Phosphane effects on formation and reactivity of [Ru(L)(PR 3)('N2Me2S2')] complexes with L=N2, N2H4, NH3, and CO

Article abstract of DOI:10.1016/j.ica.2004.03.014

Metal-sulfur complex fragments, to which small molecules like N ₂, N₂H₂, N₂H₄, NH ₃, or CO can bind, are desirable model compounds concerning enzymatic N₂ fixation. This paper re

Full text of DOI:10.1016/j.ica.2004.03.014

Inorganica Chimica Acta 357 (2004) 3336–3350
www.elsevier.com/locate/ica
Phosphane effects on formation and reactivity of [Ru(L)(PR3)
(‘N2Me2S2’)] complexes with L ¼ N2, N2H4, NH3, and CO q
1
D. Sellmann , A. Hille , A. Rosler, F.W. Heinemann, M. Moll
*
€
Institute of Inorganic Chemistry II, University of Erlangen-Nuremberg, Egerlandstrasse 1, D-91058 Erlangen, Germany
Received 8 March 2004; accepted 13 March 2004
Available online 30 April 2004
Abstract
Metal-sulfur complex fragments, to which small molecules like N2, N2H2, N2H4, NH3, or CO can bind, are desirable model
compounds concerning enzymatic N2 fixation.
This paper reports on the effects of the phosphane co-ligand on formation and reactivity of [Ru(L)(PR3)(‘N2Me2S2’)]
[‘N2Me2S2’2ꢀ ¼ 1,2-ethanediamine-N; N0-dimethyl-N; N0-bis(2-benzenethiolate)(2))] complexes with nitrogenase relevant ligands,
especially N2, N2H4, NH3, and CO.
Treatment of [Ru(NCCH3)4Cl2] with Li2‘N2Me2S2’, excessive LiOMe, bulky PPh3 or PCy3, respectively, led to the formation of
two series of [Ru(L)(PR3)(‘N2Me2S2’)] complexes [for R ¼ Ph: 1b, 1c (L ¼ NCCH3), 6b (L ¼ N2H4), 7b (L ¼ N2), 8b1–3 (L ¼ CO), 9b
(L ¼ NH3); for R ¼ Cy: 1a (L ¼ NCCH3), 6a (L ¼ N2H4), 7a (L ¼ N2), 8a (L ¼ CO), 9a (L ¼ NH3)]. While the use of PPh3 (h ¼ 145°)
yielded cis,trans and cis,cis isomers of [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] (1b, 1c), no isomer formation was observed with the bulkier
phosphane PCy3 (h ¼ 170°). Sterically less demanding phosphanes (h ¼ 118–132°) afforded bisphosphane complexes
[Ru(PR3)2(‘N2Me2S2’)] [2d (R ¼ Me), 2e (R ¼ Et), 2f (R ¼ nPr), and 2g (R ¼ nBu)], which were practically inert and could only be
converted in two cases and under drastic reaction conditions into the CO complexes [Ru(CO)(PR3)(‘N2Me2S2’)] [4e (R ¼ Et), 4f
(R ¼ nPr)]. The chelating bidentate phosphane dppe (bisdiphenylphosphanoethane) yielded exclusively the mononuclear complex
[Ru(dppe)(‘N2Me2S2’)] (3).
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: Enzyme models; Ligand effects; Nitrogenases; Phosphanes; S ligands
1. Introduction
resulting [FeMoco]–N2 adducts remains unknown. This
led to a discussion, of whether the N2 molecule is ac-
tivated at the iron or at the molybdenum center(s) of
the FeMo cofactor. Earlier, G.N. Schrauzer and later
R.R. Schrock emphasized the significance of the single
molybdenum atom [6–9]. However, the uncommon
building principle of the cofactors, the discovery of
molybdenum-free [FeFe] and [FeV] nitrogenases, and
recent theoretical calculations point towards a special
role of the metal-sulfur entities of nitrogenase [10–19].
For this reason, transition metal complex fragments
with sulfur ligands, that bind molecular nitrogen under
ambient and biologically compatible conditions to give
the corresponding N2 complexes, are a major target in
N2 fixation research [20]. However, until now only a
few such complexes have become known. These rare
examples are [Mo(N2)(Me8-16(ane)S4)] [Me8-16(ane)
In spite of long lasting and intensive efforts, in-
cluding the X-ray crystal structure determination of
FeMo nitrogenases and its FeMo cofactors, the
mechanism of biological N2 fixation is still poorly
understood [2–5]. This concerns even the primary steps
of activating the inert N2 molecule. Although all
mechanistic proposals postulate a binding of N2 to the
FeMo cofactors of nitrogenase, the structure of the
q Transition metal complexes with sulfur ligands. Part CLVIII. For
2)
Part CLVII see Ref. [1]; N2Me2S2 =1,2-ethanediamine-N; N0-dimeth-
yl-N; N0-bis(2-benzenethiolate)(2)).
* Corresponding author. Tel.: +49-9131-852-73-92; fax: +49-9131-
852-73-67.
E-mail address: hille@anorganik.chemie.uni-erlangen.de (A. Hille).
1
Deceased.
0020-1693/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.03.014

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3337
S4 ¼ 3,3,7,7,11,11,15,15-octamethyl-1,5,9,13-tetrathiacy-
clohexadecane] [21], [Re(SAr)3(PPh3)] (SAr ¼ SC6H2-
2,4,6-Pr-iso3) [22], [Ru(N2)(PiPr3)(‘N2Me2S2’)] [‘N2-
Me2S2’2ꢀ ¼ 1,2-ethanediamine-N; N0-dimethyl-N; N0-bis
(2-benzenethiolate)(2))] [23,24], and [l-N2{Ru(PiPr3)
(‘N2Me2S2’)}2] [25]. Of these examples, only the ru-
thenium N2 complexes meet the biological constraint
to form also at mild redox potentials that excludes the
use of alkaline metals or comparably strong and bio-
logically incompatible reductants at all stages of
synthesis. Such complexes are therefore of considerable
interest as models for the active centers of nitrogenases.
The complex [Ru(N2)(PiPr3)(‘N2Me2S2’)] has a labile
N2 ligand and could be converted into its dinuclear
homolog [l-N2{Ru(PiPr3)(‘N2Me2S2’)}2] (Fig. 1). The
[Ru(PiPr3)(‘N2Me2S2’)] fragment showed to be capable
of binding further nitrogenase relevant molecules, for
example N2H2, N2H4, NH3, and H2 [1,26].
Earlier results had shown that the choice of the
phosphane co-ligand in complexes of the Vaska-type can
have dramatic effects on whether an N2 ligand is bound
or not [27,28]. Therefore, it was now thought worth-
while to examine the influence of various phosphanes
according to their cone angles and electron-donating
character on formation and reactivity of the respective
[Ru(L)(PR3)(‘N2Me2S2’)] complexes [29]. Of additional
interest was the question, whether phosphanes can in-
fluence the formation of different stereoisomers of
[Ru(L1)(L2)(‘N2Me2S2’)] complexes since the ‘N2Me2S2’
ligand is prone to adopt different geometries [30]. The
resulting complexes can exhibit the cis,trans or cis,cis
configurations I–III, which are chiral and each form as
racemates (Fig. 2).
ing at the reduction of N2 by nitrogenase-like coupled
[2Hþ/2eꢀ] transfer steps, exclusively the cis,trans isomers
should exhibit model character concerning the function
of nitrogenase [17,20,31].
2. Experimental
2.1. General
Unless noted otherwise, all reactions and spectro-
scopic measurements were carried out at room temper-
ature under argon or nitrogen using standard Schlenk
techniques in absolute solvents derived from FlukaÒ or
Acros ChemicalsÒ. As far as possible, all reactions were
monitored by IR and NMR spectroscopy. IR spectra in
solution were recorded in CaF2 cuvettes with compen-
sation of the solvent bands, solids were measured as
KBr pellets. NMR spectra were recorded, unless other-
wise specified, at room temperature (20 °C) in the sol-
vents indicated. Chemical shifts are given in ppm and
reported relative to residual protonated solvent reso-
nances (1H, 13C) or external standards: H3PO4(31P).
Mass spectra were measured in the field-desorption
(FD) mode. The physical measurements were carried
out with the following instruments: IR: Perkin–Elmer
983, Perkin–Elmer 1600 FTIR, and Perkin–Elmer 16PC
FTIR; NMR: JEOL FT–JNM–GX 270, Lambda LA
400, JEOL Alpha 500; MS: Jeol MSTATION 700; UV/
Vis/NIR: Shimadzu UV-3101 PC; Raman: Bruker FT-
Raman RFS100/S.
PPh3 was derived from Acros ChemicalsÒ.
[Ru(NCCH3)4Cl2] [32], ‘N2Me2S2’–H2 [33], PCy3 [34],
PMe3, PEt3, PnPr3, PnBu3 [35], and dppe [36] were
prepared as described in the literature. Anhydrous N2H4
was obtained by two fold distillation of N2H4 ꢁ H2O over
KOH. Caution: Anhydrous N2H4 is an explosive sub-
stance and should always be handled behind a protec-
tion shield!
Since in the postulated mechanism trans-thiolate do-
nors are of decisive importance for any reactions aim-
Me
S
S
N
P
i
Pr3
S
N
Me
Me
P
N2
i
Pr3
N
Ru
S
N
Ru N N Ru
S
Me
N
2.2. X-ray crystal structure analyses of [Ru(NCCH3)
[Ru
N
Me
Me
S
P
Pr3
(PCy3)(‘N2Me2S2’)] ꢁ MeOH
(1a ꢁ MeOH),
i
(NCCH3)(PPh3)(‘N2Me2S2’)] ꢁ MeOH (1b ꢁ MeOH),
[Ru(PMe3)2(‘N2Me2S2’)] (2d), [Ru(N2H4)(PPh3)
(‘N2Me2S2’)] ꢁ 2THF (6b ꢁ 2THF), [Ru(N2)(PCy3)
(‘N2Me2S2’)] ꢁ THF (7a ꢁ THF), and [Ru(CO)(PPh3)
(‘N2Me2S2’)] ꢁ THF (8b3 ꢁ THF)
Fig. 1. Ru(N2)(PiPr3)(‘N2Me2S2’)] and [l-N2{Ru(PiPr3)(‘N2Me2S2’)}2].
S
S
L2
S
L1
S
Me
Me
L2
L1
Me
N
N
N
Ru
Ru
Yellow–green
plates
of
[Ru(NCCH3)(PCy3)
Ru
S
S
N
N
N
Me
Me
(‘N2Me2S2’)] (1a ꢁ MeOH) were obtained by slow cool-
ing of a hot-saturated MeOH solution of 1a to 20 °C
within three days. Yellow–orange blocks of [Ru
(NCCH3)(PPh3)(‘N2Me2S2’)] (1b ꢁ MeOH) were formed
by slow cooling of a hot-saturated MeOH/CH3CN (4:1)
solution of 1b to 20 °C within one week. Yellow columns
of [Ru(PMe3)2(‘N2Me2S2’)] (2d) were obtained by slow
Me
L1
L2
II
III
I
cis,trans
cis,cis
Fig. 2. Cis,trans and cis,cis isomers of [Ru(L1)(L2)(‘N2Me2S2’)] com-
plexes.

