Ruthenium complexes of diphenylphosphino derivatives of carboxylic amides: Synthesis and characterization of bidentate P,N- and P,O-chelate ligands and their reactivity towards [RuCl2(PPh3)3]

Article abstract of DOI:10.1016/j.poly.2016.06.013

The carboxylic amides N-methylbenzamide (HLa), phthalimidine (HLb) and pyridine-2-one (HLc) were diphenylphosphino-functionalized (with ClPPh₂and a base, n-BuLi for HLa, triethylamine for HLb and HLc) to yield the N-PPh₂derivatives o

Full text of DOI:10.1016/j.poly.2016.06.013

Accepted Manuscript
Ruthenium Complexes of Diphenylphosphino Derivatives of Carboxylic
Amides: Synthesis and Characterization of bidentate P,N- and P,O-Chelate Li-
gands and their Reactivity towards [RuCl (PPh ) ]
2
3 3
Robert Gericke, Jörg Wagler
PII:
S0277-5387(16)30246-7
DOI:
http://dx.doi.org/10.1016/j.poly.2016.06.013
POLY 12053
Reference:
To appear in:
Polyhedron
Received Date:
Accepted Date:
31 March 2016
9 June 2016
Please cite this article as: R. Gericke, J. Wagler, Ruthenium Complexes of Diphenylphosphino Derivatives of
Carboxylic Amides: Synthesis and Characterization of bidentate P,N- and P,O-Chelate Ligands and their Reactivity
towards [RuCl (PPh ) ], Polyhedron (2016), doi: http://dx.doi.org/10.1016/j.poly.2016.06.013
2
3 3
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Ruthenium Complexes of Diphenylphosphino
Derivatives of Carboxylic Amides: Synthesis and
Characterization of bidentate P,N- and P,O-Chelate
Ligands and their Reactivity towards [RuCl (PPh ) ]
2
3 3
Robert Gericke, Jörg Wagler*
Institut für Anorganische Chemie, Technische Universität Bergakademie Freiberg, D-09596
Freiberg, Germany. E-mail: joerg.wagler@chemie.tu-freiberg.de; Fax: +49 3731 39 4058
Dedicated to Professor Martin A. Bennett on the occasion of his 80th birthday
Key words: Ambidentate Ligands, NMR Spectroscopy, Quantum Chemical Calculations,
Ruthenium, Single-Crystal X-Ray Diffraction
Abstract
The carboxylic amides N-methylbenzamide (HLa), phthalimidine (HLb) and pyridine-2-one
(
HLc) were diphenylphosphino-functionalized (with ClPPh
triethylamine for HLb and HLc) to yield the N-PPh derivatives of N-methylbenzamide (1a) and
of phthalimidine (1b) as well as the O-PPh derivative 2-diphenylphosphinoxypyridine (1c).
Thus, 1a and 1b represent P,O-chelate ligands, whereas 1c is a P,N-chelate ligand. Both P,O-
ligands (1a, 1b) react with [RuCl (PPh ] in a two-step fashion to form mono-chelates with
trans-situated Cl atoms (2a, 2b) upon using a 1:1 stoichiometric ratio or Cl-trans bis-chelates
2
and a base, n-BuLi for HLa,
2
2
2
)
3 3
II
II
(
3a , 3b ) upon using two equivalents of the chelator. In contrast, reaction of [RuCl
2
(PPh
3
3
) ]
I
and the P,N-chelator 1c in 1:1 molar ratio immediately produced a bis-chelate (3c ) with an all-
cis orientation of the ligands (while 50% of the [RuCl
2
(PPh
3
)
3
] starting material remained
I
II
unreacted). Compound 3c slowly isomerizes to the Cl-trans isomer (3c ). All isolated
1

compounds were characterized with multi-nuclear NMR spectroscopy, single-crystal X-ray
diffraction and elemental analysis.
1
. Introducion
Carboxylic amides [1,2] are well known in coordination chemistry as mono-anionic chelating or
bridging ligands. Although N,O-ligands already comprise some hard-soft-ambidenticity, their
functionalization with phosphines enlarges the hard-soft variation in the donor set by formation
of neutral P,N- or P,O-ligands and generation of 1,4-bidentate ligands capable of forming five-
membered chelates. The diversity of products from phosphino-functionalization of carboxylic
amides is attributed to the formation of phosphinoamides (N-PPh
2
derivatives) and phosphinito-
imines (O-PPh derivatives) as possible tautomers [3]. (Furthermore, carboxylic amides with
2
phosphine functionalization in α-position [4,5] or other positions of the organic backbone [6],
have been studied in transition metal coordination chemistry.) In general, the P,N [7] and P,O [8]
bidentate donor sets may exhibit mono- vs. bidentate ligand characteristics, and in combination
with rather soft transition metal atoms the phosphorus atom represents the superior σ-donor over
the N or O atom in case of monodentate binding in the transition metal coordination sphere (A, B
and C in Scheme 1). This hemilabile property is supportive in many catalytic processes like
oligo- and polymerization, carbonylation as well as hydro- and dehydrogenation [8-12].
Moreover, phosphino-functionalized carboxylic amides, which still bear an acidic proton (N−H
moiety) can be utilized as mono-anionic bidentate chelators upon deprotonation, and their
coordination chemistry has been studied with a variety of transition metal compounds (some
examples are shown in Scheme 1, C, D and E) [13,14]. Phosphino-functionalized carboxylic
amides devoid of this acidic N−H feature (or in general lacking the capability of forming the
corresponding anion) can thus only serve as neutral chelators, hence lacking some electrostatic
binding force, which should render these ligands more labile. It is worth noting that literature
reports of investigations of the coordination chemistry of this flexible ligand system with
ruthenium as one of the most versatile catalytically active transitions metals are very scarce. This
served as a motivation for us to investigate the Ru-coordination chemistry of two similar new
P,O-ligands (1a, 1b, Scheme 2) and the barely known P,N-ligand 1c [15,16] starting from their
reactions with [RuCl
2
(PPh
3
3
) ].
2

2
. Experimental
2
.1. General considerations:
All preparations were carried out under an atmosphere of dry argon using standard Schlenk
techniques. Phthalimidine [17] and N-methylbenzamide [18] were prepared following literature
methods. Tetrahydrofuran (THF) and triethylamine were distilled from sodium/benzophenone
and stored under dry argon. Dichloromethane (DCM) was distilled from calcium hydride and
stored under argon. Chloroform (stabilized with amylenes) was stored over molecular sieves 3 Å.
All other chemicals used were commercially available and used without further purification.
Elemental microanalyses (C, H, N) were performed on a ‘Vario Micro Cube’ analyzer
(
Elementar, Hanau, Germany).
Yields of the products are reported with respect to the composition found by elemental analyses.
Purity of the target compound (ligand or complex) and presence of solvent of crystallization (if
1
applicable) were confirmed by H NMR spectroscopy. In some cases, crystals used for single-
crystal X-ray diffraction analyses were grown by recrystallization from other solvents. This is
pointed out where applicable.
2
.2. NMR spectroscopy:
NMR spectra of solutions were recorded on an ‘Avance 500’ or ‘Ascend 400’ spectrometer
1
(
Bruker Biospin, Rheinstetten, Germany) and internally referenced to tetramethylsilane for H
1
3
31
1
1
and C and externally referenced to 85% H
PO
3 4
for P. Signals were assigned by using H, H-
1
13
1
13
COSY, H, C-HSQC and H, C-HMBC spectroscopy.
2
.3. X-ray crystallography:
Single-crystal X-ray diffraction data sets were collected with ω-scans on an ‘IPDS-2(T)’
diffractometer (STOE, Darmstadt, Germany) using Mo K -radiation. The absorption correction
α
was performed with XShape using integration correction type. Structures were solved by direct
methods with ShelXS [19] and all non-hydrogen atoms were anisotropically refined in full-
2
matrix least-squares cycles against |F | (ShelXL) [20]. Hydrogen atoms were placed in idealized
3

