Organometallic Rh(III) complexes with the bifunctional ligand [2-(dimethylamino)ethyl]cyclopentadiene. Crystal structure of the [{η5:η1-C5H4(CH 2)2NMe2}RhIIICl2</

Article abstract of DOI:10.1016/S0022-328X(99)00069-8

The preparation of rhodium(III) complexes with [2-(dimethylamino)ethyl]cyclopentadiene is described. Starting from [{η⁵-C₅H₄(CH₂) ₂NMe₂}Rh^I(η⁴-cod)] (1) and [{η^5<

Full text of DOI:10.1016/S0022-328X(99)00069-8

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 582 (1999) 286–291
Organometallic Rh(III) complexes with the bifunctional ligand
[2-(dimethylamino)ethyl]cyclopentadiene. Crystal structure of the
[{h5:h1-C5H4(CH2)2NMe2}RhIIICl2] complex
Athanassios I. Philippopoulos a, Bruno Donnadieu b, Rene´ Poilblanc b,
Nick Hadjiliadis a,*
a Laboratory of Inorganic and General Chemistry, Department of Chemistry, Uni6ersity of Ioannina, GR-45110 Ioannina, Greece
b Laboratoire de Chimie de Coordination du CNRS,
Unite´ no 8241 liee´ par con6ention a` l’Uni6ersite´ Paul Sabatier et a` l’Institut National Polytechnique, 205 route de Narbonne, F-31077 Toulouse,
Cedex, France
Received 4 December 1998
Abstract
The preparation of rhodium(III) complexes with [2-(dimethylamino)ethyl]cyclopentadiene is described. Starting from [{h5-
C5H4(CH2)2NMe2}RhI(h4-cod)] (1) and [{h5-C5H4(CH2)2N(H)Me2}RhI(h4-cod)]+·(Cl)− (2) the complexes [{h5:h1-C5H4-
(CH2)2NMe2}RhIIICl2] (3), [{h5-C5H4(CH2)2N(H)Me2}RhIIICl(m-Cl)]22+·(Cl)2− (4), [{h5-C5H4(CH2)2NMe2}RhIIICl2(PPh3)] (5) and
[{h5-C5H4(CH2)2N(H)Me2}RhIIICl2(PPh3)]+·(Cl)− (6) were synthesized and characterized by elemental analysis, IR, 1H-, 13C-
and 31P-NMR spectroscopy. The X-ray crystal structure of complex 3 has also been determined where Rh(III) chelates through
the cyclopentadienyl and the terminal –NMe2 group. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Organometallic complexes; Cyclopentadienyl ligand; Functionalized; Rhodium complexes
Recently Flores et al. [5,6] developed the catalyst
1. Introduction
precursors[h5-(2-dimethylaminoethyl)cyclopentadienyl]-
trichlorotitanium and [h5-2,3,4,5-tetramethyl-1-(2-dime-
thylaminoethyl)cyclopentadienyl]trichlorotitanium, for
the polymerization of ethylene and propylene. Rausch et
al. [7]
also reported the use of pendent aminoalkyl-substituted
monocyclopentadienyltitanium compounds in the poly-
merization of ethylene and propylene.
Continuing our work on the use of cyclopentadiene
bearing amino functionalized side chain and of its
sodium salt, for the preparation of organometallic Rh
and Co complexes, we report here the chloro deriva-
tives of Rh(III) with the named ligand, in addition to
the iodo ligand already reported [2,4]. In addition, the
X-ray crystal structure of [{h5:h1-C5H4(CH2)2-
NMe2}RhIIICl2] (3) also supports the structure of the
corresponding iodo derivative reported earlier [2,4].
Differences in the reactions for the preparation of the
chloro complexes, in comparison to those of iodo, are
also reported.
h5-Cyclopentadienyl derivatives of transition metals
represent one of the most important classes of
organometallic compounds, since more than 80% of all
known organometallic complexes, of the transition
metals, contain the cyclopentadienyl fragment or a
derivative thereof [1].
