Carbenerhodium complexes of the half-sandwich-type: Synthesis, substitution, and addition reactions

Article abstract of DOI:10.1002/1521-3765(20001215)6:24<4461::AID-CHEM4461>3.0.CO;2-F

A series of carbenerhodium(I) complexes of the general composition [(η⁵-C₅H₅)Rh(=CRR′)(L)] (2a-2i) with R = R′ = aryl and L = SbiPr₃ or PR₃ has been prepared from the square-planar precursors trans-[RhCl(=CRR′)(L)₂] and NaC₅H₅ in excellent yields. Reaction of the triisopropylstibane derivative 2a, which contains a rather labile Rh-Sb bond, with CO, PMe₃, and CNR (R = Me, CH₂Ph, tBu) leads to the displacement of the SbiPr₃ ligand and affords the substitution products [(η⁵-C₅H₅)Rh-(=CPh₂)(L)]. (3-7). In contrast, treatment of the triisopropylphosphane compound 2c with CO and CNtBu leads to the cleavage of the Rh=CPh₂ bond and gives besides [(η⁵-C₅H₅)Rh(PiPr₃)(L)] (10, 12) by metal-assisted C-C coupling diphenylketene Ph₂C=C=O (11) or the corresponding imine Ph₂C=C=NtBu (13). While the reaction of 2a, c with C₂H₄ yields [(η⁵-C₅H₅)Rh(C₂H₄) (L)] (14, 15) and the trisubstituted olefin Ph₂C=CHCH₃ (16), treatment of 2a, c with RN₃ leads to the cleavage of both the Rh-EiPr₃ and Rh=CPh₂ bonds and gives the chelate complexes [(η⁵-C₅H₅)-Rh(κ²-RNNNNR )] (19, 20). The substitution products 3 (L = CO) and 4 (L = PMe₃) react with an equimolar amount of sulfur or selenium by addition of the chalcogen to the Rh=CPh₂ bond to generate the complexes [(η⁵-C₅H₅) Rh-(κ²-ECPh₂)(L)] (21-24) with thio- or selenobenzophenone as ligand. Similarly, treatment of 3 with CuCl affords the unusual 1:2 adduct [(η⁵-C₅H₅)(CO)Rh-(μ-CPh₂) (CuCl)₂] (25), which reacts with NaC₅H₅ to form [(η⁵-C₅H₅)(CO)Rh(μ-CPh₂)Cu (η⁵-C₅H₅)] (26). The molecular structures of 3 and 22 have been determined by X-ray crystallography.

Full text of DOI:10.1002/1521-3765(20001215)6:24<4461::AID-CHEM4461>3.0.CO;2-F

FULL PAPER
Carbenerhodium Complexes of the Half-Sandwich-Type:
Synthesis, Substitution, and Addition Reactions
Helmut Werner,* Peter Schwab, Elke Bleuel, Norbert Mahr, Bettina Windmüller, and
Justin Wolf[a]
Dedicated to Professor Dieter Sellmann on the occasion of his 60th birthday
Abstract: A series of carbenerhodiumꢀi)
complexes of the general composition
gives besides [ꢀh5-C5H5)RhꢀPiPr3)ꢀL)]
Rhꢀk2-RNNNNR)] ꢀ19, 20). The substi-
tution products 3 ꢀL ˆ CO) and 4 ꢀL ˆ
PMe3) react with an equimolar amount
of sulfur or selenium by addition of the
À
ꢀ10, 12) by metal-assisted C C coupling
5
ˆ
ˆ ˆ
[ꢀh -C5H5)Rhꢀ CRR')ꢀL)] ꢀ2a ± 2i) w ith diphenylketene Ph2C C O ꢀ11) or the
ˆ ˆ
R ˆ R' ˆ aryl and L ˆ SbiPr3 or PR3 has
corresponding imine Ph2C C NtBu
ˆ
been prepared from the square-planar
ꢀ13). While the reaction of 2a, c with
C2H4 yields [ꢀh5-C5H5)RhꢀC2H4)ꢀL)]
ꢀ14, 15) and the trisubstituted olefin
chalcogen to the Rh CPh2 bond to
precursors trans-[RhClꢀ CRR')ꢀL)2] and
generate the complexes [ꢀh5-C5H5)Rh-
ꢀk2-ECPh2)ꢀL)] ꢀ21 ± 24) with thio- or
selenobenzophenone as ligand. Similar-
ly, treatment of 3 with CuCl affords the
unusual 1:2 adduct [ꢀh5-C5H5)ꢀCO)Rh-
ꢀm-CPh2)ꢀCuCl)2] ꢀ25), which reacts with
NaC5H5 to form [ꢀh5-C5H5)ꢀCO)Rhꢀm-
CPh2)Cuꢀh5-C5H5)] ꢀ26). The molecular
structures of 3 and 22 have been deter-
mined by X-ray crystallography.
ˆ
NaC5H5 in excellent yields. Reaction of
ˆ
the triisopropylstibane derivative 2a,
Ph2C CHCH3 ꢀ16), treatment of 2a, c
À
which contains a rather labile Rh Sb
with RN3 leads to the cleavage of both
À
ˆ
bond, with CO, PMe3, and CNR ꢀR ˆ
Me, CH2Ph, tBu) leads to the displace-
ment of the SbiPr3 ligand and affords the
substitution products [ꢀh5-C5H5)Rh-
the Rh EiPr3 and Rh CPh2 bonds and
gives the chelate complexes [ꢀh5-C5H5)-
Keywords: carbene complexes
´
ˆ
ꢀ CPh2)ꢀL)] ꢀ3 ± 7). In contrast, treat-
carbonyl complexes
´
cyclopenta-
ment of the triisopropylphosphane com-
À
dienyl complexes ´ C C coupling ´
rhodium
pound 2c with CO and CNtBu leads to
ˆ
the cleavage of the Rh CPh2 bond and
PiPr3 also PiPr2Ph, PiPrPh2, PPh3, and PPh2Me could be
applied as displacing substrates and thus a manifold of
carbenerhodiumꢀi) complexes of the general composition
Introduction
In the context of our investigations on the reactivity of the
fascinating dimer [{RhClꢀPiPr3)2}2],[1] which led inter alia to a
series of organometallic cumulenes trans-[RhCl{ Cꢀ C)n-
RR'}ꢀPiPr3)2] ꢀn ˆ 1,[2] 2,[3] and 4[4]), we recently developed
also a convenient synthetic route to related rhodium carbenes
[5]
ˆ
trans-[RhClꢀ CRR')ꢀPR''3)2] was prepared. An important
ˆ
ˆ
observation of the original studies about the reactivity of
ˆ
trans-[RhClꢀ CRR')ꢀSbiPr3)2] was that not only the stibanes
but also the chloro and the carbene ligand could be replaced
by nucleophiles. If C2H4 or CO were used, for R ˆ R' ˆ Ph the
ˆ
trans-[RhClꢀ CRR')ꢀPiPr3)2]. However in order to obtain
À
these stable 16-electron species, the dimer [{RhClꢀPiPr3)2}2]
could not be used as starting material. The method of choice
was to treat the bisꢀstibane)rhodiumꢀi) compound trans-
[RhClꢀC2H4)ꢀSbiPr3)2] in the initial step with diazoalkanes
carbene did not yield a dimer or oligomer but gave the C C
coupling products shown in Scheme 1 in almost quantitative
yield.[5c]
The unusual and interesting behavior of the square-planar
ˆ
ˆ
R'RCN2 to form trans-[RhClꢀ CRR')ꢀSbiPr3)2] by displace-
ment of ethene and elimination of N2, and then substitute the
two rather weakly bound stibanes for phosphanes. Besides
compounds trans-[RhClꢀ CRR')ꢀL)2] with L ˆ SbiPr3 and
PR3 prompted us to also study in more detail the reactivity
of the corresponding half-sandwich-type complexes [ꢀh5-
ˆ
C5H5)Rhꢀ CRR')ꢀL)], of which for L ˆ PiPr3 the vinylidene
5
[6]
ˆ ˆ
[a] Prof. Dr. H. Werner, Dr. P. Schwab, Dr. E. Bleuel, Dr. N. Mahr,
Dr. B. Windmüller, Dr. J. Wolf
and allenylidene analogues [ꢀh -C5H5)Rhꢀ C CHR)ꢀL)]
5
[7]
ˆ ˆ ˆ
and [ꢀh -C5H5)Rhꢀ C C CPh2)ꢀL)] were known. Herein,
we describe the preparation of a family of these h5-cyclo-
pentadienylrhodium carbene derivatives, their reactions with
nucleophiles, and illustrate with some examples also the
Institut für Anorganische Chemie der Universität Würzburg
Am Hubland, 97074 Würzburg ꢀGermany)
Fax : ꢀ‡49)931-888-4605
E-mail: helmut.werner@mail.uni-wuerzburg.de
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H. Werner et al.
FULL PAPER
hindered. It should be mentioned that various attempts to
prepare the pentamethylcyclopentadienylrhodiumꢀi) deriva-
5
ˆ
tives [ꢀh -C5Me5)Rhꢀ CPh2)ꢀL)] ꢀL ˆ SbiPr3, PiPr3) from 1a
or 1c and LiC5Me5 or NaC5Me5 failed.
Ligand substitution reactions of the carbenerhodium7i) com-
plexes 2a and 2c: Similarly to the square-planar compound
1a,[5] also the related half-sandwich-type complex 2a contains
À
a labile Rh Sb bond and therefore the stibane ligand can
easily be displaced by CO, PMe3, and isocyanides ꢀScheme 3).
Scheme 1.
possibility of adding electron-deficient species such as sulfur,
À
selenium, or CuCl to the Rh C double bond.