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D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
diffusion of Et2O in saturated THF solutions of 2d at
20 °C within two weeks. Orange blocks of [Ru(N2H4)
(PPh3)(‘N2Me2S2’)] ꢁ 2THF (6b ꢁ 2THF) were obtained
by slow diffusion of Et2O in saturated THF solutions of
6b at 20 °C within one week. Yellow–green plates of
[Ru(N2)(PCy3)(‘N2Me2S2’)] ꢁ THF (7a ꢁ THF) were
grown upon cooling down a hot-saturated THF/MeOH
(1:4) solution of 7a to 20 °C within two weeks. Slow
diffusion of n-pentane in saturated THF solutions of 8b3
at 20 °C afforded yellow needles of [Ru(CO)(PPh3)
(‘N2Me2S2’)] ꢁ THF (8b3 ꢁ THF) within one week. Suit-
able single crystals were coated with inert perfluoro-
polyalkylether. Intensity data were collected on a
Bruker-Nonius Kappa CCD (1b ꢁ MeOH, 2d, 6b ꢁ 2THF,
8b3 ꢁ THF) or a Siemens P4 diffractometer (1a ꢁ MeOH,
have been localized in difference Fourier syntheses.
These hydrogen atoms have either been refined with a
fixed common isotropic displacement parameter (1a ꢁ
MeOH, 1b ꢁ MeOH, 2d, 6b ꢁ 2THF, 8b3 ꢁ THF) or have
not been refined (7a ꢁ THF). The hydrogen atoms of the
THF molecule in the unit cell of 7a are geometrically
positioned and allowed to ride on their carrier atoms.
Their isotropic displacement parameters have been tied
to the corresponding Ueq: parameters of their carrier
atoms by a factor of 1.2 or 1.5. The unit cells of 1a and
1b contain one MeOH molecule per formula unit each.
The unit cell of 1b ꢁ MeOH contains two symmetrically
independent molecules. The unit cell of 7a contains one
THF molecule. The complex 2d is located on a crystal-
lographic C2 axis and has therefore C2 symmetry. The
unit cell of 8b3 contains one THF molecule. The unit cell
of 6b contains two THF molecules, one of which is
disordered. The H atoms of the minority component
were geometrically positioned. Tables 1 and 2 list se-
lected crystallograpic data of the complexes 1a, 1b, 2d,
6b, 7a, and 8b3.
ꢀ
7a ꢁ THF) using Mo Ka radiation (k ¼ 0:71073 A,
graphite monochromator) and corrected for Lorentz
and polarization effects. Absorption effects have been
taken into account using either psi-scans (7a ꢁ THF) or
multi-scan procedures (1b ꢁ MeOH, 2d, 6b ꢁ 2THF,
8b3 ꢁ THF: SORTAV) [37]. The structures were solved
by direct methods (1b ꢁ MeOH, 2d, 7a ꢁ THF, 8b3 ꢁ THF)
or by the heavy-atom method (1a ꢁ MeOH, 6b ꢁ 2THF)
and refined using full-matrix least-squares procedures
2.3. [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] (1a)
(SHELXTL NT 5.10) [38]. All non-hydrogen atoms were
refined anisotropically. The positions of all H atoms
A solution of ‘N2Me2S2’–H2 (696 mg, 2.29 mmol)
and LiOMe (9.16 ml, 9.16 mmol, 1 N solution in
Table 1
Selected crystallographic data of [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] ꢁ MeOH (1a ꢁ MeOH), [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] ꢁ MeOH (1b ꢁ MeOH),
and [Ru(PMe3)2(‘N2Me2S2’)] (2d)
Complex
1a ꢁ MeOH
C37H58N3OPRuS2
757.02
1b ꢁ MeOH
C37H40N3OPRuS2
738.88
2d
Empirical formula
Mr
Crystal size (mm)
C22H36N2P2RuS2
555.66
0.72 ꢂ 0.52 ꢂ 0.40
800
triclinic
0.36 ꢂ 0.34 ꢂ 0.24
1528
triclinic
0.25 ꢂ 0.23 ꢂ 0.16
1152
F (0 0 0)
Crystal system
Space group
a (pm)
b (pm)
c (pm)
a (°)
b (°)
monoclinic
C2=c
1910.79(3)
1722.10(3)
749.82(1)
90
ꢁ
ꢁ
P1
P1
1062.1(1)
1253.6(1)
1531.5(2)
73.94(1)
81.92(1)
77.21(1)
1.9041(3), 2
1.320
1064.07(2)
1851.56(3)
1856.41(3)
91.538(2)
106.330(2)
99.485(2)
3.4516(1), 4
1.422
97.632(1)
90
c (°)
V (nm3), Z
2.44549(7), 4
1.509
0.955
qcalc: (g cmꢀ3
)
l (mmꢀ1
T (K)
)
0.595
210(2)
3.8–56.0
0.655
100(2)
100(2)
2h Range (°)
min; Tmax
6.6–56.0
0.797; 0.920
67239
6.8–60.0
0.817; 0.934
27557
T
Measured reflections
Individual reflections
Observed reflectionsꢃ
Rint
10485
9039
16449
8669
3560
2823
7714
0.0170
0.1460
0.0487; 0.0967
1051
0.0723
0.0284; 0.0614
186
R1ꢃ; wR2 (%)
0.0313; 0.0785
580
Reference parameter
Ddmax = min
Absolute structural parameter [39]
0.961; )0.458
0.545; )0.572
0.483; )0.505
* Fo 6 4:0rðF Þ.

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3339
Table 2
Selected crystallographic data of [Ru(N2H4)(PPh3)(‘N2Me2S2’)] ꢁ 2THF (6b ꢁ 2THF), [Ru(N2)(PCy3)(‘N2Me2S2’)] ꢁ THF (7a ꢁ THF), and
[Ru(CO)(PPh3)(‘N2Me2S2’)] ꢁ THF (8b3 ꢁ THF)
Complex
7a ꢁ THF
38H59N4OPRuS2
784.05
6b ꢁ 2THF
C42H53N4O2PRuS2
842.04
8b3 ꢁ THF
C39H41N2O2PRuS2
765.90
Empirical formula
Mr
Crystal size (mm)
C
0.60 ꢂ 0.18 ꢂ 0.14
1656
orthorhombic
0.41 ꢂ 0.23 ꢂ 0.18
880
triclinic
0.34 ꢂ 0.22 ꢂ 0.12
1584
monoclinic
F (0 0 0)
Crystal system
Space group
a (pm)
b (pm)
c (pm)
a (°)
b (°)
ꢁ
Pna21
P1
P21=c
1947.3(2)
1183.9(2)
1585.0(2)
90
1081.23(3)
1399.55(4)
1508.60(4)
109.454(2)
99.700(2)
109.051(2)
1.93373(9), 2
1.446
1796.34(4)
1271.20(3)
1538.93(3)
90
90
90
99.749(2)
90
c (°)
V [nm3], Z
3.6541(9), 4
1.425
0.624
3.4634(2), 4
1.469
0.657
qcalc: (g cmꢀ3
)
l (mmꢀ1
T (K)
)
0.597
100(2)
200(2)
100(2)
2h Range (°)
min; Tmax
4.0–50.0
0.574; 0.663
6681
6.6–60.0
0.855; 0.951
49594
6.8–58.0
0.800; 0.884
50076
T
Measured reflections
Individual reflections
Observed reflectionsꢃ
Rint
6426
4895
11253
9170
9155
5759
0.0324
0.0525; 0.1203
424
0.0531
0.0320; 0.0779
647
0.1225
0.0421, 0.0845
547
R1ꢃ; wR2 (%)
Reference parameter
Ddmax = min
Absolute structural parameter
0.369; )1.002
)0.06(5)
0.590; )0.976
0.584; )0.747
* Fo 6 4:0rðF Þ.
MeOH) in MeOH (35 ml) was added dropwise within
1 h to a boiling yellow suspension of [Ru(NCCH3)4Cl2]
(768 mg, 2.29 mmol) and PCy3 (1.28 g, 4.56 mmol) in
MeOH (45 ml). The resulting yellow–green suspension
was refluxed for another 45 min and cooled to 40 °C.
The yellow solid was removed, washed with MeOH (10
ml) and n-pentane (15 ml), and dried in vacuo. Yield:
980 mg (56%) of [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] ꢁ
MeOH (1a ꢁ MeOH); 1H NMR (399.65 MHz, [D8]THF):
2.4. [Ru(CO)(PCy3)(‘N2Me2S2’)] (8a)
CO was passed through a yellow solution of
1a ꢁ MeOH (380 mg, 0.5 mmol) in THF (40 ml). The re-
action was monitored by IR spectroscopy and termi-
nated, when the m(CBN) band of 1a at 2246 cmꢀ1 had
disappeared. The yellow solution was filtered and re-
duced in volume to 1 ml. Addition of MeOH (15 ml)
yielded a yellow solid, which was removed after 30 min,
washed with MeOH (10 ml) and n-pentane (15 ml) and
dried in vacuo. Yield: 330 mg (80%) of [Ru(CO)
(PCy3)(‘N2Me2S2’)] ꢁ MeOH ꢁ THF (8a ꢁ MeOH ꢁ THF);
1H NMR (269.6 MHz, CD2Cl2): d ¼ 7:52–6:85 (m, 8H,
C6H4), 3.43 (s, 3H, CH3), 3.41 (s, 3H, CH3), 3.35–2.40
(m, 4H, C2H4), 2.20–0.75 (m, 33H, P[C6H11]3); 13C{1H}
NMR (67.7 MHz, CD2Cl2): d ¼ 206:1 (d, 2JP;C ¼ 18 Hz,
CO), 152.1, 151.6, 151.1, 150.1, 131.9, 131.0, 127.2,
127.0, 122.1, 122.0 (2 signals), 121.1 (C6H4), 66.5, 62.3
3
d ¼ 7:47 (d, JH;H ¼ 8:0 Hz, 1H, C6H4), 7.35 (d,
3JH;H ¼ 7:8 Hz, 1H, C6H4), 7.28 (d, 3JH;H ¼ 8:1 Hz, 1H,
3
C6H4), 7.14 (d, JH;H ¼ 8:1 Hz, 1H, C6H4), 6.79–6.64
(m, 4H, C6H4), 3.44 (s, 3H, CH3), 3.38 (s, 3H, CH3),
2.89–2.12 (m, 4H, C2H4), 2.27 (s, 3H, CH3CN), 1.95–
1.06 (m, 33H, P[C6H11]3); 13C{1H} NMR (100.4 MHz,
[D8]THF): d ¼ 154:8, 154.7, 154.3, 153.2, 152.0, 131.7,
131.4, 126.3, 126.2 (C6H4), 123.2 (CH3CN), 120.6,
120.5, 120.0 (C6H4), 69.0, 62.1 (CH3), 50.6, 48.1 (C2H4),
1
1
38.4 (d, JP;C ¼ 19:0 Hz), 30.7, 28.8, 27.1, 26.9, 25.4
(CH3), 50.9, 49.8 (C2H4), 38.5 (d, JP;C ¼ 19:0 Hz,
(P[C6H11]3), 5.3 (CH3CN); 31P{1H} NMR (161.70
(P[CH(C5H10)]3)), 30.5, 28.4, 26.8 (P[CH(C5H10)]3);
31P{1H} NMR (161.70 MHz, CD2Cl2): d ¼ 36:70
MHz, [D8]THF): d ¼ 41:52 (P[CH(C5H10)]3); IR (KBr):
ꢀ1
m ¼ 2242 cm (CBN); MS (102Ru, THF): m=z ¼ 684
(P[CH(C5H10)]3); IR (KBr): m ¼ 1935 (CBO); MS
~
~
[Mþ–CH3CN]; elemental analysis. Anal. Calc. for
C37H58N3OPRuS2 (757.02): C 58.70, H 7.73, N 5.55, S
8.47. Found: C 59.12, H 8.29, N 5.59, S 8.70%.
(
102Ru, THF): m=z ¼ 713 [Mþ]; elemental analysis. Anal.
Calc. for C40H63N2O3PRuS2 (816.12): C 58.87, H 7.78,
N 3.43, S 7.86. Found: C 58.85, H 8.08, N 3.66, S 8.15%.

