for trans,cis,cis-RuCl2(PyP)2 (2), cis,cis,cis-RuCl2(PyP)2 (3), cis,cis,trans-RuCl2(PyP)2 (4), trans,cis,cis-OsCl2(PyP)2 (5),
[Ru(µ-Cl)(PyP)2]2[OSO2CF3]2 (7), and [Os(µ-Cl)(PyP)2]2[BPh4]2 (10)
2
3
4
6
5
9
empirical formula 2·1.5(CH2Cl2)·0.25(H2O) 3·(n-pentane)
4·1.5(CH2Cl2)
1719.98
monoclinic
P21/n
15.0764(1)
17.1534(1)
28.8099(3)
100.6436(3)
7322.39(8)
1.560
6·6(CH2Cl2)
2201.92
monoclinic
C2/c
33.779(7)
12.670(3)
26.597(5)
126.83(4)
9111(3)
1.605
5·2(CH2Cl2)
1813.24
monoclinic
P21/n
10.250(2)
19.019(4)
37.938(8)
92.48(3)
7389(3)
1.630
9·4(C3H6O)
2443.33
monoclinic
P21/n
18.4958(1)
30.2710(2)
20.4361(2)
97.2536(4)
11350.32(15)
1.430
M (g mol-1
)
864.50
792.61
crystal system
space group
a (Å)
b (Å)
c (Å)
orthorhombic
Pccn
18.5441(3)
39.6000(6)
10.2814(2)
monoclinic
P21/n
11.656(2)
15.015(3)
21.886(4)
98.44(3)
3789.1(13)
1.389
b (deg)
3
V (Å )
7550.1(2)
1.521
Dc (g·cm-3
)
Z
8
4
8
4
4
4
T (K)
200(2)
0.71073
200(2)
0.71073
0.672
200(2)
0.71073
0.913
200(2)
0.71073
0.925
200(2)
0.71073
3.858
200(2)
0.71073
2.398
λ (Mo KR) (Å)
µ (Mo KR) (mm-1) 0.887
crystal size (mm) 0.37 × 0.25 × 0.09
0.14 × 0.13 × 0.12 0.50 × 0.28 × 0.19 0.21 × 0.15 × 0.14 0.14 × 0.12 × 0.09 0.47 × 0.38 × 0.21
crystal color
crystal habit
yellow
plate
yellow
cube
yellow
plate
yellow
prism
yellow
prism
orange
plate
2θ
(deg)
hkl range
55
55
55
55
55
55
max
-23 f 24
-51 f 46
-13 f 13
87165
-15 f 15
-19 f 18
-28 f 28
72220
-19 f 19
-22 f 22
-37 f 37
145653
16722
-43 f 43
-16 f 16
-34 f 31
97540
-12 f 12
-22 f 20
-45 f 44
62906
-23 f 24
-39 f 39
-26 f 26
191655
25984
N
Nind
8647
8672
10432
12347
(Rmerge 0.075)
4654
(Rmerge 0.098)
6120
1.036
0.0489
0.0828
(Rmerge 0.039)
13871
0.957
0.0279
0.0759
(Rmerge 0.056)
7969
0.991
0.0414
0.0600
(Rmerge 0.069)
9152
1.230
0.0679
0.1025
(Rmerge 0.059)
18018
0.956
0.0242
0.0733
Nobs (I > 2θ(I))
GoF(all)
0.992
R1a (F, I > 2σ(I)) 0.0270
wR2b (F2, all data) 0.0993
a R1 ) ∑|Fo| - |Fc |/∑|Fo| for Fo > 2σ(Fo). b wR2 ) (∑w(Fo - Fc )2/∑(wFc )2)1/2 all reflections.
2
2
2
The synthesis of a series of stereoisomers of RuCl2(PyP)2 enables
us to compare bond lengths for Ru-Cl, -P, and -N trans to each
of the donor atoms N, P, and Cl. It is expected that all bonds trans
to P will be long, due to the high trans influence of P relative to Cl
and N donor ligands. Cl- and N-donor ligands have similar trans
influences, with halides being slightly stronger.34,35 The Ru-N bond
lengths, which demonstrate the most distinctive trend across 2, 3,
and 4, do not show this predicted pattern, with bonds trans to Cl
being shorter than those trans to N. Similarly, the Ru-Cl bond
lengths are shortest when trans to Cl, and comparable when trans
to either P or N. Ru-P bonds trans to either N or Cl give
comparable lengths. P-donors do not occur trans to each other in
any of the isomers due to phosphorus’s high trans influence.
The higher than expected trans influence of the pyrazole moiety
could induce ligand dissociation which would contribute to the
ability of ruthenium complexes containing PyP (1) to isomerize in
solution.
trans,cis,cis-Osmium complex 5 has very similar crystallographic
properties to its Ru analogue 2. The M-Cl, M-N, and M-P bond
lengths and P-M-N bite angles of the PyP ligand are almost
identical in 2 and 5. The only significant differences are the
Cl-M-Cl bond angles, with the osmium complex 5 showing
greater distortion from the ideal octahedral geometry (165.79(10)
and 168.43(10) Å compared to 171.38(3) Å for 2). This can be
attributed to the larger atomic radius of its metal center.
one perpendicular to the MCl2M plane, which is seen in similar
compounds reported previously.30 The structure of the Os dimer
10 was analogous to the structure of the Ru dimer 7, with respect
to all bond angles and lengths.