Cyclopentadienyl derivatives with a functionalized
side chain like [2-(dimethylamino)ethyl]cyclopentadiene
containing both a hard and a soft donor site, form the
so-called half-sandwich complexes with metals possess-
ing specific structures and reactivity. Special properties
and applications of such complexes are expected, e.g.
solubility in unusual solvents including water, antitu-
mour properties [2–4], and catalytic applications [5–7]
etc.
* Corresponding author. Fax: +30-651-44831.
E-mail address: nhadjil@cc.uoi.gr (N. Hadjiliadis)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00069-8

A.I. Philippopoulos et al. / Journal of Organometallic Chemistry 582 (1999) 286–291
287
2. Experimental
13C-NMR (CDCl3): 105.20 (s, C(CH2)2N), 92.40,
86.90 (2×d, JRh–C=6.74 Hz, C5H4), 52.07 (s, CH2N),
45.40 (s, NMe2), 29.99 (s, CH2).
2.1. General
The solid remaining was washed with diethylether
(2×5 ml) and dried in vacuo, giving 4 as an orange–
brown solid. Yield: 55%.
All reactions (unless otherwise noted) were carried
out under a nitrogen atmosphere, using standard
Schlenk techniques. Gaseous Cl2 was prepared from the
oxidation of HCl by KMnO4. Solvents and reagents
were purified and dried by standard methods and were
distilled immediately prior to use. The ligand C5H5-
(CH2)2NMe2 and its sodium salt Na[C5H4(CH2)2NMe2]
were prepared according to literature methods [2]. The
starting materials [Rh(cod)Cl]2 [8], [{h5-C5H4-
(CH2)2NMe2}RhI(h4-cod)] (1) [2] and [{h5-C5H4-
(CH2)2N(H)Me2}RhI(h4-cod)]+·(Cl)− (2) [2], were also
prepared according to published procedures. Conduc-
tivity measurements were performed using an E365B
Conductoscope, Metrhom Ltd, Herisau, Switzerland.
Melting points were determined on a Buchi 510 capil-
lary apparatus and are uncorrected. Microanalyses
were performed by the Service de Microanalyses, Labo-
ratoire de Chimie de Coordination and by the Micro-
analysis Center of the University of Ioannina. For
chromatography of organometallic compounds, the sil-
ica gel was dried for 48 h at 110°C and then flushed
with nitrogen saturated solvent. IR spectra were
recorded on a Perkin–Elmer model 783 grating spec-
trometer, as CsBr pellets. All NMR spectra were ob-
tained on Bruker AMX 400 MHz and AC 200FT
spectrometers of the University of Ioannina and the
Laboratoire de Chimie de Coordination, respectively.
The spectra were calibrated using signals of residual
protons from the solvent referenced to SiMe4. Shifts
quoted for the 31P-NMR spectra are relative to 85%
H3PO4.
M.p. 221–222°C. \M (H2O): 251 V−1 cm2 mol−1
.
Anal. Found: C, 31.58; H, 4.40; N, 4.14. Calc. for
C18H30N2Rh2Cl6: C, 31.19; H, 4.36; N, 4.04%.
IR (CsBr): 3050, 3020 (m, ꢀCH), 2930 (m, –CH),
2652 (s, NH+), 1460, 1440 (m, CꢀC), 1245, 1010, 950,
795, 310 (m, wRh–Cl), 282 (m, wRh–Cl), 251 (m, wRh–Cl
)
cm−1
.
1H-NMR (D2O): (using 3-(trimethylsilyl)propane-
sulfonic acid (TSP) as internal standard): 5.88, 5.82
(2×s, 4H, C5H4), 3.56 (t, 2H, J=6.4 Hz, CH2N), 2.97
1
(s, 6H, NMe2), 2.69 (t, 2H, J=6.4 Hz, CH2). H-NMR
(DMSO-d6): 10.64 (br. s, NH+), 5.99, 5.87 (2×t, 4H,
J=1.4 Hz, C5H4) [2], 3.38 (t, 2H, J=6.4 Hz, CH2N),
2.76 (d, 6H, JNH–CH=4.80 Hz, NMe2), 2.67 (t, 2H,
J=6.4 Hz, CH2).
