Thermodynamically Controlled Formation of Diastereopure Three-Legged Piano-Stool Complexes. the Substitution Chemistry of [RuCp(aminophosphinoferrocene)(CH3CN)]PF6

Article abstract of DOI:10.1021/om990307a

Treatment of [RuCp(CH₃CN)₃]⁺ with the chiral ligands PN* = (R_c,S _pl)-2-(1-N,N-dimethylaminoethyl)-1-diphenylphosphinoferrocene, (S_pl)-2-(N,N-dimethylaminomethyl)-1-diphenylphosphinoferrocene, and (R_c,S _pl)-2-(1-N,N-diethylaminoethyl)-1-diphenylphosphinoferrocene affords diastereoselectively the labile cationic complexes [(S_Ru)-RuCp(PN*)(CH₃CN)]⁺. The exchange kinetics of CH₃CN has been studied as a function of temperature, revealing a dissociative mechanism, and therefore thermodynamic control is responsible for the diastereoselective formation of [(S_Ru)-RuCp(PN*)(CH₃CN)]⁺. These react with HC≡CPh to give the chiral vinylidene complexes [(R_Ru)-RuCp(PN*)(=C=CHPh)]⁺ in highly diastereoselective fashion. With CO complexes [RuCp(PN*)(CO)]⁺ are obtained in high yields but with significantly decreased stereoselectivity due to kinetic control of the substitution reaction. Under photochemical conditions epimerization occurs to give [(R_Ru)-RuCp(PN*)-(CO)]⁺ with a de of >98%. In the case of [RuCp((R_c,S _pl)-2-(1-N,N-diethylaminoethyl)-1-diphenylphosphinoferrocene)(CO)] ⁺, the diastereomeric excess increases from 87 to >98% upon heating due to an intramolecular epimerization. The absolute configuration of representative complexes has been determined by X-ray crystallography.

Full text of DOI:10.1021/om990307a

Organometallics 1999, 18, 3865-3872
3865
Th er m od yn a m ica lly Con tr olled F or m a tion of
Dia ster eop u r e Th r ee-Legged P ia n o-Stool Com p lexes. Th e
Su bstitu tion Ch em istr y of
[Ru Cp (a m in op h osp h in ofer r ocen e)(CH3CN)]P F 6
Christian Slugovc,† Walter Simanko,† Kurt Mereiter,‡ Roland Schmid,† and
Karl Kirchner*,†,#
Institute of Inorganic Chemistry and Institute of Mineralogy, Crystallography, and Structural
Chemistry, Technical University of Vienna, Getreidemarkt 9, A-1060 Wien, Austria
Li Xiao and Walter Weissensteiner
Institute of Organic Chemistry, University of Vienna, Wa¨hringer Strasse 38,
A-1090 Wien, Austria
Received April 26, 1999
Treatment of [RuCp(CH3CN)3]+ with the chiral ligands PN* ) (Rc,Spl)-2-(1-N,N-dimethy-
laminoethyl)-1-diphenylphosphinoferrocene, (Spl)-2-(N,N-dimethylaminomethyl)-1-diphe-
nylphosphinoferrocene, and (Rc,Spl)-2-(1-N,N-diethylaminoethyl)-1-diphenylphosphinofer-
rocene affords diastereoselectively the labile cationic complexes [(SRu)-RuCp(PN*)(CH3CN)]+.
The exchange kinetics of CH3CN has been studied as a function of temperature, revealing
a dissociative mechanism, and therefore thermodynamic control is responsible for the
diastereoselective formation of [(SRu)-RuCp(PN*)(CH3CN)]+. These react with HCtCPh to
give the chiral vinylidene complexes [(RRu)-RuCp(PN*)(dCdCHPh)]+ in highly diastereo-
selective fashion. With CO complexes [RuCp(PN*)(CO)]+ are obtained in high yields but
with significantly decreased stereoselectivity due to kinetic control of the substitution
reaction. Under photochemical conditions epimerization occurs to give [(RRu)-RuCp(PN*)-
(CO)]+ with a de of >98%. In the case of [RuCp((Rc,Spl)-2-(1-N,N-diethylaminoethyl)-1-
diphenylphosphinoferrocene)(CO)]+, the diastereomeric excess increases from 87 to >98%
upon heating due to an intramolecular epimerization. The absolute configuration of
representative complexes has been determined by X-ray crystallography.
In tr od u ction
ruthenium pseudo-tetrahedral three-legged piano-stool
complexes are particularly interesting as chiral Lewis
acids, e.g., in catalytic asymmetric Diels-Alder reac-
tions.2g,5 In this regard we are interested in the well-
known chiral phosphinoamineferrocenes (PN*) as coli-
gands. This class of chiral asymmetric bidentate ligands
imposing not only a steric but also an electronic bias
on an prochiral substrate6 has received little attention
in ruthenium chemistry,2g,7 despite its extensive use in
Enantio- and diastereopure organometallic complexes
have become increasingly useful in mechanistic studies
and in organic synthesis.1 With respect to ruthenium,
most work has been done on half-sandwich Ru(arene),2
and RuCp and RuCp* complexes3,4 containing C2 sym-
metric bisphosphines or tethered functional groups as
chiral auxiliaries. Configurationally stable chiral at
† Institute of Inorganic Chemistry.
‡ Institute of Mineralogy, Crystallography, and Structural Chem-
istry.
(3) For recent examples of chiral RuCp and RuCp* complexes see:
(a) Rasley, B. T.; Rapta, M.; Kulawiec, R. J . Organometallics 1996,
15, 2852. (b) Schenk, W. D.; Du¨rr, M. Chem. Eur. J . 1997, 3, 713. (c)
Feiken, N.; Pregosin, P. S.; Trabesinger, G.; Albinati, A. Evoli, G. L.
Organometallics 1997, 16, 5756. (d) Brunner, H.; Neuhierl, T.; Nuber,
B. J . Organomet. Chem. 1998, 563, 173. (e) Koelle, U.; Rietmann, C.;
Raabe, G. Organometallics 1997, 16, 3273. (f) Nishibayashi, Y.; Takei,
I.; Hidai, M. Organometallics 1997, 16, 3091. (g) Ganter, C.; Brassat,
L.; Glinsbo¨ckel, C.; Ganter, B. Organometallics 1997, 16, 2862. (h)
Trost, B. M.; Vidal, B.; Thommen, M. Chem. Eur. J . 1999, 5, 1055.
(4) For related [RuCp(pp*)(L)]+ complexes see: (a) Consiglio, G.;
Morandini, F.; Sironi, A. J . Organomet. Chem. 1986, 306, C45. (b)
Consiglio, G.; Pregosin, P.; Morandini, F. J . Organomet. Chem. 1986,
308, 345. (c) Consiglio, G.; Morandini, F. J . Organomet. Chem. 1986,
310, C66. (d) Consiglio, G.; Morandini, F. Inorg. Chim. Acta 1987, 127,
79. (e) Consiglio, G.; Morandini, F. Chem. Rev. 1987, 87, 761.
(5) Ku¨ndig, E. P.; Saudan, C. M.; Bernardinelli, G. Angew. Chem.,
Int. Ed. 1999, 38, 1219.
#
E-mail: kkirch@mail.zserv.tuwien.ac.at.
(1) Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley:
New York, 1994. Ojima, I. Catalytic Asymmetric Synthesis; VCH: New
York, 1993. Gladysz, J . A.; Boone, B. J . Angew. Chem. 1997, 109, 566.
Transition Metals for Organic Synthesis; Beller, M., Bolm, C., Eds.;
Wiley-VCH: Weinheim, 1998. Applied Homogeneous Catalysis with
Organometallic Compounds; Cornils, B., Herrmann, W. A., Eds.; Wiley-
VCH: Weinheim, 1996.
(2) For recent examples of chiral Ru(arene) complexes see: (a) Attar,
S.; Catalano, V. J .; Nelson, J . H. Organometallics 1996, 15, 2932. (b)
Enders, D.; Gielen, H.; Raabe, G.; Runsink, J .; Teles, J . H. Chem. Ber.
1997, 130, 1253. (c) Haack, K.-J .; Hashiguchi, S.; Fujii, A.; Ikariya,
T.; Noyori, R. Angew. Chem. 1997, 109, 297. (d) Gu¨l, N.; Nelson, J . H.
Organometallics 1999, ASAP. (e) Therrien, B.; Ward, T. R. Angew.