The Ru-Cl bond lengths for complexes which contain the RuCl2Ru
fragment are usually close to 2.46 Å, and the Ru-Cl-Ru and
Cl-Ru-Cl bond angles lie within the ranges 95.1–98.4 and 81.6–84.9
Å, respectively.36–40 [Ru(µ-Cl)(PyP)2]2[OSO2CF3]2 has a Ru-Cl bond
length of 2.48(14) Å, and Ru-Cl-Ru and Cl-Ru-Cl bond angles
which fall just outside these values, 99.68(3) and 80.32(3)°, respec-
tively. It is thought longer Ru · · ·Ru distances are needed to allow
dissociation of the dimer into the five-coordinate species, as has been
observed for a similar compound with average Ru-Cl-Ru and
Cl-Ru-Cl bond angles of 101.85 and 78.15°, respectively.30
Experiments with CO. The reactivity of both 2 and the
ruthenium dimer 9 (containing the BPh4- counterion) with carbon
monoxide was tested by monitoring a DCM-d2 solution of each
metal complex under an atmosphere of COg by NMR spectroscopy
(in the case of 2 at -60 °C and room temperature and in the case
1
of 9 at room temperature). The H, 13C, and 13P NMR spectra
indicated that at room temperature both 2 and 9 did indeed react
cleanly with COg to form new products.
CO is a strongly binding ligand; hence it easily causes the dimeric
9 to dissociate into monomeric units by binding to the Ru center,
most likely trans to the P donor atoms, forming complex 11
(Scheme 4). This was confirmed by the 31P NMR spectrum, which
shows a pair of doublets at 28.8 and 0.1 ppm (Hz coupling ) 25.7).
This splitting pattern is typical for inequivalent P atoms which are
cis to each other. The chemical shifts exhibited here are comparable
As mentioned earlier, the dimeric species 7 and 10 have the same
configuration about the metal center as the cis,cis,trans-isomers 4
and 6, with both P atoms trans to Cl. The complexes have three
2-fold axes of symmetry, one through Cl · · · Cl and M · · · M and
(31) Khan, M. M. T.; Reddy, A. D. Polyhedron 1987, 6, 2009–2018.
(32) Bressan, M.; Rigo, P. J. Inorg. Nucl. Chem. 1976, 38, 592–593.
(33) Shen, J.-Y.; Slugovc, C.; Wiede, P.; Mereiter, K.; Schmid, R.; Kirchner,
K. Inorg. Chim. Acta 1998, 268, 69–76.
(34) Appleton, T. G.; Clark, H. C.; Manzer, L. E. Coord. Chem. ReV. 1973,
10, 335–422.
(35) Coe, B. J.; Glenwright, S. J. Coord. Chem. ReV. 2000, 203, 5–80.
(36) Southern, T. G.; Dixneuf, P. H.; Marouille, Y. L.; Grandjean, D. Inorg.
Chem. 1979, 18, 2987–2991.
(37) Teulon, P.; Roziere, J. J. Organomet. Chem. 1981, 214, 391–397.
(38) Deschamps, B.; Mathey, F.; Fischer, J.; Nelson, J. H. Inorg. Chem.
1984, 23, 3455–3462.
3040 Inorganic Chemistry, Vol. 47, No. 8, 2008

Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand
Scheme 4. All Experiments Performed at RT in CD2Cl2 unless
Otherwise Stated
the first example of three of the possible five stereoisomers
of a complex of general formula RuCl2(P∩N)2 being syn-
thesized. All five complexes were characterized by NMR
spectroscopy and exhibited a certain amount of rigidity and
steric hindrance about the ligands of the complexes in the
solution state. Four of the complexes, 2, 3, 4, and 5, were
also characterized by X-ray crystallography, which confirmed
their geometry and showed negligible distortion from other
similar literature compounds.
The isomerization of the Ru and Os complexes of the type
MCl2(PyP)2 was investigated under a range of reaction
conditions. The isomers formed in chlorinated solvents
differed from those formed in ethanol. Tetrahydrofuran and
acetone induced no isomerization in the complexes. The
osmium analogue 5 of the ruthenium complex 2 exhibited
similar isomerization processes which is unsurprising con-
sidering the similar spectroscopic and structural properties
of 2 and 5. Osmium complex 6, however, was far more stable
toward isomerization than the analogous ruthenium complex
4; this could be due to the larger atomic radius of Os
compared to Ru, which would decrease the degree of steric
strain about the metal center. The bimetallic analogues of
the above complexes, [M(µ-Cl(PyP)2]2[X]2 (where M ) Ru
or Os and X ) OSO2CF3, BF4 or BPh4), (7–10), were
synthesized either by addition of a silver salt at room
temperature in dichloromethane or by addition of a sodium
salt in EtOH at reflux to complexes 2 or 5. No dissociation
of the chloride of the starting material 2 or 5 was seen
without the presence of counterion. The solid-state structures
of these complexes were also determined using X-ray
crystallography.
The isomerization of Ru isomers 2, 3, and 4 in solution
could be due either to the hemilability of the bidentate PyP
ligand or to dissociation and reassociation of the Cl- ligand.
If the PyP is hemilabile, the “opening” and subsequent
recoordination of one ligand arm to a different position on
the metal center could induce isomerization of the complex.