Results and Discussion
Preparation of h5-cyclopentadienylrhodium7i) complexes with
diarylcarbenes as ligands: In contrast to the rhodium vinyl-
ˆ ˆ
idenes trans-[RhClꢀ C CHR)ꢀPiPr3)2], which are rather inert
toward lithium or sodium cyclopentadienyl, the square-planar
compounds 1a ± i react with NaC5H5 in THF at room temper-
ature to give the h5-cyclopentadienyl complexes 2a ± i
ꢀScheme 2) in good to excellent yield. After chromatographic
Scheme 3.
In pentane at room temperature, the reactions of 2a with
these Lewis bases proceed quite smoothly and afford the
corresponding h5-cyclopentadienyl derivatives 3, 4, and 5 ± 7
in 83 ± 89% yield. In contrast to PMe3, the more bulky
triisopropylphosphane appears to be unable to substitute the
stibane moiety and therefore after stirring a solution of 2a and
PiPr3 in pentane for 6 h the starting material 2a was re-
isolated. Typical spectroscopic features of 3 are the strong
nꢀCO) absorption at 1982 cmÀ1 in the IR spectrum and the
two low-field signals ꢀboth doublets) at d ˆ 286.7 and 192.7 for
the 13C nuclei of the carbene and the CO ligand in the
13C NMR spectrum. The resonance for the carbene-carbon
atoms CPh2 appears in the 13C NMR spectra of 5 ± 7 at around
d ˆ 268 ± 269 and is thus shifted somewhat up-field compared
with that of 3, which is in agreement with the stronger s-donor
character of the isocyanides.
Scheme 2.
workup, the analytically pure products were isolated as deeply
colored solids which are only moderately air-sensitive and
readily soluble in most common organic solvents ꢀwith the
exception of methanol). The 13C NMR spectra of 2a, b and
2d ± i display ꢀsimilarly to 2c[5c]) a resonance for the carbene
carbon atom in the low-field region at d ꢀ 250 ± 270, which
compared with the 16-electron precursors 1a ± i is shifted up-
field by about 45 ± 75 ppm. Like the signal for the cyclo-
The molecular structure of compound 3 is shown in
Figure 1. The molecule possesses the expected two-legged
À
piano-stool configuration with a Rh CO distance ꢀ1.844ꢀ4) Š)
that is about 0.04 Š longer than in related carbonylrhodiumꢀi)
complexes with a heteroatom-stabilized carbene ligand of the
Fischer type.[8] On the other hand, the Rh Ccarbene bond length
À
of 3 ꢀ1.906ꢀ3) Š) is somewhat shorter than in these com-
pounds ꢀ1.925ꢀ3) ± 1.994ꢀ7) Š),[8] which is in accord with the
general bonding scheme.[9] Compared with the data of 1a and
ˆ
pentadienyl carbon atoms, also the Rh C resonance is split
into a doublet of doublets due to 13C ± 31P and 13C ± 103Rh
coupling. The 1H NMR spectra of 2a, b and 2d, e exhibit only
one set of resonances for the protons of the diastereotopic
methyl groups of the isopropyl substituents, indicating that on
the NMR time scale ꢀin solution at room temperature) the
rotation around the metal ± carbene bond is not significantly
1c,[5] the Rh C1 distance in 3 is slightly longer, which could be
À
due to the presence of two strong donating stibane or
phosphane ligands in the square-planar precursors.
The reaction of 2a with diphenyl- and bisꢀp-tolyl)diazo-
À
methane, which was undertaken to find out whether a C C
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Chem. Eur. J. 2000, 6, No. 24

Half-Sandwich-Type Carbenerhodium Complexes
4461±4470
À
and the ketenimine 13 are formed by C C coupling in the
coordination sphere of rhodium.
The diphenylcarbene complexes 2a and 2c also react even
at room temperature with ethene. In this case, instead of the
stibane or phosphane ligand the carbene unit is displaced and
besides the ethene half-sandwich-type complex 14 or 15,
respectively, the trisubstituted olefin 16 is generated
ꢀScheme 5). This olefin is formally built up by two carbene
Figure 1. Molecular structure of 3. Principal bond lengths [Š] and
À
angles [8] ꢀwith estimated standard deviations in parentheses): Rh C1
À
À
À
À
1.906ꢀ3), Rh C14 1.844ꢀ4), C1 C2 1.485ꢀ4), C1 C8 1.482ꢀ4), C14 O
À
À
À
À
1.137ꢀ4), Rh C15 2.264ꢀ4), Rh C16 2.260ꢀ4), Rh C17 2.253ꢀ4), Rh C18
À
2.235ꢀ4), Rh C19 2.269ꢀ4); C1-Rh-C14 92.53ꢀ14), C2-C1-C8 112.4ꢀ2), Rh-
C1-C2 119.34ꢀ19), Rh-C1-C8 128.3ꢀ2).
Scheme 5.
coupling between the carbene ligand and the CR2 fragment of
the substrate occurs, followed an unexpected pathway. Instead
of an olefin Ph2C CR2 or a bisꢀcarbene) complex [ꢀh5-
fragments, one originating from the CPh2 unit of 2a, c and the
other from ethene. There is, however, a difference between
the square-planar precursors 1a, c and the cyclopentadienyl
compounds 2a, c in the behavior toward C2H4 insofar, as 1c
reacts with ethene to give 16, while treatment of 1a with C2H4
ˆ
C5H5)RhꢀCPh2)ꢀCR2)], obtained by substitution of SbiPr3 for
CR2, the respective diazine 8 or 9 was formed. After column
chromatography of the crude product, besides the diazine
most of the starting compound 2a was re-isolated. With
regard to the mechanism of the reaction of 2a with R2CN2, w e
assume that in the initial step a highly labile 1:1 adduct of the
18-electron half-sandwich-type complex 2a and CR2 is
generated, which reacts with a second molecule of R2CN2 to
affords the isomer CH2 CHCHPh2 as the main product.[5] We
ˆ
note that in neither case, with 1a, c or with 2a, c and C2H4 as
starting materials, another isomer of 16, namely 1.1-diphe-
nylcyclopropane, is formed. In addition it should be men-
tioned that the ethene complex 14 is accessible not only from
2a and excess C2H4 but also from the precursors 17 or 18 and
NaC5H5 ꢀsee Scheme 5).
À
give the C N coupling product.
The reaction of the triisopropylphosphane compound 2c
with CO and CNtBu did not lead to the displacement of PiPr3
but took a different course. Instead of 3 and 7 ꢀsee Scheme 3),
the carbonyl and isocyanide derivatives 10[10] and 12 were
formed ꢀScheme 4). As the organic products, diphenylketene
A mechanistic proposal for the formation of 16 from 2a, c
and C2H4 is outlined in Scheme 6. In agreement with earlier
results,[5] we assume that in the initial stage of the reaction
Scheme 4.
11 and N-tert-butylketenimine 13 were obtained. They were
separated from the metal-containing compounds by column
chromatography and identified by their IR and 13C NMR
spectra. It is quite noteworthy that despite the difference in
the electronic configuration between 1a, c on one hand and
2a, c on the other, the compounds 1c and 2c behave
completely analogously toward CO and CNtBu. Since tetra-
phenylethene, which is produced from CPh2 generated in
situ,[11] could not be detected as a by-product in the reactions
of 2c with CO and CNtBu, we assume that both the ketene 11
Scheme 6.
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H. Werner et al.
FULL PAPER
both the carbene CPh2 and ethene are coordinated to
rhodium. Although the proposed intermediate A is a 20-
electron species, we prefer not to exclude route ꢀa) since it is
known that ligand substitution reactions of half-sandwich-
type rhodiumꢀi) complexes followan associative mecha-
nism.[12] The next step either on path ꢀa) or ꢀb) could be the
formation of a metallacyclobutane ꢀB or B*), which, via a b-H
shift, should afford a ꢀh3-allyl)hydridorhodiumꢀiii) intermedi-
ate. Either C or C* could then react by reductive coupling of
the hydrido ligand and the less shielded CH2 carbon atom of
the allylic moiety to generate 16. We note that this mecha-
nistic scheme is in line with the original hypothesis for the
rhodium-catalyzed formation of the trisubstituted olefin 16
from ethene and free diphenyldiazomethane which involves a
plexes 3 and 4 equally react with sulfur and selenium by attack
À
of the chalcogen at the Rh C double bond. After stirring a
solution of 3 or 4 with an equimolar amount of sulfur or
selenium in benzene, followed by column chromatography of
the reaction mixture, the compounds 21 ± 24 are obtained as
light yellowꢀ 21), light brown ꢀ22), or orange-yellowꢀ 23, 24)
solids in 65 ± 95% yield ꢀScheme 8). Both the elemental
[13]
ˆ
labile Rhꢀ CPh2) compound as an intermediate.
Attempts to connect a carbene and a nitrene fragment in
the coordination sphere of rhodium and generate a ketimine
ˆ
À
Ph2C NR by C N coupling led to an unexpected result. If the
starting materials 2a or 2c are treated with phenyl- or p-
tolylazide in pentane, instead of an addition of the azide or the
À
corresponding nitrene to the Rh C double bond the displace-
ment of both the carbene and the stibane or phosphane
ligands takes place. After chromatographic workup, the
products 19 and 20 ꢀsee Scheme 7) are obtained as red,
Scheme 8.
analyses and the mass spectra of 21 ± 24 indicate that half-
sandwich-type rhodium complexes with thio- or selenobenzo-
phenone as ligands were formed. The 13C NMR spectra of
21 ± 24 display a resonance for the ECPh2 carbon atom at d ꢀ
79 ± 96 which is significantly shifted upfield ꢀby 175 ± 195 ppm)
compared with the signal of the CPh2 carbon atom of the
carbene precursor. Since there is also a dramatic difference in
the chemical shift for the signal of the 13C nuclei of SCPh2 in
21 ꢀd ˆ 93.3) and 23 ꢀd ˆ 79.1) on one hand and of free
thiobenzophenone ꢀd ˆ 240.1)[19] on the other, we assume that
the bonding between rhodium and ECPh2 is best represented
by a three-membered ring structure as shown in Scheme 8.