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D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
2.5. [Ru(NH3)(PCy3)(‘N2Me2S2’)] (9a)
C34H51N4S2PRu (711.97): C 57.37, H 7.22, N 7.87, S
9.01. Found: C 58.02, H 57.74, N 7.65, S 8.79%.
An intense stream of NH3 gas was passed through a
yellow solution of 1a ꢁ MeOH (800 mg, 1.16 mmol) in
THF (50 ml) at 50 °C for 1 h. Solvent was replaced every
20 min. The reaction was monitored by IR spectroscopy
and terminated, when the m(CBN) band of 1a at 2246
cmꢀ1 had disappeared. The red solution was filtered and
reduced in volume to 3 ml by a stream of NH3 gas.
Addition of MeOH (20 ml) yielded a yellow solid which
was removed after 30 min, washed with MeOH (10 ml)
and n-pentane (15 ml), and dried in vacuo. Yield: 700
mg (94%) of [Ru(NH3)(PCy3)(‘N2Me2S2’)] (9a); 1H
NMR (399.65 MHz, [D8]THF): d ¼ 7:55 (d, 3JH;H ¼ 7:8
Hz, 1H, C6H4), 7.39 (d, 3JH;H ¼ 7:8 Hz, 1H, C6H4), 7.31
2.7. [Ru(N2H4)(PCy3)(‘N2Me2S2’)] (6a)
Anhydrous N2H4 (4.5 ll, 0.14 mmol) was added to a
yellow solution of [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a) (25
mg, 0.035 mmol) in [D8]THF (0.8 ml). Within 15 min
[Ru(N2H4)(PCy3)(‘N2Me2S2’)] (6a) was formed and was
1
directly characterized by NMR spectroscopy: H NMR
3
(399.65 MHz, [D8]THF): d ¼ 7:56 (d, JH;H ¼ 7:2 Hz,
3
1H, C6H4), 7.39 (d, JH;H ¼ 7:2 Hz, 1H, C6H4), 7.37 (d,
3JH;H ¼ 6:9 Hz, 1H, C6H4), 7.09 (d, 3JH;H ¼ 7:0 Hz, 1H,
2
C6H4), 6.83–6.62 (m, 4H, C6H4), 4.44 (d, JH;H ¼ 10:8
2
Hz, 1H, RuNH2NH2), 4.16 (d, JH;H ¼ 10:8 Hz, 1H,
3
3
(d, JH;H ¼ 6:8 Hz, 1H, C6H4), 7.10 (d, JH;H ¼ 8:2 Hz,
1H, C6H4), 6.81–6.61 (m, 4H, C6H4), 3.31 (s, 3H, CH3),
3.24 (s, 3H, CH3), 3.06–2.17 (m, 4H, C2H4), 2.00–1.07
(m, 33H, P[C6H11]3), 1.41 (s, 3H, NH3); 13C{1H} NMR
(100.40 MHz, [D8]THF): d ¼ 156:3, 156.1, 154.8, 152.0,
132.5, 132.1, 125.7, 125.5, 122.3, 120.1, 119.9, 119.5
(C6H4), 69.6, 62.6 (CH3), 54.3, 46.7 (C2H4), 31.0, 29.9,
28.9, 27.2, 26.8, 25.9 (P[C6H11]3); 31P{1H} NMR (161.70
MHz, [D8]THF): d ¼ 45:78 (P[C6H11]3); IR (KBr):
RuNH2NH2), 3.62 (s, 2H, RuNH2NH2), 3.42 (s, 3H,
CH3), 3.28 (s, 3H, CH3), 2.86–2.11 (m, 4H, C2H4), 1.75–
1.10 (m, 33H, P[C6H11]3); 13C{1H} NMR (100.40 MHz,
[D8]THF): d ¼ 156:3, 156.1, 154.8, 152.0, 132.5, 132.1,
129.2, 128.4, 125.7, 125.6, 122.3, 119.5 (C6H4), 69.6, 62.6
1
(CH3), 54.3, 46.7 (C2H4), 32.22 (d, JP;C ¼ 18:1 Hz,
P[CH(C5H10)]3), 31.7, 28.9, 28.1, 27.2, 27.1
(P[CH(C5H10)]3); 31P{1H} NMR (161.70 MHz,
[D8]THF): d ¼ 41:34 (P[C6H11]3).
m ¼ 3383, 3328, 3239, 3166 cmꢀ1 (N–H); MS
~
(
102Ru,THF): m=z ¼ 684 [Mþ–NH3]; elemental analysis.
Anal. Calc. for C34H54N3S2PRu (701.00): C 58.26, H
7.77, N 5.99, S 9.15. Found: C 58.00, H 8.09, N 5.89, S
8.75%.
2.8. [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] (1b)
A solution of ‘N2Me2S2’–H2 (1.05 g, 3.44 mmol) in
MeOH (53 ml) and LiOMe (13.8 ml, 13.8 mmol, 1 N
solution in MeOH) was added dropwise (2 h) to a
boiling yellow suspension of [Ru(NCCH3)4Cl2] (1.16 g,
3.44 mmol) and PPh3 (1.80 g, 6.88 mmol) in MeOH (55
ml). A yellow–brown solution was formed, which was
refluxed for 45 min. The solution was filtered hot, re-
duced in volume to 30 ml, and cooled to )34 °C over-
night. The yellow–green precipitate was isolated, washed
with cold MeOH (10 ml) and n-pentane (20 ml) and
dried in vacuo. The crude product was dissolved in
boiling CH3CN (50 ml) and refluxed for 1 h. The solu-
tion was filtered hot and reduced in volume to 2 ml.
Addition of MeOH (25 ml) yielded a yellow solid, which
was removed after 30 min, washed with MeOH (10 ml)
and n-pentane (20 ml) and dried in vacuo. Yield: 960 mg
(38%) of [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] ꢁ MeOH
(1b ꢁ MeOH); 1H NMR (399.65 MHz, [D8]THF):
d ¼ 7:67–6:53 (m, 23H, C6H4, C6H5), 3.48 (s, 3H, CH3),
2.92 (s, 3H, CH3), 3.25–2.28 (m, 4H, C2H4), 1.92 (s, 3H,
CH3CN); 13C{1H} NMR (100.40 MHz, [D8]THF):
d ¼ 154:1, 154.2, 153.5, 152.5, 137.0, 136.6, 133.7 (d,
1JP;C ¼ 9:1 Hz, P[C(C5H5)]3), 130.6, 127.5, 127.5, 126.3,
124.7, 121.1, 120.0, 119.4, 118.9 (C6H4, C6H5), 124.1
(CH3CN), 67.2, 62.0 (CH3), 50.5, 47.2 (C2H4), 2.2
(CH3CN); 31P{1H} NMR (161.70 MHz, [D8]THF):
d ¼ 55:57 (P[C6H5]3); IR (KBr): ~m ¼ 2252 cmꢀ1 (CBN);
MS (102Ru, MeOH): m=z ¼ 666 [Mþ–CH3CN]; elemen-
2.6. [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a)
A vigorous stream of N2 gas was passed through a
yellow suspension of [Ru(NH3)(PCy3)(‘N2Me2S2’)] (9a)
(1.15 g, 1.64 mmol) in toluene (200 ml) at 55 °C for 3 h.
Solvent was replaced every 30 min. The reaction was
monitored by IR spectroscopy and terminated, when no
further increase of the m(NBN) band of 7a at 2114 cmꢀ1
was observed. The yellow solution was filtered and re-
duced in volume to 3 ml by a stream of N2. Addition of
n-pentane (50 ml) yielded a yellow solid, which was re-
moved after 30 min, washed with n-pentane (20 ml) and
dried in a stream of N2 for 2 h. Yield: 1.05 g (90%) of
[Ru(N2)(PCy3)(‘N2Me2S2’)] (2a); 1H NMR (399.65
3
MHz, [D8]THF): d ¼ 7:50 (d, JH;H ¼ 8:2 Hz, 1H,
3
C6H4), 7.39–7.35 (m, 2H, C6H4), 7.27 (d, JH;H ¼ 8:2
Hz, 1H, C6H4), 6.91–6.76 (m, 4H, C6H4), 3.41 (s, 3H,
CH3), 3.39 (s, 3H, CH3), 3.33–2.31 (m, 4H, C2H4),
1.92)0.87 (m, 33H, (P[C6H11]3)); 13C{1H} NMR (100.40
MHz, [D8]THF): d ¼ 153:7, 152.7, 151.3, 151.0, 131.9,
131.5, 126.7, 126.6, 122.2, 121.3, 121.3, 120.6 (C6H4),
68.6, 62.1 (CH3), 51.9, 47.7 (C2H4), 38.5, 30.7, 28.7,
28.6, 26.9, 25.9 (P[C6H11]3); 31P{1H} NMR (161.70
MHz, [D8]THF): d ¼ 34:99 (P[CH(C5H10)]3); IR (KBr):
ꢀ1
m ¼ 2115 cm (NBN); MS (102Ru, THF): m=z ¼ 684
~
[Mþ–N2]; elemental analysis. Anal. Calc. for