Chem., Int. Ed. 1999, 38, 405. (f) Zanetti, N. C.; Spindler, F.; Spencer,
J .; Togni, A.; Rihs, G. Organometallics 1996, 15, 860. (g) Carmona,
D.; Cativiela, C.; Elipe, S.; Lahoz, F. J .; Lamata, M. P.; Lo´pez-Ram de
V´ıu, M. P.; Oro, L. A.; Vega, C.; Viguri, F. J . Chem. Soc., Chem.
Commun. 1997, 2351.
(6) Ward, T. R. Organometallics 1996, 15, 2836.
(7) Song, J .-H.; Cho, D.-J .; J eon, S.-J .; Kim, Y.-H.; Kim, T.-J .; J eong,
J . H. Inorg. Chem. 1999, 38, 893.
10.1021/om990307a CCC: $18.00 © 1999 American Chemical Society
Publication on Web 09/13/1999

3866 Organometallics, Vol. 18, No. 19, 1999
Slugovc et al.
Ta ble 1. Rea ction of 1 w ith Ch ir a l
Am in op h osp h in efer r ocen es
ligand
product
R1
R2
product
yield
dea
2a
2b
2c
3
4
5
Me
H
Me
Me
Me
Et
SRu, RC, Spl
96%
98%
96%
>98%
>98%
>98%
S
S
Ru, Spl
Ru, RC, Spl
F igu r e 1. Structural view of 3 showing 20% thermal
ellipsoids (PF6- and aromatic hydrogen atoms omitted for
clarity). Priority for the assignment of the absolute con-
figuration at Ru: Cp > PPh2 > CH3CN > NMe2.
a
Determined by NMR spectroscopy.
palladium chemistry.8 In the present paper we report
first results of the synthesis, structure, and exchange
kinetics of the diastereopure complexes [RuCp(PN*)-
(CH3CN)]+ containing the ligands PN* ) (Rc,Spl)-2-(1-
N,N-dimethylaminoethyl)-1-diphenylphosphinofer-
rocene(2a),(Spl)-2-(N,N-dimethylaminomethyl)-1-diphenyl-
phosphinoferrocene (2b), and (Rc,Spl)-2-(1-N,N-diethy-
laminoethyl)-1-diphenylphosphinoferrocene (2c). From
those, other diastereopure Ru(II) complexes are acces-
sible. X-ray structures of representative compounds are
given.
Resu lts a n d Discu ssion
Syn th esis a n d Kin etics. Treatment of [RuCp(CH3-
CN)3]+ (1) with 1 equiv of the chiral ligands PN* (2a ,
2b, or 2c) in CH2Cl2 at room temperature provides the
cationic complexes [RuCp(PN*)(CH3CN)]+ (3-5) in high
yields (Table 1). The formation of 3-5 is highly dias-
tereoselective (de >98%) irrespective of the substituents
on the -NR2 group (R ) Me, Et) and the substituent
on the benzylic bridging carbon atom -CHR- (R ) H,
Me) (as indicated by an asterisk in Table 1). All
complexes have been characterized by 1H, 13C{1H}, and
31P{1H} NMR spectroscopies and elemental analysis.
The structural identity and the absolute configuration
of 3 and 5 has been determined by single-crystal X-ray
diffraction. ORTEP diagrams are depicted in Figures1
and 2 with selected bond distances given in Table 2.
The CH3CN ligand in 3-5 is substitutionally labile
and is replaced by CD3CN (15 equiv) in a solution of
3-5 in CDCl3 at room temperature. Interestingly, this
exchange is completely stereospecific with retention of
the configuration at the ruthenium center, as indicated
by the absence of the second diastereomer. The kinetics
F igu r e 2. Structural view of 5‚CH2Cl2 showing 20%
thermal ellipsoids (PF6-, CH2Cl2, and aromatic hydrogen
atoms omitted for clarity). Priority for the assignment of
the absolute configuration at Ru: Cp > PPh2 > CH3CN >
NEt2.
NMR spectroscopy as a function of temperature, with
an Eyring plot shown in Figure 3.
The first-order rate constant obtained is 9.2 × 10-2
s-1 at room temperature (cf. 5.6 s-1 for 19). The large
activation enthalpy (23.2 kcal mol-1) and a positive
entropy of activation (14.6 cal mol-1 K-1) are charac-
teristic of a unimolecular process (dissociative mecha-
nism). Evidence is provided by the fact that the reaction
rate is independent of the free CH3CN concentration.
It may thus be argued that the observed preference of
1
of this process in 3 has been studied in detail by H
(8) Richards, C. J .; Locke, A. J . Tetrahedron: Asymmetry 1998, 9,
2377. Ferrocenes, Homogeneous Catalysis, Organic Synthesis, Material
Science; Togni, A., Hayashi, T., Eds.; VCH: Weinheim, 1995. Brunner,
H.; Zettlmeier, W. Handbook of Enantioselective Catalysis with Transi-
tion Metal Compounds; VCH: Weinheim, 1993.
(9) Luginbu¨hl, W.; Zbinden, P.; Pittet, P. A.; Armbruster, T.; Bu¨rgi,
H.-B.; Merbach, A. E.; Ludi, A. Inorg. Chem. 1991, 30, 2350.

[RuCp(aminophosphinoferrocene)(CH3CN)]PF6
Organometallics, Vol. 18, No. 19, 1999 3867
Ta ble 2. Liga n d Exch a n ge Rea ction s of 3-5
Pr2), promoting the formation of vinylidene complexes
as well as the deprotonation of the vinylidene ligand to
afford reactive coordinatively unsaturated alkynyl spe-
cies. These in turn, in the absence of potential 2e donor
ligands, may undergo various (uncontrollable) reactions
as in the present case. The structural identity and
stereochemistry of 6a has been established by X-ray
crystallography (Figure 4). Selected bond distances and
angles are reported in Table 2.
The formation of the vinylidene complexes is highly
diastereoselective, again with retention of configuration
at ruthenium. In view of the lability of the CH3CN
ligand in complexes 3-5 and the dissociative nature of
substitution, the following reaction mechanism seems
likely: HCtCPh attacks the chiral 16e [RuCp(PN*)]+
intermediate predominantly from one diastereoface to
give an η2-HCtCPh complex, which subsequently tau-
tomerizes irreversibly to the corresponding vinylidene
complex (note that a reversible formation of vinylidene
complexes has been reported11). Diastereoface selection
may be based on steric arguments, since the intermedi-
ate side-on coordinated alkyne is sterically more de-
manding than the linear vinylidene ligand. Accordingly,
the diastereoselectivity of the overall reaction appears
to be kinetically controlled. In this context it has to be
mentioned that at elevated temperatures no epimeriza-
tion between 6a and 6b is observed and the diastereo-
meric ratio 6a /6b remains unchanged.
educt
ligand
products yield RRu SRu ratioa
deb
3
3
4
4
5
5
dCdCHPh
CO
dCdCHPh
CO
dCdCHPh
CO
6a /6b
7a /7b
8a /8b
9a /b
96% 6a b
90% 7a b
92% 8a b
93% 9a
6b
7b
8b
9b
21:1
91%
2.4:1 42%c
28:1
1.8:1 28%
96%
decomposition
10a /b
95% 10a b 10b 15:1
87%d
a
b
Determined by NMR spectroscopies. Isolated compound.
c Under photochemical conditions 7a is formed with a de of >98%.
Upon heating at 62 °C for 36 h a de of >98% is obtained.
d
Similar to HCtCPh, also CO reacts with 3-5, giving
complexes 7a /b, 9a /b, and 10a /b in high yields (Table
3). However, while with 5 the de is still 87%, in the case
of 3 and 4 the de has significantly dropped to 42 and
28%, respectively. Characterization of 7a , 9a , and 10a
1
was again accomplished by H, 13C{1H}, and 31P{1H}
NMR spectroscopies and elemental analysis. The iso-
mers 7b, 9b, and 10b could not be isolated in pure form,
but their identity has been established by NMR spec-
troscopy. There was no evidence for the formation of any
dicarbonyl species, as inferred from the resonances of
the NMe2 (two singlets rather than one singlet as
observed for the free PN ligand) and NEt2 (multiplet
resonances rather than a quartet and a triplet as
observed for the free PN ligand) groups. The identity
and stereochemistry of the major isomers were again
determined by X-ray crystallography (Figure 5). The
formation of complexes 7 and 9 is kinetically controlled.
The CO molecule is sterically undemanding, and the
steric bias between the two diastereofaces is small.
