Carbodiimide metal complexes and four-membered metallacycles from isocyanide metal precursors and aryl azides

Article abstract of DOI:10.1016/S0022-328X(97)00520-2

The reaction of C₅H₅Co(CNR)(PMe₃) (R=CH₂Ph, C₆H₁₁) with aryl azides ArN₃ leads to a mixture of products with the carbodiimide complexes C₅H₅Co(κ²-C,N-RN=C=NAr)(PMe₃) (3, 4) and the four-membered metallacycles C₅H₅Co[κ²-C,C-C(NR)N(Ar)C(NR)](PMe ₃) (5, 6) being the dominating species. For R=C₆H₁₁ and Ar=C₆H₅, an equilibrium between 6 and the isomer C₅H₅Co[κ²-C,C-C(NAr)N(R)C(NR)](PMe ₃) (7) has been confirmed by NMR spectroscopy. Treatment of C₅H₅Rh(CNMe)(PMe₃) with ArN₃ affords exclusively the carbodiimide complexes C₅H₅Rh(κ²-C,N-MeN=C=NAr)(PMe₃) (9, 10) in good yields. Methylation of 9 and 10 with CF₃SO₃Me, in the presence of NH₄PF₆, gives the cyclic carbene-type derivatives 11 and 12, of which the first has been characterized by X-ray crystal structure analysis.

Full text of DOI:10.1016/S0022-328X(97)00520-2

Ž
.
Journal of Organometallic Chemistry 551 1998 367–373
Carbodiimide metal complexes and four-membered metallacycles from
1
isocyanide metal precursors and aryl azides
)
H. Werner , G. Horlin, N. Mahr
¨
Institut fur Anorganische Chemie der UniÕersitat Wurzburg, Am Hubland, D-97074 Wurzburg, Germany
¨
¨
¨
¨
Received 18 July 1997
Abstract
Ž
.Ž
Ž
. Ž
carbodiimide complexes C5H5Co k -C,N-RN5C5NAr PMe3 3, 4 and the four-membered metallacycles C5H5Co k -C,C-
. Ž . Ž .xŽ . Ž
.
The reaction of C5H5Co CNR PMe3 RsCH2Ph, C6H11 with aryl azides ArN3 leads to a mixture of products with the
2
2
.Ž
. Ž
.
w
Ž
.
C NR N Ar C NR PMe3 5, 6 being the dominating species. For RsC6H11 and ArsC6H5, an equilibrium between 6 and the
isomer C5H5Co k -C,C-C NAr N R C NR PMe3 7 has been confirmed by NMR spectroscopy. Treatment of C5H5Rh CNMe PMe3
with ArN3 affords exclusively the carbodiimide complexes C5H5Rh k -C,N-MeN5C5NAr PMe3 9, 10 in good yields. Methylation
of 9 and 10 with CF3SO3Me, in the presence of NH4PF6, gives the cyclic carbene-type derivatives 11 and 12, of which the first has been
characterized by X-ray crystal structure analysis. q 1998 Elsevier Science S.A.
2
w
Ž
. Ž . Ž .xŽ .
. Ž .
Ž
.Ž
2
Ž
.Ž
. Ž
.
Keywords: Carbodiimide metal complexes; Metallacycles; Aryl azides; Isocyanide metal complexes; Ortho-metallation
1. Introduction
cles and reports on the preparation as well as on the
unusual ortho-metallation reaction of the half-
sandwich-type carbodiimide rhodium derivatives.
Following earlier work from our laboratory on cy-
cloaddition reactions of isocyanide cobalt compounds
Ž
.Ž
.
w x
C5H5Co CNR PMe3 with 1,2- and 1,3-dipoles 1 , we
recently found that the same starting materials react
with diazoalkanes to yield ketenimine cobalt derivatives
2. Results and discussion
w
x
2–4 . This prompted us to study the reactivity of both
The benzylisocyanide cobalt compound 1 reacts with
phenylazide in ether to give the corresponding carbo-
Ž
.Ž
.
C5H5Co CNR PMe3 and the analogous rhodium com-
plexes also toward azides RN3 with the hope that the
d iim id e
c o m p le x
5 H 5 C o k 2 -C , N -
Ž
C
X
nitrene fragment :NR, like the carbene unit: CRR in the
reactions with R RCN2 , would add to the M–CNR bond
to form a carbodiimide ligand. While the initial results
w ith
C5Me5Co CNMe PMe3 as starting materials seemed
to be in complete agreement with our strategy 5 , we
later discovered that besides the expected carbodiimide
cobalt complexes also four-membered metallacycles,
built up by the C5H5 PMe3 Co moiety, two isocyanide
molecules and a :NAr unit can be formed. The present
paper describes the characterization of these metallacy-
.Ž
.
w x
PhCH2 N5C5NPh PMe3 in moderate yield 5 . In
contrast, on treatment of 1 with p-tolylazide under the
same conditions a mixture of products is formed which
contains the carbodiimide derivate 3 ca. 60% and the
cobaltacycle 5 ca. 40% as the main components
X
Ž
. Ž .