13C-NMR (D2O): 101.50 (s, C(CH2)2N), 86.30, 86.20
(2×s, C5H4), 57.31 (s, CH2N), 45.98 (s, NMe2), 24.23
(s, CH2). 13C-NMR (DMSO-d6): 107.90 (s, C(CH2)2N),
87.70, 86.10 (2×s, C5H4), 53.60 (s, CH2N), 42.10 (s,
NMe2), 21.10 (s, CH2).
2.2.2. [{p5-C5H4(CH2)2N(H)Me2}RhIII
Cl(v-Cl)]22+·(Cl)−2 (4)
-
To a stirred solution of 2 (90 mg, 0.23 mmol) in
CH2Cl2 (10 ml) Cl2 gas was bubbled over a period of 10
min affording an orange–brown precipitate. After
filtration the solid was washed with CH2Cl2 (2×5 ml),
diethylether (10 ml), and dried in vacuo. Yield: 85%.
Note. An authentic sample prepared in this way gave
the same spectroscopic data (i.e. IR, NMR) as those
referred to in the preparation in Section 2.2.1.
2.2. Preparations
2.2.1. [{p5:p1-C5H4(CH2)2NMe2}RhIIICl2] (3)
2.2.3. [{p5-C5H4(CH2)2N(H)Me2}RhIII
Cl2(PPh3)]+·(Cl)− (5)
-
To a stirred solution of 1 (70 mg, 0.20 mmol) in Et2O
(5 ml) Cl2 gas was bubbled over a period of 10 min
affording an orange precipitate. After filtration, the
solid remaining was extracted with CH2Cl2 (2×10 ml).
Evaporation of the extracts to a small volume, followed
by addition of cold diethylether (10 ml) yielded com-
plex 3 as an orange microcrystalline solid. Yield: 35%.
M.p. 172–173°C.
To a stirred suspension of 4 (84 mg, 0.24 mmol) in
CH3CN (10 ml), solid PPh3 (63.8 mg, 0.24 mmol) was
added. Gradually the insoluble solid dissolved affording
a clear orange solution, which was stirred for one more
hour. After removal of about half of the solvent by
evaporation, diethyether was added in excess (15 ml).
An orange solid was precipitated and after filtration it
was dried in vacuo. The solid was dissolved to the
minimum amount of CH2Cl2 (3 ml) and was then
subjected to flash chromatograph on silica gel (230–400
mesh, 10% MeOH in CH2Cl2). A deep red band was
collected, giving complex 5 as an orange–red solid and
in a 68% yield.
Anal. Found: C, 35.04; H, 4.96; N, 4.71. Calc. for
C9H14NRhCl2: C, 34.86; H, 4.56; N, 4.51%.
IR (CsBr): 3100, 3050 (m, ꢀCH), 2930 (m, –CH),
1475, 1455 (m, CꢀC), 1385, 1320, 1210, 1070, 905, 865,
775, 475, 290 (m, wRh–Cl), 260 (m, wRh–Cl) cm−1
.
1H-NMR (CDCl3): 5.63, 5.27 (2×t, 4H, J=1.6 Hz,
C5H4) [2], 3.63 (t, 2H, J=6.4 Hz, CH2N), 2.65 (s, 6H,
NMe2), 2.52 (t, 2H, J=6.4 Hz, CH2).
M.p. 188–190°C. \M (CH3CN): 150 V−1 cm2
mol−1
.

288
A.I. Philippopoulos et al. / Journal of Organometallic Chemistry 582 (1999) 286–291
Anal. Found: C, 53.40; H, 4.67; N, 2.25. Calc. for
C27H30NRhCl3P: C, 53.28; H, 4.96; N, 2.30%.