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3341
tal analysis. Anal. Calc. for C37H40N3OPRuS2 (738.88):
C 60.15, H 5.46, N 5.69, S 8.69. Found: C 60.03, H 5.22,
N 5.73, S 8.69%.
2.11. [Ru(N2H4)(PPh3)(‘N2Me2S2’)] (6b)
Anhydrous N2H4 (1 M in THF, 10 ml, 10 mmol) was
added to solid, yellow–green 1b ꢁ MeOH (370 mg, 0.50
mmol). Within 3 h, a yellow suspension was formed. The
yellow solid was removed and dried without further
washing in vacuo for 2 h. Yield: 200 mg (44%) of
[Ru(N2H4)(PPh3)(‘N2Me2S2’)] ꢁ N2H4 (6b ꢁ N2H4); 1H
NMR (399.65 MHz, [D8]THF): d ¼ 7:54–6:58 (m, 23H,
2.9. [Ru(CO)(PPh3)(‘N2Me2S2’)] (8b3)
CO was passed through a dark yellow solution of
1b ꢁ MeOH (500 mg, 0.68 mmol) in THF (20 ml) for 10
min. The solution was stirred for additional 12 h under
an atmosphere of CO. The green–yellow solution was
filtered and reduced in volume to 3 ml. Addition of
MeOH (30 ml) led to the precipitation of a bright yel-
low, microcrystalline solid, which was separated after 2
h, washed with MeOH (5 ml) and n-pentane (15 ml), and
dried in vacuo. Yield: 300 mg (63%) of
[Ru(CO)(PPh3)(‘N2Me2S2’)] (8b3); 1H NMR (399.65
MHz, [D8]THF): d ¼ 7:70–6:70 (m, 23H, C6H4, C6H4),
3.58 (s, 3H, CH3), 2.69 (s, 3H, CH3), 3.15–2.25 (m, 4H,
C2H4); 13C{1H} NMR (100.40 MHz, [D8]THF):
2
C6H4, C6H5), 4.43 (d, JH;H ¼ 10:4 Hz, 1H, RuNH2
NH2), 4.22 (d, 2JH;H ¼ 10:4 Hz, 1H, RuNH2NH2) 3.49 (s,
3H, CH3), 3.13 (s, 2H, RuNH2NH2), 3.07 (s, 3H, CH3),
2.99 (s, free N2H4), 2.82)2.25 (m, 4H, C2H4); 13C{1H}
NMR (100.40 MHz, [D8]THF): d ¼ 155:2, 154.4, 153.9,
153.8, 139.0, 138.6, 134.8, 134.7, 132.1, 131.5, 128.3, 127.2
1
(d, JP;C ¼ 8:2 Hz, P[C(C5H5)]3), 122.4, 120.6, 118.3
(C6H4, C6H5); 31P{1H} NMR (161.70 MHz, [D8]THF):
d ¼ 58:72 (P[C6H5]3) (NMR-spectra were measured in
[D8]THF (0.6 ml) to which anhydrous hydrazine (40 ll,
~
0.12 mmol) had been added); IR (KBr): m ¼ 3173, 3234,
2
d ¼ 205:2 (d, JP;C ¼ 20:7 Hz, CO), 153.1, 151.4, 150.9,
3298, 3352 cmꢀ1 (N–H); MS (102Ru, THF): m=z ¼ 666
[Mþ]; elemental analysis. Anal. Calc. for C34H41N6PRuS2
(729.88): C 55.17, H 5.58, N 11.34, S 8.66. Found: C 54.85,
H 5.70, N 11.77, S 8.28%.
1
150.8, 135.1, 134.6 (d, JP;C ¼ 9:8 Hz, P[C(C5H5)]3),
131.4, 131.0, 129.7, 129.7, 127.8, 126.5, 122.1, 121.9,
121.8, 121.6 (C6H4, C6H5), 66.0, 63.0 (CH3), 50.8, 47.3
(C2H4); 31P{1H} NMR (161.70 MHz, [D8]THF):
ꢀ1
~
d ¼ 49:12 (P[C6H5]3); IR (KBr): m ¼ 1940 cm (CBO);
2.12. [Ru(N2)(PPh3)(‘N2Me2S2’)] (7b)
MS (102Ru, THF): m=z ¼ 694 [Mþ]; elemental analysis.
Anal. Calc. for C35H33N2OPRuS2 (693.83): C 60.59, H
4.79, N 4.04, S 9.24. Found: C 60.16, H 4.61, N 4.07, S
9.13%.
A vigorous stream of N2 was passed through a yellow
solution of 9b (500 mg, 0.73 mmol) in toluene (200 ml)
at 50 °C for 9 h. Removed solvent was replaced every 30
min. The reaction was monitored by IR spectroscopy
and terminated, when the intensity of the m(NBN) band
at 2130 cmꢀ1 showed no further increase. A green so-
lution was formed, which was filtered hot and reduced in
volume to 10 ml. Addition of n-pentane (70 ml) yielded a
green solid, which was separated after 1 h, washed with
n-pentane (25 ml) and dried in vacuo. Yield: 420 mg of
[Ru(N2)(PPh3)(‘N2Me2S2’)] (7b) (75%) and 9b (25%).
2.10. [Ru(NH3)(PPh3)(‘N2Me2S2’)] (9b)
A vigorous stream of NH3 gas was passed through
a dark yellow suspension of 1b ꢁ MeOH (500 mg, 0.68
mmol) in THF (40 ml) at 50 °C for 70 min. Removed
solvent was replaced every 20 min. A red solution was
formed, which was filtered hot and reduced in volume
to 2 ml. Addition of MeOH (20 ml) yielded a dark
yellow solid, which was removed after 1 h, washed
with MeOH (10 ml) and n-pentane (15 ml), and dried
in vacuo. Yield: 300 mg (65%) of [Ru(NH3)
(PPh3)(‘N2Me2S2’)] (9b); 1H NMR (399.65 MHz,
[D8]THF): d ¼ 7:63–6:64 (m, 23H, C6H5, C6H4), 3.38
(s, 3H, CH3), 3.05 (s, 3H, CH3), 3.16–2.33 (m, 4H,
C2H4), 1.34 (s, 3H, NH3); 13C{1H} NMR (100.40
MHz, [D8]THF): d ¼ 156:0, 154.8, 153.7, 153.3, 138.6,
1
Spectroscopic data for complex 7b: H NMR (399.65
MHz, [D8]THF): d ¼ 7:48–6:58 (m, 23H, C6H4, C6H5),
3.54 (s, 3H, CH3), 2.90 (s, 3H, CH3), 3.16–2.26 (m, 4H,
C2H4); 13C{1H} NMR (100.40 MHz, [D8]THF):
d ¼ 153:7, 152.7, 152.6, 151.9, 151.1, 135.5, 135.1, 134.7,
1
134.5 (d, JP;C ¼ 9:1 Hz, P[C(C5H5)]3), 134.3, 131.3,
129.5, 128.4, 127.9, 127.8, 127.4, 126.5 (C6H4, C6H5),
67.4, 62.8 (CH3), 50.5, 48.3 (C2H4); 31P{1H} NMR
(161.70 MHz, [D8]THF): d ¼ 46:92 (P[C6H5]3); IR
(KBr): ~m ¼ 2130 cmꢀ1 (NBN); MS (102Ru, THF):
m=z ¼ 666 [Mþ].
1
138.3, 135.0 (d, JP;C ¼ 9:1 Hz, P[C(C5H5)]3), 134.3,
132.3, 131.7, 128.3, 127.4, 125.8, 125.5, 122.3, 120.5
(C6H4, C6H5), 68.4, 63.7 (CH3), 53.7, 47.1 (C2H4);
31P{1H} NMR (161.70 MHz, [D8]THF): d ¼ 60:82
2.13. [Ru(PR3)2(‘N2Me2S2’)], general method
~
(P[C6H11]3); IR (KBr): m ¼ 3340, 3304, 3240, 3162
cmꢀ1 (N–H); MS (102Ru, THF): m=z ¼ 666 [Mþ–
A colorless solution of ‘N2Me2S2’–H2 (696 mg, 2.29
mmol) and LiOMe (9.16 ml, 9.16 mmol, 1 N in MeOH)
in MeOH (35 ml) was added dropwise within 1 h to a
boiling yellow suspension of [Ru(NCCH3)4Cl2] (768 mg,
NH3];
elemental
analysis.
Anal.
Calc.
for
C34H36N3PRuS2 (682.82): C 58.27, H 5.31, N 6.15, S
9.39. Found: C 58.74, H 5.70, N 5.91, S 8.85%.

3342
D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
2.29 mmol) and PR3 in MeOH (35 ml). The resulting
yellow–brown mixture was refluxed for another 45 min
and cooled to room temperature. The yellow to orange
solids were separated, washed with MeOH (10 ml) and
n-pentane (15 ml) and dried in vacuo.
2.13.4. [Ru(PnBu3)2(‘N2Me2S2’)] (2g)
PnBu3 (1.14 ml, 4.58 mmol). Yield: 640 mg (34%) of
[Ru(PnBu3)2(‘N2Me2S2’)] (2g). H NMR (399.65 MHz,
1
[D8]THF): d ¼ 7:40 (d, 3JH;H ¼ 7:9 Hz, 2H, C6H4), 7.23
(d, 3JH;H ¼ 7:7 Hz, 2H, C6H4), 6.79–6.70 (m, 4H, C6H4),
3.39 (s, 6H, CH3), 2.94–2.86 (m, 2H, C2H4), 2.12)2.14
(m, 2H, C2H4), 1.65–0.81 (m, 54H, P[C4H9]3); 13C{1H}
NMR (100.40 MHz, [D8]THF): d ¼ 156:8, 152.9, 132.1,
125.7, 121.2, 120.6 (C6H4), 65.8 (CH3), 49.7 (C2H4),
28.7 (vt, P[CH2C3H7]3), 28.1, 26.2, 13.5 (P[CH2C3H7]3);
31P{1H} NMR (161.70 MHz, [D8]THF): d ¼ 26:27
(P[C4H9]3); MS (102Ru, THF): m=z ¼ 808 [Mþ], 606
[Mþ–PnBu3]; elemental analysis. Anal. Calc. for
C40H72N2RuP2S2 (808.13): C 59.45, H 8.98, N 3.47, S
7.94. Found: C 59.46, H 9.24, N 3.51, S 7.67%.
2.13.1. [Ru(PMe3)2(‘N2Me2S2’)] (2d)
PMe3 (0.71 ml, 6.87 mmol). Yield: 600 mg (47%) of
1
[Ru(PMe3)2(‘N2Me2S2’)] (2d); H NMR (399.65 MHz,
[D8]THF): d ¼ 7:38 (d, 3JH;H ¼ 7:8 Hz, 2H, C6H4), 7.26
(d, 3JH;H ¼ 8:0 Hz, 2H, C6H4), 6.80–6.72 (m, 4H, C6H4),
3.41 (s, 6H, CH3), 2.91–2.87 (m, 2H, C2H4), 2.38–2.24
(m, 2H, C2H4), 1.23 (vt, P[CH3]3); 13C{1H} NMR
(100.40 MHz, [D8]THF): d ¼ 156:3, 153.3, 132.5, 126.3,
122.2, 121.2 (C6H4), 66.3 (CH3), 49.8 (C2H4), 19.8 (vt,
P[CH3]3); 31P{1H} NMR (161.70 MHz, [D8]THF):
d ¼ 16:4 (P[CH3]3); MS (102Ru, THF/Et2O): m=z ¼ 556
2.14. [Ru(dppe)(‘N2Me2S2’)] (3)
[Mþ];
elemental
analysis.
Anal.
Calc.
for
C22H36N2RuP2S2 (555.66): C 47.55, H 6.53, N 5.04, S
11.54. Found: 47.66, H 6.65, N 5.09, S 11.11%.
Diphenylphosphanoethane (dppe) (912 mg, 2.29
mmol). Yield: 800 mg (17.5%) of [Ru(dppe)(‘N2Me2S2’)]
(3); H NMR (399.65 MHz, [D8]THF): d ¼ 7:60–6:59
1
(m, 28H, C6H4, C6H5), 3.29 (s, 6H, CH3), 3.14–3.11 (m,
4H, PC2H4), 2.57–2.25 (m, 4H, C2H4); 13C{1H} NMR
(100.40 MHz, [D8]THF): d ¼ 153:1, 151.8, 139.7, 135.9,
134.3, 133.0, 131.7, 129.2, 128.3, 127.8, 126.5 (C6H5),
125.6, 120.9, 120.6 (C6H5, C6H4, signals partially su-
perimposed), 65.6 (CH3), 51.6 (C2H4), 30.3 (PCH2CH2);
31P{1H} NMR (161.70 MHz, [D8]THF): d ¼ 68:09
(P(C6H5)3); MS (102Ru, THF): m=z ¼ 802 [Mþ]; ele-
mental analysis. Anal. Calc. for C42H42N2P2RuS2
(801.95): C 62.90, H 5.28, N 3.49, S 8.00. Found: C
62.45, H 4.96, N 3.61, S 7.75%.
2.13.2. [Ru(PEt3)2(‘N2Me2S2’)] (2e)
PEt3 (0.67 ml, 4.58 mmol). Yield: 545 mg (29%) of
[Ru(PEt3)2(‘N2Me2S2’)] (2e); 1H NMR (399.65 MHz,
[D8]THF): d ¼ 7:38 (d, 3JH;H ¼ 8:0 Hz, 2H, C6H4), 7.22
(d, 3JH;H ¼ 8:0 Hz, 2H, C6H4), 6.79–6.70 (m, 4H, C6H4),
3.38 (s, 6H, CH3), 2.89–2.86 (m, 2H, C2H4), 2.17–2.15
(m, 2H, C2H4), 1.81–1.67 (m, 12H, P[CH2CH3]3), 1.08–
0.89 (m, 18H, P[CH2CH3]3); 13C{1H} NMR (100.40
MHz, [D8]THF): d ¼ 156:4, 152.8, 132.0, 125.8, 121.2,
120.6 (C6H4), 65.8 (CH3), 49.7 (C2H4), 20.5 (vt,
P[CH2CH3]3), 9.16 (s, P[CH2CH3]3); 31P{1H} NMR
(161.70 MHz, [D8]THF): d ¼ 31:36 (P[C2H5]3); MS
(
102Ru, THF): m=z ¼ 640 [Mþ], 522 [Mþ–PEt3]; ele-
2.15. [Ru(CO)(PEt3)(‘N2Me2S2’)] (4e)
mental analysis. Anal. Calc. for C28H48N2RuP2S2
(639.81): C 52.56, H 7.56, N 4.38, S 10.02. Found: C
52.51, H 7.80, N 4.47, S 9.82%.
A yellow solution of 2e (530 mg, 0.83 mmol) in THF
(50 ml) was stirred under an atmosphere of CO (80 bars)
at 60 °C for 5 d. The resulting yellow solution was re-
duced in volume to 2 ml. Addition of MeOH (20 ml)
yielded a yellow solid which was separated after 30 min,
washed with MeOH (10 ml) and n-pentane (10 ml) and
dried in vacuo. Yield: 320 mg (71%) of
[Ru(CO)(PEt3)(‘N2Me2S2’)] (4e); 1H NMR (399.65
MHz, [D8]THF): d ¼ 7:40–7:31 (m, 4H, C6H4), 6.91–
6.80 (m, 4H, C6H4), 3.45 (s, 3H, CH3), 3.38 (s, 3H,
CH3), 3.16–2.15 (m, 4H, C2H4), 1.95–1.67 (m, 6H,
P[CH2CH3]3), 1.08–1.01 (m, 9H, P[CH2CH3]3); 13C{1H}
NMR (100.40 MHz, [D8]THF): d ¼ 204:7 (d,
2JP;C ¼ 19:0 Hz, CO), 151.7, 151.4, 150.5, 150.1, 130.9,
130.8, 125.8, 121.0, 120.7, 119.8 (C6H4), 65.0, 62.1
2.13.3. [Ru(PnPr3)2(‘N2Me2S2’)] (2f)
PnPr3 (0.92 ml, 4.58 mmol). Yield: 910 mg (49%) of
[Ru(PEt3)2(‘N2Me2S2’)] ꢁ 0.3Et2O (2f ꢁ 0.3Et2O); 1H
NMR (269.6 MHz, CDCl3): d ¼ 7:54–7:48 (m, 2H,
C6H4), 7.17–7.12 (m, 2H, C6H4), 6.88–6.79 (m, 4H,
C6H4), 3.37 (s, 6H, CH3), 2.89–2.86 (m, 2H, C2H4),
2.17–2.15 (m, 2H, C2H4), 1.70–1.15 (m, 24H,
P[CH2C2H5]3), 1.08–0.89 (m, 18H, P[CH2C2H5]3);
13C{1H} NMR (67.7 MHz, CDCl3): d ¼ 154:7, 152.2,
131.7, 125.9, 120.9, 120.8 (C6H4), 65.5 (CH3), 50.1
(C2H4), 30.7 (vt, P[CH2C2H5]3), 18.7, 16.2
(P[CH2C2H5]3); 31P{1H} NMR (161.70 MHz, CDCl3):
d ¼ 23:5 (P[C2H5]3); MS (102Ru, THF): m=z ¼ 725
[Mþ], 564 [Mþ–PnPr3]; elemental analysis. Anal. Calc.
for C35:33H63:33N2O0:33RuP2S2 (748.62): C 56.68, H
8.53, N 3.74, S 8.57. Found: C 56.78, H 8.91, N 4.09, S
8.86%.
1
(CH3), 50.0, 48.2 (C2H4), 17.6 (d, JP;C ¼ 28:0 Hz,
P(CH2CH3)3), 6.8 (P[CH2CH3]3); 31P{1H} NMR
(161.70 MHz, [D8]THF): d ¼ 31:29 (P[C2H5]3); IR
(KBr): ~m ¼ 1934 cmꢀ1 (CBO); MS (102Ru, THF):
m=z ¼ 550 [Mþ]; elemental analysis. Anal. Calc. for