It is generally observed that the N-donor is more weakly
coordinating and, hence, is the most likely donor to labilize/
recoordinate.9,11 Dissociation and reassociation of the chlo-
ride anion would lead to the same product. In situ NMR
studies of the reaction of 2 and 9 with carbon monoxide
showed that these compounds react cleanly with CO.
Complex 14, which was formed from reaction with CO and
2, exhibited dissociation of the N-donor atom of PyP and no
dissociation of Cl-. The reactivity of 2 with CO, and stability
of the subsequent complex 14, indicated that the mechanism
of isomerization between the three isomers could be due to
the hemilability of the PyP ligand. However, it is possible
that hemilability of the PyP ligand might be induced only
through binding of a strong donor ligand, such as carbon
monoxide. Suppression of isomerization between the ruthe-
nium complexes in the presence of excess chloride ions was
observed through studies of solutions of 2 and 4 with
tetrabutylammonium chloride. This indicates that the isomer-
ization process most likely involves dissociation and rebind-
ing of the Cl- coligand, with the possibility of Ru-N bond
dissociation also occurring.
a
Performed at RT and -60 °C.
to compounds similar to 11 which have been previously reported.30
We saw no isomerization of 11, even after 48 h at room temperature.
The initial 31P NMR spectra of the reaction between CO and 2
exhibited a pair of doublets at 30.1 ppm and 1.8 ppm (Hz coupling
) 30.2 Hz) which is indicative of inequivalent cis P atoms about
the metal center, and similar to product 11 (or the analogous 12).
The 1H NMR spectrum, however, was significantly different to that
of 11, which suggests the product is not 12 but 13. Complex 13,
undergoes isomerization after only a few hours at room temperature,
into the new product 14 (Scheme 4). This new isomer exhibited a
pronounced AB splitting pattern in the 31P{1H} spectrum, with a
pair of coupled doublets at 24.5 and 15.5 ppm (JPP ) 335.7 Hz).
The 13C{1H} resonances of the carbonyl group of 14 appeared as
a triplet in the 13C NMR spectrum, with a chemical shift of 205.3
ppm (JCP ) 15.3 Hz). The splitting patterns exhibited in both the
31P{1H} and 13C{1H} spectra are indicative of a complex containing
two inequivalent P atoms which are trans to each other and can
best be attributed to a complex such as 14.
Complex 14 was isolated when the reaction was performed on
a large scale; the ruthenium complex 2 was stirred under an
atmosphere of COg for 8 h, the subsequent removal of solvent
yielded 14 as a yellow solid, as confirmed by electrospray mass
spectroscopy. The mass spectrum exhibited a m/z peak for the
positively charged ion [RuCl2(CO)(PyP)2 + H]+; for such a species
to exist the complex must contain one ligand bound through only
one donor atom. The splitting pattern of the 31P and 13C NMR
spectra indicate then that where one of the PyP ligands is pendant
the P-donor atom remains bound to the metal center.
Conclusions
trans,cis,cis-RuCl2(PyP)2 (2), cis,cis,cis-RuCl2(PyP)2 (3),
cis,cis,cis,trans-RuCl2(PyP)2 (4), trans,cis,cis-OsCl2(PyP)2
(5), and cis,cis,trans-OsCl2(PyP)2 (6) have been synthesized
from PyP and MCl2(PPh3)3 (where M ) Ru or Os). This is
(39) Kojima, T.; Matsuo, H.; Matsuda, Y. Inorg. Chim. Acta 2000, 300–302,
661–667.
(40) Marchenko, A. V.; Huffman, J. C.; Valerga, P.; Tenorio, M. J.; Puerta,
M. C.; Caulton, K. G. Inorg. Chem. 2001, 40, 6444–6450.
Inorganic Chemistry, Vol. 47, No. 8, 2008 3041

Dabb et al.
(m, P CH2) ppm. ESI-MS (DCM), m/z (%): 732.1 (100) [M+]. IR
(KBr disk) υ 3022 (m), 1434 (s), 1098 (s), 744 (s), 696 (s), 522 (s)
Experimental Section
All reactions were performed under N2(g) or Ar(g). Solvents were
purified and dried under Ar(g) using conventional methods.41 Except
where specified, chemicals were purchased from either Aldrich
Chemical Co., Inc., Precious Metals Online PMO P/L, or Cambridge
Isotope Laboratory and used as received unless otherwise stated.
[n-Bu4N]Cl·H2O was recrystallized from acetone/Et2O and dried
cm-1
.
Synthesis of cis,cis,cis-RuCl2(PyP)2 (3). PyP (0.254 g, 0.906
mmol) and RuCl2(PPh3)3 (0.433 g, 0.452 mmol) were refluxed in
toluene (30 mL) for 4 h, during which time the red suspension
became tan colored. The mixture was filtered and the tan solid
washed with EtOH (3 × 10 mL) and MeOH (2 × 10 mL). The
combined washings were concentrated in vacuo, and Et2O was
sadded to precipitate out a yellow solid which was collected by
filtration. The solid was recrystallized from DCM/Et2O. Yield: 0.111
g, 34%.
Crystals suitable for X-ray crystallography were grown from
DCM/n-pentane layering to give yellow cubes. (This method
produced a mixture of crystals of both trans,cis,cis-RuCl2(PyP)2
and cis,cis,cis-RuCl2(PyP)2.)