This proposal is supported not only by the NMR data but also
by the mass spectra of 21 ± 24 in which the peak for the
Scheme 7.
moderately air-stable solids in about 70% yield. The elemen-
tal analyses, the mass spectra, and also the NMR spectro-
scopic data confirm that besides the cyclopentadienyl ring
only the fragment N4R2 ꢀR ˆ Ph, p-Tol) is coordinated to
rhodium. There is precedence for the formation of tetraaza-
diene complexes of the general composition [ꢀh5-C5R5)Mꢀk2-
R'NNNNR')] from half-sandwich-type precursors [ꢀh5-
C5R5)MꢀL)2] and R'N3 insofar as both Nakamura and
Otsuka[14] and Trogler and co-workers[15] found that [ꢀh5-
C5H5)CoꢀCO)2] reacts with organic azides R'N3 to afford the
compounds [ꢀh5-C5H5)Coꢀk2-R'NNNNR')] by displacement
of the two CO ligands. Moreover, we observed that also the
‡
fragment ion [ꢀC5H5)RhꢀECPh2)] appears with relative high
intensity. In this context we note that to the best of our
knowledge only one other type of transition metal complexes
with SeCPh2 as ligand, namely [Mꢀk2-SeCPh2)ꢀCO)5] ꢀM ˆ Cr,
W) is known and has been prepared from the corresponding
metal diphenylcarbenes and phenylisoselenocyanate.[20]
Moreover, it should be mentioned that analogously to 4 the
triisopropylphosphane counterpart 2c also reacts with an
equimolar amount of sulfur to afford the corresponding
thiobenzophenonerhodium complex [ꢀh5-C5H5)RhꢀSCPh2)-
ꢀPiPr3)] which however is rather labile and rapidly decom-
poses in solution or during chromatographic workup.
bisꢀtrimethylphosphane)cobalt
derivative
[ꢀh5-C5Me5)-
CoꢀPMe3)2] upon treatment with PhN3 gives [ꢀh5-C5Me5)-
Coꢀk2-PhNNNNPh)].[16] The general experience is that tet-
raazadienes possess relatively strong p-acceptor properties
and are thus able to stabilize electron-rich molecular frag-
ments such as [ꢀh5-C5R5)Co], [ꢀh5-C5H5)Rh], etc.[17]
Addition reactions of the carbenerhodium7i) complexes 3 and
4: Similarly to the vinylidene compounds [ꢀh5-C5H5)Rh-
The X-ray crystal structure analysis of 22 ꢀFigure 2)
confirms the linkage of selenobenzophenone through sele-
nium and carbon to the metal center. The coordination
ˆ ˆ
ꢀ C CHR)ꢀPiPr3)], which were shown to undergo addition
reactions with electrophilic substrates,[2c, 18] the carbene com-
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Half-Sandwich-Type Carbenerhodium Complexes
4461±4470
Since the signal of the CPh2 carbon atom is shifted upfield by
about 70 ppm compared to that of 3, we assume that the
carbene occupies a bridging position and thus for 25 a
structure like A or B seems to be possible.
The reaction of 25 with excess NaC5H5 in THF affords the
substitution product 26 which, according to the analytical
data, contains rhodium and copper not in the ratio of 1:2 but
1:1. In agreement with the structural proposal, which is shown
1
in Scheme 8, both the H and 13C NMR spectra of 26 display
two signals for the protons and the carbon nuclei of the
cyclopentadienyl ligands of which in either case only one is
1
split into a doublet. Therefore, this signal ꢀin the H NMR
Figure 2. Molecular structure of 22. Principal bond lengths [Š] and angles
spectrum at d ˆ 4.97 and in the 13C NMR spectrum at d ˆ 90.3)
can be assigned to the C,H atoms of the five-membered ring
bonded to rhodium. An analogous compound in which the
À
[8] ꢀwith estimated standard deviations in parentheses): Rh Se 2.4421ꢀ10),
À
À
À
À
Rh C1 2.152ꢀ5), Rh C14 1.865ꢀ8), Rh C15 2.193ꢀ8), Rh C16 2.229ꢀ8),
À
À
À
À
Rh C17 2.267ꢀ8), Rh C18 2.222ꢀ9), Rh C19 2.230ꢀ8), Se C1 1.908ꢀ5),
unsaturated carbene C CH2 bridges a ꢀh5-C5H5)RhꢀPiPr3)
À
À
À
O C14 1.128ꢀ10), C1 C2 1.506ꢀ10), C1 C8 1.510ꢀ8); Se-Rh-C1 48.58ꢀ14),
Rh-Se-C1 57.75ꢀ16), Rh-C1-Se 73.67ꢀ18), Se-Rh-C14 89.6ꢀ2), Rh-C14-O
176.0ꢀ7), C1-Rh-C14 93.7ꢀ3), Se-C1-C2 118.4ꢀ4), Se-C1-C8 115.8ꢀ4), C2-
C1-C8 113.0ꢀ5), Rh-C1-C2 110.9ꢀ4), Rh-C1-C8 119.9ꢀ4).
ˆ
and a ꢀh5-C5H5)Cu unit has been obtained from the respective
5
ˆ
precursor
NaC5H5.[18b]
[ꢀh -C5H5)ꢀPiPr3)Rhꢀm-C CH2)CuCl]
and
geometry around the rhodium center can be described as
pseudo-trigonal planar with the carbon atom C14, the mid-
point of the cyclopentadienyl ring, and the centroid of the
Conclusion
À
Se C1 bond at the corners. The two planes ꢀRh,Se,C1) and
ꢀC14,Rh,Se) lie nearly perpendicular to the plane formed by
The work presented herein has shown that half-sandwich-type
complexes of the general composition [ꢀh5-C5H5)Rh-
the three carbon atoms C1, C2, and C8. The bond length
À
ˆ
Se C1 ꢀ1.908ꢀ5) Š) is almost identical to that in the related
ꢀ CRR')ꢀL)], where R and R' is aryl and L a two-electron
selenoaldehyde complex [ꢀh5-C5H5)Rhꢀk2-SeCHMe)ꢀPiPr3)]
ꢀ1.917ꢀ5) Š)[21] and only slightly longer than that in the
tungsten compound [WꢀCO)5ꢀk2-SeCHPh)] ꢀ1.86ꢀ2) and
donor ligand, are easily accessible and offer a rich chemistry.
While the compound with R ˆ R' ˆ Ph and L ˆ SbiPr3 reacts
smoothly with CO, PMe3, and isocyanides by substitution of
1.88ꢀ2) Š)[22]. Compared with SeꢀCH3)2 ꢀ1.98ꢀ1) Š)[23] and
both Se CH2 and Se CHMe ꢀ1.758ꢀ1) Š),
the stibane ligand, the Rh L bond in the corresponding
À
[24]
ˆ
ˆ
the distance
À
complex with L ˆ PiPr3 is quite stable. Therefore, treatment of
5
À
ˆ
Se C1 in 22 corresponds more to that of a carbon selenium
[ꢀh -C5H5)Rhꢀ CPh2)ꢀPiPr3)] with CO and CNtBu does not
5
ˆ
single bond which is in agreement with the proposed
lead to [ꢀh -C5H5)Rhꢀ CPh2)ꢀCX)] ꢀX ˆ O, NtBu) but instead
5
À
À
selenometallacyclopropane structure. Besides the Se C1
gives [ꢀh -C5H5)RhꢀCX)ꢀPiPr3)] and, by metal-assisted C C
À
À
ˆ ˆ
bond length, also the distances Rh Se and Rh C1 as well as
the bond angles Rh-Se-C1, Rh-C1-Se, and Se-Rh-C1 are quite
similar to that in [ꢀh5-C5H5)Rhꢀk2-SeCHMe)ꢀPiPr3)].[21] The
bond lengths Rh C14 and C14 O in 22 are virtually the same
as in the carbene complex 3 which means that the addition of
coupling, diphenylketene Ph2C C O and the related keten-
imine Ph2C C NtBu. Most remarkably, the reactions of
ethene with both [ꢀh -C5H5)Rhꢀ CPh2)ꢀSbiPr3)] and [ꢀh -
C5H5)Rhꢀ CPh2)ꢀPiPr3)] also occur by cleavage of the
ˆ ˆ
5
5
ˆ
À
À
ˆ
ˆ
Rh CPh2 bond and yield besides the ethene compounds
[ꢀh5-C5H5)RhꢀC2H4)ꢀL)] ꢀL ˆ SbiPr3, PiPr3) the trisubstituted
À
the selenium to the Rh C double bond has nearly no
influence on the bonding between rhodium and CO.
ˆ
olefin Ph2C CHCH3. In contrast to CO, CNtBu, and C2H4,
Following earlier attempts to generate mixed-metal rho-
dium ± copper compounds with bridging vinylidene li-
gands,[18b] we also investigated the reactivity of the carbene
complex 3 toward CuCl. Treatment of a solution of 3 in
benzene with one equivalent of CuCl gave, after stirring for
2 h at room temperature, a reaction mixture which still
contained considerable amounts of the starting material 3.