C
Ž
5 H 5 C o C N C H 2 P h P M e 3
a n d
Ž
.
.Ž
.
Ž
.
w x
Ž
.
Scheme 1 . The analogous reaction of the cyclo-
hexylisocyanide complex 2 with phenylazide equally
Ž
.
affords a mixture of the carbodiimide compound 4 ca.
Ž
.
.
Ž
80% and the corresponding metallacycle 6 ca. 20% as
the dominating species. Attempts to separate the mix-
tures of 3–5 and 4–6 by column chromatography were
only partially successful. While the carbodiimide com-
plexes 3 and 4 could not be obtained in analytically
)
Corresponding author.
Ž
pure state and have therefore been characterized by
spectroscopic means , the metallacycles 5 and 6 were
1 Dedicated to Professor Peter Maitlis on the occasion of his 65th
birthday in recognition of his important contributions to organometal-
lic chemistry.
.
isolated as yellow crystalline solids in low yield. The
0022-328Xr98r$19.00 q 1998 Elsevier Science S.A. All rights reserved.

(
)
368
H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
Scheme 1.
most typical spectroscopic features of 5 and 6 are the
strong C5N stretching frequency at 1605 cmy1 in the
IR spectra and the doublet at d 164.0 for 5 and 158.6
has been confirmed by an experiment, carried out in an
NMR tube, which illustrated that upon addition of
CNC6 H11 to a mixture of 4 and 6 in C6 D6, the amount
of the metallacycle increased on the expense of the
carbodiimide species.
Ž
.
Ž
.
for 6 , assigned to the resonance of the CoCN carbon
atoms of the metallacycle, in the 13C NMR spectra. The
Ž
.
large P–C coupling constant ca. 30 Hz of this signal is
consistent with the structural proposal. We note that
In benzene solution, compound 6 is somewhat labile
and slowly rearranges to the unsymmetrical isomer 7
w x
w x
Ž
.
both Hessell and Jones 6 and Riera et al. 7 have
see Scheme 2 . After 45 days at room temperature, an
already reported the preparation of compounds of the
equilibrium is attained revealing a ratio 6:7 of ca. 45:55.
Diagnostic for the formation of a four-membered metal-
lacycle with two different NC6 H11 units is the 13C
NMR spectrum of 7 which displays two distinct signals
at d 63.2 and 54.3 for the NCH carbon atoms and eight
resonances at d ca. 35–25 for the CH2 carbon atoms of
the inequivalent cyclohexyl rings. In order to explain
the rearrangement of 6 to 7, we assume that after
breaking one of the N–C bonds of the four-membered
ring a zwitterionic intermediate A is generated which
2
w
Ž
. Ž X . Ž
.
x
general composition Ln M k -C,C-C NR N R C NR
Ž
.
MsRh, Fe , the spectroscopic data of which are in
good agreement with those of the cobalt complexes 5
and 6.
With regard to the mechanism of the formation of
compounds 5 and 6, we assume that they result from the
Ž
insertion of isocyanide produced by partial decomposi-
.
tion of the starting materials 1 and 2 into the Co–N
bond of the corresponding carbodiimide complex. This
Scheme 2.

(
)
H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
369
Scheme 3.
Ž . Ž . Ž .
cle rearrange thermally to the CoC S N Me C NR iso-
upon rotation around the Co–C bond forms the thermo-
dynamically somewhat more stable four-membered ring.
There is precedence for the conversion of 6 to 7 and
vice versa insofar as related cyclopentadienylcobalt
w x
mers 8 .
In contrast to the reaction of 1 and 2 with aryl azides,
the corresponding reaction of the isocyanide rhodium
complex 8 with PhN3 and p-MeC6 H4 N3 in ether at low
Ž
.
Ž
.
derivatives containing a CoC NMe SC NR metallacy-
Ž
.
Fig. 1. Molecular structure ORTEP diagram of the cation of compound 11.

(
)
370
H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
Table 1
temperatures proceeds cleanly and gives the carbo-
˚
Ž .
Ž
.
Ž
Selected bond distances A and bond angles deg of 11 with e.s.d.s
in parentheses
diimide compounds 9 and 10 as red-brown low-melting
.
Ž
.
solids in 60–70% yield Scheme 3 . Similar to the IR
spectra of 3 and 4, those of 9 and 10 also display a
strong N5C5N stretching frequency at 1720–1740
cmy1 which is indicative for the dihapto coordination
of the carbodiimide unit. This absorption is significantly
˚
Ž .
Bond distances A
Ž
.
Bond angles deg
Ž .
1.977 3
Ž .