Furthermore, complexes 7 and 9 are inert at ambient
temperatures and, thus, once formed do not epimerize
anymore (cf. 3-5). In the case of 5 the steric bias is
enhanced due to the bulkier NEt2 group of the PN*
ligand 2c accounting for the higher de. However, 2c in
contrast to 2a and 2b may become hemilabile, leading
to Ru-N bond rupture. Accordingly, rotation of 2c about
the Ru-P bond can lead to the thermodynamically
favorable isomer 10a , as shown in Scheme 2. This has,
indeed, been demonstrated by heating a mixture of
10a /b in CDCl3 for 36 h at 62 °C, leading to an increase
of the de from 87 to >98%. Under the same conditions,
F igu r e 3. Temperature dependence of the acetonitrile
exchange rate constants of 3.
one diastereomer over the other is likely of thermody-
namic rather than kinetic origin (Scheme 1).
The reactivity of 3-5 toward substitution has been
further investigated as follows. Treatment of 3 and 4
with HCtCPh yields the corresponding chiral vi-
nylidene complexes 6 and 8 in high yields. These
products are obtained as mixtures of the two diastere-
omeric complexes 6a /b and 8a /8b in 21:1 (de ) 91%)
and 28:1 (de ) 96%) ratios, respectively (Table 3). With
5, on the other hand, the reaction is not clean, with
several as yet intractable materials formed. This may
be explained by the hemilability of the sterically more
demanding (Rc,Spl)-2-(1-N,N-diethylaminoethyl)-1-diphe-
nylphosphinoferrocene (2c). We have previously shown10
that aminophosphine ligands are hemilabile if the
nitrogen site is sufficiently bulky (NMe2 < NEt2 < N-i-
(10) (a) Slugovc, C.; Mauthner, K.; Kacetl, M.; Mereiter, K.; Schmid,
R.; Kirchner, K. Chem. Eur. J . 1998, 4, 2043. (b) Slugovc, C.; Wiede,
P.; Mereiter, K.; Schmid, R.; Kirchner, K. Organometallics 1997, 16,
2768. (c) Mauthner, K.; Slugovc, C.; Mereiter, K.; Schmid, R.; Kirchner,
K. Organometallics 1997, 16, 1956.
(11) (a) Consiglio, G.; Bangerter, F.; Darpin, C.; Morandini, F.;
Luccini, V. Organometallics 1984, 3, 1446. (b) Slugovc, C.; Sapunov,
V. N.; Wiede, P.; Mereiter, K.; Schmid, R.; Kirchner, K. J . Chem. Soc.,
Dalton Trans. 1997, 4209.

3868 Organometallics, Vol. 18, No. 19, 1999
Slugovc et al.
Sch em e 1
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles (d eg) for 3, 5‚CH2Cl2, 6a , a n d 7a
3
5‚CH2Cl2
6a a
7a
stereochemistry
L
S
Ru, RC, Spl
SRu, RC, Spl
CH3CN
2.051(3)
2.282(1)
2.288(3)
2.178(4)
1.827(2)
125.1(1)
123.6(1)
126.7(1)
88.9(1)
RRu, RC, Spl
dCdCHPh
RRu, RC, Spl
CO
CH3CN
2.063(3)
2.287(1)
2.251(3)
2.187(4)
1.828(2)
123.8(1)
123.3(1)
127.0(1)
91.7(1)
Ru-L
1.811(7)/1.823(8)
2.305(2)/2.330(2)
2.219(6)/2.211(6)
2.258(8)/2.247(11)
1.916(4)/1.911(5)
126.2(2)/124.4(2)
121.1(2)/119.7(2)
127.3(2)/127.7(2)
91.9(2)/97.0(2)
88.1(3)/87.0(3)
91.8(2)/91.9(2)
1.861(2)
2.300(1)
2.223(2)
2.235(3)
1.888(1)
123.5(1)
121.5(1)
125.6(1)
93.1(1)
Ru-P
Ru-N
Ru-Ccp
b
Ru-rccp
rccp-Ru-L
rccp-Ru-P
rccp-Ru-N
L-Ru-P
L-Ru-N
P-Ru-N
87.2(1)
93.4(1)
89.3(1)
92.3(1)
90.9(1)
93.4(1)
a
b
Two crystallographically independent Ru complexes present. rc is the centroid of the Cp ring.
F igu r e 4. Structural view of 6a showing 20% thermal
ellipsoids (PF6- and aromatic hydrogen atoms omitted for
clarity). Only one of the two crystallographically indepen-
dent complexes is shown. Priority for the assignment of
the absolute configuration at Ru: Cp > PPh2 > NMe2
dCdHPh.
>
and even at higher temperatures (toluene, 110 °C) and
prolonged heating of 7a /b and 9a /b, no epimerization
is observed. However, UV irradiation of a solution of
7a /7b in CD3NO2 under a CO atmosphere labilizes the
CO ligand,12 and epimerization takes place to give 7a
with a de of >98% together with small amounts of two
unidentified byproducts (<5%), as indicated by31P{1H}
NMR spectroscopy.
F igu r e 5. Structural view of 7a showing 20% thermal
ellipsoids (PF6- and aromatic hydrogen atoms omitted for
clarity). Priority for the assignment of the absolute con-
figuration at Ru: Cp > PPh2 > NMe2 > CO.
X-r a y Str u ctu r es of 3, 5‚CH2Cl2, 6a , a n d 7a . All
four investigated compounds (3, 5‚CH2Cl2, 6a , 7a )
crystallize in chiral space groups (Table 4), and their
absolute configurations were unequivocally determined
via significant anomalous dispersion effects. Whereas
(12) Crocker, M.; Froom, S. F. T.; Green, M.; Nagle, K. R.; Orpen,
A. G.; Thomas, D. M. J . Chem. Soc., Dalton Trans. 1997, 2803.

[RuCp(aminophosphinoferrocene)(CH3CN)]PF6
Organometallics, Vol. 18, No. 19, 1999 3869
Sch em e 2
Ta ble 4. Cr ysta llogr a p h ic Da ta for 3, 5‚CH2Cl2, 6a , a n d 7a
3
5‚CH2Cl2
6a
7a
formula
fw
C
33H36F6FeN2P2Ru
C36H42Cl2F6FeN2P2Ru
906.48
C39H39F6FeNP2Ru
854.57
C32H33F6FeNOP2Ru
780.45
793.50
cryst size, mm
space group
a, Å
b, Å
c, Å
0.60 × 0.24 × 0.12
P212121 (No. 19)
10.730(3)
11.576(3)
27.868(5)
94.78(1)
3462.1(15)
4
1.522
295(2)
1.005
multiscan
1608
0.70 × 0.56 × 0.10
0.50 × 0.40 × 0.30
P212121 (No. 19)
11.363(5)
15.338(7)
42.054(15)
0.60 × 0.55 × 0.40
P212121 (No. 19)
10.603(3)
14.106(3)
21.044(4)
P21 (No. 4)
9.925(3)
13.515(3)
14.608(3)
â, deg
V, Å3
Z
1952.6(8)
2
1.543
295(2)
1.034
multiscan
920
7329(5)
8
1.549
295(2)
0.955
multiscan
3472
3147.5(13)
4
1.647
295(2)
1.106
multiscan
1576
F
calc, g cm-3
T, K
µ, mm-1 (Mo KR)
abs corr
F(000)
transmiss factor
min/max
0.92-0.77
0.80-0.65
0.93-0.75
0.76-0.64
θ
max, deg
27
99.7
-13 e h e 13
-14 e k e 14
-35 e l e 35
41748
7541
6824
407
0.036
25
99.8
-11 e h e 11
-16 e k e 16
-17 e l e 17
20281
6842
6365
468
0.030
25
98.7
-13 e h e 13
-18 e k e 18
-50 e l e 50
63364
12729
11216
901
0.060
30
99.6
-14 e h e 14
-19 e k e 19
-29 e l e 29
46381
9110
8421
398
0.026
data completness (%)
index ranges
no. of rflns measd
no. of unique rflns
no. of rflns I > 2σ(I)
no. of params
R1 (I > 2σ(I))a
R1 (all data)
0.042
0.140
-0.44/0.48
0.080
0.084
-0.25/0.51
0.070
0.118
-0.96/0.52
0.032
0.063
-0.42/0.37
wR2 (all data)b
diff Four peaks
a
2
R1 ) ∑||Fo| - |Fc||/∑|Fo|. bwR2 ) [∑(w(Fo - Fc2)2)/∑(w(Fo2)2)]1/2
.
3, 5‚CH2Cl2, and 7a contain only one crystallographi-
cally independent Ru complex in the asymmetric unit,
the structure of 6a contains two independent Ru com-
plexes in an orthorhombic unit cell with a longest
dimension of c ) 42.05 Å. All four compounds adopt a
typical three-legged piano-stool coordination with a
four compounds the ferrocene moieties13 as well as the
conformation of the six-membered chelate ring show
only insignificant variations.