1
in vacuo for 6 h. The H, 31P, and 13C spectra were recorded on
1
Bruker DPX300, DMX500, or DMX600 spectrometers. H NMR
and 13C NMR chemical shifts were referenced internally to residual
solvent resonances. 31P NMR was referenced externally using
H3PO4 (85% in D2O) in a capillary taken to be at 0.0 ppm. 19F was
referenced externally using R,R,R-trifluorotoluene in CDCl3. IR
spectra were recorded using an ATI Mattson Genesis Series FTIR
spectrometer or an Avatar 370 FTIR spectrometer as KBr disks.
Elemental analyses were carried out at the Campbell Microanalytical
Laboratory, University of Otago, New Zealand. Single-crystal X-ray
analysis was performed by Dr. Matthew Smith and Dr. Anthony
Willis at the Research School of Chemistry, Australian National
University, Canberra. X-ray diffraction data were measured at 200
K on a Nonius KappaCCD diffractometer using Mo KR radiation.
Intensity data were collected with ψ and ω scans and corrected for
absorption analytically. The structures were solved with the use of
SIR92 and refined using the SHELXL-97 or CRYSTALS software
packages. Mass spectra were acquired at the BioAnalytical Mass
Spectrometry Facility (BMSF), University of New South Wales.
ESI-MS were performed by Dr. Russel Pickford or Tharusha
Jayasena using a Finnigan or Micromass QToF mass spectrometer.
In reporting mass spectral data, M is defined as the molecular weight
of the compound of interest. In the case of the ESI-MS of cationic
compounds, M is defined as the molecular weight of the cationic
fragments.
Anal. Calcd for C34H34Cl2N4P2Ru·CH2Cl2: C, 51.42; H, 4.44;
1
N, 6.85. Found: C, 51.67; H, 4.88; N, 6.85. H NMR (300 MHz
CDCl3) δ 9.07 (br d, J ) 1.9 Hz, 1H, H′5), 8.30 (m, 2H, -CH of
PPh2), 7.72 (t, J ) 9.4 Hz, 2H, -CH of PPh2), 7.56 (br s, 1H,
H′3), 7.40 (t, J ) 8.7 Hz, 2H, -CH of PPh2), 7.23–7.16 (m, 6H,
H3 and -CH of PPh2), 7.03–6.90 (m, 5H, -CH of PPh2), 6.73
(m, 2H, -CH of PPh2), 6.53 (d, J ) 1.9 Hz, 1H, H5), 6.44–6.34
(m, 3H, H′4 and -CH of PPh2), 5.86 (t, J ) 2.6 Hz, 1H, H4),
5.53–5.40 (m, 1H, -NC′H), 5.22–5.08 (m, 1H, -NCH), 4.61–4.45
(m, 1H, -NC′H), 3.78–3.62 (m, 1H, -NCH), 3.12–2.99 (m, 1H,
-PCH), 2.71–2.62 (m, 1H, -PC′H), 2.54–2.30 (m, 2H, -NCH
and -NC′H) ppm. 31P{1H} NMR (121 MHz, CDCl3) δ 35.9 (d,
2J(P-P) ) 36.1 Hz), 29.1 (d, 2J(P-P) ) 37.0 Hz) ppm. 13C{1H} NMR
(150 MHz, CD2Cl2) δ 146.0 (m, C5 and C′5), 138.9–135.8 (m, 4
× ipso-C of PPh2), 134.9 (s, -C6H5), 134.3 (s, -C6H5 or C3),
133.6 (s, C′3), 132.9 (d, J ) 8.7 Hz, -C6H5), 132.0 (d, J ) 8.43
Hz, -C6H5), 129.5 (s, -C6H5 or C3), 129.0 (s, -C6H5 or C3),
129.0 (s, -C6H5), 127.8 (m, 2 × -C6H5), 127.7 (d, J ) 9.5 Hz,
-C6H5), 127.2 (s, -C6H5 or C3), 127.1 (s, -C6H5 or C3), 106.1
(s, C4), 105.7 (s, C’4), 47.2 (s, -N CH2 and -N C’H2), 31.5 (d, J
) 25.6 Hz, -P C′H2), 23.7 (d, J ) 28.4 Hz, ′-PCH2) ppm. ESI-MS
(DCM), m/z (%): 663.3 (100) [M - 2Cl]+, 697.0 (50) [M - Cl]+,
732.0 (20) [M]+. IR (KBr disk) υ 3643 (br), 3446 (br), 3053 (br),
The ligand PyP28 (1) and complexes RuCl2(PPh3)342 and OsCl2-
43
(PPh3)3 were synthesized by following the reported methods.
Synthesis of trans,cis,cis-RuCl2(PyP)2 (2). Dichloromethane
(DCM) (50 mL) was added to a mixture of RuCl2(PPh3)3 (1.060 g,
1.106 mmol) and PyP (0.628 g, 2.241 mmol) to produce a red
solution which was stirred for 5 h. The solution was concentrated
in vacuo and n-hexanes added to produce a yellow precipitate. The
solid was collected by filtration, washed thoroughly with n-hexanes
(3 × 10 mL), and dried in vacuo to give a yellow solid. Yield:
0.728 g, 90%.
The product was recrystallized from DCM/n-hexanes and then
redissolved in DCM and filtered through celite. n-Hexanes was
layered over the filtrate to give yellow plates suitable for X-ray
crystallography.