78.6 1
Rh–C1
Rh–C4
Rh–P1
C1–Rh–C4
C1–Rh–P1
C4–Rh–P1
C1–N1–C9
C1–N2–C2
C1–N2–C3
C2–N2–C3
N1–C1–N2
Rh–C1–N2
Rh–C1–N1
Rh–C4–C9
Rh–C4–C5
N1–C9–C4
Ž .
Ž .
91.3 1
2.028 3
2.236 1
2.243 4
2.184 4
2.160 4
2.220 4
2.272 4
1.345 4
1.373 4
1.301 4
1.445 5
1.454 5
Ž .
Ž .
85.7 1
Ž .
Ž .
117.5 3
Rh–C10
Rh–C11
Rh–C12
Rh–C13
Rh–C14
N1–C1
N1–C9
N2–C1
N2–C2
N2–C3
shifted to a lower energy relative to both that of the free
Ž .
Ž .
121.3 3
y1
Ž
.
carbodiimide 2120–2140 cm
and that expected for
Ž .
Ž .
122.9 3
w x
an N-bonded ligand 9 . Further evidence for the coordi-
nation of a C,N-bonded moiety comes from the 13C
NMR spectra which possess a doublet of doublets at d
Ž .
Ž .
115.8 3
Ž .
Ž .
117.1 3
Ž .
Ž .
127.5 3
Ž .
Ž .
115.4 2
Ž
.
Ž
.
156.2 for 9 and 156.9 for 10 assigned to the central
carbon atom of the MeN5C5NAr unit. In particular,
the large Rh–C coupling constant of ca. 17.5 Hz sug-
gests that the carbodiimide is bonded via N and C to the
rhodium. The 13C NMR spectra of the cobalt com-
Ž .
Ž .
115.0 2
Ž .
Ž .
129.0 3
Ž .
Ž .
113.4 3
Ž
.
pounds 3 and 4 see Scheme 1 also display a resonance
Ž
.
Ž .
doublet due to P–C coupling at d 162.7 3 and 157.7
Ž .
cycle Rh–C1–N1–C9–C4 is almost perfectly planar
and the carbon atoms C5–C8 of the annelated ring are
located in the same plane. The dihedral angle between
the five- and the six-membered rings is 1.28. In agree-
ment with the carbene-like structure, the distance Rh–C1
is somewhat shorter than Rh–C4 and lies in the range of
Rh–C bond lengths found in other half-sandwich-type
carbene rhodium complexes 11–15 . A partial p-bond
contribution is also indicated in the C1–N1 and C1–N2
distances Table 1 which are expectedly longer than
that of a C5N double bond 16 but significantly shorter
than the N2–C2 and N2–C3 bonds. The distances be-
tween the metal and the cyclopentadienyl carbon atoms
differ slightly but overall agree with those of other
C5H5Rh complexes with a piano-stool configuration
4 , respectively, thus supporting the structural proposal.
The methylation of 9 and 10 takes an unexpected
course. While the analogous cobalt complex
2
Ž
.Ž
.
C5Me5Co k -C,N-MeN5C5NAr PMe3 react with
methyliodide to give the cationic species
2
w
Ž
.Ž
.
xq
C5 Me5Co k -C, N-Me2 N5C5NAr PMe3
, still
w
x
containing a CoCN three-membered ring, on treatment
of 9 and 10 with methyltriflate, in the presence of
NH4 PF6, the orthometallated compounds 11 and 12 are
formed. The ionic structure shown in Scheme 3 has
been confirmed by conductivity measurements which
are consistent with the presence of 1:1 electrolytes. In
the IR spectra of 11 and 12 the N5C5N stretch is
shifted by 160–180 cmy1 to lower wave numbers com-
pared with the precursors 9 and 10, which indicates that
in the methylated products the C5NR double bond
Ž
.
w
x
w
x
17–27 . Finally, we note that a cationic cobalt com-
pound with the same structure as that of 11 is known
1
character is significantly reduced. Since in the H NMR
but has been prepared on a completely different route
Ž
.
w
x
spectra of 11 and 12, two signals for the N CH3
28 .
2
Ž
.
protons of which only one is split into a doublet of
equal intensity are observed, we conclude that like in
w
x
other aminocarbene complexes 10 the rotation around
the C–NMe2 bond is strictly hindered. In the 13C NMR
spectra of 11 and 12, the resonance for the carbene-type
3. Experimental section
All experiments were carried out under an atmo-
sphere of argon by using Schlenk techniques. The start-
Ž
.
Ž
carbon atom appears at d 202.5 for 11 and 202.1 for
12 and that of the metal-bonded C atom of the aryl ring
at d 142.4 for 11 and 12 . Both signals show strong
Rh–C and P–C couplings. The presence of a NH
moiety in the five-membered RhCCNC ring of 11 and
.
w x
w x
w x
ing materials 1 5 , 2 3 and 8 29 were prepared by
published methods. IR: Perkin-Elmer 1420; NMR: Jeol
FX 90 Q and Bruker AMX 400. Equivalent conductiv-
ity L was measured in CH3NO2. Melting and decom-
position points were determined by DTA.