2.2.4.2. Method B. To an ice-cooled solution of NaH (16
mg, 0.67 mmol) in CH3CN (5 ml) (the NaH was
prewashed twice with pentane and dried in vacuo) an
equivalent amount of 5 (380.5 mg, 0.63 mmol) in CH3CN
(10 ml) was added under nitrogen. The solution was
stirred for 30 min at this temperature followed by gentle
warming to ambient temperature and was then stirred for
another hour. After filtration through a small pad of
Celite and removal of about half of the solvent by
evaporation, diethylether was added in excess (15 ml). An
orange solid was precipitated and after filtration it was
dried in vacuo. Yield: 70%. M.p. 174–176°C.
IR (CsBr): 3050 (m, ꢀCH), 2950 (m, –CH), 2675 (s,
NH+), 1480, 1435 (m, CꢀC), 1100, 1035, 750, 700, 530,
280 (m, wRh–Cl), 230 (m, wRh–Cl) cm−1
.
1H-NMR (CDCl3): 10.66 (br, s, NH+), 7.97–7.34 (m,
15H, Ph), 5.21, 4.81 (2×s, 4H, C5H4), 3.53 (m, 2H,
CH2N), 3.06 (m, 2H, CH2), 2.85 (s, 6H, NMe2).
13C-NMR (CDCl3): 135.44–128.54 (m, Ph), 114.20 (s,
C(CH2)2N), 88.68, 84.97 (2×s, C5H4), 65.86 (s, CH2N),
44.11 (s, NMe2), 22.41 (s, CH2).
31P-NMR (CD3CN): 32.29 (d, JRh–P=138.65 Hz).
Anal. Found: C, 56.90; H, 4.97; N, 2.25. Calc. for
C27H29NRhCl2P: C, 56.66; H, 5.10; N, 2.45%.
2.2.4. [{p5-C5H4(CH2)2NMe2}RhIIICl2(PPh3)] (6)
IR (CsBr): 3020 (m, ꢀCH), 2900 (m, –CH), 1470, 1425
(m, CꢀC), 1085, 740, 685, 510, 275 (m, wRh–Cl), 235 (m,
2.2.4.1. Method A. To a stirred solution of complex 3 (70
mg, 0.23 mmol) in CH2Cl2 (10 ml), solid PPh3 (58 mg,
0.22 mmol) was added at room temperature and the
solution was stirred for ca. 4 h. After removal of about
half of the solvent by evaporation, diethylether was
added in excess (15 ml). An orange solid was precipitated
and after filtration it was dried in vacuo. The solid was
then dissolved with CH2Cl2 (3 ml) and flash column
chromatographed on silica gel (230–400 mesh, 10%
MeOH in CH2Cl2). An orange band was collected and
evaporated to dryness to leave an orange solid in a 40%
yield.
wRh–Cl) cm−1
.
1H-NMR (CDCl3): 7.66–7.37 (m, 15H, Ph), 5.10, 4.82
(2×s, 4H, C5H4), 2.82 (m, 4H, CH2CH2N), 2.33 (s, 6H,
NMe2).
13C-NMR (CDCl3): 131.31–128.46 (m, Ph), 110.20 (s,
C(CH2)2N), 88.47, 84.94 (2×s, C5H4), 54.94 (s, CH2N),
43.66 (s, NMe2), 22.27 (s, CH2).
31P-NMR (CDCl3): 32.48 (d, JRh–P=133.95 Hz).
2.3. X-ray crystallography and structure solution of
complex 3
Crystal data and full details of the data collection and
data processing are listed in Table 1. A single crystal of
compound 3 was mounted on a four-circle Enraf–Non-
ius diffractometer using Mo–Ka radiation and a graphite
monochromator. Final lattice parameters were deter-
mined from the least-squares refinement of the setting
angles 25 well centered reflections.
Corrections were made for Lorentz polarization ef-
fects, a semi-empirical absorption correction [9], and a
scheme of ponderation [10], were applied. Calculations
were carried out using the CRYSTALS package [11]
adapted on a PC.