Con clu sion
We have shown that the pseudo-tetrahedral three-
legged piano-stool complexes [RuCp(PN*)(CH3CN)]+
are formed in >98% de for thermodynamic reasons.
The diastereoselectivity is essentially controlled by
the planar chirality of the ferrocene moiety. Despite
their configurational stability, these complexes are
substitutionally labile, providing readily a vacant co-
ordination site, and may therefore be useful as Lewis
acid catalysts in asymmetric C-C bond-forming
reactions such as Diels-Alder and Mukaiyama reac-
tions.14
S
RuRCSpl configuration for 3 and 5‚CH2Cl2 and a RRu
-
RCSpl configuration for 6a and 7a . The acetonitrile
complexes 3 and 5‚CH2Cl2 agree well in all major
geometric features (Table 3), except for the Ru-N(1)
bond distance, which is longer in 5‚CH2Cl2 by 0.037 Å,
presumably due to the higher sterical demand of the
NEt2 moiety compared with NMe2. In comparison to the
acetonitrile complexes, the short Ru-C(vinylidene, CO)
bonds of 6a (Ru-C ) 1.81-1.82 Å) and 7a (Ru-C )
1.86 Å) are accompanied by a distinct lengthening of
the Ru-C bonds to the Cp rings by 0.07 Å, a lengthening
of the Ru-P bonds by 0.02-0.05 Å, as well as a
shortening of the Ru-N(amine) bonds by 0.03-0.08 Å.
These effects may be attributed to pronounced back-
bonding effects of the vinylidene and CO ligands. In all
(13) For a molecular structure of 2a see: Einstein, F. W. B.; Willis,
A. C. Acta Crystallogr. 1980, B36, 39.
(14) Hollis, T. K.; Odenkirk, W.; Robinson, N. P.; Whelan, J .;
Bosnich, B. Tetrahedron 1993, 49, 5415.

3870 Organometallics, Vol. 18, No. 19, 1999
Slugovc et al.
Ep im er iza tion of 3. A sealed NMR tube was charged with
3 in either CDCl3 or CD3NO2 as the solvent was cooled to -10
°C and then gradually warmed in steps of 10 °C up to 100 °C
and kept at this temperature for 2 h. The reaction was
monitored by 1H and 31P{1H} NMR spectroscopy. Despite a
broadening of the resonance for acetonitrile upon heating and
some small shifts for the N-methyl resonances, no other
changes are observed.
Exp er im en ta l Section
Gen er a l In for m a tion . All manipulations were performed
under an inert atmosphere of argon by using Schlenk tech-
niques. All chemicals were standard reagent grade and used
without further purification. The solvents were purified ac-
cording to standard procedures.15 The deuterated solvents were
purchased from Aldrich and dried over 4 Å molecular sieves.
[RuCp(CH3CN)3]PF6 (1),16 (Rc,Spl)-2-(1-N,N-dimethylaminoet-
hyl)-1-diphenylphosphinoferrocene (2a ), (Spl)-2-(N,N-dimethy-
laminomethyl)-1-diphenyl-phosphinoferrocene (2b), and (Rc,Spl)-
2-(1-N,N-diethylaminoethyl)-1-diphenylphosphinoferrocene (2c)
were prepared according to the literature.17 1H, 13C{1H}, and
31P{1H} NMR spectra were recorded on a Bruker AC-250
spectrometer operating at 250.13, 62.86, and 101.26 MHz,
respectively, or on a Bruker Avance DRX-400 spectrometer
operating at 400.13, 100.62, and 161.97 MHz, and were
referenced to SiMe4 and H3PO4 (85%). The diastereomeric
excess (de) was determined by 1H NMR spectroscopy. The
superscript in the assignment of Cps refers to the substituted
FeCp ring. The assignment of the configuration has been made
according to the literature.18 Microanalyses were done by
Microanalytical Laboratories, University of Vienna.
[(S R u ,S p l )-R u C p (2-(N ,N -d im e t h y la m in o m e t h y l)-1-
d ip h en ylp h osp h in ofer r ocen e)(CH3CN)]P F 6 (4). This com-
pound was prepared analogously to 3 with 1 (168 mg, 0.387
mmol) and 2b (165 mg, 0.387 mmo) as the starting materials.
Yield: 295 mg (98%). In the 31P{1H} NMR a small resonance
(39.8 ppm intensity of <1/100 of the resonance of 4) of a
byproduct is observed, which may be due to the formation of
another diasteromer. Anal. Calcd for C32H34F6FeN2P2Ru: C,
49.31; H, 4.40. Found: C, 49.38; H, 4.66. 1H NMR (δ, acetone-
d6, 20 °C): 8.22-8.14 (m, 2H, Ph), 7.75-7.65 (m, 3H, Ph),
7.35-7.30 (m, 3H, Ph), 7.09-7.01 (m, 2H, Ph), 4.66-4.51 (m,
2
3H, FeCps), 4.39 (d, J HH ) 13.7 Hz, 1H, CH2NMe2), 4.30 (s,
5H, RuCp), 3.78 (s, 5H, FeCp), 3.25 (s, 3H, NMe2), 3.04 (d, 2J HH
5
) 13.7 Hz, 1H, CH2NMe2), 2.65 (d, J HP ) 1.1 Hz, 3H, NtC-
CH3), 2.63 (s, 3H, NMe2). 13C{1H} NMR (δ, acetone-d6, 20 °C):
1
1
145.6 (d, J CP ) 51.8 Hz, 1C, Ph1), 137.6 (d, J CP ) 48.0 Hz,
Syn th esis. [(SRu ,RC,Sp l)-Ru Cp (2-(1-N,N-d im eth yla m i-
n oet h yl)-1-d ip h en ylp h osp h in o fer r ocen e)(CH 3CN)]P F 6
(3). A solution of 1 (100 mg, 0.230 mmol) and 2a (101 mg, 0.230
mmol) in CH2Cl2 (4 mL) was stirred at room temperature for
4 h, whereupon the color changed from yellow to orange. The
solvent was removed under reduced pressure and the residue
redissolved in 1 mL of CH2Cl2. On addition of Et2O (3 mL) a
bright orange precipitate was formed, which was collected on
a glass frit, washed with Et2O (3 × 1 mL), and dried in vacuo.
Yield: 176 mg (96%). Anal. Calcd for C33H36F6FeN2P2Ru: C,
49.95; H, 4.57. Found: C, 50.16; H, 4.77. 1H NMR (δ, acetone-
d6, 20 °C): 8.23-8.14 (m, 2H, Ph), 7.76-7.66 (m, 3H, Ph),
7.34-7.29 (m, 3H, Ph), 7.07-6.98 (m, 2H, Ph), 4.72-4.70 (m,
1C, Ph1′), 136.3 (d, J CP ) 13.0 Hz, 2C, Ph2,6), 131.9 (d, J CP
)
2
3
10.2 Hz, 1C, NtC-CH3), 132.3 (d, 2J CP ) 10.4 Hz, 2C, Ph2′,6′),
4
4
132.2 (d, J CP ) 2.7 Hz, 1C, Ph4), 130.2 (d, J CP ) 1.6 Hz, 1C,
Ph4′), 129.7 (d, J CP ) 10.4 Hz, 2C, Ph3,5), 129.3 (d, J CP ) 9.8
3
3
Hz, 2C, Ph3′,5′), 90.7 (d, J CP ) 22.9 Hz, 1C, FeCp2), 78.3 (d,
2
2J CP ) 2.2 Hz, RuCp), 75.3 (d, J CP ) 1.0 Hz, 1C, FeCps), 74.1
(d, J CP ) 8.4 Hz, 1C, FeCps), 72.7 (d, J CP ) 34.3 Hz, 1C,
1
FeCp1), 71.9 (s, 5C, FeCp), 71.4 (d, J CP ) 4.4 Hz, 1C, FeCps),
3
3
64.8 (d, J CP ) 1.6 Hz, 1C, NMe2), 61.4 (d, J CP ) 2.2 Hz, 1C,
3
CH2NMe2), 56.4 (d, J CP ) 1.6 Hz, 1C, NMe2), 5.2 (s, 1C, Nt
C-CH3). 31P{1H} NMR (δ, acetone-d6, 20 °C): 40.3 (PPh2),
-142.7 (1J PF ) 709.7 Hz, PF6).