Anal. Calcd for C34H34Cl2N4P2Ru·2H2O: C, 53.13; H, 4.98; N,
7.29. Found: C, 52.82; H, 4.69; N, 7.17. 1H NMR (600 MHz, THF-
d8) δ 7.72 (d, 3J(H4-H3) ) 1.8 Hz, 2H, H5), 7.50 (m, 2H, H3), 7.33
(m, 8H, o-C H of PPh2), 7.11 (apparent t, J ) 7.0 Hz, 4H, p-C H
of PPh2), 6.95 (apparent t, J ) 7.5 Hz, 4H, m-C H of PPh2), 6.19
(apparent t, 3J(H3-H4,H5-H4) ) 2.2 Hz, 2H, H4), 5.39 (br s, 4H, NC
H2), 2.65 (m, 4H, PC H2) ppm. 31P{1H} NMR (121 MHz, CDCl3)
δ 34.4 (s) ppm. 13C{1H} NMR (151 MHz, THF-d8) δ 146.7 (s,
C5), 139.8 (br s, ipso-C of PPh2), 134.7 (apparent t, J ) 0.03 Hz,
o-C of PPh2), 132.8 (s, C3), 128.4 (s, p-C of PPh2), 126.8 (apparent
t, J ) 0.03 Hz, m-C of PPh2), 104.4 (s, C4), 48.3 (s, N CH2), 34.6
1622 (s), 1434 (s), 1101 (s), 850 (s), 745 (s), 697 (s) cm-1
.
Synthesis of cis,cis,trans-RuCl2(PyP)2 (4). 2 (0.098 g, 0.134
mmol) was refluxed in EtOH for 1.25 h. The reaction mixture was
evacuated to dryness to give a yellow solid. Yield: 0.083 g, 84%.
Crystals suitable for X-ray crystallography were grown from
DCM/n-pentane layering to give yellow plates.
Anal. Calcd for C34H34Cl2N4P2Ru ·H2O·CH2Cl2: C, 50.31; H,
1
4.58; N, 6.71. Found: C, 50.35; H, 4.58; N, 6.69. H NMR (300
3
MHz CD2Cl2) δ 7.83 (d, J(H4-H5) ) 1.3 Hz, 2H, H5), 7.62 (d,
3J(H4-H3) ) 2.2 Hz, 2H, H3), 7.44 (m, 4H, o-CH of PPh), 7.32–7.11
(m, 8H, m-CH and p-CH of PPh, p-C H of PPh′), 6.94 (apparent
t, J ) 7.3 Hz, 4H, m-CH of PPh′), 6.24 (apparent t, J ) 8.2 Hz,
3
4H, o-CH of PPh′), 6.13 (t, J(H3-H4,H5-H4) ) 7.9 Hz, 2H, H4),
5.82–5.70 (m, 2H, -NCHH′), 4.78–4.62 (m, 2H, -NCHH′),
2.80–2.56 (m, 4H, PCH2) ppm. 31P{1H} NMR (121 MHz, CD2Cl2)
δ 32.7 (s) ppm. 13C{1H} NMR (151 MHz, CD2Cl2) δ 148.7 (s,
C5), 137.8 (m, ipso-C of PPh2), 136.3 (m, ipso-C of PPh2), 134.7
(s, C3), 134.1(s, o-C of PPh), 130.4 (s, o-C of PPh′), 129.3 (s, p-C
of PPh′), 129.0 (p-C of PPh), 128.5 (s, m-C of PPh′), 127.3 (s,
m-C of PPh), 105.6 (s, C4), 48.4 (s, N CH2), 25.5 (m, P CH2)
ppm. ESI-MS (DCM), m/z (%): 720.9 (100) [RuCl(PyP)2 + Na]+,
685.2 (20) [Ru(PyP)2 + Na]+. IR (KBr disk) υ 2957 (br s), 1434
(41) Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory
Chemicals, 3rd ed.; Pergamon Press: Oxford, 1993.
(42) Stephenson, T. A.; Wilkinson, G. J. Inorg. Nucl. Chem. 1966, 28,
945–956.
(43) Elliott, G. P.; Mcauley, N. M.; Roper, W. R. Inorg, Synth. 1989, 26,
184–189.
(s), 104 (s), 852 (s), 757 (s), 698 (s) 534 (s) cm-1
.
3042 Inorganic Chemistry, Vol. 47, No. 8, 2008

Ru and Os Complexes Containing a P,N-Donor Heterotopic Ligand
Synthesis of trans,cis,cis-OsCl2(PyP)2 (5). DCM (50 mL) was
added to a mixture of OsCl2(PPh3)3 (0.786 g, 0.750 mmol) and
PyP (0.424 g, 1.51 mmol) to produce a brown solution which was
stirred for 5 h. The solution was concentrated in vacuo and
n-hexanes added to produce an olive-green precipitate. The solid
was collected by filtration, washed thoroughly with n-hexanes (3
× 10 mL), and dried in vacuo to give an olive-green solid. Yield:
0.566 g, 92%.