positions and refined isotropically (riding model). Selected parameters of data collection and
refinement of the herein presented structures are listed in the Supporting Information (Tables
S20 – S22). In the course of our investigations we determined the crystal structure of
phthalimidine (hitherto unknown) and of the new solvate [RuCl
2
(PPh
3
3
) ]⋅MeOH (see Supporting
Information.)
2
.4. Computational details:
Optimizations of molecular structures were carried out using the Gaussian09 software [21] at
DFT-PBEPBE level with cc-pVTZ for C H N O Cl P atoms and SDD for Ru. NBO analyses
were performed using NBO5.G [22] with Gaussian03 [23] at the DFT-B3LYP/6-311+G(d) level
for all atoms.
2
2 3 3
.5. Synthesis of [RuCl (PPh ) ]
Following literature methods [24, 25], which report the synthesis of [RuCl
commercial RuCl ⋅ 3H O, we prepared [RuCl (PPh ] from elemental Ruthenium without
isolating the intermediate Ru(III)-chloride: A mixture of Ruthenium powder (0.750 g, 7.42
mmol), NaOH (4.00 g, 100 mmol) and NaClO (2.63 g, 24.7 mmol) was cautiously heated in a
2
(PPh
3
)
3
] from
3
2
2
)
3 3
3
crucible (using a Bunsen burner) for 15 min (until the evolution of gas from the deep red melt
ceased). The mixture was allowed to cool to ambient temperature and was then dissolved in
conc. hydrochloric acid (≈ 250 mL). The acidic solution was evaporated to almost dryness by
heating, whereupon further conc. HCl (5 mL) was added and again evaporated by heating (this
was repeated three times) before the volatile components were finally evaporated to dryness. The
residue was dispensed in MeOH (200 mL) and filtered. The solid residue was washed with
MeOH (50 mL). Through the combined filtrate and washings argon was bubbled for 10 min.
Subsequently, the mixture was heated under reflux for 10 min, then PPh
was added and the mixture was heated under reflux for 3h. The precipitate was filtered, washed
with MeOH (10 mL) and Et O (40 mL) and dried in vacuo to yield 6.33g (6.61 mmol, 89%) of
RuCl (PPh ]. This solvent free compound was used as starting material for the following
syntheses.
3
(12.0 g, 45.8 mmol)
2
[
2
)
3 3
4

Prior to the development of the above mentioned protocol, in a test batch a small amount of
crude ruthenium chloride was treated with a larger volume of methanolic PPh solution (stirring,
reflux). Because of the lower concentration of the reactants, the product did not precipitate as a
fine powder but formed some crystals of [RuCl (PPh ]·MeOH , which were analyzed by
3
2
)
3 3
single-crystal X-ray diffraction (see Supporting Information). To the best of our knowledge, this
solvate has not been reported in the literature so far.
Also, for [RuCl
2
(PPh
3
3
) ] we obtained additional spectroscopic data which needs to be mentioned
3
1
here. Whereas Norton et al. [24] reported only one P NMR signal (of PPh
3
, δ = −4 ppm) for a
], we observed a more complex P NMR spectrum of a CDCl
solution of our product. In addition to the main signal at 41.0 ppm (which was very broad) we
observed a signal of PPh and two sets of dublets (both of them characteristic of cis-situated Ru-
bound PPh groups). We attribute these sets of dublets to two diastereomers of the complex
(Ph P) ClRu(µ-Cl) RuCl(PPh ]. This compound has already been characterized
crystallographically [26] and in the solid state each Ru atom carries two chemically different
PPh ligands cis to each other (apical and basal position in a square planar coordination sphere).
3
1
CDCl
3
solution of [RuCl
2
(PPh
3
)
3
3
3
3
[
3
2
2
)
3 2
3
3
1
1
P{ H} NMR (CDCl
3
, δ ppm): 50.9 (d, J = 28.6 Hz), 47.1 (d, J = 28.6 Hz), 41.0 (br. m,
).
[
RuCl (PPh ]), 40.6 (d, J = 25.5 Hz), 39.4 (d, J = 25.5 Hz), −5.4 (s, free PPh
2
3
)
3
3
2
.6. Syntheses of ligands 1a, 1b and 1c
1
a: N-Methylbenzamide (1.01 g, 7.50 mmol) was dissolved in THF (20 mL) and cooled with an
ice/ethanol mixture (to ca. −10°C). A solution of 2.5M n-BuLi in hexanes (3 mL) was added
dropwise. The white suspension was stirred with cooling for 1.5 h and subsequently allowed to
attain room temperature. Chlorodiphenylphosphine (1.66 g, 7.59 mmol) was added and the clear
solution was stirred for 1 h at ambient temperature. The mixture was evaporated to dryness and
subsequently suspended in hot CHCl (40 mL) for 30 min. After cooling to room temperature the
3
suspension was filtered through Celite. From the filtrate the solvent was removed in vacuo and
the residue was recrystallized in THF (3 mL). The white crystalline product was suitable for
single-crystal X-ray diffraction. The supernatant was decanted and the white solid was dried in
vacuo to yield 0.529 g (1.66 mmol, 22%) of 1a.
5