1H, FeCps), 4.60-4.55 (m, 2H, FeCps), 4.46 (q, J HH ) 6.9 Hz,
3
[(S R u ,R C ,S p l)-R u Cp (2-(1-N ,N -d ie t h yla m in oe t h yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(CH3CN)]P F 6 (5). This com-
pound was prepared analogously to 3 with 1 (111 mg, 0.252
mmol) and 2c (119 mg, 0.252 mmol) as the starting materials.
Yield: 199 mg (96%). Anal. Calcd for C35H40F6FeN2P2Ru: C,
51.17; H, 4.91. Found: C, 51.34; H, 5.08. 1H NMR (δ, acetone-
d6, 20 °C): 8.16-8.08 (m, 2H, Ph), 7.74-7.72 (m, 3H, Ph),
7.36-7.33 (m, 3H, Ph), 7.15-7.07 (m, 2H, Ph), 4.79-4.77 (m,
1H, CH(Me)(NMe2)), 4.26 (s, 5H, RuCp), 3.81 (s, 5H, FeCp),
5
3.39 (s, 3H, NMe2), 2.64 (d, J HP ) 1.4 Hz, 3H, NtC-CH3),
2.56 (s, 3H, NMe2), 1.46 (d, 3J HH ) 6.9 Hz, 3H, CH(Me)(NMe2)).
13C{1H} NMR (δ, acetone-d6, 20 °C): 145.4 (d, 1J CP ) 52.9 Hz,
2
1
1C, Ph1), 136.7 (d, J CP ) 12.5 Hz, 2C, Ph2,6), 136.6 (d, J CP
)
3
47.4 Hz, 1C, Ph1′), 132.4 (d, J CP ) 10.4 Hz, 1C, NtC-CH3),
131.9 (d, J CP ) 9.8 Hz, 2C, Ph2′,6′), 131.6 (d, J CP ) 2.7 Hz,
2
4
4
3
1C, Ph4), 129.5 (d, J CP ) 2.2 Hz, 1C, Ph4′), 129.0 (d, J CP
)
3
1H, FeCps), 4.71-4.66 (m, 2H, FeCps), 4.60 (q, J HH ) 6.9 Hz,
3
10.4 Hz, 2C, Ph3,5), 128.5 (d, J CP ) 9.3 Hz, 2C, Ph3′,5′), 94.1
1H, CH(Me)NEt2), 4.34 (s, 5H, RuCp), 3.80 (s, 5H, FeCp),
3.43-3.24 (m, 2H, NCH2CH3), 3.16 (m, 1H, NCH2CH3), 2.91
2
2
(d, J CP ) 22.3 Hz, 1C, FeCp2), 78.1 (d, J CP ) 2.2 Hz, CpRu),
1
76.5 (d, J CP ) 1.0 Hz, 1C, FeCps), 74.3 (d, J CP ) 33.2 Hz, 1C,
5
(m, 1H, NCH2CH3), 2.62 (d, J HP ) 1.4 Hz, 3H, NtC-CH3),
FeCp1), 71.5 (d, J CP ) 4.9 Hz, 1C, FeCps), 71.4 (s, 5C, FeCp),
3
1.84 (t, 3H, NCH2CH3), 1.55 (d, J HH ) 6.9 Hz, 3H, CH(Me)-
3
71.2 (d, J CP ) 8.7 Hz, 1C, FeCps), 62.5 (d, J CP ) 1.8 Hz, 1C,
NEt2), 0.93 (t, 3H, NCH2CH3). 13C{1H} NMR (δ, acetone-d6,
3
1
1
20 °C): 145.2 (d, J CP ) 50.7 Hz, 1C, Ph1), 137.8 (d, J CP
)
CH(Me)(NMe2)), 56.9 (d, J CP ) 2.2 Hz, 1C, NMe2), 48.9 (d,
3J CP ) 1.1 Hz, 1C, NMe2), 10.6 (s, 1C, CH(Me)(NMe2)), 4.4 (s,
1C, NtC-CH3). 31P{1H} NMR (δ, acetone-d6, 20 °C): 41.7
(PPh2), -143.6 (1J PF ) 713.3 Hz, PF6).
49.6 Hz, 1C, Ph1′), 137.2 (d, J CP ) 12.0 Hz, 2C, Ph2,6), 132.9
2
3
2
(d, J CP ) 10.9 Hz, 1C, NtC-CH3), 132.4 (d, J CP ) 9.8 Hz,
2C, Ph2′,6′), 132.3 (d, J CP ) 2.2 Hz, 1C, Ph4), 130.3 (d, J CP
)
4
4
2.1 Hz, 1C, Ph4′), 129.7 (d, 3J CP ) 10.4 Hz, 2C, Ph3,5), 129.4 (d,
[(SR u ,RC,Sp l)-R u Cp (2-(1-N,N-d im et h yla m in oet h yl)-1-
d ip h en ylp h osp h in o)fer r ocen e)(CD3CN)]P F 6 (3D). A sealed
NMR tube charged with 3 (20 mg, 25 µmol) and CD3CN (20
µL, 383 µmol) in acetone-d6 was kept at room temperature for
15 min and was then transferred to the probe head. The 1H
NMR showed almost quantitative replacement of CH3CN (<5%
of 3 remained as determined by integration of the remaining
CH3CN resonance at 2.64 ppm). The NMR spectroscopic data
for 3D are essentially the same as for 3.
3J CP ) 9.3 Hz, 2C, Ph3′,5′), 95.3 (d, J CP ) 22.9 Hz, 1C, CpFe2),
2
78.6 (d, 2J CP ) 2.1 Hz, CpRu), 77.1 (d, J CP ) 1.1 Hz, 1C, FeCps),
74.1 (d, J CP ) 33.2 Hz, 1C, FeCp1), 72.5 (d, J CP ) 4.9 Hz, 1C,
2
FeCps), 72.1 (s, 5C, FeCp), 72.0 (d, J CP ) 9.3 Hz, 1C, FeCps),
3
3
59.8 (d, J CP ) 1.7 Hz, 1C, CH(Me)NEt2), 59.3 (d, J CP ) 2.3
Hz, 1C, NCH2CH3), 57.3 (d, 3J CP ) 2.1 Hz, 1C, NCH2CH3), 15.4
(1C, NCH2CH3), 15.2 (1C, NCH2CH3), 14.0 (s, 1C, CH(Me)-
NEt2), 5.4 (s, 1C, NtC-CH3). 31P{1H} NMR (δ, acetone-d6, 20
°C): 43.2 (PPh2), -142.7 (1J PF ) 709.5 Hz, PF6).
[(R/SRu ,RC,Sp l)-Ru Cp (2-(1-N,N-d im eth yla m in oeth yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(dCdCHP h )]P F 6 (6a /6b ).
To a solution of 3 (85 mg, 0.107 mmol) in CH2Cl2 (4 mL) was
added HCtCPh (35 µL, 0.321 mmol), and the mixture was
stirred for 4 h at room temperature. The solvent was removed
under reduced pressure, and the residue was dissolved in 3
mL of CH2Cl2. Additional HCtCPh (12 µL, 0.107 mmol) was
(15) Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory
Chemicals, 3rd ed.; Pergamon: New York, 1988.
(16) Gill, T. P.; Mann, K. R. Organometallics 1982, 1, 485.
(17) Hayashi, T.; Mise, T.; Fukushima, M.; Kagotani, M.; Na-
gashima, N.; Hamada, Y.; Matsumoto, A.; Kawakami, S.; Konishi, M.;
Yamamoto, K.; Kumada, M. Bull. Chem. Soc. J pn. 1980, 53, 1138.
(18) Brunner, H. Enantiomer 1997, 2, 133. Brunner, H. Angew.
Chem. 1999, 111, 1248.

[RuCp(aminophosphinoferrocene)(CH3CN)]PF6
Organometallics, Vol. 18, No. 19, 1999 3871
added, and the mixture was stirred for another 2 h. After that
time, the solvent was removed in vacuo and the residue
redissolved in 1 mL of CH2Cl2. On addition of Et2O (3 mL) a
brown precipitate formed, which was collected on a glass frit,
washed with Et2O (3 × 1 mL), and dried in vacuo. Yield: 85
mg (93%) of a mixture of two diasteromeres in a ratio of 21:1
(de ) 91%). Anal. Calcd for C39H39F6FeNP2Ru: C, 54.81; H,
4.60. Found (from the mixture of both diastereomeres): C,
55.06; H, 4.88. Complex 6b could not be isolated, and spec-
troscopic data are taken from the NMR spectra of the mixture.