Addition of a second equivalent of CuCl led to the formation
of a clear solution from which after column chromatography a
deep red, moderately air-stable solid was isolated in 87%
yield. Both the elemental analysis and the mass spectrum
confirmed that instead of the expected 1:1 the corresponding
1:2 adduct 25 of 3 and CuCl was obtained ꢀsee Scheme 8). The
13C NMR spectrum of 25 displays in the low-field region two
resonances ꢀboth doublets) at d ˆ 217.0 and 189.9 which show
aryl azides RN3 react with the carbenerhodium precursors by
displacement of the carbene and the stibane or phosphane
ligand to give the chelate complexes [ꢀh5-C5H5)Rhꢀk2-
RNNNNR)] in excellent yields.
ˆ
The Rh CPh2 unit can also be used as building block for the
generation of molecules such as SCPh2 or SeCPh2 which is
illustrated by the formation of [ꢀh5-C5H5)Rhꢀk2-ECPh2)ꢀCO)]
and [ꢀh5-C5H5)Rhꢀk2-ECPh2)ꢀPMe3)] ꢀE ˆ S, Se) from [ꢀh5-
5
ˆ
ˆ
C5H5)Rhꢀ CPh2)ꢀCO)] or [ꢀh -C5H5)Rhꢀ CPh2)ꢀPMe3)] and
equimolar amounts of sulfur or selenium, respectively. More-
over, CuCl also adds to the Rh CPh2 bond of the carbon-
ylꢀcarbene)rhodium complex and yields a heterobimetallic
compound with the carbene in a bridging position. Finally, we
note that PF3 behaves completely differently toward [ꢀh5-
C5H5)Rhꢀ CPh2)ꢀPiPr3)] than CO and gives by migratory
insertion of the carbene ligand into a C H bond the ring-
substituted product [ꢀh5-C5H4CHPh2)RhꢀPF3)ꢀPiPr3)].
ˆ
ˆ
a rather large 13C ± 103Rh coupling and are assigned to the 13
nuclei of the carbene and the carbonyl ligand, respectively.
C
À
[25]
Chem. Eur. J. 2000, 6, No. 24
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0624-4465 $ 17.50+.50/0
4465

H. Werner et al.
FULL PAPER
stirred for 15 min at room temperature, the volatile components were
removed in vacuo. The oily residue was extracted with pentane ꢀ20 mL),
and the extract concentrated to 2 mL in vacuo. The solution was
chromatographed on Al2O3 ꢀneutral, activity grade V, height of column
2.5 cm). With pentane, a blue fraction was eluted, which after removal of
the solvent gave a blue solid. Recrystallization from methanol/pentane ꢀ2/
1.5 mL) at À208C gave blue crystals, which were separated from the
mother liquor and dried; yield 57 mg ꢀ80%); m.p. 858C ꢀdecomp); 1H NMR
ꢀC6D6, 400 MHz): d ˆ 7.73, 7.69 ꢀboth m, 2H each; ortho-H of C6H5 and
C6H4CH3), 7.18 ± 6.76 ꢀm, 5H; meta- and para-H of C6H5 and meta-H of
C6H4CH3), 5.00 ꢀbr s, 5H; C5H5), 2.02 ꢀs, 3H; C6H4CH3), 1.51 ꢀbr sept,
JꢀH,H) ˆ 7.2 Hz, 3H; PCHCH3), 0.99 ꢀdd, JꢀP,H) ˆ 13.1, JꢀH,H) ˆ 7.2 Hz,
18H; PCHCH3); 13C NMR ꢀC6D6, 100.6 MHz): d ˆ 261.4 ꢀdd, JꢀRh,C) ˆ
Experimental Section
All experiments were carried out under an atmosphere of argon by Schlenk
techniques. The starting materials 1a ± d, 1 f ± i,[5c] 2c,[5c] 17,[26] and 18[26] were
prepared as described in the literature. NMR spectra were recorded at
room temperature on Bruker AC 200 and Bruker AMX 400 instruments,
and IR spectra on a Perkin-Elmer 1420 or an IFS 25 FT-IR infrared
spectrometer. Melting points were measured by differential thermal
analysis ꢀDTA). Abbreviations used: s, singlet; d, doublet; t, triplet; vt,
virtual triplet; sept, septet; m, multiplet; br, broadened signal; N ˆ
3JꢀP,H)‡5JꢀP,H) or JꢀP,C)‡3JꢀP,C).
1
ˆ
ˆ
trans-[RhCl{ C7p-Tol)2}7PiPr3)2] 71e): A solution of trans-[RhCl{ Cꢀp-
Tol)2}ꢀSbiPr3)2][5c] ꢀ149 mg, 0.18 mmol) in pentane ꢀ10 mL) was treated with
PiPr3 ꢀ68 mL, 0.36 mmol) and stirred for 30 min at room temperature. The
reaction mixture was concentrated to about 2 mL in vacuo, and the solution
was chromatographed on Al2O3 ꢀneutral, activity grade V, height of column
5 cm). With pentane, a green fraction was eluted, which was concentrated
to about 5 mL in vacuo and then stored for two days at À788C. Green
crystals precipitated, which were separated from the mother liquor and
dried; yield 112 mg ꢀ96%); m.p. 698C ꢀdecomp); 1H NMR ꢀC6D6,
400 MHz): d ˆ 8.00 ꢀm, 4H; ortho-H of C6H4CH3), 6.85 ꢀm, 4H; meta-H
of C6H4CH3), 2.38 ꢀm, 6H; PCHCH3), 1.80 ꢀs, 6H; C6H4CH3), 1.22 ꢀdvt,
N ˆ 13.2, JꢀH,H) ˆ 6.7 Hz, 36H; PCHCH3); 13C NMR ꢀC6D6, 100.6 MHz):
ˆ
51.5, JꢀP,C) ˆ 17.2 Hz; Rh C), 145.9, 144.7 ꢀboth s; ipso-C of C6H5 and
C6H4CH3), 135.6 ꢀs; para-C of C6H4CH3), 131.9, 130.4, 130.1, 129.1, 128.3
ꢀall s; ortho-, meta- and para-C of C6H5 and ortho- and meta-C of
C6H4CH3), 86.1 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ 3.2 Hz; C5H5), 26.7 ꢀd, JꢀP,C) ˆ
19.1 Hz; PCHCH3), 21.7 ꢀs; C6H4CH3), 20.4 ꢀs; PCHCH3); 31P NMR ꢀC6D6,
162.0 MHz): d ˆ 58.0 ꢀd, JꢀRh,P) ˆ 244.1 Hz); elemental analysis for
C28H38PRh ꢀ508.5): calcd: C 66.14, H 7.53; found: C 66.02, H 7.39.
5
ˆ
[7h -C5H5)Rh{ C7p-Tol)2}7PiPr3)] 72e): Compound 2e was prepared as
described for 2d, from 1e ꢀ74 mg, 0.11 mmol) and NaC5H5 ꢀ50 mg,
0.56 mmol) in THF ꢀ10 mL); yield 50 mg ꢀ84%). Deep blue crystals; m.p.
368C ꢀdecomp); 1H NMR ꢀC6D6, 400 MHz): d ˆ 7.76 ± 6.79 ꢀm, 8H; ortho-
and meta-H of C6H4CH3), 5.05 ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.9 Hz, 5H; C5H5),
1.92 ꢀs, 6H; C6H4CH3), 1.54 ꢀbr sept, JꢀH,H) ˆ 7.2 Hz, 3 H ; PCHCH3), 1.00
ꢀdd, JꢀP,H) ˆ 13.0, JꢀH,H) ˆ 7.2 Hz, 18H; PCHCH3); 13C NMR ꢀC6D6,
ˆ
d ˆ 317.0 ꢀdt, JꢀRh,C) ˆ 38.1, JꢀP,C) ˆ 8.3 Hz; Rh C), 160.0 ꢀs; ipso-C of
C6H4CH3), 158.3 ꢀs; para-C of C6H4CH3), 131.0, 130.1, 129.3, 129.0, 128.8,
128.6, 128.3, 126.9 ꢀall s; ortho- and meta-C of C6H4CH3), 25.3 ꢀvt, N ˆ
17.8 Hz; PCHCH3), 22.6 ꢀs; C6H4CH3), 20.7 ꢀs; PCHCH3); 31P NMR ꢀC6D6,
162.0 MHz): d ˆ 23.3 ꢀd, JꢀRh,P) ˆ 171.2 Hz); elemental analysis for
C33H56ClP2Rh ꢀ653.1): calcd: C 60.69, H 8.64; found: C 61.00, H 8.48.
ˆ
100.6 MHz): d ˆ 262.0 ꢀdd, JꢀRh,C) ˆ 50.2, JꢀP,C) ˆ 17.2 Hz; Rh C), 142.0
ꢀs; ipso-C of C6H4CH3), 136.0 ꢀs; para-C of C6H4CH3), 131.9, 128.9, 128.3,
127.7 ꢀall s; ortho- and meta-C of C6H4CH3), 86.2 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ
2.5 Hz; C5H5), 26.8 ꢀd, JꢀP,C) ˆ 20.3 Hz; PCHCH3), 21.6 ꢀs; C6H4CH3), 20.5
ꢀs; PCHCH3); 31P NMR ꢀC6D6, 162.0 MHz): d ˆ 58.5 ꢀd, JꢀRh,P) ˆ
245.8 Hz); elemental analysis for C29H40PRh ꢀ522.5): calcd: C 66.66, H
7.72; found: C 66.25, H 7.58.