Anal. Calc. for C20H18NOP (MW: 319.3), requires: C, 75.22; H, 5.68; N, 4.39. Found: C, 75.09;
1
H, 5.75; N, 4.40%. H NMR (CDCl
3
, δ ppm): 2.88 (s, -CH
.53 (m, aryl, 2H). C{ H} NMR (CDCl , δ ppm): 32.6 (d, J = 7.6 Hz), 127.8 (d, J = 6.2 Hz),
28.1 (s), 128.7 (d, J = 5.8 Hz), 129.6 (s), 130.2 (s), 132.0 (d, J = 20.7 Hz), 134.9 (d, J = 16.9
3
, 3H), 7.35-7.49 (br. m, aryl, 13H),
1
3
1
7
1
3
3
1
1
Hz), 136.9 (d, J = 3.2 Hz), 177.0 (d, J = 33.4 Hz). P{ H} NMR (CDCl , δ ppm): 57.0 (s).
3
1
b: Phthalimidine (1.60 g, 12.0 mmol) was dissolved in THF (80 mL). Triethylamine (1.34 g,
3.2 mmol) was added dropwise and the mixture was stirred for 5 min at ambient temperature.
1
Chlorodiphenylphosphine (2.65 g, 12.0 mmol) was added and the mixture was stirred for three
days, whereupon the white precipitate was filtered and washed with THF (2×3 mL). The
combined filtrate and washings were evaporated to dryness (condensation of volatiles into a cold
trap under reduced pressure) and the residue was recrystallized from THF (27.5 mL). The white
crystalline product was suitable for single-crystal X-ray diffraction. The supernatant was
decanted, the white solid was washed with Et O (3 mL) and dried in vacuo to yield 2.33 g (7.34
2
mmol, 61%) of 1b.
Anal. Calc. for C20H16NOP (MW: 317.3), requires: C, 75.70; H, 5.08; N, 4.41. Found: C, 75.83;
1
H, 5.18; N, 4.43%. H NMR (CDCl
3
, δ ppm): 4.18 (s, -CH
2
-, 2H), 7.33 (d, J = 7.54 Hz, aryl,
1
H), 7.38-7.50 (br. m, aryl, 11H), 7.54 (dt, J = 7.45 Hz, J =1.10 Hz, aryl, 1H), 7.94 (d, J = 7.54
1
3
1
Hz, aryl, 1H). C{ H} NMR (CDCl
3
, δ ppm): 49.2 (d, J = 7.1 Hz), 123.0 (s), 124.6 (s), 128.2
(
s), 128.7 (d, J = 6.2 Hz), 129.6 (s), 132.1 (s), 132.2 (s), 132.5 (d, J = 21.1 Hz), 135.7 (d, J = 14.4
3
1
1
Hz), 143.8 (s), 173.3 (d, J = 17.3 Hz), P{ H} NMR (CDCl , δ ppm): 29.7 (s).
3
1
c: This compound was synthesized according to a procedure of Opatz et al. [12] (modified
procedure). To a solution of 2-hydroxypyridine (2.00 g, 21.0 mmol) and triethylamine (2.14 g,
1.0 mmol) in THF (30 mL) at 40°C chlorodiphenylphosphine (4.65 g, 21.0 mmol) was added
2
with stirring. The white suspension was stirred at ambient temperature for 1.5 h, then filtered and
the white solid was washed with THF (5 mL). The combined filtrate and washings were
evaporated to dryness to afford the pure white solid product. Yield: 4.78 g (18.0 mmol, 86%).
Crystals suitable for single-crystal X-ray diffraction were obtained by recrystallisation from n-
hexane. The compound is highly hygroscopic.
6

Anal. Calc. for C17
C, 69.68; H, 5.15; N, 4.85%. H NMR (CDCl
aryl, 6H), 7.58-7.65 (m, aryl, 5H), 8.19 (m, aryl, 1H). C{ H} NMR (CDCl
C3, PyO), 118.0 (s, C5, PyO), 128.4 (d, J = 17.2 Hz, meta-Ph), 129.6 (s, para-Ph), 130.9 (d, J =
H
14NOP·0.7H
2
O (MW: 291.9), requires: C, 69.95; H, 5.32; N, 4.80. Found:
1
3
, δ ppm): 6.91-6.96 (m, aryl, 2H), 7.34-7.41 (m,
1
3
1
3
, δ ppm): 112.3 (s,
2
1
3.4 Hz, ortho-Ph), 139.1 (s, C4, PyO), 140.7 (d, J = 18.9 Hz, ipso-Ph), 147.6 (s, C6, PyO),
31
1
62.5 (d, J = 6.9 Hz, C2, PyO). P{ H} NMR (CDCl
3
, δ ppm): 100.6 (s).
II
.7. Syntheses of Ru-complexes 2a, 2b, 3a , 3b , 3c and 3c
II
I
II
2
2
a: This compound was synthesized in an analogous manner to 2b from 128 mg (400 µmol) 1a
and 384 mg (400 µmol) [RuCl
yield (256 mg, 243 µmol). Although the single-crystal used for structure analysis revealed a
solvent content of 0.5 Et O, elemental analysis indicates that the bulk of the crystalline product
consists of CHCl /Et O solvates of variable solvent site occupancy. Both CHCl and Et O proton
signals were detected in a H NMR spectrum of 2a recorded in CD
2
(PPh
3
)
3
]. The orange crystalline product was obtained in 61%
2
3
2
3
2
1
2
Cl .
2
Anal. Calc. for C56
H
48Cl
2
NOP
3
Ru·0.2CHCl
3
·0.3Et
2
O (MW: 1062.0), requires: C, 64.92; H, 4.86;
, δ ppm): 2.50 (d, J = 3.72 Hz, -
1
N, 1.32. Found: C, 64.92; H, 4.83; N, 1.38%. H NMR (CDCl
3
CH
3
, 3H), 6.74-6.85 (br. m, meta-PPh
.02 (m, ortho-PPh , 6H), 7.08 (m, para-PPh
.24-7.31 (m, meta-(MeNCOPh), meta-Ph P(MeNCO), 6H), 7.37 (t, J = 7.46 Hz, para-
3
, 12H), 6.89 (d, J = 7.50 Hz, ortho-(MeNCOPh), 2H),
7
7
3
3
, 3H), 7.11-7.21 (m, para-PPh , ortho-PPh , 9H),
3
3
2
1
3
1
(
MeNCOPh), 1H), 7.40-7.47 (m, ortho-Ph
NMR (CDCl , δ ppm): 35.6 (s, -CH ), 126.4 (d, J = 8.3 Hz, meta-PPh
MeNCOPh)), 127.0 (d, J = 9.2 Hz, meta-PPh ), 127.4 (d, J = 8.8 Hz, meta-Ph
27.9 (s, meta-(MeNCOPh)), 128.5 (s, para-PPh ), 128.8 (s, para-PPh ), 129.5 (m, ipso-
P(MeNCO)), 129.8 (s, para-(MeNCOPh)), 130.1 (s, para-Ph P(MeNCO)), 132.5 (d, J = 34.3
Hz, ipso-PPh ), 133.9 (s, ipso-(MeNCOPh)), 134.1 (d, J = 9.7 Hz, ortho-Ph P(MeNCO)), 134.9
d, J = 9.4 Hz, ortho-PPh ), 136.2 (d, J = 8.0 Hz, ortho-PPh ), 136.4 (d, J = 44.0 Hz, ipso-PPh ),
, δ ppm): 108.2 (dd, J = 342 Hz, J = 29 Hz,
, 1P), 19.0 (dd, J = 342 Hz, J = 29 Hz, PPh , 1P).
2
P(MeNCO), para-Ph
2
P(MeNCO), 6H). C{ H}
), 126.9 (s, ortho-
P(MeNCO)),
3
3
3
(
3
2
1
3
3
Ph
2
2
3
2
(
3
3
3
3
1
1
1
83.2 (d, J = 13.8 Hz, NCO). P{ H} NMR (CDCl
3
Ph
2
P(MeNCOPh), 1P), 41.4 (t, J = 29 Hz, PPh
3
3
2
b: 1b (145 mg, 457 µmol) and [RuCl
2
(PPh
3
)
3
] (438 mg, 457 µmol) were dissolved in CHCl
3
(5
mL). The deep red solution was stirred for 3 h and then stored undisturbed at room temperature.
7