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3343
C23H33N2OPRuS2 (549.70): C 50.26, H 6.05, N 5.10, S
11.67. Found: C 50.14, H 6.26, N 4.90, S 11.92%.
had been the labile acetonitrile complex [Ru(NCCH3)
(PiPr3)(‘N2Me2S2’)]. PCy3 and PPh3 were the only
phosphanes found to form analogous complexes. PCy3
and PPh3 have cone angles of 170° and 145°, compara-
ble to that of PiPr3 (160°) [29]. Treatment of
[Ru(NCCH3)4Cl2] with Li2‘N2Me2S2’ and two equiva-
lents of PR3 in the presence of additional LiOMe in
boiling MeOH afforded complexes of the [Ru(NCCH3)
(PR3)(‘N2Me2S2’)] type (1a–c) according to Eq. (1).
2.16. [Ru(PEt3)2(‘NMeS’)2] (5e)
A colorless solution of ‘N2Me2S2’–H2 (173 mg, 0.57
mmol) and LiOMe (2.28 ml, 2.28 mmol, 1 N in MeOH) in
MeOH (10 ml) was added dropwise within 20 min to a
boiling yellow suspension of [Ru(NCCH3)4Cl2] (192 mg,
0.57 mmol) and PEt3 (0.17 ml, 1.15 mmol). The resulting
reaction mixture was refluxed for 4 h and cooled to room
temperature. The orange solid was removed and washed
with MeOH (10 ml). After extraction of the crude prod-
uct with n-pentane (30 ml), the solvent was evaporated
to dryness. Yield: 30 mg of a mixture of 2e and
[Ru(PEt3)2(‘NMeS’)2] (5e). Spectroscopic data for 5e: 1H
NMR (399.65 MHz, [D8]THF): d ¼ 7:53 (d, 3JH;H ¼ 8:2
Hz, 2H, C6H4), 7.33 (d, 3JH;H ¼ 8:1 Hz, 2H, C6H4), 6.99–
6.90 (m, 4H, C6H4), 2.68 (s, 6H, CH3), 1.28–1.09 (m, 39H,
P[C2H5]3); 13C{1H} NMR (100.40 MHz, [D8]THF):
d ¼ 158:4, 152.5, 131.84, 125.0, 120.1, 117.9 (C6H4), 43.8
(CH3), 19.7 (vt, P[CH2CH3]3), 8.5 (s, P[CH2CH3]3);
31P{1H} NMR (161.70 MHz, [D8]THF): d ¼ 30:96
(P[C2H5]3); MS (102Ru, THF): m=z ¼ 612 [Mþ].
SH
SH
+ [Ru(NCCH3)4Cl2
+ PR3, + LiOMe
]
S
S
Me
Me
Me
N
PR3
PR3
S
N
N
Ru
S
NCCH3+
Ru
N
N
MeOH, 65 ˚C
Me
Me
N
Me
NCCH3
1c (R = Ph)
1a (R = Cy)
1b (R = Ph)
ð1Þ
It is to be noted that, although two equivalents of
PR3 were employed, only monophosphane complexes
were formed. The excess of phosphane and LiOMe was
added in order to prevent the formation of
[Ru(‘N2HMe2j2S2’)(‘N2Me2S2’)] (10) (Fig. 3) [40].
This complex had been previously found to form as
major product in attempts to synthesize [Ru(NCCH3)
(PiPr3)(‘N2Me2S2’)] from [Ru(NCCH3)4Cl2], PiPr3, and
Li2‘N2Me2S2’, if no additional LiOMe had been added.
According to Eq. (1) the use of PCy3 exclusively
yielded the cis,trans isomer of [Ru(NCCH3)(PCy3)
(‘N2Me2S2’)] (1a). However, in the case of PPh3, under
identical reaction conditions, two stereoisomers of
[Ru(NCCH3)(PPh3)(‘N2Me2S2’)] were obtained. They
could be separated by fractional crystallization and
identified as the cis,trans isomer 1b and the cis,cis isomer
1c by X-ray crystal structure determination. The pres-
ence of a mixture of stereoisomers was also indicated by
subsequent reaction with CO to complexes exhibiting
different m(CBO) frequencies (see below). In order to
avoid the time consuming process of separating 1b from
1c, methods were sought for converting 1c into 1b, and it
was finally found that 1c readily isomerizes to 1b in
boiling acetonitrile. The synthesis of preparative
amounts of cis,trans-[Ru(NCCH3)(PPh3)(‘N2Me2S2’)]
(1b) therefore includes heating of the mixture of 1b and
1c in boiling acetonitrile.
2.17. [Ru(CO)(PnPr3)(‘N2Me2S2’)] (4f)
CO was passed through a yellow solution of
2f ꢁ 0.3Et2O (100 mg, 0.13 mmol) in THF (50 ml) at 65
°C for 5 h. The resulting yellow solution was evaporated
to dryness and the oily product dissolved in CH2Cl2 (20
ml). The yellow solution was filtered through Al2O3
(grade II), the Al2O3 washed with CH2Cl2 and the
combined solutions evaporated to dryness. Complex 4f
was spectroscopically characterized. 1H NMR (269.6
MHz, CD2Cl2): d ¼ 7:44–6:92 (m, 8H, C6H4), 3.45 (s,
3H, CH3), 3.16 (s, 3H, CH3), 2.89–2.55 (m, 4H, C2H4),
1.86–1.42 (m, 12H, P[C2H4CH3]3), 1.08–0.89 (m, 9H,
P[C2H4CH3]3); 13C{1H} NMR (67.7 MHz, CD2Cl2):
2
d ¼ 205:4, (d, JP;C ¼ 19:0 Hz, CO), 150.2, 131.7, 131.2,
127.2, 127.0, 122.1, 122.0, 121.9, 121.7 (C6H4), 65.9, 62.9
1
(CH3), 51.3, 49.6 (C2H4), 28,8 (d, JP;C ¼ 28:0 Hz,
P[CH2C2H5]3), 17.6, 16.0 (P[CH2C2H5]3); 31P{1H}
NMR (161.70 MHz, CD2Cl2): d ¼ 23:2 (P[C3H7]3); IR
ꢀ1
~
(KBr): m ¼ 1932 cm
(CBO), MS (102Ru, THF):
m=z ¼ 592 [Mþ]; elemental analysis. Anal. Calc. for
C23H33N2OPRuS2 (549.70): C 50.26, H 6.05, N 5.10, S
11.67. Found: C 50.14, H 6.26, N 4.90, S 11.92%.
3.2. Synthesis of [Ru(PR3)2(‘N2Me2S2’)] complexes
with R ¼ Me, Et, nPr, nBu, and of [Ru(dppe)
(‘N2Me2S2’)]
3. Results
3.1. Synthesis of [Ru(NCCH3)(PR3)(‘N2Me2S2’)]
complexes with R ¼ Cy, Ph
No [Ru(NCCH3)(PR3)(‘N2Me2S2’)] complexes could
be obtained with smaller phosphanes PR3 having cone
angles ranging from 118° (PMe3) to 132° (PnBu3). In-
The precursor complex for the synthesis of [Ru(N2)
(PiPr3)(‘N2Me2S2’)] and [l-N2{Ru(PiPr3)(‘N2Me2S2’)}2]
stead,
treatment
of
[Ru(NCCH3)4Cl2]
with
Li2‘N2Me2S2’ and the respective phosphanes according