5
ˆ
[7h -C5H5)Rh7 CPh2)7SbiPr3)] 72a): A solution of 1a ꢀ83 mg, 0.10 mmol)
in THF ꢀ10 mL) was treated with NaC5H5 ꢀ44 mg, 0.50 mmol) at room
temperature. A spontaneous change of color from green to deep blue
occurred. After the reaction mixture was stirred for 30 min, the solvent was
removed in vacuo. The oily residue was extracted with pentane ꢀ10 mL),
and the extract concentrated to 1 mL in vacuo. The solution was
chromatographed on Al2O3 ꢀneutral, activity grade V, height of column
5 cm). With hexane, a blue fraction was eluted, which after removal of the
solvent gave a blue solid. This was washed twice with small portions of
methanol and recrystallized from pentane at À308C. After 18 h, blue
crystals precipitated which were separated from the mother liquor, washed
with a small quantity of pentane and dried; yield 47 mg ꢀ78%); m.p. 308C
5
ˆ
[7h -C5H5)Rh7 CPh2)7PiPr2Ph)] 72 f): Compound 2 f was prepared as
described for 2d, from 1 f ꢀ84 mg, 0.12 mmol) and NaC5H5 ꢀ53 mg,
0.60 mmol) in THF ꢀ10 mL); yield 53 mg ꢀ84%). Deep blue crystals; m.p.
458C ꢀdecomp.); 1H NMR ꢀC6D6, 200 MHz): d ˆ 7.61 ± 7.51 ꢀm, 6H; ortho-
H of C6H5P and C6H5), 7.06 ± 6.99 ꢀm, 9H; meta- and para-H of C6H5P and
C6H5), 4.91 ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.8 Hz, 5H; C5H5), 1.53 ꢀm, 2H;
PCHCH3), 0.82 ꢀdd, JꢀP,H) ˆ 15.2, JꢀH,H) ˆ 6.9 Hz, 6H; PCHCH3), 0.76
ꢀdd, JꢀP,H) ˆ 13.6, JꢀH,H) ˆ 6.8 Hz, 6H; PCHCH3); 13C NMR ꢀC6D6,
‡
‡
ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 585 ꢀ0.3; [M ]), 334 ꢀ2.7; [M À SbiPr3]),
ˆ
50.3 MHz): d ˆ 265.1 ꢀdd, JꢀRh,C) ˆ 50.4, JꢀP,C) ˆ 18.0 Hz; Rh C), 135.7,
‡
‡
‡
1
ˆ
269 ꢀ0.6; [Rh CPh2] ), 251 ꢀ55; [SbiPr3] ), 168 ꢀ15; [RhC5H5] ); H NMR
ꢀC6D6, 200 MHz): d ˆ 7.69 ꢀm, 4H; ortho-H of C6H5), 7.13 ± 6.98 ꢀm, 6H;
meta- and para-H of C6H5), 5.00 ꢀd, JꢀRh,H) ˆ 0.9 Hz, 5H; C5H5), 1.35
ꢀsept, JꢀH,H) ˆ 7.0 Hz, 3H; SbCHCH3), 1.10 ꢀd, JꢀH,H) ˆ 7.0 Hz, 18H;
SbCHCH3); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 261.0 ꢀd, JꢀRh,C) ˆ 46.9 Hz,
135.3 ꢀboth s; ipso-C of C6H5), 135.2 ꢀd, JꢀP,C) ˆ 31.1 Hz; ipso-C of C6H5P),
134.9 ꢀd, JꢀP,C) ˆ 18.9 Hz; meta-C of C6H5P), 134.3 ꢀd, JꢀP,C) ˆ 9.8 Hz;
ortho-C of C6H5P), 129.0, 128.3, 128.2, 127.5, 126.8, 125.2 ꢀall s; para-C of
C6H5P and ortho-, meta-, and para-C of C6H5), 86.9 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ
2.5 Hz; C5H5), 20.0 ꢀd, JꢀP,C) ˆ 18.9 Hz; PCHCH3), 18.1 ꢀs; PCHCH3); 31
P
ˆ
Rh C), 166.7, 160.0 ꢀboth s; ipso-C of C6H5), 132.1, 129.8, 129.7, 129.1, 128.3,
NMR ꢀC6D6, 81.0 MHz): d ˆ 53.5 ꢀd, JꢀRh,P) ˆ 248.0 Hz); elemental
analysis for C30H34PRh ꢀ528.5): calcd: C 68.18, H 6.48; found: C 68.19, H
6.79.
128.1 ꢀall s; ortho-, meta-, and para-C of C6H5), 82.8 ꢀd, JꢀRh,C) ˆ 3.8 Hz;
C5H5), 21.6 ꢀs; SbCHCH3), 18.3 ꢀd, JꢀRh,C) ˆ 3.2 Hz; SbCHCH3); ele-
mental analysis for C27H36RhSb ꢀ585.2): calcd: C 55.41, H 6.20, Rh 17.58;
found: C 55.39, H 6.34, Rh 17.61.
5
ˆ
[7h -C5H5)Rh7 CPh2)7PiPrPh2)] 72g):
A
solution of 1g ꢀ89 mg,
0.12 mmol) in THF ꢀ10 mL) was treated with NaC5H5 ꢀ51 mg, 0.58 mmol)
and stirred for 30 min at room temperature. The solvent was removed in
vacuo, and the bluish-black residue was extracted with pentane ꢀ15 mL).
The extract was concentrated to about 2 mL in vacuo, and the solution was
chromatographed on Al2O3 ꢀneutral, activity grade V, height of column
2.5 cm). With hexane, a blue-violet fraction was eluted, from which after
removal of the solvent a deep blue solid was obtained; yield 53 mg ꢀ79%);
m.p. 448C ꢀdecomp); 1H NMR ꢀC6D6, 200 MHz): d ˆ 7.61 ± 7.46 ꢀm, 8H;
ortho-H of C6H5P and C6H5), 7.10 ± 7.01 ꢀm, 12H; meta- and para-H of
C6H5P and C6H5), 4.88 ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.8 Hz, 5H; C5H5), 1.28 ꢀm,
1H; PCHCH3), 1.02 ꢀdd, JꢀP,H) ˆ 16.0, JꢀH,H) ˆ 7.0 Hz, 3H; PCHCH3),
0.70 ꢀdd, JꢀP,H) ˆ 15.1, JꢀH,H) ˆ 6.9 Hz, 3H; PCHCH3); 13C NMR ꢀC6D6,
5
ˆ
[7h -C5H5)Rh{ C7o-Tol)Ph}7SbiPr3)] 72b) was prepared as described for
2a, from 1b ꢀ82 mg, 0.10 mmol) and NaC5H5 ꢀ44 mg, 0.50 mmol) in THF
ꢀ10 mL); yield 44 mg ꢀ73%). Blue-violet oil; 1H NMR ꢀC6D6, 200 MHz):
d ˆ 7.57 ꢀm, 3H; ortho-H of C6H5 and C6H4CH3), 7.33 ± 6.83 ꢀm, 6H; meta-
and para-H of C6H5 and C6H4CH3), 4.63 ꢀbr s, 5H; C5H5), 2.04 ꢀs, 3H;
C6H4CH3), 1.74 ꢀsept, JꢀH,H) ˆ 7.1 Hz, 3H; SbCHCH3), 1.29 ꢀd, JꢀH,H) ˆ
7.1 Hz, 18H; SbCHCH3); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 253.7 ꢀd,
ˆ
JꢀRh,C) ˆ 46.6 Hz; Rh C), 155.7, 154.6 ꢀboth s; ipso-C of C6H5 and
C6H4CH3), 130.1, 129.3, 128.3, 127.2, 124.6, 124.5, 122.8, 122.4 ꢀall s; ortho-,
meta-, and para-C of C6H5 and C6H4CH3), 88.3 ꢀd, JꢀRh,C) ˆ 3.8 Hz; C5H5),
22.7 ꢀs; C6H4CH3), 21.4 ꢀs; SbCHCH3), 18.3 ꢀs; SbCHCH3); elemental
analysis for C28H38RhSb ꢀ599.3): calcd: C 56.12, H 6.39; found: C 56.49, H
6.05.
ˆ
100.6 MHz): d ˆ 264.2 ꢀdd, JꢀRh,C) ˆ 49.8, JꢀP,C) ˆ 17.6 Hz; Rh C), 138.4
ꢀd, JꢀP,C) ˆ 35.2 Hz; ipso-C of C6H5P), 134.1 ꢀd, JꢀP,C) ˆ 10.1 Hz; ortho-C
of C6H5P), 131.3 ꢀd, JꢀP,C) ˆ 10.6 Hz; meta-C of C6H5P), 131.0, 130.2 ꢀboth
s; ipso-C of C6H5), 128.8, 128.7, 128.5, 128.1, 127.9, 127.5, 127.4 ꢀall s; para-C
of C6H5P and ortho-, meta-, and para-C of C6H5), 87.9 ꢀdd, JꢀRh,C) ˆ
JꢀP,C) ˆ 2.9 Hz; C5H5), 22.0 ꢀd, JꢀP,C) ˆ 21.8 Hz; PCHCH3), 19.1 ꢀs;
PCHCH3); 31P NMR ꢀC6D6, 162.0 MHz): d ˆ 51.9 ꢀd, JꢀRh,P) ˆ
5
ˆ
[7h -C5H5)Rh{ C7p-Tol)Ph}7PiPr3)] 72d):
A solution of 1d ꢀ89 mg,
0.14 mmol) in THF ꢀ10 mL) was treated with NaC5H5 ꢀ61 mg, 0.70 mmol)
and stirred for 30 min at room temperature. A change of color from green
to deep blue occurred. The reaction mixture was concentrated to 2 mL in
vacuo, and MeI ꢀ1.0 mL, 16 mmol) was added. After the suspension was
4466
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0624-4466 $ 17.50+.50/0
Chem. Eur. J. 2000, 6, No. 24

Half-Sandwich-Type Carbenerhodium Complexes
4461±4470
250.7 Hz); elemental analysis for C33H32PRh ꢀ562.5): calcd: C 70.46, H 5.73;
found: C 69.97, H 5.79.