1H NMR (δ, acetone-d6, 20 °C): 3.90 (s, 5H, FeCp), 1.82 (d,
3J HH ) 7.0 Hz, CH(Me)NMe2), all other resonances could not
be observed. 13C{1H} NMR (δ, acetone-d6, 20 °C): 72.8 (s, 5C,
FeCp), all other resonances could not be observed. 31P{1H}
NMR (δ, acetone-d6, 20 °C): 40.0 (PPh2), -143.6 (1J PF ) 713.3
Hz, PF6). Slow diffusion of Et2O into a CH2Cl2 solution of the
mixture yields red crystals of the major isomer 6a in 60% yield
(55 mg). 1H NMR (δ, acetone-d6, 20 °C): 8.01-7.92 (m, 2H,
Ph), 7.78-7.71 (m, 3H, Ph), 7.42-7.30 (m, 7H, Ph), 7.19-7.12
6.5 Hz, 1C, FeCps), 71.9 (d, J CP ) 9.3 Hz, 1C, FeCps), 71.2 (s,
5C, FeCp), 70.9 (d, 1J CP ) 34.9 Hz, 1C, FeCp1), 70.6 (d, 3J CP
)
3
1.3 Hz, 1C, CH(Me)NMe2), 61.2 (d, J CP ) 2.0 Hz, 1C, NMe2),
3
48.9 (d, J CP ) 1.0 Hz, 1C, NMe2), 10.9 (s, 1C, CH(Me)NMe2).
31P{1H} NMR (δ, CD3NO2, 20 °C): 40.1 (PPh2), -145.9 (1J PF
) 707.0 Hz, PF6). 31P{1H} NMR (δ, acetone-d6, 20 °C): 42.8
(PPh2), -143.2 (1J PF ) 707.4 Hz, PF6).
Ep im er iza tion of 7a /7b. In a sealed NMR tube, a solution
of 7a /7b in CD3NO2 at room temperature under a CO atmo-
sphere was irradiated with UV light (75W) under a CO
atmosphere for 2 h. The reaction was monitored by 1H and
31P{1H} NMR spectroscopy, indicating that epimerization took
place to give 7a with a de of >98%. In addition, small amounts
(<5%) of two not identifiable byproducts were detected.
[(R/SR u ,Sp l)-R u Cp (2-(1-N,N-d im et h yla m in om et h yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(dCdCHP h )]P F 6 (8a /8b ).
This compound was prepared analogously to 8a /8b with 4 (119
mg, 0.153 mmol) and HCtCPh (first 50 µL and then 17 µL)
as the starting materials. Yield: 119 mg (92%) of a brown
precipitate containing a mixture of diasteromeres in a ratio
of 28:1 (de ) 96%) as an estimation, taken from the integration
of the 31P{1H} NMR resonances. Anal. Calcd for C38H37F6-
FeNP2Ru: C, 54.30; H, 4.44. Found (both diastereomers): C,
54.22; H, 4.57. Complex 8b could not be isolated, and NMR
data are taken from the isomeric mixture. 31P{1H} NMR (δ,
acetone-d6, 20 °C): 36.2 (PPh2), -143.6 (1J PF ) 713.3 Hz, PF6).
8a was purified by redissolving the isomeric mixture in CH2-
Cl2 and precipitation with Et2O. Yield: 90 mg (70%): 1H NMR
(δ, acetone-d6, 20 °C): 8.00-7.92 (m, 2H, Ph), 7.77-7.68 (m,
3H, Ph), 7.46-7.32 (m, 7H, Ph), 7.20-7.15 (m, 1H, Ph), 7.10-
7.03 (m, 2H, Ph), 5.50 (m, 6H, RuCp, dCdCHPh), 5.03 (d, 2J HH
) 13.9 Hz, 1H, CH2NMe2), 4.88 (m, 1H, FeCps), 4.77 (m, 2H,
4
(m, 1H, Ph), 7.05-6.69 (m, 2H, Ph), 5.50 (d, J PH ) 2.4 Hz,
3
1H, dCdCHPh), 5.46-5.40 (q, J HH ) 6.7 Hz, 1H, CH(Me)-
NMe2), 5.42 (s, 5H, RuCp), 4.85 (m, 2H, FeCps), 4.78 (m, 1H,
FeCps), 3.86 (s, 5H, FeCp), 3.13 (s, 3H, NMe2), 2.47 (s, 3H,
3
NMe2), 1.35 (d, J HH ) 6.7 Hz, CH(Me)NMe2). 13C{1H} NMR
2
(δ, acetone-d6, 20 °C): 350.0 (d, J PC ) 15.3 Hz, dCdCHPh),
1
2
144.4 (d, J CP ) 52.1 Hz, 1C, Ph1), 136.6 (d, J CP ) 12.7 Hz,
2C, Ph2,6), 136.5 (d, J CP ) 42.0 Hz, 1C, Ph1′), 133.3 (d, J CP
)
1
4
2.5 Hz, 1C, Ph4), 132.4 (d, J CP ) 8.9 Hz, 2C, Ph2′,6′), 131.5 (d,
2
4J CP ) 2.5 Hz, 1C, Ph4′), 130.7 (2C, PhR3,5), 130.0 (d, J CP
)
3
10.2 Hz, 2C, Ph3,5), 129.95 (d, 3J CP ) 11.4 Hz, 2C, Ph3′,5′), 129.7
(1C, PhR1), 128.1 (1C, PhR4), 127.7 (2C, PhR2,6), 121.0 (d, J CP
3
) 2.5 Hz, 1C, dCdCHPh), 95.3 (d, 2J CP ) 20.4 Hz, 1C, FeCp2),
94.6 (d, J CP ) 2.2 Hz, RuCp), 77.6 (1C, FeCps), 73.4 (d, J CP
)
2
2
FeCps), 3.87 (s, 5H, FeCp), 3.03 (d, J HH ) 13.9 Hz, 1H, CH2-
6.3 Hz, 1C, FeCps), 73.0 (d, J CP ) 8.3 Hz, 1C, FeCps), 72.7 (s,
NMe2), 3.08 (s, 3H, NMe2), 2.59 (s, 3H, NMe2). 13C{1H} NMR
5C, FeCp), 71.4 (d, J CP ) 50.9 Hz, 1C, FeCp1), 67.6 (1C, CH-
1
2
(δ, acetone-d6, 20 °C): 349.9 (d, J PC ) 16.2 Hz, dCdCHPh),
2
1
(Me)NMe2), 63.5 (1C, NMe2), 51.0 (1C, NMe2), 11.9 (1C, CH-
(Me)NMe2). 31P{1H} NMR (δ, acetone-d6, 20 °C): 41.7 (PPh2),
-143.6 (1J PF ) 713.3 Hz, PF6).
346.6 (d, J PC ) 15.3 Hz, dCdCHPh), 143.8 (d, J CP ) 51.2
Hz, 1C, Ph1), 136.8 (d, 1J CP ) 43.1 Hz, 1C, Ph1′), 136.5 (d, 2J CP
) 12.6 Hz, 2C, Ph2,6), 133.3 (d, J CP ) 2.7 Hz, 1C, Ph4), 132.3
4
(d, 2J CP ) 9.9 Hz, 2C, Ph2′,6′), 131.5 (d, 4J CP ) 2.7 Hz, 1C, Ph4′),
130.8 (bs, 2C, PhR3,5), 130.1 (d, 3J CP ) 9.9 Hz, 2C, Ph3,5), 130.0
[(R/SRu ,RC,Sp l)-Ru Cp (2-(1-N,N-d im eth yla m in oeth yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(CO)]P F6 (7a /7b). A solution
of 3 (100 mg, 0.126 mmol) in CH2Cl2 (4 mL) was purged with
CO for 2 min and was stirred for 3 h at room temperature.
After removal of the solvent, the residue was redissolved in 1
mL of CH2Cl2 and the product was precipitated upon addition
of Et2O (3 mL). Yield: 89 mg (90%) of a mixture of two
diasteromeres in a ratio of 2.4:1 (de ) 42%). Anal. Calcd for
(d, J CP ) 11.7 Hz, 2C, Ph3′,5′), 129.7 (1C, PhR1), 128.1 (1C,
3
PhR4), 127.6 (1C, PhR2,6), 127.5 (1C, PhR2,6), 120.8 (d, J CP
)
3
2
2.8 Hz, 1C, dCdCHPh), 94.4 (d, J CP ) 0.8 Hz, RuCp), 91.3
(d, J CP ) 20.6 Hz, 1C, FeCp2), 78.2 (d, J CP ) 1.0 Hz, 1C,
2
FeCps), 74.7 (d, J CP ) 9.0 Hz, 1C, FeCps), 72.3 (d, J CP ) 6.3
Hz, 1C, FeCps), 72.6 (s, 5C, FeCp), 69.7 (d, J CP ) 52.1 Hz,
1
1C, FeCp1), 67.8 (1C, CH2NMe2), 67.2 (1C, NMe2), 57.7 (1C,
NMe2). 31P{1H} NMR (δ, acetone-d6, 20 °C): 45.5 (PPh2),
-142.7 (1J PF ) 709.5 Hz, PF6).