After one week, red crystals, suitable for single-crystal X-ray diffraction, were obtained by vapor
diffusion of Et O into the reaction mixture. The supernatant was removed by decantation and the
solid was washed with Et O (3 mL) and dried in vacuo. Yield: 355 mg (307 µmol, 67%). The
2
2
product exhibits poor solubility in various organic solvents. Whereas singe-crystal X-ray
diffraction analysis confirms a higher solvent content of the crystal used, the average content of
solvent of crystallization of the product was found to be lower (by elemental analysis).
Anal. Calc. for C56
H
46Cl
2
NOP
3
Ru·1.2CHCl (MW: 1157.1), requires: C, 59.37; H, 4.11; N, 1.21.
3
3
1
1
Found: C, 59.51; H, 4.05; N, 1.25%. P{ H} NMR (CD
2
Cl
, 1P), 20.8 (dd, J = 31 Hz, J = 344 Hz, PPh
in solution: 110.8 (d, J = 37 Hz, Ph P(phthal.), 0.1P), 52.2 (d,
, 0.1P), −5.6 (s, PPh , 0.1P).
2
, δ ppm): 84.2 (dd, J = 31 Hz, J =
3
1
44 Hz, Ph
2
P(phthal.), 1P), 41.7 (t, J = 31 Hz, PPh
3
3
,
P), compound shows loss of PPh
3
2
J = 37 Hz, PPh
3
3
II
II
3
1
a : This compound was synthesized in an analogous manner to 3b from 100 mg (313 µmol)
a and 150 mg (156 µmol) [RuCl (PPh ]. The compound was obtained as an orange crystalline
O into a CHCl
2
)
3 3
solid by vapor diffusion of Et
2
3
solution, followed by decantation and drying in
1
vacuo. As this solid was a very fine powder and contained some impurities (according to H
NMR), the crude product was dissolved in CH
2
Cl (2 mL) and crystallized by vapor diffusion of
2
Et O, followed by decantation and drying in vacuo. Yield: 52 mg (61 µmol, 39%). In addition to
2
II
solvent free crystals (see single-crystal structure analysis of 3a , crystals obtained from this
preparation), elemental analysis indicates that the bulk of the crystalline product also consists of
CH
2
Cl solvates.
2
Anal. Calc. for C40
.32. Found: C, 57.48; H, 4.22; N, 3.15%. H NMR (CDCl
m, meta-Ph P, 8H), 7.37-7.48 (br. m, aryl, 10H), 7.54 (m, aryl, 8H), 7.70 (m, aryl, 4H). C{ H}
NMR (CDCl , δ ppm): 36.9 (s, -CH ), 127.5 (m, meta-Ph P), 128.1 (s, aryl, (MeNCOPh)), 128.2
s, aryl, (MeNCOPh)), 130.5 (s, para-Ph P), 130.7 (s, para-(MeNCOPh)), 131.1 (br. m, ipso-
Ph P), 134.0 (m, ipso-(MeNCOPh)), 134.6 (m, ortho-Ph
CDCl , δ ppm): 135.6 (s).
H
36Cl
2
N
2
O
2
P
2
Ru·0.4CH
2
Cl
2
(MW: 844.6), requires: C, 57.45; H, 4.39; N,
1
3
3
, δ ppm): 3.04 (m, -CH , 6H), 7.22
3
1
3
1
(
2
3
3
2
(
2
3
1
1
2
2
P), 183.0 (m, NCO). P{ H} NMR
(
3
8

II
3
b : 1b (200 mg, 630 µmol) and [RuCl
2
(PPh
3
)
3
] (302 mg, 315 µmol) were dissolved in CHCl (2
3
mL). The red solution was stirred for 5 min and subsequently stored at room temperature. After
one day, orange crystals, suitable for single-crystal X-ray diffraction, were formed. The
supernatant was removed by decantation and the solid was washed with Et O (2 mL) and dried in
2
vacuo. Yield: 137 mg (138 µmol, 44%). From this crystalline product a crystal structure of the
II
solvate 3b ⋅7 CHCl
3
was determined, the solvent was heavily disordered and had to be treated
with SQUEEZE (see Supporting Information). As indicated by elemental analysis, the bulk of
this crystalline product has lower CHCl
3
content. Crystals of better quality for single-crystal X-
II
ray diffraction were obtained by vapor diffusion of Et
2
O into a CH
2
Cl
2
solution of 3b .
Anal. Calc. for C40
.82. Found: C, 50.28; H, 3.51; N, 2.65%. H NMR (CD
dd, J = 7.37 Hz, J = 7.94 Hz, meta-Ph, 8H), 7.39 (m, ortho-Ph, 4H), 7.42 (t, J = 7.37 Hz, para-
Ph, 8H), 7.48 (d, J = 7.49 Hz, -H4 (phthal.), 2H), 7.61 (dd, J = 7.58 Hz, J = 7.99 Hz, -H6
H
32Cl
2
N
2
O
2
P
2
Ru·1.55CHCl
3
(MW: 991.7), requires: C, 50.32; H, 3.41; N,
1
2
2
Cl , δ ppm): 4.61 (s, -CH -, 4H), 7.20
2
2
(
(
phthal.), 2H), 7.66 (ddd, J = 1.30 Hz, J = 7.49 Hz, J = 7.99 Hz, -H5 (phthal.), 2H), 8.25 (d, J =
1
3
1
7
.58 Hz, -H7 (phthal.), 2H). C{ H} NMR (CD
2
Cl , δ ppm): 48.8 (s, C3 (phthal.)), 124.1 (s, C4
2
(
(
phthal.)), 125.5 (s, C7 (phthal.)), 127.7 (m, meta-Ph), 129.1 (s, C6 (phthal.)), 129.5 (m, C7a
phthal.)), 131.3 (s, para-Ph), 132.3 (br. m, ipso-Ph), 133.6 (s, C5 (phthal.)), 135.0 (m, ortho-
3
1
1
Ph), 147.6 (s, C3a (phthal.)), 182.2 (m, C1 (phthal.)). P{ H} NMR (CD
2
Cl , δ ppm): 118.6 (s).
2
I
3
c : 1c (116 mg, 415 µmol) and [RuCl
2
(PPh
3
3
) ] (200 mg, 209 µmol) were dissolved in THF (3
mL). The deep red solution was heated under reflux for 10 min, whereupon the yellow
suspension was filtered. The yellow solid was washed with THF (2 mL) and dried in vacuo.
1
Yield: 45 mg (60 µmol, 29%). Elemental analysis and H NMR spectroscopy confirm the solvent
content of this product. Crystals of a CHCl
3
solvate, suitable for single-crystal X-ray diffraction
I
were obtained by vapor diffusion of pentane into a CHCl
3
solution of 3c .
Anal. Calc. for C34
H
28Cl
2
N
2
O
2
P
2
Ru·0.3THF (MW: 752.2) requires: C, 56.21; H, 4.07; N, 3.72.
1
Found: C, 56.17; H, 4.07; N, 3.68%. H NMR (CDCl
3
, δ ppm): 6.36 (ddd, J = 1.31 Hz, J = 5.96
Hz, J = 7.31Hz, -H5 (PyO-2), 1H), 6.71 (m, PPh, 2H), 6.93-7.04 (br. m, -H3 (PyO-2), -H6 (PyO-
), PPh, 6H), 7.09-7.19 (br. m, PPh, 4H), 7.27-7.40 (br. m, -H3 (PyO-1), -H5 (PyO-1), -H4
PyO-2), PPh, 7H), 7.56-7.64 (br. m, PPh, 4H), 7.89 (m, -H4 (PyO-1), 1H), 8.24 (m, PPh, 2H),
2
(
9