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D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
S
S
Me
Me
Me
PPh2
PPh2
S
S
N
N
N
H
Ru
S
Ru
S
N
N
N
Me
Me
Me
10
Fig. 3. [Ru(‘N2HMe2j2S2’)(‘N2Me2S2’)] (10).
3
Fig. 4. [Ru(dppe)(‘N2Me2S2’)] (3).
to Eq. (2) afforded the bisphosphane complexes
[Ru(PR3)2(‘N2Me2S2’)] [2d (R ¼ Me), 2e (R ¼ Et), 2f
(R ¼ nPr), and 2g (R ¼ nBu)].
could only be characterized by spectroscopic methods.
In spite of intensive purification efforts, no pure samples
of complex 4f could be obtained.
In the course of the investigations, it was also found
that the [Ru(‘N2Me2S2’)] fragment of [Ru(PR3)2
(‘N2Me2S2’)] complexes is not absolutely inert but can
lose its C2H4 bridge under certain reaction conditions.
This observation was made, when the reaction mixture
of [Ru(NCCH3)4Cl2], Li2‘N2Me2S2’, excessive LiOMe
and PEt3 was heated for prolonged times. Such solu-
tions contained, besides [Ru(PEt3)2(‘N2Me2S2’)] (2e),
which still represented the major product, the amido
complex [Ru(PEt3)2(‘NMeS’)2] (5e), which formed
according to Eq. (3) and was characterized by NMR,
mass spectroscopy, and by X-ray crystal structure
determination.
SH
+ [Ru(NCCH3)4Cl2]
+ PR3, + LiOMe
S
Me
Me
N
PR3
PR3
N
Ru
S
N
MeOH, 65 ˚C
ð2Þ
N
Me
Me
SH
2d (R = Me), 2e (R = Et)
2f (R = nPr),2g (R = nBu)
It proved impossible to trap the potential
[Ru(NCCH3)(PR3)(‘N2Me2S2’)] intermediates, irrespec-
tive of whether the reactions were carried out in boiling
MeOH or CH3CN, or if 1:1 ratios of [Ru(NCCH3)4Cl2]
and PR3 were used. In the last case, in addition to the
respective [Ru(PR3)2(‘N2Me2S2’)] complexes, only un-
changed [Ru(NCCH3)4Cl2] was recovered from the re-
action solutions. Analogously, only the mononuclear
[Ru(dppe)(‘N2Me2S2’)] complex (3) was obtained when
solutions containing 1:1 ratios of [Ru(NCCH3)4Cl2] and
Li2‘N2Me2S2’ with varying amounts of dppe were pre-
pared under different reaction conditions (Fig. 4).
No evidence for the formation of species such as [l-
dppe{Ru(NCCH3)(‘N2Me2S2’)}2] was obtained.
PEt3
Ru
S
Me
Me
MeOH, 65 ˚C, 5 h
PEt3
PEt3
S
N
N
S
N
Ru
S
− C2H4
N
ð3Þ
Me
Me
PEt3
5e
2e
However, it proved impossible to find a rational
synthesis for [Ru(PEt3)2(‘NMeS’)2] (5e). This remained
a notorious obstacle with regard to the isolation of
preparative amounts of 5e.
3.3. Reactions of [Ru(PR3)2(‘N2Me2S2’)] complexes
3.4. Exchange reactions of [Ru(NCCH3) (PR3)
(‘N2Me2S2’)] complexes
The bisphosphane complexes [Ru(PR3)2(‘N2Me2S2’)]
[2d (R ¼ Me), 2e (R ¼ Et), 2f (R ¼ nPr), and 2g
(R ¼ nBu)], or the dppe complex [Ru(dppe)(‘N2Me2S2’)]
(3) proved inert or nearly inert towards substitution,
even under drastic reaction conditions. No exchange of
one of the PR3 ligands for N2 or other nitrogenous li-
gands, for example N2H4 or NH3, could be observed.
Success was only achieved with CO, which led to the
formation of the mono carbonyl derivatives
[Ru(CO)(PR3)(‘N2Me2S2’)], which show strong m(CBO)
bands in the region from 1926 to 1934 cmꢀ1. These re-
actions, however, required long reaction times, CO
pressures of up to 80 bar, and elevated temperatures
(60–80 °C). Of the resulting complexes [Ru(CO)
(PEt3)(‘N2Me2S2’)] (4e) could be characterized both by
elemental analysis and spectroscopic methods, whereas
the PnPr3 derivative [Ru(CO)(PnPr3)(‘N2Me2S2’)] (4f)
Since all bisphosphane complexes [Ru(PR3)2
(‘N2Me2S2’)] proved inert or nearly inert towards ex-
change of one PR3 ligand for other molecules, ligand
exchange reactions were performed with the labile
[Ru(NCCH3)(PR3)(‘N2Me2S2’)] complexes with R ¼ Cy
(1a) and Ph (1b). The subsequent reactions of 1a and 1b
with CO, N2, NH3, and N2H4 are summarized in
Scheme 1.
With the exception of the complexes in square
brackets, the N2H4 complex [Ru(N2H4)(PCy3)
(‘N2Me2S2’)] (6a) and the N2 complex [Ru(N2)
(PPh3)(‘N2Me2S2’)] (7b), all complexes indicated in
Scheme 1 could be isolated in pure form and in solid
state and represented the cis,trans-[Ru(L)(PR3)
(‘N2Me2S2’)] stereoisomers.

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3345
The characteristic m(CBN) bands of [Ru(NCCH3)
(PCy3)(‘N2Me2S2’)] (1a) (2242 cmꢀ1) and [Ru(NCCH3)
(PPh3)(‘N2Me2S2’)] (1b) (2242 cmꢀ1) as well as the
m(CBO) bands of [Ru(CO)(PCy3)(‘N2Me2S2’)] (8a)
(1932 cmꢀ1) and [Ru(CO)(PPh3)(‘N2Me2S2’)] (8b3)
(1940 cmꢀ1), or the m(NBN) bands of [Ru(N2)(PCy3)
(‘N2Me2S2’)] (7a) (2113 cmꢀ1) and [Ru(N2)(PPh3)
(‘N2Me2S2’)] (7b) (2130 cmꢀ1) enabled the IR-spectro-
scopic monitoring of the reactions. Stereoisomeric pu-
rity of the isolated complexes could be confirmed by
one reaction product. The low-field shift and splitting
pattern of signals at d ¼ 17:04 ppm (d, 3JH;H ¼ 27:6 Hz,
1H, RuNHNH) and d ¼ 16:18 ppm (d, 3JH;H ¼ 27:6 Hz,
1
1H, RuNHNH) in the H NMR spectrum further in-
dicated the formation of a mononuclear diazene com-
plex of the [Ru(N2H2)(PCy3)(‘N2Me2S2’)] type [41–46].
This was taken as evidence that N2H4, when binding to
the [Ru(PCy3)(‘N2Me2S2’)] fragment, disproportionates
giving rise to N2H2 and NH3 complexes according to
Eq. (4).
1
their H and 31P NMR spectra. For example, the 31P
NMR spectra of all isolated complexes showed only one
31P singlet each (see below).
S
S
S
Me
Me
Me
PCy3
N2H4
PCy3
NH3
PCy
3+ 2
N2H2
N
N
N
3
Ru
S
Ru
S
Ru
S
N
N
N
Passing a stream of NH3 gas through THF solutions
of 1a or 1b at slightly elevated temperatures of 50 °C
gave the NH3 complexes [Ru(NH3)(PR3)(‘N2Me2S2’)]
[9a (R ¼ Cy), 9b (R ¼ Ph)]. Treatment of the PPh3
complex 1b with N2H4 yielded pure [Ru(N2H4)
(PPh3)(‘N2Me2S2’)] (6b). The analogous PCy3 complex
[Ru(N2H4)(PCy3)(‘N2Me2S2’)] (6a) could not be iso-
lated in solid state, although both 1H and 31P NMR
spectra indicated the exclusive formation of
[Ru(N2H4)(PCy3)(‘N2Me2S2’)] (6a) when N2H4 was
added to THF solutions of either the acetonitrile com-
plex [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] (1a) or the N2
complex [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a). As evidenced
by the color change of the resulting yellow solutions to
deep blue in the course of 4–6 h, the hydrazine complex
6a decomposed to give further products. 1H and 31P
NMR spectra enabled the unambiguous identification of
the NH3 complex [Ru(NH3)(PCy3)(‘N2Me2S2’)] (9a) as
Me
Me
Me
6a
9a
ð4Þ
Similar observations had been made previously with
the analogous PiPr3 complex [Ru(N2H4)(PiPr3)
(‘N2Me2S2’)] and are described elsewhere in detail
[1]. Particular emphasis was paid to the synthesis of
the N2 complexes [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a) and
[Ru(N2)(PPh3)(‘N2Me2S2’)] (7b). Passing a vigorous
stream of N2 through toluene solutions of the CH3CN
complexes 1a or 1b at slightly elevated temperatures (55
°C) led to replacement of the CH3CN ligands by N2 and
to the formation of the N2 complexes 7a and 7b. This
was unambiguously indicated by the increasing intensity
of the m(NBN) bands of 7a (2114 cmꢀ1) and 7b (2130
cmꢀ1), respectively. However, it proved impossible to
drive the reactions to completeness. The isolated prod-
ucts always were mixtures of the starting CH3CN and
product N2 complexes, and attempts to separate these
mixtures remained unsuccessful. Therefore, it was a
considerable progress to find that also the NH3 com-
plexes 9a and 9b proved labile enough for exchanging
their NH3 for N2 ligands. At least in the case of the
PCy3 complex, the exchange of NH3 by N2 could be
driven to completeness, affording yields of up to 90% of
the N2 complex [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a). This
was not the case with the analogous PPh3 complex. In
analogy to the aforementioned reaction, treatment of
the PPh3 derivative [Ru(NH3)(PPh3)(‘N2Me2S2’)] (9b)
with N2 always yielded mixtures of ca. 75% N2 complex
7b and 25% starting NH3 complex 9b. It remained as yet
inexplicable as to why no pure samples of 7b could be
obtained by this synthetic route.
S
Me
PR3
CO
N
8a (R = Cy)
8b3 (R = Ph)
Ru
S
N
Me
a)
S
S
S
Me
Me
Me
PR3
NH3
b)
PR3
NCCH3
c)
PR3
N2H4
N
N
N
Ru
S
Ru
S
Ru
S
N
N
N
Me
Me
Me
1a (R = Cy)
1b (R = Ph)
[6a] (R = Cy)
6b (R = Ph)
d)
9a (R = Cy)
9b (R = Ph)
f)
e)
S
Me
Treatment of the acetonitrile complex 1a with CO
exclusively resulted in the formation of cis,trans-
[Ru(CO)(PCy3)(‘N2Me2S2’)] (8a).
However, when the analogous reaction was carried
out with the PPh3 derivative cis,trans-[Ru(NCCH3)
(PPh3)(‘N2Me2S2’)] (1b), unexpected observations were
made. IR spectra (Fig. 5a–c) that were taken from a
solution of 1b [m(CBN) ¼ 2257 cmꢀ1, Fig. 5a] directly
PR3
N2
N
Ru
S
N
Me
7a (R = Cy)
[7b] (R = Ph)
Scheme 1. Syntheses and reactions of [Ru(NCCH3)(PR3)(‘N2Me2S2’)]
complexes [1a (R ¼ Cy), 1b (R ¼ Ph)]; (a) + CO/THF/10 min/RT; (b)
+NH3/THF/1 h/50 °C; (c) +N2H4/THF/RT/10 min; (d) +N2/toluene/
12 h/55 °C; (e) +N2/toluene/2 h/55 °C, (f) +N2H4/THF/1 min/RT.