C
32H33F6FeNOP2Ru: C, 49.25; H, 4.26. Found (from the
mixture of both diastereomers): C, 49.43; H, 4.41. The minor
diasteromer 7b could not be isolated, and spectroscopic data
are taken from the mixture. 1H NMR (δ, acetone-d6, 20 °C):
[(R/SR u ,Sp l)-R u Cp (2-(1-N,N-d im et h yla m in om et h yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(CO)]P F 6 (9a /9b). This com-
pound was prepared analogously to 7a with 4 (100 mg, 0.128
mmol) as the starting material. Yield: 91 mg (93%) of a yellow
precipitate containing a mixture of two diasteromeres in a ratio
of 1.8:1 (de ) 28%), taken from the integration of the 1H
and31P{1H} NMR spectra. Anal. Calcd for C31H31F6FeNOP2-
Ru: C, 48.58; H, 4.08. Found (from the mixture of both
diasteromers): C, 48.89; H, 4.33. Complexes 9a /b could not
be separated, and NMR data are taken from the mixture: 9a
(assignment was afforded by comparing the NMR spectra with
those of 7a /b and 10a ). 1H NMR (δ, CDCl3, 20 °C): 7.90-7.87
(m, 2H, Ph), 7.74 (m, 3H, Ph), 7.46-7.32 (m, 3H, Ph), 7.12-
3
5.45 (s, 5H, RuCp), 3.89 (s, 5H, FeCp), 1.50 (d, J HH ) 6.6 Hz,
CH(Me)NMe2), all other resonances could not be assigned
unequivocally. 13C{1H} NMR (δ, acetone-d6, 20 °C): 87.7 (d,
2J CP ) 1.6 Hz, 5C, RuCp), all other resonances could not be
assigned unambiguously. 31P{1H} NMR (δ, acetone-d6, 20
°C): 39.8 (PPh2), -143.2 (1J PF ) 707.4 Hz, PF6). The major
isomer 7a could be obtained in pure form by washing the
mixture with small amounts (3 × 0.2 mL) of acetone. Yield:
1
25 mg (25%) of a bright yellow powder. H NMR (δ, CD3NO2,
20 °C): 7.99-7.91 (m, 2H, Ph), 7.72 (m, 3H, Ph), 7.47-7.34
(m, 3H, Ph), 7.08-6.99 (m, 2H, Ph), 4.99 (s, 5H, RuCp), 4.84-
4.74 (m, 4H, FeCps, CH(Me)NMe2), 3.87 (s, 5H, FeCp), 3.29
3
2
(s, 3H, NMe2), 2.45 (s, 3H, NMe2), 1.53 (d, J HH ) 6.7 Hz, 3H,
6.94 (m, 2H, Ph), 4.97 (s, 5H, RuCp), 5.00 (d, J HH ) 13.5 Hz,
CH(Me)NMe2). 13C{1H} NMR (δ, CD3NO2, 20 °C): 204.8 (d,
1H, CH2NMe2), 4.86-4.65 (m, 3H, FeCps), 3.80 (s, 5H, FeCp),
1
2
2J CP ) 18.0 Hz, 1C, CO), 142.6 (d, J CP ) 52.9 Hz, 1C, Ph1),
3.13 (d, J HH ) 13.5 Hz, 1H, CH2NMe2), 3.17 (s, 3H, NMe2),
2
1
135.11 (d, J CP ) 12.0 Hz, 2C, Ph2,6), 135.08 (d, J CP ) 62.7
2.66 (s, 3H, NMe2). 13C{1H} NMR (δ, CDCl3, 20 °C): 206.6 (d,
Hz, 1C, Ph1′), 132.0 (d, J CP ) 2.7 Hz, 1C, Ph4), 131.0 (d, J CP
2J CP ) 19.3 Hz, 1C, CO), 142.4 (d, J CP ) 49.5 Hz, 1C, Ph1),
4
2
1
) 9.8 Hz, 2C, Ph2′,6′), 130.1 (d, J CP ) 2.7 Hz, 1C, Ph4′), 128.6
136.7 (d, J CP ) 63.4 Hz, 1C, Ph1′), 135.2 (d, J CP ) 11.2 Hz,
4
1
2
(d, J CP ) 11.4 Hz, 2C, Ph3,5), 128.5 (d, J CP ) 10.4 Hz, 2C,
2C, Ph2,6), 133.2 (d, J CP ) 2.3 Hz, 1C, Ph4), 131.38 (d, J CP
)
3
3
4
2
Ph3′,5′), 92.8 (d, J CP ) 20.7 Hz, 1C, FeCp2), 88.1 (d, J CP ) 1.6
9.9 Hz, 2C, Ph2′,6′), 131.34 (d, J CP ) 2.4 Hz, 1C, Ph4′), 129.5
2
2
4
Hz, RuCp), 75.7 (d, J CP ) 1.0 Hz, 1C, FeCps), 72.1 (d, J CP
)
(d, J CP ) 10.2 Hz, 2C, Ph3,5), 129.4 (d, J CP ) 10.1 Hz, 2C,
3
3

3872 Organometallics, Vol. 18, No. 19, 1999
Slugovc et al.
2
2
Ph3′,5′), 95.2 (d, J CP ) 20.1 Hz, 1C, FeCp2), 88.2 (d, J CP ) 1.7
d6. After adjusting to the temperature the deuterated aceto-
nitrile was added by syringe and spectra were taken at regular
intervals. The time dependence of the mole fraction x ) [CH3-
CN]c/([CH3CN]c + [CH3CN]f) of coordinated nondeuterated
acetonitrile, obtained by integration of the signals, was fitted
to eq 2, where x0 and x∞ are the values of x at t ) 0 and ∞, and
Hz, RuCp), 74.8 (d, J CP ) 1.1 Hz, 1C, FeCps), 73.6 (d, J CP
)
6.5 Hz, 1C, FeCps), 73.4 (d, J CP ) 10.2 Hz, 1C, FeCps), 71.7 (s,
5C, FeCp), 70.4 (d, 1J CP ) 55.9 Hz, 1C, FeCp1), 66.7 (1C, CH2-
NMe2), 65.9 (1C, NMe2), 55.8 (1C, NMe2). 31P{1H} NMR (δ,
CDCl3, 20 °C): 41.5 (PPh2), -143.4 (1J PF ) 712.1 Hz, PF6). 9b
(minor diastereomer): 1H NMR (δ, CDCl3, 20 °C): 7.91-7.86
(m, 2H, Ph), 7.74 (m, 3H, Ph), 7.46-7.32 (m, 3H, Ph), 7.09-
x ) x∞ + (xo - x∞) exp[-kt/(1 - x∞)]
(2)
2
6.97 (m, 2H, Ph), 5.18 (s, 5H, RuCp), 5.04 (d, J HH ) 13.7 Hz,
k is the observed first-order rate constant for the exchange of
a particular solvent molecule. The adjustable parameters were
x0, x∞, and k. Above 55 °C the exchange reaction is fast enough
1H, CH2NMe2), 4.88-4.65 (m, 3H, FeCps), 3.70 (s, 5H, FeCp),
2
3.23 (d, J HH ) 13.7 Hz, 1H, CH2NMe2), 3.18 (s, 3H, NMe2),
2.51 (s, 3H, NMe2). 13C{1H} NMR (δ, CDCl3, 20 °C): 210.1 (d,
1
to be followed by H NMR line broadening. From the variable-
2J CP ) 17.9 Hz, 1C, CO), 143.2 (d, J CP ) 49.5 Hz, 1C, Ph1),
1
temperature NMR studies, exchange rate constants were
determined by visual comparison of the observed and computer-
simulated spectra using the DNMR3 program.19 Temperature
readings were calibrated by using the method of Raiford et
al.,20 corrected to 250.13 MHz, by adding a capillary of
methanol to the experimental sample. The temperature de-
pendence of the rate constants is given by the Eyring equation
(eq 3). The values of ∆Hq and ∆Sq were obtained from a plot
135.2 (d, J CP ) 10.7 Hz, 2C, Ph2,6), 135.0 (d, J CP ) 59.4 Hz,
2
1
1C, Ph1′), 133.2 (d, J CP ) 2.4 Hz, 1C, Ph4), 131.6 (d, J CP
)
4
2
10.1 Hz, 2C, Ph2′,6′), 131.3 (d, J CP ) 2.4 Hz, 1C, Ph4′), 129.4
4
(d, J CP ) 10.0 Hz, 2C, Ph3,5), 129.2 (d, J CP ) 9.9 Hz, 2C,
3
3
2
2
Ph3′,5′), 93.8 (d, J CP ) 19.2 Hz, 1C, FeCp2), 87.2 (d, J CP ) 1.7
Hz, RuCp), 77.4 (d, J CP ) 7.1 Hz, 1C, FeCps), 75.8 (d, J CP
)
1.1 Hz, 1C, FeCps), 72.3 (d, J CP ) 9.9 Hz, 1C, FeCps), 72.1 (d,
1J CP ) 55.9 Hz, 1C, FeCp1), 71.8 (s, 5C, FeCp), 66.5 (1C, CH2-
NMe2), 64.0 (1C, NMe2), 53.2 (1C, NMe2). 31P{1H} NMR (δ,
CDCl3, 20 °C): 41.4 (PPh2), -143.4 (1J PF ) 712.1 Hz, PF6).