Ž
.
1
12 is shown by a broadend signal at d;8.4 in the H
NMR and a corresponding absorption at 3370–3375
cmy1 in the IR spectra.
(
)(
) ( )
3.1. Reaction of C5 H5Co CNCH2 Ph PMe3 1 with
In order to confirm the proposed structure for the
orthometallated compounds, an X-ray crystal structure
analysis of 11 was carried out. The ORTEP drawing
Fig. 1 reveals that the rhodium is coordinated in a
pseudo-octahedral fashion with the cyclopentadienyl
ligand occupying three coordination sites. The metalla-
p-MeC6 H4 N3
Ž
.
A solution of 295 mg 0.93 mmol of 1 in 20 ml of
ether was treated at y788C with 0.53 ml of a 1.74 M
Ž
.
Ž
.
solution 0.93 mmol of p-tolylazide in ether. A rapid
change of color from orange-red to dark green, accom-

(
)
H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
371
1
Ž
.
Ž
.
Ž
panied by the evolution of gas N2 , occurred. After the
solution was warmed to room temperature, the solvent
was removed in vacuo. The oily residue was dissolved
in 4 ml of ether and the solution was chromatographed
4: H NMR 90 MHz, C6 D6 : d 9.07–6.37 m; 5H;
.
Ž
.
Ž
.
C6 H5 , 4.48 s; 5H; C5H5 , 4.05 m; 1H; NCH , 2.32–
Ž
.
Ž
Ž
.
0.35 m; 10H; CH2 of C6 H11 , 0.70 d; J PH s9.7
13
.
Ž
.
Hz; 9H; PMe3 . C NMR 100.6 MHz, C6 D6 : d 157.7
Ž
.
Ž
Ž
.
.
Ž
Ž
on Al2O3 neutral, activity grade V, 5 cm column .
With ether, a green fraction was eluted which was
brought to dryness in vacuo. Due to the 1H NMR
spectrum, the oily green residue consisted besides some
impurities of ca. 60% of 3 and ca. 40% of 5. The
mixture of products was then extracted with 15 ml of
pentane and the residue recrystallized from ether–pen-
tane 1:3. Upon storing the solution at y788C for 12 h, a
yellow crystalline solid 5 was obtained. Yield 20 mg
4% ; dec. temp. 1518C. The pentane extract contained
mainly compound 3, which could not be separated from
d; J PC s13.3 Hz; CoCN , 150.9 s; ipso-C of
.
.
C6 H5 , 129.7, 129.1, 128.1, 122.0, 119.3 all s; C6 H5 ,
Ž
.
Ž
Ž
.
.
82.1 s; C5H5 , 64.9 d; J PC s2.7 Hz; NCH , 37.2,
Ž
Ž
.
Ž
36.1, 26.7, 25.8, 25.7 all s; CH2 of C6 H11 , 17.8 d;
.
Ž
.
.
J PC s27.5 Hz; PCH3 .
6: Anal. Found: C, 65.94; H, 8.37; N, 8.18.
C28 H41CoN3P calcd.: C, 66.00; H, 8.11; N, 8.25. IR
C6 H6 : n C5N 1605 cmy1 1H NMR 90 MHz,
.
Ž
Ž
.
Ž
.
.
Ž
.
Ž
Ž
.
C6 D6 : d 9.13–6.35 m, 5H; C6 H5 , 4.69 d, J PH s
Ž
.
.
Ž
.
Ž
0.4 Hz; 5H; C5H5 , 2.92 m; 2H; NCH , 1.82–0.86 m,
.
Ž
Ž
.
20H; CH2 of C6 H11 , 0.95 d; J PH s9.9 Hz; 9H;
13
.
Ž
.
Ž
Ž
small amounts of byproducts and was therefore charac-
PMe3 . C NMR 100.6 MHz, C6 D6 : d 158.6 d,
Ž
.
.
Ž
.
terized by spectroscopic techniques.
J PC s30.0 Hz; CoCN , 140.6 d; J PC s4.1 Hz;
3: IR C6 H6 : n N5C5N 1710 cm
.
1H NMR
y1
Ž
.
Ž
.
.
Ž
Ž
ipso-C of C6 H5 , 128.6, 127.9, 127.8, 123.8, 122.5 all
Ž
.
Ž
Ž
.
Ž
.
.
Ž
90 MHz, C6 D6 : d 8.06–6.94 m; 9H; C6 H5 and
s; C6 H5 , 84.4 d; J PC s2.0 Hz; C5H5 , 63.6 s, br;
.
Ž
.
Ž
.
.
Ž
C6 H4 , 5.41 s; 2H; NCH2 , 4.45 d; J PH s0.5 Hz;
NCH , 36.3, 36.2, 26.6, 25.5, 25.4 all s; CH2 of
.