JꢀP,C) ˆ 26.3 Hz; PCH3); 31P NMR ꢀCDCl3, 81.0 MHz): d ˆ À10.0 ꢀd,
JꢀRh,P) ˆ 248.5 Hz); elemental analysis for C21H24PRh ꢀ410.3): calcd: C
61.47, H 5.90; found: C 61.42, H 6.09.
5
ˆ
[7h -C5H5)Rh7 CPh2)7PPh3)] 72h): Compound 2h was prepared as
5
described for 2g, from 1h ꢀ99 mg, 0.12 mmol) and NaC5H5 ꢀ53 mg,
0.60 mmol) in THF ꢀ10 mL); yield 47 mg ꢀ66%). Blue-violet solid; m.p.
568C ꢀdecomp); 1H NMR ꢀC6D6, 400 MHz): d ˆ 7.60 ꢀm, 10H; ortho-H of
C6H5P and C6H5), 6.96 ꢀm, 15H; meta- and para-H of C6H5P and C6H5),
4.86 ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.8 Hz, 5H; C5H5); 13C NMR ꢀC6D6,
ˆ
[7h -C5H5)Rh7 CPh2)7CNMe)] 75): A solution of 2a ꢀ159 mg, 0.27 mmol)
in pentane ꢀ15 mL) was treated with MeNC ꢀ15 mL, 0.27 mmol) and stirred
for 1 h at room temperature. A change of color from blue to red-violet
occurred. The solvent was removed in vacuo, the residue was dissolved in
diethyl ether ꢀ1 mL) and the solution was chromatographed on Al2O3
ꢀneutral, activity grade III, height of column 3.0 cm). With benzene, a red-
violet fraction was eluted which was brought to dryness in vacuo. The
residue was recrystallized from pentane ꢀ5 mL). Upon storing the solution
at À788C for 2 d, red-violet crystals precipitated, which were separated
from the mother liquor, washed twice with small quantities of pentane
ꢀÀ208C) and dried; yield 84 mg ꢀ83%); m.p. 948C ꢀdecomp); MS ꢀ70 eV):
ˆ
100.6 MHz): d ˆ 269.1 ꢀdd, JꢀRh,C) ˆ 49.8, JꢀP,C) ˆ 16.1 Hz; Rh C),
138.6 ꢀd, JꢀP,C) ˆ 41.3 Hz; ipso-C of C6H5P), 134.5 ꢀd, JꢀP,C) ˆ 13.1 Hz;
meta-C of C6H5P), 134.2, 134.1 ꢀboth s; ipso-C of C6H5), 128.8, 128.1, 127.9,
126.8, 124.9 ꢀall s; para-C of C6H5P and ortho-, meta-, and para-C of C6H5),
127.6 ꢀd, JꢀP,C) ˆ 9.1 Hz; ortho-C of C6H5P), 88.3 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ
3.0 Hz; C5H5); 31P NMR ꢀC6D6, 162.0 MHz): d ˆ 47.7 ꢀd, JꢀRh,P) ˆ
258.7 Hz); elemental analysis for C36H30PRh ꢀ596.5): calcd: C 72.49, H
5.07; found: C 72.67, H 5.10.
‡
‡
‡
m/z ꢀIr): 375 ꢀ5.2; [M ]), 334 ꢀ11; [M À CNMe]), 209 ꢀ0.7; [M À CPh2]),
168 ꢀ11; [RhC5H5] ); IR ꢀKBr): nÄ ˆ 2129 cmÀ1 ꢀC N); 1H NMR ꢀC6D6,
‡
ꢁ
5
200 MHz): d ˆ 7.68 ꢀm, 4H; ortho-H of C6H5), 7.10 ± 6.97 ꢀm, 6H; meta- and
para-H of C6H5), 5.12 ꢀd, JꢀRh,H) ˆ 0.6 Hz, 5H; C5H5), 2.00 ꢀd, JꢀRh,H) ˆ
0.9 Hz, 3H; CNCH3); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 268.4 ꢀd, JꢀRh,C) ˆ
ˆ
[7h -C5H5)Rh7 CPh2)7PMePh2)] 72i): Compound 2i was prepared as
described for 2g, from 1i ꢀ92 mg, 0.13 mmol) and NaC5H5 ꢀ57 mg,
0.65 mmol) in THF ꢀ10 mL); yield 43 mg ꢀ62%). Red-violet solid; m.p.
328C ꢀdecomp); 1H NMR ꢀC6D6, 400 MHz): d ˆ 7.71 ± 7.44 ꢀm, 8H; ortho-
H of C6H5P and C6H5), 7.05 ꢀm, 12H; meta- and para-H of C6H5P and
C6H5), 4.80 ꢀbr s, 5H; C5H5), 1.04 ꢀdd, JꢀP,H) ˆ 8.4, JꢀRh,H) ˆ 1.6 Hz, 3H;
PCH3); 13C NMR ꢀC6D6, 100.6 MHz): d ˆ 265.7 ꢀdd, JꢀRh,C) ˆ 50.8,
ˆ
51.3 Hz; Rh C), 165.4, 163.2 ꢀboth s; ipso-C of C6H5), 150.4 ꢀd, JꢀRh,C) ˆ
96.7 Hz; RhCN), 138.8, 136.4, 132.0, 130.8, 125.9, 122.8 ꢀall s; ortho-, meta-
and para-C of C6H5), 86.8 ꢀd, JꢀRh,C) ˆ 3.4 Hz; C5H5), 28.2 ꢀs; CNCH3);
elemental analysis for C20H18NRh ꢀ375.3): calcd: C 64.01, H 4.83, N 3.73;
found: C 63.93, H 4.64, N 3.92.
ˆ
JꢀP,C) ˆ 17.6 Hz; Rh C), 142.4 ꢀd, JꢀP,C) ˆ 40.2 Hz; ipso-C of C6H5P),
132.5 ꢀd, JꢀP,C) ˆ 13.1 Hz; meta-C of C6H5P), 132.0 ꢀd, JꢀP,C) ˆ 11.1 Hz;
ortho-C of C6H5P), 130.2 ꢀs; ipso-C of C6H5), 128.8, 127.9, 124.7, 124.3 ꢀall s;
para-C of C6H5P and ortho-, meta-, and para-C of C6H5), 87.8 ꢀdd,
JꢀRh,C) ˆ JꢀP,C) ˆ 3.0 Hz; C5H5), 15.7 ꢀdd, JꢀP,C) ˆ 26.2, JꢀRh,C) ˆ
2.8 Hz; PCH3); 31P NMR ꢀC6D6, 162.0 MHz): d ˆ 24.5 ꢀd, JꢀRh,P) ˆ
257.2 Hz); elemental analysis for C31H28PRh ꢀ534.4): calcd: C 69.67, H
5.28; found: C 70.05, H 5.14.
5
ˆ
[7h -C5H5)Rh7 CPh2)7CNCH2Ph)] 76): Compound 6 was prepared as
described for 5, from 2a ꢀ139 mg, 0.24 mmol) and PhCH2NC ꢀ29 mL,
0.24 mmol) in pentane ꢀ15 mL); yield 91 mg ꢀ84%). Red-violet crystals;
‡
‡
m.p. 978C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 451 ꢀ1.3; [M ]), 334 ꢀ1.9; [M À
‡
‡
CNCH2Ph]), 285 ꢀ28; [M À CPh2]), 168 ꢀ35; [RhC5H5] ); IR ꢀKBr): nÄ ˆ
2122 cmÀ1 ꢀC N); H NMR ꢀC6D6, 400 MHz): d ˆ 7.69 ꢀm, 2H; ortho-H of
1
ꢁ
CH2C6H5), 7.50 ± 7.44 ꢀm, 4H; ortho-H of C6H5), 7.13 ± 6.91 ꢀm, 9H; meta-
and para-H of C6H5 and CH2C6H5), 5.13 ꢀd, JꢀRh,H) ˆ 0.5 Hz, 5H; C5H5),
3.85 ꢀbr s, 2H; CH2C6H5); 13C NMR ꢀC6D6, 100.6 MHz): d ˆ 269.9 ꢀd,
5
ˆ
[7h -C5H5)Rh7 CPh2)7CO)] 73): A slowstream of CO was passed through
a solution of 2a ꢀ70 mg, 0.12 mmol) in pentane ꢀ10 mL) for 30 s at room
temperature. While the solution was stirred for 1 h, a change of color from
blue to violet and finally to deep red occurred. The solvent was removed,
the residue was dissolved in hexane ꢀ2 mL), and the solution was
chromatographed on Al2O3 ꢀneutral, activity grade III, height of column
3.0 cm). With hexane, a red fraction was eluted, from which after removal
of the solvent a red solid was obtained. The solid was washed twice with
small quantities of methanol ꢀÀ208C) and recrystallized from pentane
ꢀ3 mL). Upon storing at À788C for 3 h, red needles were formed, which
were separated from the mother liquor, washed with small quantities of
pentane ꢀÀ208C), and dried; yield 38 mg ꢀ87%); m.p. 498C ꢀdecomp); MS
ˆ
JꢀRh,C) ˆ 50.8 Hz; Rh C), 165.5, 163.2, 160.1 ꢀall s; ipso-C of C6H5 and
CH2C6H5), 153.2 ꢀd, JꢀRh,C) ˆ 98.6 Hz; RhCN), 130.7, 128.8, 127.0, 126.2,
125.7, 125.0, 124.5, 124.4, 123.6 ꢀall s; ortho-, meta- and para-C of C6H5 and
CH2C6H5), 87.1 ꢀd, JꢀRh,C) ˆ 3.1 Hz; C5H5), 47.4 ꢀs; CH2C6H5); elemental
analysis for C26H22NRh ꢀ451.4): calcd: C 69.19, H 4.92, N 3.11; found: C
68.89, H 4.93, N 2.99.