6.67 (d, 3J(H4-H5) ) 2.0 Hz, 4H, H5), 5.85 (br s, 8H, o-CH of PPh′),
3
5.77 (t, J(H5-H4,
) 2.7 Hz, 4H, H4), 5.10–4.93 (m, 8H,
H3-H4)
NCH2), 2.59 (m, 8H, PCH2) ppm. 31P{1H} NMR (121 MHz,
CD2Cl2) δ 35.1 (s) ppm. 13C{1H} NMR (125 MHz, CD2Cl2) δ 146.5
(s, C3/5), 135.4 (s, C3/5), 134.5 (m, ipso-C of PPh′), 133.2 (s, m-
or p-CH of PPh′), 131.3 (m, ipso-C of PPh′), 130.1 (s, o-CH of
PPh′), 130.0 (s, o-CH of PPh′), 129.6 (m, m- or p-CH of PPh′),
128.6 (s, m- or p-CH of PPh′), 127.5 (s, m- or p-CH of PPh′),
106.6 (s, C4), 47.7 (s, NCH2), 24.9 (m, PCH2) ppm. 19F NMR
(282 MHz, CD2Cl2) δ -79.10 ppm. ESI-MS (DCM), m/z (%):
1325.9 (60) [M - 2Cl + H]+, 748.09 (100). MALDI-TOF, m/z
(%): 697.2 (65) [RuCl(PyP)2]+, 811.2 (95), 850.3 (100). IR (KBr
disk) υ 2958 (m), 2926 (m), 1634 (w), 1435 (s), 1279 (m), 1260
Crystals suitable for X-ray crystallography were grown by DCM/
n-hexanes layering to give yellow prisms.
Anal. Calcd for C34H34Cl2N4P2Os·CH2Cl2: C, 46.36; H 4.00;
1
N, 6.18. Found: C, 46.61; H, 3.83; N, 6.07. H NMR (300 MHz
3
3
CDCl3) δ 7.52 (d, J(H4-H3) ) 2.0 Hz, 2H, H5), 7.33 (d, J(H4-H3)
) 2.0 Hz, 2H, H3), 7.17–7.12 (m, 12H, o-CH of PPh2, p-CH of
(m), 1031 (s), 698 (s), 638 (s) cm-1
.
PPh2), 7.01 (apparent t, J ) 7.7 Hz, 8H, m-C H of PPh2), 6.24
(1b) Synthesis of [Ru(µ-Cl)PyP)2]2[BF4]2 (8) Using AgBF4.
Method is the same as in (1a), but AgBF4 was used in place of
AgOSO2CF3. Yield: 83%.
3
(apparent t, J(H3-H4,
) 2.7 Hz, 2H, H4), 5.29 (br s, 4H,
H5-H4)
NCH2), 2.67 (br s, 4H, PC H2) ppm. 31P{1H} NMR (121 MHz,
CDCl3) δ -28.2 (s) ppm. 13C{1H} NMR (125 MHz, CD2Cl2) δ
145.8 (s, C5), 139.8 (br s, ipso-C of PPh2), 133.7 (s, o-C of PPh2),
132.7 (s, C3), 128.4 (s, p-C of PPh2), 126.7 (s, m-C of PPh2), 104.8
(s, C4), 48.5 (s, N CH2), 33.3 (br s, P CH2) ppm. ESI-MS (DCM),
m/z (%): 822.2 (100) [M+]. IR (KBr disk) υ 3050 (m), 1434 (s),
Anal. Calcd for C80H78B2Cl2F8N8P4Ru2: C, 52.09; H, 4.37; N,
7.15. Found: C, 51.78; H, 4.51; N, 7.16. 31P{1H} NMR (121 MHz,
CD2Cl2) δ 35.0 (s) ppm. 19F NMR (282 MHz, CD2Cl2) δ -153.11
ppm. ESI-MS (DCM), m/z (%): 748.03 (100). IR (KBr disk) υ 2963
(m), 1634 (w), 1434 (s), 1262 (s), 1084 (s), 852 (s), 804 (s), 747
1095 (s), 744 (s), 697 (s), 524 (s) cm-1
.
(s), 698 (s) cm-1
.
Synthesis of cis,cis,trans-OsCl2(PyP)2 (6). trans,cis,cis-OsCl2-
(PyP)2 (52.6 mg, 0.064) was refluxed in EtOH for 2 h. The solution
was cooled to RT and concentrated in vacuo. Et2O was added to
the concentrated solution and the subsequent precipitate collected
by filtration and dried in vacuo to give an olive-green solid. Yield:
33.5 mg, 64%.
(2a) Synthesis of [Ru(µ-Cl)(PyP)2]2[BPh4]2 (9) using NaBPh4
in EtOH. 2 (0.159 g, 0.217 mmol) and NaBPh4 (0.821 g, 0.240
mmol) were refluxed in EtOH for 3.5 h. The resulting suspension
was cooled to RT and the solvent removed in vacuo. The residue
was suspended in DCM and filtered through celite. The filtrate was
concentrated in vacuo and n-hexanes added to precipitate out a
yellow solid which was washed with n-hexanes (2 × 2 mL) and
dried in vacuo. Yield: 0.179 g, 81%.