Ž
.
Ž
Ž
.
.
.
Ž
Ž
.
.
5H; C5H5 , 2.14 s; 3H; C6 H4C H3 , 0.63 d; J PH s
C6 H11 , 19.8 d; J PC s30.2 Hz; PCH3 .
13
.
Ž
10.4 Hz; 9H; PMe3 . C NMR 100.6 MHz, C6 D6 : d
3.3. Partial rearrangement of 6 to 7
Ž
Ž
.
.
Ž
162.7 d; J PC s13.7 Hz; CoCN , 147.6, 143.9 both
.
s; ipso-C of C6 H5 and C6 H4 , 129.9, 129.5, 128.3,
Ž
.
A solution of 20 mg 0.04 mmol of 6 in 2 ml of
C6 D6 was stored in an NMR tube at room temperature.
After 14 d, a ratio of 6:7s60:40 was determined. After
45 d, the ratio 6:7 had been changed to 45:55. The
isomer 7 was characterized by spectroscopic techniques.
Ž
.
127.8, 126.4, 125.1, 121.9 all s; C6 H5 and C6 H4 ,
Ž
Ž
.
.
Ž
128.6 d; J PC s1.7 Hz; C6 H5 or C6 H4 , 82.2 d;
Ž
.
.
Ž
Ž
.
.
J PC s1.9 Hz; C5H5 , 60.1 d; J PC s2.8 Hz;
.
.
Ž
.
Ž
Ž
NCH2 , 21.1 s; C6 H4CH3 , 17.7 d; J PC s27.6 Hz;
PCH3 .
5: Anal. Found: C, 68.82; H, 6.38; N, 7.76.
C31H35CoN3P calcd.: C, 69.01; H, 6.54; N, 7.79. IR
1
y1
Ž
.
Ž
.
Ž
IR C6 H6 : n C5N 1575 cm . H NMR 90 MHz,
.
Ž
.
Ž
Ž
.
C6 D6 : d 9.14–6.75 m; C6 H5 , 4.55 d; J PH s0.4
.
Ž
.
Ž
Hz; C5H5 , 2.77 m; NCH , 2.22–0.67 m; CH2 of
C6 H6 : n C5N 1605 cmy1 1H NMR 90 MHz,
.
Ž
Ž
.
Ž
.
C6 H11 , 1.03 d; J PH 9.9 Hz; PMe3 . 13C NMR
.
Ž
Ž
.
.
.
.
Ž
Ž
.
C6 D6 : d 9.12–7.05 m; 14H; C6 H5 and C6 H4 , 4.68
Ž
Ž
.
Ž
.
100.6 MHz, C6 D6 : d 158.6 d; J PC s30.0 Hz;
Ž
.
Ž
.
.
s; 4H; NCH2 , 4.58 d; J PH s0.4 Hz; 5H; C5H5 ,
.
Ž
Ž
CoCN , 153.7 s; ipso-C of C6 H5 , 129.1, 128.5, 128.1,
Ž
.
Ž
Ž
.
.
2.10 s; 3H; C6 H4C H3 , 0.80 d; J PH s9.8 Hz; 9H;
.
Ž
Ž
.
123.2, 121.3 all s; C6 H5 , 84.1 d; J PC s2.0 Hz;
13
.
Ž
Ž
PMe3 . C NMR 100.6 MHz, C6 D6 : d 164.0 d;
.
Ž
.
C5H5 , 63.2, 54.3 both s; NCH , 36.5, 36.3, 30.8, 26.8,
Ž
.
.
Ž
.
J PC s29.8 Hz; CoCN , 143.6 s; ipso-C of C6 H4 ,
Ž
.
Ž
26.7, 26.6, 26.1, 25.7 all s; CH2 of C6 H11 , 20.0 d;
Ž
Ž
.
.
138.2 d; J PC s4.2 Hz; ipso-C of C6 H5 , 132.0,
Ž
.
.
J PC s30.1 Hz; PCH3 .
129.7, 128.7, 128.6, 128.1, 127.9, 127.3, 126.4, 123.6,
Ž
.
Ž
Ž
.
.
.
2
119.8 all s; C6 H5 and C6 H4 , 84.5 d; J PC s1.9
(
3 .4 . P rep a ra tio n o f C 5 H 5 R h k -C ,N -
MeN5C5 NPh PMe3
.
.
Ž
Ž
Ž
Ž
.
.
Ž
Hz; C5H5 , 59.4 d; J PC s1.2 Hz; NCH2 , 21.0 s;
)( ) ( )
9
C6 H4CH3 , 19.7 d; J PC s30.5 Hz; PCH3 .
Ž
.
A solution of 301 mg 1.06 mmol of 8 in 15 ml of
(
)(
) ( )
2 with
3.2. Reaction of C5 H5Co CNC6 H11 PMe3
PhN3
Ž
.
ether was treated at y788C with 115 ml 1.06 mmol of
phenylazide. A change of color from orange-yellow to
Ž
.