[(R/SR u ,RC,Sp l)-R u Cp (2-(1-N,N-d iet h yla m in oet h yl)-1-
d ip h en ylp h osp h in ofer r ocen e)(CO)]P F 6 (10a /b). This com-
pound was prepared analogously to 7a with 5 (100 mg, 0.122
mmol) as the starting material. Yield: 94 mg (95%) of a yellow
precipitate containing a mixture of two diasteromeres in a ratio
of 15:1 (de ) 87%). Anal. Calcd for C34H37F6FeNOP2Ru: C,
50.51; H, 4.61. Found (both diasteromeres): C, 50.88; H, 4.87.
Complex 10b could not be isolated, and NMR spectroscopic
k ) (kBT/h)(exp(-(∆Hq - T∆Sq)/RT)
(3)
of ln(k/T) versus 1/T (Figure 3) by a weighted linear least-
squares regression.21
X-r a y Str u ctu r e Deter m in a tion for 3, 5‚CH2Cl2, 6a , a n d
7a . Crystals of 3, 5‚CH2Cl2, and 6a were obtained by diffusion
of Et2O into CH2Cl2 solutions. 7a was obtained by slow
evaporation of an acetone solution. Crystal data and experi-
mental details are given in Table 4. X-ray data were collected
on a Siemens Smart CCD area detector diffractometer (graphite-
monochromated Mo KR radiation, λ ) 0.71073 Å, nominal
crystal-to-detector distance of 4.45 cm, 0.3° ω-scan frames).
Corrections for Lorentz and polarization effects, for crystal
decay, and for absorption (program SADABS22) were applied.
The structures were solved by direct methods using the
program SHELXS97.23 Structure refinement on F2 was carried
out with program SHELXL97.24 All non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were inserted in
idealized positions and were refined riding with the atoms to
which they were bonded.
1
data are taken from the mixture. H NMR (δ, CDCl3, 20 °C):
5.31 (s, 5H, RuCp), 4.18 (s, 5H, FeCp), 1.35 (t, 3H, NCH2CH3),
1.10 (t, 3H, NCH2CH3). 31P{1H} NMR (δ, CDCl3, 20 °C): 43.4
(PPh2), -143.6 (1J PF ) 713.3 Hz, PF6). 10a could be obtained
by heating of the mixture of diasteromeres at 62 °C in CDCl3
1
for 36 h. H NMR (δ, CDCl3, 20 °C): 7.75-7.71 (m, 2H, Ph),
7.69-7.65 (m, 3H, Ph), 7.42-7.38 (m, 3H, Ph), 7.04-6.97 (m,
3
2H, Ph), 5.00 (s, 5H, RuCp), 4.85 (q, J HH ) 6.4 Hz, 1H,
CH(Me)NEt2), 4.76 (m, 1H, FeCps), 4.72 (vt, J HH ) 2.7 Hz,
3
1H, FeCps), 4.60 (m, 1H, FeCps), 3.78 (s, 5H, FeCp), 3.23-
3.12 (bm, 1H, NCH2CH3), 2.98-2.73 (bm, 3H, NCH2CH3), 1.74
3
(t, 3H, NCH2CH3), 1.51 (d, J HH ) 6.4 Hz, 3H, CH(Me)NEt2),
Ack n ow led gm en t. Financial support by the “Fonds
zur Fo¨rderung der wissenschaftlichen Forschung” is
gratefully acknowledged (Project No. 11896). L. X.
acknowledges a Ph.D. grant of the Austrian Ministry
of Foreign Affairs (Aktion Nord-Su¨d Dialog, Projekt-
nummer 894/98).
0.84 (t, 3H, NCH2CH3). 13C{1H} NMR (δ, CDCl3, 20 °C): 205.7
(d, 2J CP ) 19.2 Hz, 1C, CO), 141.6 (d, 1J CP ) 50.5 Hz, 1C, Ph1),
136.0 (d, J CP ) 63.4 Hz, 1C, Ph1′), 135.0 (d, J CP ) 11.7 Hz,
1
2
2C, Ph2,6), 132.6 (d, J CP ) 2.4 Hz, 1C, Ph4), 131.3 (d, J CP
)
4
2
10.0 Hz, 2C, Ph2′,6′), 131.0 (d, J CP ) 2.4 Hz, 1C, Ph4′), 129.40
4
(d, J CP ) 10.0 Hz, 2C, Ph3,5), 129.38 (d, J CP ) 10.2 Hz, 2C,
3
3
2
2
Ph3′,5′), 93.6 (d, J CP ) 19.8 Hz, 1C, FeCp2), 88.7 (d, J CP ) 1.8
Hz, RuCp), 75.0 (d, J CP ) 1.0 Hz, 1C, FeCps), 72.6 (d, J CP
)
Su p p or tin g In for m a tion Ava ila ble: Listings of atomic
coordinates, anisotropic temperature factors, bond lengths and
angles, and least-squares planes for 3, 5‚CH2Cl2, 6a , 7a , and
superpositions of 6a and 6a ′, 3 and 5, and 7a and 3. This
material is available free of charge via the Internet at
http://pubs.acs.org.
5.8 Hz, 1C, FeCps), 72.4 (d, J CP ) 10.0 Hz, 1C, FeCps), 71.4 (s,
5C, FeCp), 70.4 (d, J CP ) 49.9 Hz, 1C, FeCp1), 67.1 (1C, CH-
1
(Me)NEt2), 59.0 (1C, NCH2CH3), 57.3 (1C, NCH2CH3), 15.3 (1C,
NCH2CH3), 14.6 (1C, NCH2CH3), 14.1 (1C, CH(Me)NEt2). 31P-
{1H} NMR (δ, CDCl3, 20 °C): 42.6 (PPh2), -143.5 (1J PF ) 712.1
Hz, PF6).
Acet on it r ile E xch a n ge Kin et ics on 3 in Acet on e-d 6.
The CH3CN exchange in 3 (eq 1) was studied as a function of
temperature (Table 2) by monitoring the increase in intensity
of the proton NMR signal of free CH3CN (at 1.97 ppm) and
OM990307A
(19) (a) Binsch, G.; Kleier, D. DNMR3, Program 165, QCPE, Indiana
University, Bloomington, IN, 1970. (b) Binsch, G.; Kessler, H. Angew.
Chem. 1980, 92, 445.
(20) Raiford, D. S.; Fisk, C. L.; Becker, E. D. Anal. Chem. 1979, 51,
2050.
(21) Bevington, P. R. Data Reduction and Error Analysis for the
Physical Sciences; McGraw-Hill: New York, 1969.
(22) Sheldrick, G. M. SADABS: Program for Absorption Correction;
University of Go¨ttingen: Germany, 1996.
[RuCp(PN*)(CH3CN)]PF6 + CD3CN f
[RuCp(PN*)(CD3CN)]PF6 + CH3CN (1)
(23) Sheldrick, G. M. SHELXS97: Program for the Solution of
Crystal Structures; University of Go¨ttingen: Germany, 1997.
(24) Sheldrick, G. M. SHELXL97: Program for Crystal Structure
Refinement; University of Go¨ttingen: Germany, 1997.
the decrease of the bound CH3CN (at +2.63 ppm) after
injection of CD3CN (pn* ) 2a ) in the temperature range below
-2 °C. Typically 10 mg of 3 was dissolved in 0.5 mL of acetone-