3346
D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
after CO was injected showed a strong band at 1932
cmꢀ1 (Fig. 5b). In the course of several hours, this band
disappeared and a new band at 1946 cmꢀ1 was formed,
which had a small shoulder at 1922 cmꢀ1 (Fig. 5c). The
occurrence of these bands was tentatively assigned to the
formation of three stereoisomers of [Ru(CO)(PPh3)
(‘N2Me2S2’)].
The formation of such isomers was further confirmed
by 31P NMR spectroscopy. Directly after CO was in-
jected into [D8]THF solutions of 1b, the 31P NMR
spectrum displayed a singlet at d ¼ 48:36 ppm. This
singlet had disappeared in the course of 6 h. Meanwhile,
a large singlet at d ¼ 49:12 ppm and a small singlet at
d ¼ 50:13 ppm appeared. After 12 h, only the singlet at
d ¼ 49:12 and a small singlet at d ¼ ꢀ5:12 ppm, which
was assigned to free PPh3, remained. The product that
was finally isolated after 12 h from this solution was the
cis,trans isomer of [Ru(CO)(PPh3)(‘N2Me2S2’)] (8b3).
The cis,trans arrangement of the ‘N2Me2S2’ ligand was
authenticated by spectroscopic methods and by X-ray
crystal structure determination.
(‘N2Me2S2’)] (8b3), which is the most stable isomer and
therefore does not undergo further isomerization.
Particular emphasis was paid to the synthesis of [l-
N2{Ru(PCy3)(‘N2Me2S2’)}2], which was expected to
form similar to the dinuclear PiPr3 derivative (see
above). However, lowering the N2 pressure by sweeping
a stream of argon through yellow toluene or benzene
solutions of 7a resulted in the formation of deep blue
solutions which showed neither a m(NBN) band in the
IR nor in the Raman spectrum [the m(NBN) stretching
mode of the hypothetical bridged N2 complex should be
IR inactive due to symmetric reasons]. 31P NMR spectra
that were taken from such solutions exclusively dis-
played one singlet at d ¼ 22:84 ppm. Treatment of these
blue solutions with N2 immediately recovered the N2
complex 7a, confirming that the reaction was reversible.
From these experimental observations, it is very likely
that loss of the N2 ligand in 7a results in a 16 valence
electron [Ru(PCy3)(‘N2Me2S2’)] species in which the free
coordination site is blocked by an agostic C–H ! M
interaction [Eq. (5)].
The formation of three stereoisomers of [Ru(CO)
(PPh3)(‘N2Me2S2’)] (8b1–3) agrees with the ability of the
‘N2Me2S2’ ligand to form a pair of cis,trans enantiomers
and two cis,cis diastereomers (see above). A likely
mechanism is given in Scheme 2.
S
S
Me
Me
toluene, 50 ˚C
PCy3
N2
PCy2
N
N
Ru
S
Ru
S
N
N
ð5Þ
−/+ N2
H
Me
Me
Dissociation of the labile CH3CN ligand in 1b forms
a five-coordinate [Ru(PPh3)(‘N2Me2S2’)] fragment A
7a
The ability of the PCy3 ligand to stabilize free coor-
dination sites via agostic C–H ! M interactions is
demonstrated, for example, in [W(CO3)(PCy3)2], which
is also a 16 valence electron species [47]. Steric reasons
due to the bulky PCy3 apparently disfavored the for-
mation of a dinuclear N2 complex with a structure
similar to that of [l-N2{Ru(N2)(PiPr3)(‘N2Me2S2’)}2].
which isomerizes to give
a
cis,cis configurated
[Ru(PPh3)(‘N2Me2S2’)] fragment. Subsequent reaction
with CO yields one isomer of cis,cis-[Ru(CO)(PPh3)
(‘N2Me2S2’)] (8b1), which gives rise to a m(CBO) band at
1932 cmꢀ1 in the IR spectrum (Fig. 5b) and to a singlet
at d ¼ 48:36 ppm in the 31P NMR spectrum. Dissocia-
tion of the PPh3 ligand, which is also labile, isomeri-
zation of the five-coordinate intermediate B and
re-addition of the phosphane result in a second cis,cis
isomer of [Ru(CO)(PPh3)(‘N2Me2S2’)] (8b2) [m(CBO):
3.5. X-ray crystal structure analyses
1922 cmꢀ1
,
the phosphane, isomerization and re-addition of the
phosphane finally yield cis,trans-[Ru(CO)(PPh3)
31P NMR: d ¼ 50:13 ppm]. Dissociation of
The structures of the [Ru(L)(PR3)(‘N2Me2S2’)]
complexes 1a ꢁ MeOH, 1b ꢁ MeOH, 1c ꢁ THF, 7a ꢁ
THF, 8a ꢁ THF, 8b3 ꢁ THF, 9b, 6b ꢁ 2THF, of the
(a)
(b)
(c)
2257 ν(CN)
1922
ν(CO)
1932 ν(CO)
1946 ν(CO)
cm–1
cm–1
cm–1
2300
1850
2300
1850
2300
1850
Fig. 5. IR spectroscopic monitoring of the reaction of 1b with CO; (a) 1b in THF; (b) +CO, 1 min; (c) after 6 h.

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3347
S
S
S
Me
Me
Me
PPh3
PPh3
+ CO
N
N
N
N2
Ru
S
Ru
S
PPh3
Ru
N2
S
N
N
NCCH3
N
− CH CN Me
3
Me
S2
Me
S2
N1
Ru1
N1
P1
P1
CO
Ru1
N3
1b
A
8b1
S1
C1
N3
S1
− PPh3
C1
1b
1a
S
S
S
Me
Me
Me
PPh3
+/− PPh3
CO
S
+ PPh3
N
N
N
Ru
S
Ru
Ru
S
N
N
N
NCCH3
Me
Me
Me
N2
PPh3
8b2
CO
N1A
S2
8b3
B
S1A
Ru1
P1
N1
N1
Ru1
H3B
P1A
S1
Scheme 2. Postulated mechanism for the formation of cis,cis and
cis,trans isomers of [Ru(CO)(PPh3)(‘N2Me2S2’)] (8b1–3).
H3A
S1
H4A
N4
H4B
N3
P1
2d
6b
[Ru(PR3)2(‘N2Me2S2’)] complexes 2d, 2e, 2f, 2f ꢁ Et2O,
2g ꢁ 0.5MeOH, of [Ru(PR3)2(‘NMeS’)2] (5e), and of
[Ru(‘N2HMe2j2S2’)(‘N2Me2S2’)] ꢁ 2CH2Cl2(10 ꢁ 2CH2C-
l2) were determined by X-ray crystal structure analysis.
Fig. 6 depicts the molecular structures of the complexes
1a, 1b, 7a, 2d, 8b3, and 6b, which are exemplary for the
complexes reported.
The crystallographic data for the structure determi-
nations of 1c ꢁ THF, 2e, 5e, 2f, 2f ꢁ Et2O, 2g ꢁ 0.5MeOH,
8a ꢁ THF, 9b, and of 10 ꢁ 2CH2Cl2 will not be reported
here in detail but have been deposited within the CSD
(see supplementary material).
N2
N2
S2
S2
N1
N1
Ru1
P1
P1
Ru1
C1
O1
S1
N3
N4
S1
8b3
7a
Fig. 6. Molecular structures of [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] ꢁ
MeOH (1a ꢁ MeOH), [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] ꢁ MeOH (1b ꢁ
MeOH),
[Ru(PMe3)2(‘N2Me2S2’)]
(2d),
[Ru(N2H4)(PPh3)
The ruthenium centers of the [Ru(L)(PR3)
(‘N2Me2S2’)] and [Ru(PR3)2(‘N2Me2S2’)] complexes
exhibit pseudo-octahedral coordination and trans-thio-
late donors.
(‘N2Me2S2’)] ꢁ 2THF (6b ꢁ 2THF), [Ru(N2)(PCy3)(‘N2Me2S2’)] ꢁ THF
(7a ꢁ THF), and [Ru(CO)(PPh3)(‘N2Me2S2’)] ꢁ THF (8b3 ꢁ THF); (50%
probability ellipsoids; C-bound H atoms and solvent molecules omit-
ted for clarity).
Table 3 lists selected bond distances and angles and
shows that the distances and angles within the
[Ru(PR3)(‘N2Me2S2’)] cores of all complexes lie in the
usual range.
The following points are worth to be noted: The Ru–
L1 distances in the N2H4 complex 6b [212.6(2) pm] and
in the bisphosphane complex 2d [226.8(1) pm] are
Table 3
Selected bond distances (pm) and angles (°) within [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] ꢁ MeOH (1a ꢁ MeOH), [Ru(NCCH3)(PPh3)(‘N2Me2S2’)] ꢁ MeOH
(1b ꢁ MeOH), [Ru(PMe3)2(‘N2Me2S2’)] (2d), [Ru(N2H4)(PPh3)(‘N2Me2S2’)] ꢁ 2THF (6b ꢁ 2THF), [Ru(N2)(PCy3)(‘N2Me2S2’)] ꢁ THF (7a ꢁ THF), and
[Ru(CO)(PPh3)(‘N2Me2S2’)] ꢁ THF (8b3 ꢁ THF)
Complex
1a ꢁ MeOH
1b ꢁ MeOH
2d
6b ꢁ 2THF
7a ꢁ THF
8b3 ꢁ THF
Ru1–N1
Ru1–N2/N1A
Ru1–S1
227.6(2)
221.1(2)
239.0(1)
236.9(1)
233.5(1)
198.8(2)
113.8(3)
225.8(3)
220.1(3)
238.5(2)
237.9(2)
227.1(2)
201.1(3)
111.8(5)
228.0(2)
228.0(2)
237.2(1)
237.2(1)
226.8(1)
226.8(1)
227.2(2)
220.4(2)
237.8(1)
238.7(1)
227.2(1)
212.6(2)
144.9(2)
226.1(5)
219.9(5)
237.9(2)
237.8(2)
236.8(2)
190.3(6)
110.8(8)
225.1(2)
228.3(2)
237.3(1)
239.8(1)
231.9(1)
182.6(3)
Ru1–S2/S2A
Ru1–P1/P1A
Ru1–L1ꢃ
L1ꢃ–C1/N4
L1ꢃ–O1
116.2(3)
81.2(1)
172.3(1)
86.8(1)
83.5(1)
N1–Ru1–N2/N1A
S1–Ru1–S2/S1A
P1–Ru1–L1ꢃ
N1–Ru1–S1
82.1(1)
171.6(1)
89.4(1)
82.7(1)
82.8(1)
173.9(1)
87.6(1)
83.2(1)
80.8(1)
174.3(1)
91.7(1)
83.8(1)
82.7(1)
173.1(1)
91.7(1)
83.4(1)
82.9(2)
170.3(1)
87.7(2)
82.6(2)
* L1 ¼ N3 (1a ꢁ MeOH, 1b ꢁ MeOH, 6b ꢁ 2THF, 7a ꢁ THF); L1 ¼ P1 (2d); L1 ¼ C1 (8b3 ꢁ THF).