This reaction was performed analogously as de-
scribed in Section 3.1. using 552 mg 1.78 mmol of 2
and 195 ml. 1.78 mmol of phenylazide as starting
materials. The mixture of products, which was obtained
after column chromatography on Al2O3, consisted be-
sides some impurities of ca. 80% of 4 and ca. 20% of
6. The subsequent work-up procedure gave 6 as a
yellow crystalline solid. Yield 30 mg 3% ; dec. temp.
1408C. Compound 4 could not be separated from some
byproducts and was characterized by spectroscopic
techniques.
red-brown, accompanied by the evolution of gas N2 ,
occurred. The solution was warmed to room tempera-
ture, and the solvent was removed in vacuo. The oily
residue was extracted with 25 ml of pentane, the extract
was filtered, and the filtrate was concentrated to ca. 10
ml in vacuo. After the solution was stored at y788C,
red-brown crystals precipitated which became an oil
upon warming to ca. 108C. Yield 255 mg 64% . Anal.
Found: C, 50.41; H, 5.43; N, 7.40. C16 H22 N2 PRh
calcd.: C, 51.08; H, 5.89; N, 7.45. IR C6 H6 :
n N5C5N 1740, 1720 cm
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.
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1
y1
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H NMR 90 MHz,

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H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
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C6 D6 : d 7.78–6.68 m; 5H; C6 H5 , 4.85 dd; J PH
1.38 dd; J PH s11.4, J RhH s1.0 Hz; 9H; PMe3 .
13C NMR 100.6 MHz, CD3NO2 : d 202.5 dd;
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s1.1, J RhH s0.7 Hz; 5H; C5H5 , 3.42 d; J RhH
.
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s 0.3 Hz; 3H; NCH3 , 0.82 dd; J PH s 10.4,
J RhC s49.8, J PC s19.2 Hz; RhCN , 152.0 s;
13
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J RhH s1.1 Hz; 9H; PMe3 . C NMR 100.6 MHz,
C 2 of C6 H4 , 142.4 dd; J RhC s32.7, J PC s17.3
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C6 D6 : d 156.2 dd; J RhC s17.4, J PC s7.2 Hz;
Hz; ipso-C of C6 H4 , 141.6, 125.7, 122.9, 113.3 all s;
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RhCN , 152.3 s; ipso-C of C6 H5 , 128.6, 121.5, 120.0
C6 H4 , 93.2 dd; J PC sJ RhC s2.6 Hz; C5H5 ,
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all s; C6 H5 , 85.7 dd; J PC sJ RhC s3.4 Hz;
50.3, 38.4 both s; NCH3 , 18.6 dd; J PC s36.2,
J RhC s1.3 Hz; PCH3 . 31 P NMR 36.2 MHz,
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C5H5 , 43.3 s; NCH3 3,1 19.4 dd; J PC s30.6,
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J RhC s1.2 Hz; PCH3 . P NMR 36.2 MHz, C6 D6 :
CD3NO2 : d 10.2 d; J RhP s135.0 Hz; PMe3 ,
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d 8.0 d; J RhP s186.1 Hz .
y144.4 sept; J PF s707.2 Hz; PF6 .
2
2
(
[
(
C 5 H 5 R h k -C ,C -
3 .5 . P rep a ra tio n o f C 5 H 5 R h k -C ,N -
MeN5C5 NC6 H4-p-CH3 PMe3 10
3 .7 . P rep a ra tio n o f
)(
)( ) (
)
(
)
)] ( )
C NMe2 NHC6 H3 Me PMe3 PF6 12
Compound 10 was prepared as described for 9, using
Compound 12 was prepared as described for 11,
using 80 mg 0.20 mmol of 10, 30 ml 0.27 mmol of
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172 mg 0.60 mmol of 8 and 347 ml of a 1.74 M
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solution 0.60 mmol of p-tolylazide in ether as starting
methyltriflate and 34 mg 0.21 mmol of NH4 PF6 as
starting materials. A yellow-brown solid was isolated.
materials. A red-brown solid, which melts above ca.
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158C, was isolated. Yield 146 mg 62% . Anal. Found:
Yield 81 mg 72% , dec. temp. 2478C. Anal. Found: C,
C, 52.25; H, 6.40; N, 7.57. C17 H24 N2 PRh calcd.: C,
39.50; H, 4.88; N, 5.05. C18 H27 F6 N2 P2 Rh calcd.: C,
39.29; H, 4.95; N, 5.09. L 79 cm2 Vy1 moly1. IR
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52.32; H, 6.20, N, 7.18. IR C6 H6 : n N5C5N 1725
1
cmy1. H NMR 90 MHz, C6 D6 : d 7.77–6.96 m; 4H;
y1
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KBr : n NH 3370, n C5N 1560, n PF 840 cm
.