Positions of the heavy atoms were determined by direct
methods SIR92 [12]. All other non-hydrogen atoms were
located from a difference-Fourier synthesis. All non-hy-
drogen atoms were refined with anisotropic thermal
parameters. Hydrogen atoms were located by Fourier
differences, but their coordinates were introduced in
processes as fixed contributors with fixed thermal
parameters. Refinements converged with R=0.0267 for
1522 observed reflections. Selected bond lengths and
bond angles are given in Table 2.
Table 1
Summary of crystal and intensity collection data for [{h5:h1-
C5H4(CH2)2NMe2}RhIIICl2] (3)
Chemical formula
Formula weight (g mol−1
Crystal size (mm3)
Habit
Crystal system
Space group
C9H14NCl2Rh
310.03
)
0.47×0.25×0.13
Red needles
Monoclinic
P21/c (no. 14)
11.990(8)
8.213(2)
11.858(2)
113.40(2)
1067(3)
,
a (A)
,
b (A)
,
c (A)
i (°)
3
,
V (A )
v (mm−1
)
90.47
Diffractometer
Radiation
Temperature (K)
Data collection method
Theta range for cell parameters
(°)
Enraf–Nonius CAD-4
,
Mo–Ka (u=0.71073 A)
293
ꢀ/2q; qmax: 25o
11–12
Reflections collected
Independent reflections
Parameters refined
Refinement method
Final R indices [I\3|(I)]
2091
1882 (Rm=0.0155)
119
Full-matrix least-squares on F
R
a=0.0267
b
Rw
0.0306
1.12
GoF c
3. Results and discussion
a R=ꢀ(ꢁFoꢂ−ꢂFcꢁ)/ꢀꢂFoꢂ.
b Rw=[ꢀw(ꢁFoꢂ−ꢂFcꢁ)2/ꢀ(ꢂFoꢂ)2]1/2
.
The reactions studied are summarized in Fig. 1 for the
c GoF=[ꢀ(ꢂFo−Fcꢂ)2/[Nobs−Nparameters
] .
case of [{h5-C5H4(CH2)2NMe2}RhI(h4-cod)] (1) and
1/2

A.I. Philippopoulos et al. / Journal of Organometallic Chemistry 582 (1999) 286–291
289
Table 2
complex 3 is soluble in CH2Cl2. Thus, the two
complexes were readily separated after the addition of
CH2Cl2 to the mixture of 3 and 4. It should be noted
here, that reaction of 1 with I2 solely produced the
corresponding iodo derivative of 3 and not 4 as in the
present case [4].
,
Selected bond distances (A) and angles (°) for 3
Bond distances
Rh(1)–Cl(1)
Rh(1)–Cl(2)
Rh(1)–N(1)
Rh(1)–C(1)
Rh(1)–C(2)
Rh(1)–C(3)
Rh(1)–C(4)
Rh(1)–C(5)
2.401(1)
2401(1)
2.196(4)
2.120(6)
2.159(6)
2.160(6)
2.121(6)
2.096(6)
C(1)–C(2)
C(1)–C(5)
C(2)–C(3)
C(3)–C(4)
C(4)–C(5)
C(5)–C(50)
C(5)–C(51)
N(1)–C(51)
1.419(9)
1.410(9)
1.396(9)
1.412(9)
1.430(9)
1.520(8)
1.514(8)
1.490(7)
The IR spectrum of 3 shows the typical metallocene
skeletal vibrations at 3050, 3045, 2930, 1455, 1070 and
905 cm−1 [14]. The far-IR spectrum showed two
strong wRh–Cl bands at 290 and 260 cm−1 [15,16]. The
compound is stable under atmospheric conditions and
soluble in CH2Cl2, CHCl3, (CH3)2CO, CH3OH and
Bond angles
Cl(1)–Rh(1)–Cl(2)
Cl(1)–Rh(1)–N(1)
Cl(2)–Rh(1)–N(1)
Rh(1)–N(1)–C(51)
89.38(5) C(5)–C(50)–C(51)
91.9(1)
95.7(1)
108.2(5)
C(51)–N(1)–C(100) 109.4(5)
N(1)–C(5)–C(50)
C(1)–C(5)–C(4)
1
DMSO. The H-NMR spectrum of 3 in CDCl3 shows
111.8(5)
107.5(5)
two sets of pseudotriplets for the cyclopentadienyl