Anal. Calcd for C34H34Cl2N4OsP2 ·2H2O: C, 46.61; H, 4.47; N,
6.53. Found: C, 47.11; H, 4.45; N, 6.27. 1H NMR (600 MHz
CD2Cl2) δ 7.90 (s, 2H, H5) 7.54 (s, 2H, H3), 7.30 (m, 4H, o-CH
of PPh), 7.23 (m, 2H, p-CH of PPh), 7.17 (m, 4H, m-CH of PPh),
7.09 (apparent t, J ) 7.7 Hz, p-CH of PPh′), 6.92 (apparent t, J )
7.2 Hz, 4 H, m-CH of PPh′), 6.33 (apparent t, J ) 7.7 Hz, 4H,
o-CH of PPh′), 6.12 (s, 2H, H4), 5.59–5.53 (m, 2H, -NCHH′),
4.63–4.55 (m, 2H, -NCHH′), 2.94–2.88 (m, 2H, PCHH′), 2.55–2.50
(m, 2H, PCH H′) ppm. 31P{1H} NMR (121 MHz, CD2Cl2) δ -22.4
(s) ppm. 13C{1H} NMR (125 MHz, CD2Cl2) δ 147.6 (s, C5), 136.8
(m, ipso-C of PPh and PPh′), 133.2 (s, o-CH of PPh, C3), 130.1
(s, o-CH of PPh′), 128.5 (s, p-CH of PPh′), 128.2 (s, p-CH of PPh),
127.8 (s, m-CH of PPh′), 126.7 (s, m-CH of PPh), 105.0 (s, C4),
48.7 (s, -NCH2), 26.2 (m, -PCH2) ppm. ESI-MS (DCM), m/z
(%): 810.9 (100) [OsCl(PyP)2+Na]+. IR (KBr disk) υ 3419 (m),
1434 (s), 1279 (s), 1127 (s), 1106 (s), 697 (s), 746 (s), 698 (s)
Anal. Calcd for C116H108B2Cl2N8P4Ru2: C, 68.54; H, 5.36; N,
5.51. Found: C, 68.25; H, 5.50; N, 5.54. 31P{1H} NMR (121 MHz,
CD2Cl2) δ 34.8 (s) ppm. ESI-MS (DCM), m/z (%): 748.03 (100),
721 (40), 697 (40) [M - Cl]+. MALDI-TOF (DCM), m/z (%):
697.11 (75) [Ru(PyP)2Cl]+, 850.18 (100). IR (KBr disk) υ 3053
(br s), 1479 (s), 1434 (s), 1105 (s), 854 (s), 745 (s), 703 (s) cm-1
.
Synthesis of [Os(µ-Cl)(PyP)2]2[BPh4]2 (10). NaBPh4 (89 mg,
0.260 mmol) was added to a suspension of trans,cis,cis-OsCl2(PyP)2
(0.193 g, 0.235 mmol) in EtOH (30 mL). The mixture was refluxed
for 3 h and then cooled to RT. The solid was collected by filtration
and washed with acetone (7 × 10 mL) to leave behind a white
solid. The washings were combined and evacuated to dryness in
vacuo to give a yellow/green solid. Yield: 0.173 g, 67%.
Crystals suitable for X-ray crystallography were grown from
acetone/n-pentane layering to give orange plates.
cm-1
.
Methods for Synthesis of [Ru(µ-Cl)(PyP)2]2[X]2. (1a) Syn-
thesis of [Ru(µ-Cl)(PyP)2]2[OSO2CF3]2 (7) Using AgOSO2CF3.
Silver triflate (76.6 mg, 0.299 mmol) was added to a solution of 2
(0.219 g, 0.299 mmol) in DCM. The solution was stirred for 3 h,
during which time it became cloudy. The reaction mixture was
filtered through celite and the filtrate concentrated in vacuo.
n-Hexanes was added to produce a dark yellow precipitate which
was collected by filtration, washed with n-hexanes (3 × 3 mL),
and dried in vacuo. Yield: 0.184 g, 72%.
Anal. Calcd for C116H108B2Cl2N8Os2P4: C, 63.01; H, 4.92; N,
1
5.07. Found: C, 62.41; H, 5.04; N, 5.09. H NMR (500 MHz,
3
(CD3)2CO) δ 7.78 (d, J ) 2.3 Hz, 4H, H3), 7.53–7.46 (m, 12H,
p-CH and m-CH of PPh), 7.36–7.33 (m, 16H, o-CH of BPh4), 7.27
(apparent t, J ) 8.5 Hz, 8H, o-CH of PPh), 7.18 (apparent t, J )
7.5 Hz, 4H, p-CH of PPh′), 6.99 (m, 8H, m-CH of PPh′), 6.92
3
(apparent t, J ) 7.4 Hz, 16H, m-CH of BPh4), 6.83 (d, J ) 2.1
Hz, 4H, H5), 6.78 (t, J ) 7.2 Hz, 8H, p-CH of BPh4), 6.08 (m,
3
8H, o-CH of PPh′), 5.84 (t, J(H3-H4,H5-H4) ) 2.6 Hz, 4H, H4),
Crystals suitable for X-ray crystallography were grown by DCM/
n-hexanes layering to give yellow prisms.