5
ˆ
[7h -C5H5)Rh7 CPh2)7CNtBu)] 77): Compound 7 was prepared as descri-
bed for 5, from 2a ꢀ84 mg, 0.14 mmol) and CNtBu ꢀ17 mL, 0.14 mmol) in
pentane ꢀ15 mL); yield 53 mg ꢀ89%). Red-violet needles; m.p. 888C
‡
‡
ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 417 ꢀ42; [M ]), 334 ꢀ100; [M À CNtBu]),
‡
‡
‡
ꢀ70 eV): m/z ꢀIr): 362 ꢀ13; [M ]), 334 ꢀ100; [M À CO]), 297 ꢀ5.4; [M À
‡
‡
‡
ˆ
269 ꢀ5.0; [Rh CPh2] ), 251 ꢀ0.4; [M À CPh2]), 168 ꢀ61; [RhC5H5 ]); IR
‡
‡
ˆ
C5H5]), 269 ꢀ3.3; [Rh CPh2] ), 196 ꢀ0.3; [M À CPh2]), 168 ꢀ55;
ꢀKBr): nÄ ˆ 2118 cmÀ1 ꢀC N); H NMR ꢀC6D6, 400 MHz): d ˆ 7.55 ± 7.45 ꢀm,
1
ꢁ
[RhC5H5] ); IR ꢀKBr): nÄ ˆ 1982 cmÀ1 ꢀCO); 1H NMR ꢀC6D6, 200 MHz):
‡
4H; ortho-H of C6H5), 7.11 ꢀm, 2H; para-H of C6H5), 7.01 ꢀm, 4H; meta-H
d ˆ 7.43 ꢀm, 4H; ortho-H of C6H5), 7.14 ± 6.91 ꢀm, 6H; meta- and para-H of
C6H5), 4.92 ꢀd, JꢀRh,H) ˆ 0.7 Hz, 5H; C5H5); 13C NMR ꢀC6D6, 50.3 MHz):
of C6H5), 5.14 ꢀd, JꢀRh,H) ˆ 0.4 Hz, 5H; C5H5), 0.78 ꢀs, 9H; CꢀCH3)3);
13
ˆ
C NMR ꢀC6D6, 100.6 MHz): d ˆ 267.9 ꢀd, JꢀRh,C) ˆ 50.3 Hz; Rh C),
ˆ
d ˆ 286.7 ꢀd, JꢀRh,C) ˆ 48.0 Hz; Rh C), 192.7 ꢀd, JꢀRh,C) ˆ 101.7 Hz;
165.6, 163.9 ꢀboth s; ipso-C of C6H5), 148.2 ꢀd, JꢀRh,C) ˆ 98.3 Hz; RhCN),
127.5, 127.0, 126.3, 125.6, 125.4, 125.0 ꢀall s; ortho-, meta- and para-C of
C6H5), 86.7 ꢀd, JꢀRh,C) ˆ 3.9 Hz; C5H5), 55.9 ꢀs; CꢀCH3)3), 30.1 ꢀs;
CꢀCH3)3); elemental analysis for C23H24NRh ꢀ417.4): calcd: C 66.19, H
5.80, N 3.36; found: C 66.50, H 6.04, N 3.23.
À
Rh CO), 164.1, 161.6 ꢀboth s; ipso-C of C6H5), 128.8, 128.3, 127.7, 127.0,
126.8, 125.2 ꢀall s; ortho-, meta- and para-C of C6H5), 89.7 ꢀd, JꢀRh,C) ˆ
3.5 Hz; C5H5); elemental analysis for C19H15ORh ꢀ362.2): calcd: C 63.00, H
4.17; found: C 63.08, H 4.12.
5
ˆ
[7h -C5H5)Rh7 CPh2)7PMe3)] 74): A solution of 2a ꢀ59 mg, 0.10 mmol) in
Reaction of compound 2a with R2CN2 7R ˆ Ph, p-Tol): A solution of 2a
ꢀ59 mg, 0.10 mmol) in pentane ꢀ10 mL) was treated at À788C with a
solution of Ph2CN2 ꢀ19 mg, 0.10 mmol) in pentane ꢀ2 mL). On warming the
mixture to room temperature, a change of color from blue to brown
occurred. After the solvent was removed in vacuo, an oily residue was
obtained, which was identified by 1H and 13C NMR spectroscopy as a
pentane ꢀ10 mL) was treated with a solution of PMe3 ꢀ10 mL, 0.10 mmol) in
pentane ꢀ3 mL) and stirred for 1 h at room temperature. A gradual change
of color from blue to violet occurred. The solvent was removed in vacuo,
and the violet residue was washed with small quantities of methanol
ꢀÀ208C). The solid was recrystallized from pentane ꢀ5 mL). Upon storing
at À788C for 1 h, violet crystals were formed, which were separated from
the mother liquor, washed with small quantities of pentane ꢀÀ208C), and
dried; yield 34 mg ꢀ83%); m.p. 1138C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 410
ˆ À ˆ
mixture of the starting material 2a and Ph2C N N CPh2 ꢀ8). If an excess
of Ph2CN2 was used, 8 was formed in quantitative yield while a partial
decomposition of 2a took place. Column chromatography on Al2O3
afforded a pure sample of 8, which was identified by elemental analysis.
The reaction of 2a with ꢀp-Tol)2CN2 proceeded analogously and gave ꢀp-
‡
‡
‡
ꢀ49; [M ]), 345 ꢀ0.7; [M À C5H5]), 334 ꢀ66; [M À PMe3]), 332 ꢀ100;
‡
‡
‡
[C2Ph4] ), 244 ꢀ1.4; [M À CPh2]), 242 ꢀ10; [Ph2CPMe3] ), 168 ꢀ38;
‡
1
[RhC5H5] ); H NMR ꢀCDCl3, 200 MHz): d ˆ 7.30 ± 7.16 ꢀm, 4H; ortho-H
of C6H5), 7.11 ± 7.00 ꢀm, 6H; meta- and para-H of C6H5), 4.95 ꢀdd,
JꢀRh,H) ˆ JꢀP,H) ˆ 0.8 Hz, 5H; C5H5), 1.11 ꢀdd, JꢀP,H) ˆ 8.9 Hz,
JꢀRh,H) ˆ 1.4 Hz, 9H; PCH3); 13C NMR ꢀCDCl3, 50.3 MHz): d ˆ 263.2
ˆ À ˆ
Tol)2C N N Cꢀp-Tol)2 ꢀ9) in 95% yield.
Reaction of compound 2c with CO: A slowstream of CO was passed
through a solution of 2c ꢀ49 mg, 0.10 mmol) in pentane ꢀ10 mL) for 30 s at
room temperature. While the solution was stirred for 5 h, a change of color
from blue to red-violet occurred. The solvent was removed in vacuo, the
oily residue was dissolved in hexane ꢀ1 mL), and the solution was
ˆ
ꢀdd, JꢀRh,C) ˆ 50.9, JꢀP,C) ˆ 16.5 Hz; Rh C), 166.0, 164.0 ꢀboth s; ipso-C
of C6H5), 127.0, 126.5, 125.5, 125.0, 124.2, 123.7 ꢀall s; ortho-, meta- and
para-C of C6H5), 85.9 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ 3.0 Hz; C5H5), 22.5 ꢀd,
Chem. Eur. J. 2000, 6, No. 24
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0624-4467 $ 17.50+.50/0
4467

H. Werner et al.
FULL PAPER
chromatographed on Al2O3 ꢀneutral, activity grade III, height of column
6.0 cm). With hexane, a orange-yellow fraction was eluted, from which after
removal of the solvent an orange oil was obtained. This was identified by
IR, 1H, and 13C NMR spectroscopy as [ꢀh5-C5H5)RhꢀCO)ꢀPiPr3)] ꢀ10).[10]
With hexane/benzene ꢀ1:1), a red fraction was eluted, which contained
diphenylketene ꢀ11), identified by IR and 13C NMR spectroscopy;[27] yield
105 mg ꢀ55%).
ortho-, meta- and para-C of C6H5), 81.6 ꢀd, JꢀRh,C) ˆ 6.4 Hz; C5H5);
elemental analysis for C17H15N4Rh ꢀ378.2): calcd: C 53.98, H 4.00, N 14.81;
found: C 53.76, H 3.74, N 14.91.
[7h5-C5H5)Rh{k2-7p-Tol)NNNN7p-Tol)}] 720): Compound 20 was prepared
as described for 19, from 2a ꢀ71 mg, 0.12 mmol) or 2c ꢀ59 mg, 0.12 mmol)
and ꢀp-Tol)N3 ꢀ72 mL, 0.48 mmol) in pentane ꢀ10 mL); yield 35 mg ꢀ71%).