protons at 5.63 and 5.27 ppm, a singlet for the –NMe2
protons at 2.65 ppm and two triplets for the (a)-CH2
and (b)-CH2N protons at 2.52 and 3.63 ppm,
respectively. Both the (a)-CH2 triplet at 2.52 ppm and
the –NMe2 singlet at 2.65 ppm are down field shifted
by ca. 0.1 and 0.46 ppm, respectively in comparison to
those of complex 1. The most significant shift
(Dl=0.69 ppm) however, is observed for the
(b)-CH2N protons adjacent to the nitrogen
coordination site of the metal. These differences
indicate a profound change in the environment of the
nitrogen atom in 3. The change in environment that
104.3(3)
C(100)–N(1)–C(101) 106.8(4)
Rh(1)–C(5)–C(50) 113.1(4)
1
caused the shift in the H-NMR signals of the ligand is
undoubtedly due to nitrogen coordination of the
rhodium atom. Additional evidence for the
intramolecular coordination of the dimethylamino
group arises from the change of the multiplicity
pattern for the signals of the methylene hydrogen
atoms (i.e. –CH2CH2N). In
1 they appear as
multiplets; here they show clear triplets. Corresponding
downfield shifts for the methylene and methyl groups
adjacent to the nitrogen atom are also observed in the
13C-NMR spectrum on passing from 1 to 3.
Final proof for the intramolecular coordination of
the –(CH2)2NMe2 side chain group to the Rh metal in
complex 3, is provided by X-ray crystal structure
analysis. Suitable crystals were grown by slow
diffusion of ether into a saturated dichloromethane
solution of 3 (see Section 3.1). This is the first reported
structure of a rhodium chelated compound with a
C5H4(CH2)2NMe2 ligand.
Fig. 1. Pathways towards the rhodium(III) complexes of [2-(dimethyl-
amino)ethyl]cyclopentadiene. (i) Cl2, Et2O; (ii) Cl2, CH2Cl2; (iii)
PPh3, CH2Cl2, 4 h; (iv) PPh3, CH3CN, 2 h; (v) NaH, CH3CN, 0°C.
On the other hand, the dimer 4 was obtained as an
orange–brown solid in an almost quantitative yield
(85%) by the passage of gaseous Cl2 through a
dichloromethane solution of 2. Complex 4 had a \M
(molar conductance) value of about 251 V−1 cm2
mol−1, in aqueous solutions [17], indicating possibly
hydrolysis of the terminal and bridging chloride anions.
The IR spectrum of 4 is similar to that of complex 3
except for the presence of a broad band at ca. 2650
[{h5-C5H4(CH2)2N(H)Me2}RhI(h4-cod)]+·(Cl)− (2) as
starting materials.
Both complexes 1 and 2 in ether and in CH2Cl2
react with Cl2 to give compounds 3 and 4, respectively.
Thus, the oxidative addition of gaseous Cl2 to an
etheral solution of 1 yielded a mixture of 3 [13] and 4
in approximately equal proportions. The cationic
complex 4 is very soluble in water while the neutral

290
A.I. Philippopoulos et al. / Journal of Organometallic Chemistry 582 (1999) 286–291
at 280 and 230 cm−1. These values are comparable to
the ones reported for the [h5-C5Me5RhIIICl2(PMe3)]
complex [19].