1
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C6 H4 , 4.91 dd; J PH s1.1, RhH s0.7 Hz; 5H;
H NMR 90 MHz, CD3NO2 : d 8.37 s, br; 1H; NH ,
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C5H5 , 3.48 d; J RhH s0.4 Hz; 3H; NCH3 , 2.13 s;
7.34 s, br; 1H; one H of C6 H3 , 6.85 m; 2H; two H of
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3H; C6 H4C H3 , 0.86 dd; J PH s10.4, J RhH s1.1
C6 H3 , 5.62 dd; J PH s1.2, J RhH s0.4 Hz; 5H,
13
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Hz; 9H; PMe3 . C NMR 100.6 MHz, C6 D6 : d 156.9
C5H5 , 3.62 s; 3H; NCH3 , 3.31 d; J PH s1.0 Hz;
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dd; J RhC s17.5, J PC s7.2 Hz; RhCN , 149.9 s;
3H; NCH3 , 2.26 s; 3H; C6 H3C H3 , 1.37 dd; J PH
13
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ipso-C of C6 H5 , 129.3, 128.9, 121.4 all s; C6 H5 ,
s11.4, J RhH s1.0 Hz; 9H; PMe3 . C NMR 100.6
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85.8 dd; J PC sJ RhC s3.3 Hz; C5H5 , 43.4 s;
MHz, CD3NO2 : d 202.1 dd; J RhC s49.4, J PC
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NCH3 , 20.9 s; C6 H4C H3 , 19.5 dd; J PC s29.9,
s19.1 Hz; RhCN , 149.6 s; C 2 of C6 H3 , 142.4 dd;
31
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J RhC s1.1 Hz, PCH3 . P NMR 36.2 MHz, C6 D6 :
J RhC s32.6, J PC s17.3 Hz; ipso-C of C6 H3 ,
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d 8.0 d; J RhP s187.6 Hz .
142.2 d; J PC s3.0 Hz, one C of C6 H3 , 132.5 s;
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C 5 of C6 H3 , 93.1 dd; J PC sJ RhC s2.4 Hz;
2
[
(
C 5 H 5 R h k -C ,C -
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3 .6 . P rep a ra tio n o f
C5H5 , 50.2, 38.3 both s; NCH3 , 21.1 s; C6 H3C H3 ,
18.6 d; J PC s36.6 Hz; PCH3 . 31 P NMR 36.2
(
)
)(
)]
( )
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C NMe2 NHC6 H4 PMe3 PF6 11
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MHz, CD3NO2 : d 10.2 d; J RhP s135.0 Hz; PMe3 ,
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A solution of 95 mg 0.25 mmol of 9 in 5 ml of
y144.4 sept; J PF s707.2 Hz; PF6 .
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ether was treated at y788C with 35 ml 0.31 mmol of
methyltriflate. A brown oily precipitate was formed
which was separated from the almost colorless mother
liquor. After the residue was washed twice with 5 ml
portions of ether, it was stirred with a solution of 45 mg
3.8. Crystal structure analysis of 11
Single crystals were grown by slow diffusion of ether
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into a solution of 11 in methanol–acetone 1:5 . Crystal
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0.28 mmol of NH4 PF6 in 3 ml of methanol. A light-
data from 25 reflections with 118-Q-148 : mono-
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brown solid precipitated which was filtered, washed
twice with 2 ml portions of methanol and dried in
vacuo. The solid was dissolved in 3 ml of methanol–
clinic, space group P21rc no. 14 , as8.196 1 A,
˚
˚
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Ž .
bs15.212 3 A, cs16.729 3 A, bs100.39 1 8, Vs
2051.5 6 A , Zs4, dcalcd s1.736 g cmy3, ms1.037
3
˚
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mmy1. Crystal size 0.2=0.3=0.4 mm3. Enraf Nonius
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acetone 1:5 , the solution was layered with 20 ml of
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ether and stored at 08C. After 12 h, yellow-brown
CAD4 diffractometer, Mo K a radiation 0.70930 A ,
graphite monochromator, Ts293 K, vrQ scan, max.
2Qs488; 3569 reflections measured, 3315 reflections
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crystals were obtained. Yield 100 mg 74% ; dec. temp.
2868C. Anal. Found: C, 38.01; H, 4.68; N, 5.18.
C17 H25F6 N2 P2 Rh calcd.: C, 38.08; H, 4.70; N, 5.22. L
w
independent, 3023 regarded as being observed I)
85 cm2 Vy1 moly1. IR C6 H6 : n NH 3375, n C5N
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x
2s I ; intensity data corrected for Lorentz and polar-
ization effects, empirical absorption correction applied,
minimum transmission 95.44%. The structure was
solved by direct methods; atomic coordinates were re-
1
y1
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1550, n PF 840 cm . H NMR 90 MHz, CD3NO2 :
d 8.44 s, br; 1H; NH , 7.52–6.69 m; 4H; C6 H4 , 5.64
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dd; J PH s1.2, J RhH s0.4 Hz; 5H; C5H5 , 3.64
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s; 3H; NCH3 , 3.34 d; J PH s1.0 Hz; 3H; NCH3 ,
fined by full-matrix least squares 278 parameters, unit

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H. Werner et al.rJournal of Organometallic Chemistry 551 1998 367–373
373
w x
Ž .