1
3
1
9
.89 (m, -H6 (PyO-1), 1H). C{ H} NMR (CDCl , δ ppm): 111.1 (m, 2x C3 (PyO)), 118.3 (s,
3
C5 (PyO-2)), 119.7 (d, J = 2.0 Hz, C5 (PyO-1)), 127.6 (d, J = 10.4 Hz, PPh), 127.7 (d, J = 10.9
Hz, PPh), 127.8 (d, J = 9.7 Hz, PPh), 128.1 (d, J = 10.7 Hz, PPh), 128.5 (d, J = 12.5 Hz, PPh),
1
1
1
1
4
29.1 (d, J = 11.2 Hz, PPh), 129.8 (d, J = 2.0 Hz, para-PPh), 129.9 (d, J = 2.1 Hz, para-PPh),
30.5 (d, J = 2.1 Hz, para-PPh), 131.0 (d, J = 1.6 Hz, para-PPh), 131.2 (d, J = 12.4 Hz, PPh),
33.3 (d, J = 11.6 Hz, PPh), 133.9 (d, J = 49.1 Hz, ipso-PPh), 134.3 (d, J = 49.2 Hz, ipso-PPh),
37.2 (d, J = 47.5 Hz, ipso-PPh), 138.4 (s, C4 (PyO-2)), 140.8 (s, C4 (PyO-1)), 140.9 (dd, J =
.0 Hz, J = 52.6 Hz, ipso-PPh), 150.1 (s, C6 (PyO-2)), 150.2 (s, C6 (PyO-1)), 163.1 (m, C2
3
1
1
(
(
PyO)), 165.0 (m, C2 (PyO)). P{ H} NMR (CDCl
3
, δ ppm): 173.3 (d, J = 35.2 Hz, 2P), 172.5
d, J = 35.2 Hz, 1P).
II
II
I
3
c : Compound 3c was synthesized by isomerization of 3c (80 mg, 110 µmol) in CHCl
3
(1
mL) solution. After stirring for 6 weeks at room temperature the suspension was filtered, the
yellow solid was washed with CHCl (0.5 mL) and dried in vacuo. Yield: 19 mg (26 µmol,
3
2
4%). Crystals of a CH
2
Cl
2
solvate, suitable for single-crystal X-ray diffraction analysis, were
II
grown by vapor diffusion of Et
2
O into a CH
2
Cl
2
solution of 3c .
Anal. Calc. for C34
H
28Cl
2
N
2
O
2
2
P Ru (MW: 730.5), requires: C, 55.90; H, 3.86; N, 3.83. Found: C,
5
5.47; H, 3.98; N, 3.76%.
1
H NMR (CDCl
3
, δ ppm): 7.15 (m, -H5 (PyO), 2H), 7.21 (m, meta-PPh
, 6H), 7.77 (m, -H4 (PyO), 2H), 8.57 (m, -H6 (PyO),
, δ ppm): 112.2 (s, C3), 119.2 (s, C5), 127,5 (m, meta-PPh ), 130.6
), 132.3 (m, ortho-PPh ), 136.7 (br. m, ipso-PPh ), 140.2 (s, C4), 149.7 (s, C6),
, δ ppm): 178.5 (s).
2
, 8H), 7.33 (br. m, para-
PPh
2
, -H3 (PyO), 6H), 7.41 (m, ortho-PPh
2
1
3
1
2
H). C{ H} NMR (CDCl
3
2
(
s, para-PPh
2
2
2
31
1
1
63.8 (s, C2). P{ H} NMR (CDCl
3
3
. Results and Discussion
3
.1. Chelating ligands
Reaction of the lithium salt of N-methylbenzamide (HLa) with chlorodiphenylphosphine
afforded the N-PPh derivative 1a (Scheme 2). Whereas in this case the lithium salt route proved
2
10

to be more efficient than the kinetically hampered reaction of N-methylbenzamide and
triethylamine as a supporting base (we attribute this to the lower acidity of HLa), 1b and 1c were
accessible by reaction of phthalimidine (HLb) or 2-hydroxypyridine (HLc) with
3
1
chlorodiphenylphosphine and triethylamine (Et
ppm, 1b: 29.7 ppm), both compounds feature a P−N bond, as these P NMR shifts are in good
agreement with related N-PPh substituted compounds such as Ph P-NH(COMe) (21.6 ppm) or
Ph P-NMe(COMe) (55.1 ppm) [27]. The dublet splitting of C{ H} NMR signals of the carbon
3
N). According to their P NMR shifts (1a: 57.0
3
1
2
2
1
3
1
2
2
atoms in direct contiguity of the N atoms, caused by JP,C coupling, underpins the formation of
phosphinoamides in both cases. The presence of only one set of NMR signals allows for the
conclusion that one of the tautomers was formed exclusively. Finally, single-crystal X-ray
diffraction analysis confirms the P−N bonding situation and, furthermore, reveals two interesting
differences between the molecular conformations of 1a and 1b. For the P-N-C-O sequence a
zigzag arrangement is found in 1a and a U-shape in 1b, the latter leads to a weakly capped
coordination sphere around the phosphorus atom in 1b with a P⋅⋅⋅O separation of 3.011(1) Å
(
Fig. 1). Also, the P−N bond in 1b is significantly shorter than in 1a (Table 1). This is in accord
with the lower steric demand of the phthalimidine anion because of the N atom being
incorporated in a five-membered ring and it could also be a result of electrostatic bond
strengthening. As to the latter, calculations of the Natural Charges (NCs) reveal a marginally
more negative sum of NCs at phthalimidyl in comparison to the N-methylbenzamidyl fragment
(
−0.472 vs. −0.460, respectively). The combination of these characteristics (O-capped
phosphorus coordination sphere, higher ionicity of the P−N bond, shorter P−N bond) may
3
1
contribute to the noticeable upfield shift of the P NMR signal of 1b relative to 1a (∆(δ) = −27.3
ppm).
In contrast to 1a and 1b, compound 1c features a P−O bond. This is evident from a characteristic
3
1
downfield shift of the P NMR signal, which emerges around 100 ppm and is characteristic of a
3
1
Ph
2
P-O-aryl moiety (like in Ph
2
P-O-p-C
6
H
4
-O-PPh , δ P = 110.5 ppm) [28]. Also, only for one
2
2
carbon atom (C1) JP,C coupling is observed, and the single-crystal X-ray structure (Fig. 1)
proves the identity of this compound. Retention of the aromatic character of the pyridine moiety
in 1c may play a role as a driving force for O-functionalization in this particular case.
11