cm−1, indicating protonation of the dimethylamino
group at the side chain [2–4]. The far-IR spectrum
showed two rather broad bands at 282 and 251 cm−1
for both terminal and bridging Rh–Cl bonds [18]. This
complex is also stable under atmospheric conditions
and soluble in H2O, DMF and DMSO. In the 1H-
NMR spectrum of 4 in D2O the cyclopentadienyl
triplets are observed at 5.88 and 5.82 ppm, the (b)-
CH2N triplet of the side chain is at 3.56 ppm, the
(a)-CH2 triplet is at 2.69 ppm, and the –NMe2 singlet is
at 2.97 ppm. Due to protonation both the (b)-CH2N
triplet and the –NMe2 singlet are downfield shifted by
1.10 and 0.82 ppm, respectively in comparison to those
of the free ligand. In DMSO-d6, a broad singlet can be
seen at 10.64 ppm, assigned to the protonated amino
group (NH+), while the –NMe2 group protons appear
as a doublet with JNH–CH=4.8 Hz.
The dimer 4 reacted readily with PPh3 in acetonitrile
solution to give the corresponding mononuclear com-
plex 5 in a 68% yield (See Fig. 1). The molar conduc-
tance value of 150 V−1 cm2 mol−1 indicates a 1:1
electrolyte in CH3CN solution. The IR spectrum of 5
shows the typical metallocene skeletal vibrations at
3050, 2950, 1435 and 1035 cm−1. Moreover, the far-IR
spectrum showed two strong bands for terminal wRh–Cl
In complex 5 the resonance in the 31P-NMR spec-
trum is shown at 32.29 ppm, in the expected range, split
into a doublet JRh–P=138.65 Hz by coupling to the
1
rhodium center. On the other hand the H- and 13C-
NMR spectra of this compound are similar to those of
the dimer 4.
Upon treatment of the chloride salt 5 with a slight
excess of NaH in CH3CN the deprotonated complex 6
was produced as an orange solid in a 70% yield.
Complex 6 could also be prepared but in a lower yield
after the addition of PPh3 to a dichloromethane solu-
tion of 3. The spectroscopic data (i.e. IR, 1H-, 13C-
NMR) are similar to those of complex 5. Also, the
resonance in the 31P-NMR spectrum is shown at 32.48
ppm as a doublet due to coupling to the rhodium center
(JRh–P=133.95 Hz).
3.1. Description of structure
The molecular structure of 3 is shown in Fig. 2. The
molecule comprises a dichloro rhodium(III) unit which
is bonded to a pentahapto cyclopentadienyl ligand. The
Fig. 2. An ORTEP diagram of complex 3.

A.I. Philippopoulos et al. / Journal of Organometallic Chemistry 582 (1999) 286–291
291
tertiary amino fragment coordinates to the rhodium
References
in the remaining basal site of the overall ‘piano-stool’
conformation giving a five-membered ring. The metal
[1] For a recent review see (a) P. Jutzi, U. Siemeling, J. Organomet.
Chem. 500 (1995) 175. (b) C. Janiak, H. Schumann, Adv.
Organomet. Chem. 33 (1991) 291. (c) N.J. Coville, K.E. du Plooy,
W. Pickl, Coord. Chem. Rev. 116 (1992) 1.
[2] A.I. Philippopoulos, N. Hadjiliadis, C.E. Hart, B. Donnadieu,
P.C. Gowan, R. Poilblanc, Inorg. Chem. 36 (1997) 1842.
[3] A.I. Philippopoulos, R. Bau, R. Poilblanc, N. Hadjiliadis, Inorg.
Chem. 37 (1998) 4822.
[4] A.I. Philippopoulos, R. Poilblanc, N. Hadjiliadis, Inorg. Chim.
Acta 283 (1998) 24.
[5] J.C. Flores, J.C.W. Chien, M.D. Rausch, Organometallics 13
(1994) 4140.