E.T. Hessell, W.D. Jones, Organometallics 11 1992 1496.
V. Riera, J. Ruiz, A. Tiripicchio, M. Tiripicchio Camellini, J.
6
w x
7
.
weights, Enraf Nonius SDP . The position of the hydro-
gen atom at N1 was taken from a difference Fourier
synthesis and refined by using the riding model. The
positions of the other hydrogen atoms were calculated
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.
Organomet. Chem. 327 1987 C5.
w x
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8
H. Werner, B. Strecker, J. Organomet. Chem. 413 1991 379.
B.M. Bycroft, J.D. Cotton, J. Chem. Soc., Dalton Trans. 1973
w x
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9
˚
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.
according to ideal geometry distance C–H 0.95 A .
1867.
w
w
w
x
10 H. Fischer, F.R. Kreissl, Transition Metal Carbene Complexes,
Verlag Chemie, Weinheim, 1983, pp. 70–72.
Rs0.0282, Rw s0.036; reflex:parameter ratio 11.16;
residual electron density q1.206ry0.294 e Ay3. De-
˚
x
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.
11 D.W. Macomber, R.D. Rogers, J. Organomet. Chem. 308 1986
353.
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.
tailed crystallographic data excluding structure factors
for the structure of 11 have been deposited with the
Cambridge Crystallographic Data Centre as supplemen-
tary publication no. CCDC100848. Copies of the data
can be obtained free of charge on application to the
Director, CCDC, 12 Union Road, Cambridge CB2 1EZ,
x
12 G. Erker, R. Lecht, Y.H. Tsay, C. Kruger, Chem. Ber. 120
¨
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1987 1763.
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13 G. Erker, Angew. Chem. 101 1989 411.
x
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14 G. Erker, Angew. Chem., Int. Ed. Engl. 28 1989 397.
x
15 G. Erker, M. Mena, U. Hoffmann, B. Menjon, J.L. Petersen,
´
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Organometallics 10 1991 291.
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UK fax: int. code q 1223 336-033; e-mail:
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16 G. Hafelinger, Chem. Ber. 103 1970 2902, and refs. therein.
¨
x
deposit@chemcrys.cam.ac.uk .
17 H. Werner, O. Kolb, R. Feser, U. Schubert, J. Organomet.
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Chem. 191 1980 283.
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18 H. Werner, J. Wolf, U. Schubert, Chem. Ber. 116 1983 2848.
x
19 H. Werner, W. Paul, R. Feser, R. Zolk, P. Thometzek, Chem.
Acknowledgements
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Ber. 118 1985 261.
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20 H. Werner, J. Wolf, U. Schubert, K. Ackermann, J. Organomet.
We thank the Volkswagen Stiftung and the Fonds der
Chemischen Industrie for financial support. We also
gratefully acknowledge the support of Mrs. R. Schedl
and Mr. C.P. Kneis elemental analyses and DTA and
Mrs. M.-L. Schafer and Dr. W. Buchner NMR mea-
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Chem. 317 1986 327.
x
21 J. Wolf, R. Zolk, U. Schubert, H. Werner, J. Organomet. Chem.
Ž
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340 1988 161.
x
22 H. Werner, L. Hofmann, W. Paul, U. Schubert, Organometallics
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7 1988 1106.
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23 H. Werner, W. Paul, W. Knaup, J. Wolf, G. Muller, J. Riede, J.
¨
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surements .
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Organomet. Chem. 358 1988 95.
x
24 H. Werner, U. Brekau, M. Dziallas, J. Organomet. Chem. 406
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1991 237.
x
25 H. Werner, O. Schippel, J. Wolf, M. Schulz, J. Organomet.
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Chem. 417 1991 149.
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26 H. Werner, U. Brekau, O. Nurnberg, B. Zeier, J. Organomet.
¨
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H. Werner, in: A. de Meijere, H. tom Dieck Eds. ,
Organometallics in Organic Synthesis, Springer, Berlin, 1987,
pp. 51–67 summarizing article .
B. Strecker, H. Werner, Angew. Chem. 102 1990 310.
B. Strecker, H. Werner, Angew. Chem., Int. Ed. Engl. 29 1990
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Chem. 440 1992 389.
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Ber. 129 1996 903.
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Chem. 308 1986 47.
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29 H. Werner, B. Heiser, Synth. React. Inorg. Met. Org. Chem. 15
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B. Strecker, G. Horlin, M. Schulz, H. Werner, Chem. Ber. 124
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1985 43.
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1991 285.
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¨
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