3
.2. Ruthenium(II) mono-chelates
Reaction of the coordinatively unsaturated complex [RuCl
2
(PPh
3
3
) ] with one equivalent of 1a or
1
b yields the expected mono-chelate compounds 2a and 2b, respectively, accompanied by
liberation of one equivalent of triphenylphosphine (Scheme 3). The Ru coordination spheres in
these compounds are slightly distorted octahedral with trans-situated Cl atoms (Fig. 2). The Cl-
Ru-Cl axis is significantly off linearity with the Cl atoms bent towards the P,O-chelate ligand
(
Table 2). We attribute this distortion to the greater steric demand of the cis-situated PPh
3
ligands
on the opposite side. Nonetheless, with respect to the starting material [RuCl (PPh ] (Cl-Ru-Cl
2
)
3 3
angles reported: 155.99(3)° [this paper], 157.2(2)°, 159.24(4)°, 159.83(3)°, 162.53(3)° [29-32]),
the Cl1-Ru1-Cl2 angles in 2a and 2b are widened. In 2a and 2b the Ru1−P3 bond to one of the
triphenylphosphine ligands is significantly longer than the other Ru−P bonds. Whereas P2 (also
from a triphenylphosphine) is trans to a rather weak donor (the O atom of the chelate ligand) and
thus forms a short Ru−P bond, the chelate P atom P1 is trans-disposed to P3 and, due to its lower
steric demand and chelate effect, forming a shorter Ru−P bond at the expense of Ru1−P3 bond
strength, thus resulting in a bond length difference of about 0.19 Å (2a) or 0.14 Å (2b) between
the two Ru−PPh
similar Ru coordination sphere, i.e., [RuCl
trans-disposed Ru−Cl bonds, a P,O-chelate and two monodentate phosphane ligands [33]. This
compound exhibits a difference of 0.14 Å between the two Ru−PPh (CH COOEt) bonds, the
3
bonds within one molecule. This characteristic is known from a complex with
2
(P-Ph P-CH COOEt) (κP,O-Ph P-CH COOEt)] with
2
2
2
2
2
2
2
longer being trans to the chelate P, the shorter being trans to the chelate O atom. The chelate
bonds Ru1−P1 and Ru1−O1 in compound 2b are significantly longer than the corresponding
bonds in 2a. Furthermore, there are differences in the angles between the O-C- and N-P-axes
(
59.8(1)° in 2a, 61.9(2)° in 2b) and the angle formed between the idealized pyramidal axis of the
NP pyramid and the Ru−P bond (18.5° in 2a, 19.1° in 2b). This allows for the conclusion that
C
2
steric constraints of the phthalimidine moiety pose a hindrance for the optimization of Ru−O and
Ru−P orbital interactions and the pronounced distance of the Ru atom from the chelate in 2b
serves the purpose of optimizing Ru-P orbital interactions. Whereas the P1−N1 bond in 2a and
2
b is similar to the corresponding bond in the free ligand 1a and 1b, respectively, Ru-
complexation causes bond length changes within the carboxylic moiety. In both complexes a
significantly longer (by 0.02 Å) C=O and shorter (by 0.02 Å) C−N bond is observed.
12

Incorporation of ligands 1a and 1b in Ru complexes 2a and 2b, respectively, causes a downfield
3
1
31
shift of the P resonance by about 50 ppm. The difference between both P NMR shifts (which
is 27.3 ppm between 1a and 1b) is in general retained for 2a and 2b (∆(δ) = 24.0 ppm). In the
3
1
1
P{ H} NMR spectrum compounds 2a and 2b show the expected coupling pattern of an ABX
2
2
spin system, with a characteristic trans JP,C coupling around 340 Hz and cis JP,C coupling
around 30 Hz. As already indicated by the long Ru1−P3 bond in the crystal structures of 2a and
2
b, in solution both complexes exhibit the tendency to split off a PPh
is also observed for [RuCl (PPh ], see experimental section). An extra set of signals in 1:1:1
ratio (of lower intensity) emerges in the P{ H} NMR spectrum of 2b, one of the signals
representing PPh (−5.6 ppm), whereas the other two signals (dublets at 110.8 and 52.2 ppm,
P,C = 37 Hz) are representative of cis-situated PPh and NPPh ligands. (In case of 2a, a greater
variety of low intensity signals emerges in addition to a signal of PPh ).
3
molecule (an effect which
2
)
3 3
3
1
1
3
2
J
3
2
3
3
.3. Ruthenium(II) bis-chelates
The reaction of [RuCl
2
(PPh
3
)
3
] with two equivalents of 1a or 1b leads to the formation of the Cl-
II
II
trans isomers 3a and 3b , respectively (Scheme 3). In addition to the characteristic signals of
II
II
31
1
PPh , 1a (or 1b), 2a (or 2b) and 3a (or 3b ) in both cases P{ H} NMR spectra of the crude
3
reaction mixture exhibit an extra set of dublet signals characteristic of cis-arranged chemically
2
non-equivalent NPPh
2
moieties (with ligand 1a: 137.4, 129.3 ppm, JP,C = 34.1 Hz; with ligand
2
1
b: 122.0, 107.2 ppm, JP,C = 37.2 Hz). These extra signals and the characteristic signals of 1a
II
II
(
or 1b), 2a (or 2b) decrease in favor of the singlet signal of 3a (or 3b ). This hints at the
I
I
formation of the all-cis isomers 3a and 3b as intermediates (Scheme 3).
In sharp contrast to the formation of 2a and 2b, the reaction of [RuCl (PPh
2
3
3
) ] with one
I
equivalent of 1c leads to the formation of the all-cis isomer of bis-chelate compound 3c (3c ) in
I
addition to unreacted starting material [RuCl
2
(PPh
3
)
3
] (Scheme 3). Compound 3c is also
accessible along a deliberate synthesis route by using two equivalents of 1c. In solution the all-
I
II
cis isomer 3c slowly isomerizes to the Cl-trans isomer 3c . Monitoring of the crude reaction
3
1
1
mixture by P{ H} NMR spectroscopy revealed that this isomerization does not go to
II
completion within three months. The isolation of pure Cl-trans isomer 3c was possible by
I
crystallization from chloroform, in which the all-cis isomer 3c remains in solution.
13