,
nitrogen distance is 2.196(4) A. This distance is only
,
slightly shorter than that of 2.241(5) A reported for
the [{h5-C5Me4(CH2)2NMe2}RhI2] analogue [20]. The
lengths of the Rh–Cl bonds are 2.404(1) A within the
,
normal limits. Known cyclopentadienyl dichhloro–
rhodium(III) complexes show values slightly longer
(2.419(1)
for [{h5-C5Me4C6H4CH(Me)NMe2}Rh-
,
A
Cl2]) [21] but within the same range. The distance
between the rhodium and the ring atoms vary in the
[6] J.C. Flores, J.C.W. Chien, M.D. Rausch, Macromolecules 29
(1996) 8030.
,
range of 2.096(5)–2.160(5) A, while the angles be-
tween the three basal ligands are close to 90°. The
structure also reveals that the side chain is bent by
9.45° towards the rhodium. This value is very similar
to that mentioned in the [{h5-C5Me4(CH2)2-
NMe2}RhI2] analogue. Finally an interesting detail is
that the –(CH2)2NMe2 side chain is coordinated to
the rhodium in a zigzag fashion.
[7] M.S. Blais, J.C.W. Chien, M.D. Rausch, Organometallics 17
(1998) 3775.
[8] G. Giordano, R.H. Crabtree, R.M. Heintz, D. Forster, D.E.
Morris, Inorg. Synth. 28 (1990) 88.
[9] E. Prince, Mathematical Techniques in Crystallography, Springer-
Verlag, Berlin, 1982.
[10] N. Walker, D. Stuart, Acta Crystallogr. A39 (1983) 158.
[11] D.J. Watkin, J.R. Carruthers, P.W. Betteridge, CRYSTALS User
Guide, Chemical Crystallography Laboratory, University of Ox-
ford, Oxford, 1985.
[12] International Tables for X-Ray Crystallography, vol. IV, Kynoch
Press, Birmingham, UK, 1974.
4. Supplementary material
[13] Complex 3 was also obtained in a low yield from the reaction of
Na[C5H4(CH2)2NMe2] with anhydrous Na3RhCl6. To a suspen-
sion of Na3RhCl6 (178 mg, 0.50 mmol) in a mixture of CH3CN/
THF (1:1, v/v) (15 ml), a solution of NaC5H4(CH2)2NMe2 (80 mg,
0.50 mmol) in THF (10 ml) was added under nitrogen. The
solution was heated to reflux overnight, and the resulting mixture
was evaporated to dryness. After extraction with CH2Cl2 (3×5
ml) and evaporation of the solvent, complex 3 was obtained as an
orange solid, in ca. 10% yield.
[14] H.P. Fritz, Adv. Organomet. Chem. 1 (1964) 239.
[15] K. Nakamoto, Infrared and Raman Spectra of Inorganic and
Coordination Compounds, 3rd edn., Wiley, New York, 1978.
[16] M.A. Bennett, R.J. Clark, D.L. Milner, Inorg. Chem. 6 (1967)
1647.
For the structure of complex 3, tables of (a) struc-
ture determination summary; (b) complete bond
lengths; (c) complete bond angles; (d) atomic coordi-
nates and equivalent isotropic thermal parameters for
H atoms; (e) anisotropic thermal parameters and (f)
structure factors are available on request from the
authors.
Acknowledgements
[17] W.J. Geary, Coord. Chem. Rev. 7 (1971) 81.
[18] J.W. Kang, P.M. Maitlis, J. Organomet. Chem. 30 (1971) 127.
[19] K. Isobe, P.M. Bailey, P.M. Maitlis, J. Chem. Soc. Dalton Trans.
(1981) 2003.
[20] P. Jutzi, M.O Kristen, J. Dahlaus, B. Neumann, H.G. Stammler,
Organometallics 12 (1993) 2980.
The Platon Program for the bilateral scientific and
technological cooperation (France–Greece) supported
this research. A.I.P. is grateful to the French Minis-
te´re des Affaires Etrange´res for financial support. The
authors thank the Johnson Matthey Co, for the gen-
erous loan of rhodium chloride.
[21] B. Adams, N.A. Bailey, M. Colley, P.A. Schofield, C. White, J.
Chem. Soc. Dalton Trans. (1994) 1445.
.