3348
D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
longest within the aforementioned complexes and indi-
cate single bond character. The Ru1–N3 distances in the
N2 complex 7a [190.3(6) pm] and the Ru1–C1 distance
in the CO complex 8b3 [182.6(3) pm] indicate multiple
bond character and are similar to the corresponding
distances found in [Ru(N2)(PiPr3)(‘N2Me2S2’)] [190.7(3)
pm] and [Ru(CO)(PiPr3)(‘N2Me2S2’)] [181.1(6) pm] [23–
25].
The Ru–N3 distances in the CH3CN complexes 1a
[198.8(2) pm] and 1b [201.1(3) pm] are practically iden-
tical to the respective distance found in
[Ru(NCCH3)(PiPr3)(‘N2Me2S2’)] [199.0(3) pm] [23,24].
Thus, the exchange of PiPr3 for PCy3 and PPh3, re-
spectively, does not influence the Ru–N3 distance. This
is also reflected by the exchange reactions of the CH3CN
ligand (see Scheme 1) which is comparably fast in 1a, 1b,
or in [Ru(NCCH3)(PiPr3)(‘N2Me2S2’)] [23,24].
Due to the strong trans-effect of the phosphane and
CO co-ligands, the Ru–N2 distances are longest in 2d
[228.0(2) pm] and 8b3 [228.3(2) pm]. Much shorter Ru–
N2 distances are found in the acetonitrile complex 1b
[220.1(3) pm] and in the hydrazine complex 6b [220.4(2)
pm]. Practically, no trans-effect is caused by the weak pꢃ-
acceptor ligand N2 in complex 7a [219.9(5) pm]. Natu-
rally, the electronic situation at metal centers is reflected
by the strength of the pꢃ backbonding to ligands like CO
and N2 [27,28]. Accordingly, C–O and N–N distances in
CO and N2 ligands are sensitive probes with regard to
the activation of the respective molecules. However, the
electron-withdrawing character of the PPh3 ligand is not
reflected by the C1–O1 distance in 8b3 [116.2(3) pm].
The respective distance is comparable to that found in
the CO complexes 8a [114.5(5) pm] and [Ru(CO)(PiPr3)
(‘N2Me2S2’)] [115.8(6) pm] [25]. No differences in the
N3–N4 distances were found in 7a [110.8(8) pm] and in
[Ru(N2)(PiPr3)(‘N2Me2S2’)] [111.0(4) pm], indicating
practically equal electronic effects of PiPr3 and PCy3.
The FD mass spectra perfectly reflect the stabilities of
the complexes. The bisphosphane complexes [Ru(PR3)2
(‘N2Me2S2’)] 2d–g, the dppe complex [Ru(dppe)
(‘N2Me2S2’)] (3), and the CO complexes [Ru(CO)(PR3)
(‘N2Me2S2’)] 4e, 4f, 8a, and 8b3, which are practically
inert, always show the peak for the respective molecule
ion. All complexes with labile NCCH3, N2H4, NH3, or
N2 ligands exclusively display the peak for the
[Ru(PCy3)(‘N2Me2S2’)] fragment at m=z ¼ 684 or at
m=z ¼ 666 for the [Ru(PPh3)(‘N2Me2S2’)] fragment.
The KBr IR spectra of the [Ru(L)(PR3)(‘N2Me2S2’)]
complexes (R ¼ Cy, Ph) feature the typical bands at-
tributable to the [Ru(PR3)(‘N2Me2S2’)] fragments be-
sides the specific bands for the co-ligands. Characteristic
m(N–H) absorptions are observed for the ammonia
complexes 9, and the hydrazine complex 6b in the region
between 3383 and 3161 cmꢀ1. Strong m(NBN) bands are
characteristic for the N2 complexes 7a (2115 cmꢀ1) and
7b (2130 cmꢀ1), strong m(CBO) bands for the CO
complexes 4e (1934 cmꢀ1), 4f (1935 cmꢀ1), 8a (1935
cmꢀ1), 8b3 (1940 cmꢀ1), and moderate m(CBN) bands
for the acetonitrile complexes 1a (2242 cmꢀ1) and 1b
(2252 cmꢀ1).
The NMR spectra are all in agreement with the
structures determined by X-ray crystal structure analy-
sis. The 1H NMR spectra of the C1 symmetric
[Ru(L)(PR3)(‘N2Me2S2’)] complexes exhibit the typical
pattern of complexes having the [Ru(‘N2Me2S2’)] core
and phosphane co-ligands (Fig. 7). Two signals for the
N-methyl groups and a multiplet for the C2H4 bridge
were particularly characteristic for the ‘N2Me2S2’2ꢀ li-
gand in these complexes. Besides the signals for the li-
gand system, the 1H NMR spectra also display
characteristic singlets for the CH3CN ligands in 1a
(d ¼ 2:27 ppm) and 1b (d ¼ 1:92 ppm), for the protons
of the NH3 ligands in 9a (d ¼ 1:41 ppm) and 9b
3.6. General properties and spectroscopic characterization
of the complexes 1–9
CH3
P(C6H11
)
3
◊
CH3CN
C2H4
◊
All isolated complexes have been characterized by
standard spectroscopic methods and by elemental
analysis. The hydrazine complex [Ru(N2H4)(PCy3)
(‘N2Me2S2’)] (6a), which proved stable only for a limited
period of time in the presence of excessive hydrazine,
could be characterized only in solution by NMR spec-
troscopy. All [Ru(L1)(L2)(‘N2Me2S2’)] complexes are
yellow and, with the exception of [Ru(NH3)(PCy3)
(‘N2Me2S2’)] (9a), [Ru(N2H4)(PPh3)(‘N2Me2S2’)] (6b),
and [Ru(dppe)(‘N2Me2S2’)] (7), well soluble, for exam-
ple in benzene, toluene, or THF. CH2Cl2is not suitable
as solvent for all [Ru(L)(PR3)(‘N2Me2S2’)] complexes
(R ¼ Cy, Ph) with labile NCCH3, N2H4, NH3, or N2
ligands, because it slowly chloromethylates the com-
plexes at the thiolate donors [1].
3.6
3.2
C6H4
2.8
2.4
◊
CH3CN
7.6
7.2
6.8
8
6
4
2
0
δ/ppm
Fig. 7. H NMR spectrum of [Ru(NCCH3)(PCy3)(‘N2Me2S2’)] (1a) in
[D8]THF, } ¼ [D8]THF.

D. Sellmann et al. / Inorganica Chimica Acta 357 (2004) 3336–3350
3349
vented the isolation of pure samples of the PPh3 deriv-
ative [Ru(N2)(PPh3)(‘N2Me2S2’)] (7b). In the case of the
[Ru(N2H4)(PR3)(‘N2Me2S2’)] complexes 6a (R ¼ Cy)
and 6b (R ¼ Ph), the PPh3 derivative was far more sta-
ble. It showed to be difficult, even on the basis of crys-
tallographic data, to elucidate the question whether the
more electron withdrawing character of the PPh3 ligand
in 7a (compared to PCy3 or PiPr3) could have caused
these differences.
CH3
P(CH3)3
C2H4
3.2
2.8
C6H4
7.0
2.4
7.4
6.6
◊
◊
8
7
6
5
4
3
2
1
5. Supplementary material
δ/ppm
Crystallographic data (excluding structure factors) for
the structures of 1a ꢁ MeOH, 1b ꢁ MeOH, 1c ꢁ THF,
7a ꢁ THF, 2d, 2e, 5e, 2f, 2f ꢁ Et2O, 2g ꢁ 0.5MeOH,
8a ꢁ THF, 8b3 ꢁ THF, 9b, 6b ꢁ 2THF, and of 10 ꢁ 2CH2Cl2
have been deposited with the Cambridge Crystallo-
graphic Data Centre as supplementary publication nos.
CCDC 230935 (1a ꢁ MeOH), CCDC 230936 (1b ꢁ MeOH),
CCDC 230941 (1c ꢁ THF), CCDC 230937 (7a ꢁ THF),
CCDC 230938 (2d), CCDC 230942 (2e), CCDC 230943
(5e), CCDC 230944 (2f), CCDC 230945 (2f ꢁ Et2O),
CCDC 230946 (2g ꢁ 0.5MeOH), CCDC 230947
(8a ꢁ THF), CCDC 230939 (8b3 ꢁ THF), CCDC 230948
(9b), CCDC 230940 (6b ꢁ 2THF), and CCDC 230949
(10 ꢁ 2CH2Cl2). Copies of the data can be obtained free of
charge on application to CCDC, 12 Union Road, Cam-
bridge CB 21 EZ, UK, (fax: (+44)1223-336-033; e-mail:
deposit@ccdc.cam.ac.uk).
Fig. 8.
H NMR spectrum of [Ru(PMe3)2(‘N2Me2S2’)] (2d) in
[D8]THF, } ¼ [D8]THF.
(d ¼ 1:34 ppm), and typical signal patterns for protons
of the terminal N2H4 ligands in 6a and 6b.
Typical for the 1H NMR spectra of the C2 symmetric
[Ru(PR3)2(‘N2Me2S2’)] complexes 2d–g and the dppe
complex 3 is a singlet for the N-methyl groups and
AA0BB0 multiplet for the C2H4 bridge of the ‘N2Me2S2’
ligand (Fig. 8).
The 13C NMR spectra of the C1 symmetric
[Ru(L)(PR3)(‘N2Me2S2’)] complexes showed, for exam-
ple, twelve signals for the aromatic C atoms and four
signals for the aliphatic C atoms of the N-methyl groups
and the ethylene bridge of the ‘N2Me2S2’ ligand. Half
the number of signals were observed for the C2 sym-
metric complexes [Ru(PR3)2(‘N2Me2S2’)] 2d–g and the
dppe complex 3. The 31P{1H, 13C} NMR spectra display
one signal for each complex.
Acknowledgements
Helpful discussions with Prof. Dr. H. Kisch and Dr.
J. Sutter, Institute for Inorganic Chemistry of the Uni-
versity of Erlangen-Nuremberg, and Prof. Dr. H. Zim-
mermann, Institute for Applied Physics of the
University of Erlangen-Nuremberg, are gratefully ac-
knowledged. We thank the Deutsche Forschungsgeme-
inschaft (SFB 583) and the Fonds der Chemischen
Industrie for financial support.
4. Conclusion
The results reported herein demonstrate the influence
of phosphane substituents with regard to the formation
of [Ru(L)(PR3)(‘N2Me2S2’)] complexes. While phos-
phanes with small cone angles (h ¼ 118–132°) or che-
lating dppe did not yield labile precursor complexes
suitable for exchange reactions, PPh3 and PCy3 were
found
to
form
labile
CH3CN
complexes
[Ru(NCCH3)(PR3)(‘N2Me2S2’)] (1a, 1b). These aceto-
nitrile complexes enabled the synthesis of the corre-
sponding cis,trans-[Ru(L)(PR3)(‘N2Me2S2’)] complexes
with N2, N2H4, NH3, and CO ligands. The use of PPh3
also afforded cis,cis [Ru(L)(PPh3)(‘N2Me2S2’)], which
does not exhibit the desired trans arrangement of the
thiolate donors. The [Ru(PPh3)(‘N2Me2S2’)] fragment is
less able than the respective PCy fragment to coordinate
N2. While [Ru(N2)(PCy3)(‘N2Me2S2’)] (7a), which has
almost identical properties like the previously reported
PiPr3 derivative [Ru(N2)(PiPr3)(‘N2Me2S2’)], could be
isolated in pure form, facile loss of the N2 ligand pre-
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