We succeeded in crystallizing (and determining the crystal structures of) all three trans-Cl
II
II
II
I
isomers 3a , 3b and 3c as well as of the all-cis isomer 3c (Fig. 2 and Fig. 3). The Ru−P bonds
II
II
in 3a and 3b are significantly shorter than the corresponding bonds in 2a and 2b, caused by
reduction of steric demand upon replacing the former two PPh ligands by another P,O-chelator.
3
As a result of the incorporation of the two cis-disposed P atoms in chelating ligands significant
widening of the P1-Ru1-P2 angles is observed. In spite of the overall reduced steric pressure in
the Ru coordination sphere, the cis arrangement of the two PPh
2
groups still causes notable
II
bending of the Cl1-Ru1-Cl2 axis away from the aryl groups. Unexpectedly, in 3a the Ru1−Cl1
bond (2.368(1) Å) is around 0.04 Å shorter than the trans-disposed Ru1−Cl2 bond (2.409(1) Å),
II
whereas in compounds 2a, 2b and 3b the Ru−Cl bond lengths are found within a very narrow
range (2.404(1) – 2.424(1) Å). Analysis of the molecular packing revealed a special environment
II
for atom Cl1 in 3a : a methyl group from a neighboring molecule poses a steric hindrance and
prevents the formation of multiple attractive aryl-C-H⋅⋅⋅Cl contacts with this chlorine atom (only
II
one of these contacts is found for Cl1 in 3a , whereas the other Cl atoms are involved in multiple
contacts of this kind).
II
In the structurally related Cl-trans isomer 3c , the Ru−Cl bond lengths (Table 3) are in the same
I
range as mentioned above. The different trans-donor situation in 3c , however, causes notable
Ru−Cl bond lengthening (for the three crystallographically independent molecules in the crystal
I
structure of 3c Ru−Cl bonds are found in the range 2.42-2.48 Å), with the longer Ru−Cl bond
found trans to Ru−P, the shorter one trans to Ru−N. Even more pronounced bond lengthening is
found for the Ru−N bond trans to P, whereas the other Ru−N bond (trans to Ru−Cl) is about 0.1
Å shorter.
Interestingly, the three different P,N/O-ligands 1a, 1b and 1c show similar isomerization
behavior with respect to the five possible isomers of Ruthenium bis-chelates shown in Scheme 4.
I
V
The relative energies of the isomers 3 -3 obtained by calculations at DFT-PBEPBE level (Table
II
4
) are in accord with the experimental observations. That is, with the P,O-chelators isomer 3
(
which has been isolated and characterized) is predicted as the thermodynamically stable isomer.
I
The proposed intermediate isomer 3 was predicted to be the second stable isomer (+7 and +5
kcal/mol higher in energy for 3a and 3b, respectively). With the P,N-chelating ligand 1c isomers
14

I
II
V
3
, 3 and 3 are predicted to be very similar in energy (0.0, 2.4, 2.3 kcal/mol, respectively).
I
II
Thus, it is not surprising that we were able to isolate two of these isomers (3c and 3c ). Whereas
Langer et al. [12] reported these three isomers with a similar P,N-bidentate ligand, in our study
I
of the coordination behavior of 1c towards Ru(II) we found the initial formation of 3c (as a
I
II
II
kinetic product) which slowly isomerizes into a mixture of 3c and 3c , where 3c could be
separated by crystallization. There were no spectroscopic hints at the formation of the N-trans
V
isomer 3 .
4
. Conclusions
Two new P,O-chelating ligands (1a and 1b) and one P,N-chelating ligand (1c) were synthesized
and there coordination behavior towards Ru(II) was explored. As these carboxylic amide derived
phosphanes lack acidic N−H or O−H bonds in their carboxylic amide motif, they act as non-ionic
ligands. In all cases we observed chelation of the Ru atom by these ligands with liberation of
initially Ru-bound PPh
3
ligands. Whereas the P,O-ligands 1a and 1b were able to replace one or
(PPh ], forming mono- or bis-chelate complexes,
all three PPh ligands from [RuCl
3
2
)
3 3
respectively, in a step-wise manner, the P,N-ligand 1c afforded bis-chelate complexes. Whereas
Cl-trans configuration was encountered with all three bis-chelated Ru complexes obtained from
1
a, 1b and 1c, and quantum chemical analyses proved these compounds to be the
2
2
thermodynamically favored isomers for the combinations [RuCl
2
(κ P,O-1a)
2
] and [RuCl (κ P,O-
2
3
1
1
b)
2
], we observed P NMR spectroscopic data which are consistent with the initial formation of
2
the all-cis isomers as kinetically driven intermediates. For [RuCl
2
(κ P,N-1c)
2
] we succeeded in
isolating both isomers (Cl-trans and all-cis) as crystalline solids. Even though these isomers are
similar in energy (according to computational analyses), slow isomerization of all-cis into Cl-
trans (observed by time dependent NMR spectroscopy) proved the Cl-trans isomer the favored
species in this system as well. Neither in the sterically more crowded mono-chelates
2
2
[
RuCl
2
(PPh
3
)
2
(κ -1)] nor in the bis-chelates [RuCl
2
(κ -1)
2
] hemi-labile behavior of the O- or N-
was observed in
donor site was observed. Instead, for the mono-chelates dissociation of PPh
3
solution, and for the bis-chelates solution NMR spectra are in accord with retention of the Cl-
trans octahedral Ru-coordination sphere.
15

Schemes:
Scheme 1. Examples of Ru-complexes with hemi-labile P,N- (A) and P,O-chelating ligands
(
B, C) as well as transition metal complexes with mono-anionic chelating ligands upon
carbamide deprotonation (C, D, E).
16

Scheme 2. Synthesis of compounds 1a-c.
I
Scheme 3. Synthesis of compounds 2a,b and 3a -c (E = N,O).
II
2 2
Scheme 4. Isomers of Ruthenium bis-chelates [RuCl (L) ] for the herein reported ligands L
=
1a, 1b and 1c, (E = N,O).
17

Figures:
Fig. 1. ORTEP drawing of (from left to right) compound 1a, 1b and 1c. Thermal displacement
ellipsoids are displayed at the 50% probability level.
I
Fig. 2. ORTEP drawing of (from left to right) compounds 2a, 2b and 3c . Thermal displacement
ellipsoids are displayed at the 50% probability level. H atoms and solvent molecules are omitted
I
for more clarity. For 3c only one of the three crystallographically independent (but
conformationally identical) molecules is depicted.
18

II
II
II
Fig. 3. ORTEP drawing of (from left to right) compound 3a , 3b and 3c . Thermal
displacement ellipsoids are displayed at the 50% probability level. H atoms and solvent
molecules are omitted for clarity.
19

Tables:
Table 1
Selected bond lengths (Å) and angles (°) of 1a, 1b and 1c.
1
a
1b
1c
1.6839(14)
1.825(2)
1.829(2)
1.322(3)
1.362(2)
100.67(9)
95.21(8)
P-N/O
P-C
1.7504(9)
1.8295(11)
.8376(10)
1.3802(14)
1.2269(13)
100.28(5)
101.39(4)
1.7276(11)
1.8250(14)
1.8263(14)
1.3849(16)
1.2197(17)
102.57(6)
98.81(6)
1
C
C
carbonyl-N
carbonyl-O
C-P-C
C-P- N/O
1
03.17(5)
102.45(6)
120.90(9)
125.00(13)
100.95(8)
118.91(12)
118.16(17)
P- N/O-Ccarbonyl
N-Ccarbonyl-O
120.96(7)
121.89(11)
20