5.15–4.99 (m, 8H, NCH2), 2.90–2.84 (m, 4H, PCHH′), 2.72–2.66
(m, 4H, PCH H′) ppm. 31P{1H} NMR (202 MHz, CD2Cl2) δ -20.5
(s) ppm. 13C{1H} NMR (125 MHz, (CD3)2CO) δ 163.9 (q, 1J(B-C)
) 49.60, ipso-C of BPh4), 145.8 (s, C5), 136.1 (s, o-C of BPh4),
135.0 (s, C3), 134.5 (s, ipso-C of PPh), 132.9 (s, o-CH of PPh),
132.3 (s, ipso-C of PPh′), 129.7 (s, m-CH of PPh), 129.7 (s, p-CH
of PPh′), 128.4 (s, m-CH of PPh′), 127.5 (s, p-CH of PPh), 125.0
(s, m-CH of BPh4), 121.3 (s, p-CH of BPh4), 106.2 (s, C4), 48.3
Anal. Calcd for C70H68Cl2F6N8O6P4Ru2S2: C, 49.68; H, 4.05; N,
1
6.62. Found: C, 49.54; H, 4.09; N, 6.45. H NMR (300 MHz,
3
CD2Cl2) δ 7.74 (d, J(H4-H3) ) 2.2 Hz, 4H, H3), 7.48 (t, J ) 7.5
Hz, 4H, p-CH of PPh′), 7.36 (apparent t, J ) 7.5 Hz, 8H, m-C H
of PPh′), 7.21 (m, 8H, o-CH of PPh′), 7.13 (t, J ) 7.3 Hz, 4H,
p-CH of PPh), 6.92 (apparent t, J ) 7.5 Hz, 8H, m-CH of PPh),
Inorganic Chemistry, Vol. 47, No. 8, 2008 3043

Dabb et al.
(s, N CH2), 25.4 (m, P CH2) ppm. MALDI-TOF, m/z (%): 787.3
(80) [OsCl(PyP)2]+, 940.4 (100). IR (KBr disk) υ 3052 (br s), 1481
(s), 1434 (s), 1262 (s), 1012 (s), 1031 (s), 852 (s), 745 (s), 700 (s)
Experiments with [n-Bu4N]Cl. A CD2Cl2 solution of cis,cis,
trans-RuCl2(PyP)2 and a CD2Cl2 solution of cis,cis,trans-RuCl2-
(PyP)2 and [n-Bu4N]Cl (exs) combined were monitored by 1H NMR
and 31P{1H} NMR spectroscopy; spectra were aquired every 24 h
for 7 days.
cm-1
.
Synthesis of RuCl2(CO)(K1-P-PyP)(K2-P,N-PyP) (14). trans,
cis,cis-RuCl2(PyP)2 (0.145 g, 0.198 mmol) was dissolved in DCM
and the solution degassed via one cycle of freeze-vacuum-thaw.
The atmosphere of the flask was replaced with CO(g) from a balloon,
and the solution was stirred for 8 h under this atmosphere. The
solution was evacuated to dryness to give a yellow solid. Yield:
0.094 g, 62%.
A suspension of trans,cis,cis-RuCl2(PyP)2 (26.4 mg, 0.036 mmol)
in EtOH (10 mL) and a suspension of trans,cis,cis-RuCl2(PyP)2
(26.6 mg, 0.036 mmol) and [n-Bu4N]Cl (26.0 mg, 0.094 mmol)
combined in EtOH (10 mL) were stirred for 5 h and then evacuated
1
to dryness to give orange residues. H NMR and 31P{1H} spectra
of the residues in CD2Cl2 were aquired. The two residues were
resuspended in EtOH (10 mL) and stirred for 22 h to give clear
solutions which were evacuated to dryness to give orange residues.
1H NMR and 31P{1H} spectra of the residues in CD2Cl2 were
acquired.
1H NMR (600 MHz, CD2Cl2) δ 7.78–7.75 (m, 4H, Ar H),
7.70–7.66 (m, 4H, Ar H), 7.44–7.34 (m, 15H, 12 × ArH and 3 ×
PyH), 7.21 (d, J ) 2.1 Hz, PyH), 6.16 (apparent t, J ) 1.92 Hz,
1H, H4), 5.88 (apparent t, J ) 2.4 Hz, H4), 5.17–5.12 (m, 2H,
NC′H2), 4.31–4.27 (m, 2H, NCH2), 3.24–3.20 (m, 2H, PCH2),
2.28–2.73 (m, 2H, PC′H2) ppm. 31P{1H} NMR (242 MHz, CD2Cl2)
δ 24.5, 15.5 (AB spin system, J ) 335.7 Hz) ppm. 13C{1H} NMR
(150 MHz, CD2Cl2) δ 205.3 (apparent t, J ) 15.3 Hz, CO), 147.3
(s, PyC), 139.4 (s, PyC), 134.3 (d, J ) 8.9 Hz, ArC), 133.7 (m, 1
× ArC and 1 × PyC) 133.3 (m, ipso-C of PPh2), 132.9 (m, ipso-C
of PPh2), 130.5 (s, PyC), 131.7 (s, PyC) 128.6 (d, J ) 9.3 Hz,
ArC), 128.4 (d, J ) 9.7, ArC), 105.7 (s, C4), 105.5 (s, C4), 47.9
(s, NCH2), 47.7 (s, NC′H2), 28.7 (d, J ) 21.7 Hz, PC′H2), 28.3 (d,
J ) 23.7 Hz, PCH2) ppm. ESI-MS (DCM), m/z (%): 725.0 (100)
[RuCl(CO)(PyP)2]+, 761.0 (50) [RuCl2(CO)(PyP)2 + H]+. IR (KBr
Acknowledgment. Financial support from the Australian
Research Council and The University of New South Wales
is gratefully acknowledged. S.L.D. wishes to thank the
Australian government for an Australian Postgraduate Award
scholarship.
Supporting Information Available: Crystallographic data in
CIF format for complexes 2, 3, 4, 5, 6, and 9. This material is
available free of charge via the Internet at http://pubs.acs.org.
disk) υ 1950 (CO) cm-1
.
IC7019044
3044 Inorganic Chemistry, Vol. 47, No. 8, 2008