Table 2
Selected bond lengths (Å) and angles (°) of 2a, 2b, 3a and 3b .
II
II
II
II
2
a
2b
3a
2.2005(6)
2.1925(7)
3b
2.2186(5)
2.2196(5)
Ru1-P1
Ru1-P2
Ru1-P3
Ru1-O1
Ru1-O2
Ru1-Cl1
Ru1-Cl2
P1-N1
2.2956(6)
2.3057(6)
2.4935(6)
2.3432(7)
2.3068(7)
2.4481(8)
2.1593(15) 2.1821(19) 2.1354(17) 2.1720(15)
2.1476(18) 2.1689(15)
2.4132(6)
2.4244(6)
1.757(2)
2.4152(7)
2.4180(7)
1.736(2)
2.3681(7)
2.4093(7)
1.746(2)
1.771(2)
1.816(3)
1.826(3)
1.817(3)
2.4042(6)
2.4071(6)
1.739(2)
1.749(2)
1.822(2)
1.828(2)
1.818(2)
1.836(2)
1.366(3)
1.366(3)
1.241(3)
1.242(3)
83.56(4)
83.63(4)
P2-N2
P1-C
1.830(2)
1.829(3)
1.840(3)
1.845(2)
P2-C
1
.830(3)
1.354(3)
.356(3)
1.249(3)
.243(3)
C
carbonyl-N
carbonyl-O
1.356(3)
1.247(3)
79.56(4)
1.363(4)
1.247(3)
80.00(6)
1
C
1
P1-Ru1-O1
P2-Ru1-O2
P3-Ru1-O1
P1-Ru1-P2
P2-Ru1-P3
P1-Ru1-P3
81.40(5)
81.61(5)
83.54(4)
97.65(2)
100.48(2)
159.31(2)
82.89(6)
98.03(3)
99.35(3)
161.16(3)
170.71(3)
177.11(6)
105.71(2)
103.26(2)
Cl1-Ru-Cl2 167.74(2)
169.59(3)
172.01(5)
172.63(5)
165.81(2)
172.97(4)
172.65(4)
P1-Ru-O2
P2-Ru-O1
C-P1-C
172.71(4)
103.16(10) 103.93(13) 104.92(12) 101.52(10)
102.50(12) 99.24(10)
C-P2-C
C-P1-N1
95.19(10)
96.73(13)
97.13(11)
102.05(10)
103.50(10) 103.26(12) 104.31(12) 103.21(10)
C-P2-N2
99.33(12)
102.76(9)
1
04.97(11) 103.72(10)
P-N-Ccarbonyl 115.81(15) 117.69(19) 115.08(17) 117.86(14)
16.17(17) 117.36(14)
1
N-C-O
121.9(2)
123.7(3)
121.8(2)
22.5(2)
124.3(2)
124.7(2)
1
21

Table 3
Selected bond lengths (Å) and angles (°) of 3c and 3c .
I
II
I
II
3
c
3c
Ru1-P1
Ru1-P2
Ru1-N1
Ru1-N2
Ru1-Cl1
Ru1-Cl2
P1-O1
P2-O2
C1-N1
2.220(1) - 2.224(1)
2.213(1) - 2.220(1)
2.185(3) - 2.192(3)
2.085(3) - 2.092(3)
2.476(1) - 2.484(1)
2.421(1) - 2.428(1)
1.674(3) - 1.686(3)
1.673(3) - 1.675(3)
1.336(6) - 1.345(5)
1.331(5) - 1.340(5)
1.343(5) - 1.350(6)
1.354(5) - 1.363(5)
79.76(9) - 79.84(9)
80.94(21) - 81.22(9)
98.07(4) - 98.38(4)
89.41(4) - 91.65(4)
89.73(10) - 90.02(9)
2.2142(6)
2.2153(7)
2.191(2)
2.141(2)
2.4106(6)
2.4143(6)
1.679(2)
1.685(2)
1.345(3)
1.335(3)
1.362(3)
1.365(3)
77.33(6)
77.92(6)
104.98(2)
166.46(2)
174.11(6)
C18-N2
C1-O1
C18-O2
P1-Ru1-N1
P2-Ru1-N2
P1-Ru1-P2
Cl1-Ru-Cl2
P1-Ru-N2
P2-Ru-N1
P1-O1-C1
P2-O2-C18
N1-C1-O1
N2-C18-O2
176.40(8) - 176.93(9) 177.12(6)
118.2(3) - 119.4(4)
117.8(3) - 118.0(2)
118.0(4) - 118.7(4)
118.4(4) - 118.7(3)
114.7(2)
114.4(2)
118.4(2)
118.1(2)
Table 4
Energy differences (in kcal/mol) of isomers of the Ruthenium bis-chelates [RuCl
2
(L) ] for the
2
herein reported ligands L = 1a, 1b and 1c. Energy values of the crystallographically
characterized isomers are written in bold style.
1
7.02
0.00
9.71
11.82
16.08
a
1b
5.18
0.00
11.24
12.23
20.71
1c
I
3
3
3
3
3
0.00
2.40
12.01
9.98
2.29
II
III
IV
V
22

Acknowledgements
R.G. is grateful to the Studentenwerk Freiberg and the Free State of Saxony for a Ph.D.
scholarship (Landesgraduiertenstipendium).
Appendix A. Supplementary data
I
CCDC 1470582 (1c), 1470583 (2b⋅2.59 CHCl
3
), 1470584 (2a⋅0.5 Et
2
O), 1470585 (3c ⋅2 CHCl
3
),
II
II
II
II
1
1
470586 (3c ⋅CH
2
Cl
2
), 1470587 (3b ⋅2 CH
2
Cl
2
), 1470588 (3b ⋅7 CHCl
3
), 1470589 (3a ),
470590 (1b), 1470591 (1a), 1470592 ([RuCl
2
(PPh
3
) ]⋅MeOH) and 1470593 (phthalimidine,
3
HLb) contain the supplementary crystallographic data for this article. These data can be obtained
free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
0
33; or e-mail: deposit@ccdc.cam.ac.uk. Supplementary data associated with this article (that is:
I
II
atomic coordinates and color graphics of the optimized molecular structures of 1a, 1b, 3a , 3a ,
III
IV
V
I
II
III
IV
V
I
II
III
IV
V
3
a , 3a , 3a , 3b , 3b , 3b , 3b , 3b , 3c , 3c , 3c , 3c and 3c ; Natural Charges of the
atoms of 1a and 1b; color ORTEP diagrams of phthalimidine, [RuCl (PPh ] in the mono-
2
)
3 3
II
methanol solvate and 3b in the hepta-chloroform solvate as well as tables with selected
parameters of X-ray diffraction data collection and structure refinement) can be found, in the
online version, at…
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26

Graphical abstract
27

Graphical Abstract, Synopsis:
The chelating properties of ambidentate phosphane ligands with carboxylic amide
motif were studied in the coordination sphere of Ru(II). These ligands act as P,N- or
P,O-chelators with formation of octahedral mono- and bis-chelate Ru complexes.