‡
Red solid; m.p. 1728C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 406 ꢀ29; [M ]), 378
‡
‡
‡
ꢀ24; [M À N2]), 273 ꢀ100; [C5H5RhNꢀp-Tol)] ), 168 ꢀ92; [RhC5H5] ), 133
Reaction of compound 2c with CNtBu:
A solution of 2c ꢀ49 mg,
ꢀ4; [ꢀp-Tol)N3] ); 1H NMR ꢀCDCl3, 200 MHz): d ˆ 7.59 ꢀm, 4H; ortho-H of
‡
0.10 mmol) in pentane ꢀ10 mL) was treated with CNtBu ꢀ110 mL,
1.00 mmol) at room temperature. After the reaction mixture was stirred
for 5 h, it was worked up analogously as described for the solution obtained
from 2c and CO. The products were identified by IR, 1H, and 13C NMR
spectroscopy as [ꢀh5-C5H5)RhꢀCNtBu)ꢀPiPr3)] ꢀ12) and Ph2C ˆ C ˆ NtBu
ꢀ13);[28] yield ꢀof 13) 136 mg ꢀ55%). Data for 12: IR ꢀC6H6): nÄ ˆ 2143,
C6H4CH3), 7.05 ꢀm, 4H; meta-H of C6H4CH3), 5.00 ꢀd, JꢀRh,H) ˆ 0.7 Hz,
5H; C5H5), 2.23 ꢀs, 6H; C6H4CH3); 13C NMR ꢀCDCl3, 50.3 MHz): d ˆ 154.1
ꢀd, JꢀRh,C) ˆ 3.8 Hz; ipso-C of C6H4CH3), 136.1, 129.3, 123.8 ꢀall s; para-,
ortho- and meta-C of C6H4CH3), 81.9 ꢀd, JꢀRh,C) ˆ 6.1 Hz; C5H5), 21.1 ꢀs;
C6H4CH3); elemental analysis for C19H19N4Rh ꢀ406.3): calcd: C 56.16, H
4.71, N 13.79; found: C 55.80, H 4.81, N 13.89.
2032 cmÀ1 ꢀC N); 1H NMR ꢀC6D6, 200 MHz): d ˆ 5.18 ꢀbr s, 5H; C5H5),
ꢁ
[7h5-C5H5)Rh7k2-SCPh2)7CO)] 721): A solution of 3 ꢀ57 mg, 0.16 mmol) in
benzene ꢀ10 mL) was treated with small portions of sulfur ꢀ5.0 mg,
0.16 mmol) and stirred for 1 h at room temperature. A gradual change of
color from red to brown occurred. The solvent was removed in vacuo, the
residue was dissolved in hexane ꢀ10 mL), and the solution was chromato-
graphed on Al2O3 ꢀneutral, activity grade V, height of column 5.0 cm). With
hexane, a first red-brown fraction was eluted, which was thrown away. With
diethyl ether, a second yellow fraction was eluted, which after removal of
the solvent gave a light yellow solid. This was washed with small quantities
of pentane ꢀÀ208C) and recrystallized from pentane ꢀ5 mL) at À788C.
Upon storing the solution for 3 d, a light yellowmicrocrystalline solid
precipitated, which was separated from the mother liquor, washed with
small quantities of pentane ꢀÀ208C) and dried; yield 40 mg ꢀ65%); m.p.
1.36 ꢀdsept, JꢀP,H) ˆ 13.1, JꢀH,H) ˆ 7.2 Hz, 3H; PCHCH3), 1.09 ꢀdd,
JꢀP,H) ˆ 13.1, JꢀH,H) ˆ 7.2 Hz, 18H; PCHCH3), 0.92 ꢀs, 9H; CꢀCH3)3);
31P NMR ꢀC6D6, 81.0 MHz): d ˆ 83.1 ꢀd, JꢀRh,P) ˆ 206.3 Hz).
[7h5-C5H5)Rh7C2H4)7SbiPr3)) 714): a) A solution of 17 ꢀ67 mg, 0.10 mmol)
in THF ꢀ10 mL) was treated with NaC5H5 ꢀ44 mg, 0.50 mmol) and stirred
for 45 min at room temperature. A change of color from orange-brown to
orange-yellowoccurred. The solvent was removed in vacuo, the orange-
yellowoily residue extracted with pentane ꢀ10 mL), and the extract
concentrated to 0.5 mL. The solution was then chromatographed on Al2O3
ꢀneutral, activity grade V, height of column 5.0 cm). With hexane, an
orange-yellow fraction was eluted, from which after removal of the solvent
an orange-yellow oil was obtained. This was dried at 10À3 mbar for 3 h;
yield 29 mg ꢀ65%).
‡
‡
1468C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 394 ꢀ8.6; [M ]), 366 ꢀ100; [M À
b) A solution of 18 ꢀ83 mg, 0.10 mmol) in THF ꢀ10 mL) was treated with
NaC5H5 ꢀ88 mg, 1.00 mmol) and stirred for 30 min at room temperature.
The solvent was removed in vacuo and the residue was worked up as
described for a); yield 77 mg ꢀ86%).
‡
‡
‡
CO]), 362 ꢀ1.1; [M À S]), 334 ꢀ1.7; [C5H5RhCPh2] ), 329 ꢀ14; [M À C5H5]),
‡
‡
‡
301 ꢀ26; [RhꢀS)CPh2] ), 200 ꢀ2.2; [C5H5RhS] ), 198 ꢀ41; [SCPh2] ), 196 ꢀ23;
[C5H5RhCO] ), 168 ꢀ14; [RhC5H5] ); IR ꢀKBr): nÄ ˆ 2000 cmÀ1 ꢀCO);
1H NMR ꢀC6D6, 400 MHz): d ˆ 7.83, 7.75 ꢀboth m, 2H each; ortho-H of
C6H5), 7.11, 6.96 ꢀboth m, 2H each; meta-H of C6H5), 7.03, 6.86 ꢀboth m, 1H
each; para-H of C6H5), 4.57 ꢀd, JꢀRh,H) ˆ 0.5 Hz, 5H; C5H5); 13C NMR
ꢀC6D6, 100.6 MHz): d ˆ 186.4 ꢀd, JꢀRh,C) ˆ 83.2 Hz; RhCO), 151.3, 150.6
ꢀboth s; ipso-C of C6H5), 132.1, 127.8, 127.3, 127.2, 126.5, 125.9 ꢀall s; ortho-,
meta- and para-C of C6H5), 93.3 ꢀd, JꢀRh,C) ˆ 16.6 Hz; RhCPh2), 92.2 ꢀd,
JꢀRh,C) ˆ 4.2 Hz; C5H5); elemental analysis for C19H15ORhS ꢀ394.3):
calcd: C 57.88, H 3.83; found: C 58.12, H 3.93.
‡
‡
c) A slowstream of ethene was passed through a solution of 2a ꢀ57 mg,
0.10 mmol) in pentane ꢀ10 mL) for 20 s at room temperature. While the
solution was stirred for 1 h, a change of color from deep blue to orange
occurred. The solvent was removed in vacuo and the residue was worked up
as described for a). The 1H NMR spectrum confirmed that 1.1-diphenyl-1-
propene ꢀ16)[29] was formed as the organic by-product; yield ꢀof 14) 34 mg
ꢀ77%). Data for 14: Orange-yellowoil; 1H NMR ꢀC6D6, 200 MHz): d ˆ
5.12 ꢀd, JꢀRh,H) ˆ 0.6 Hz, 5H; C5H5), 2.77 ± 2.58, 2.24 ± 2.08 ꢀboth m, 2H
each; C2H4), 1.68 ꢀsept, JꢀH,H) ˆ 7.3 Hz, 3H; SbCHCH3), 1.10 ꢀd,
JꢀH,H) ˆ 7.3 Hz, 18H; SbCHCH3); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 82.0
ꢀd, JꢀRh,C) ˆ 4.2 Hz; C5H5), 36.5 ꢀd, JꢀRh,C) ˆ 13.6 Hz; C2H4), 21.4 ꢀs;
SbCHCH3), 17.0 ꢀd, JꢀRh,C) ˆ 2.5 Hz; SbCHCH3); elemental analysis for
C16H30RhSb ꢀ447.1): calcd: C 42.99, H 6.76; found: C 43.12, H 6.62.
[7h5-C5H5)Rh7k2-SeCPh2)7CO)] 722): A solution of 3 ꢀ63 mg, 0.17 mmol) in
benzene ꢀ10 mL) was treated with small portions of red selenium ꢀ13.7 mg,
0.17 mmol) and stirred for 1 h at room temperature. The solvent was
removed in vacuo, the residue was dissolved in hexane ꢀ10 mL), and the
solution was chromatographed on Al2O3 ꢀneutral, activity grade V, height
of column 3.0 cm). With hexane/diethyl ether, an orange fraction was
eluted, which after removal of the solvent gave an orange-yellow solid. This
was recrystallized from pentane ꢀ10 mL) at À788C. Upon storing the
solution for 5 h, an orange-yellowmicrocrystalline solid precipitated, which
was separated from the mother liquor, washed twice with 2 mL portions of
pentane ꢀÀ208C) and dried; yield 63 mg ꢀ82%); m.p. 1118C ꢀdecomp); MS
Reaction of compound 2c with ethene: In an NMR tube, a slowstream of
ethene was passed through a solution of 2c ꢀ25 mg, 0.05 mmol) in C6D6
ꢀ0.5 mL) for 10 s at room temperature. During 2 h, a change of color from
deep blue to orange-yellowoccurred. The 1H NMR spectrum confirmed
that both 15[30] and 1.1-diphenyl-1-propene ꢀ16)[29] were formed; yield
virtually quantitative.
‡
‡
‡
ꢀ70 eV): m/z ꢀIr): 441 ꢀ8.8; [M ]), 413 ꢀ68; [M À CO), 362 ꢀ0.2; [M À Se]),
[7h5-C5H5)Rh7k2-PhNNNNPh)] 719): a)
A solution of 2a ꢀ68 mg,
‡
‡
‡
348 ꢀ26; [RhSeCPh2] ), 334 ꢀ3.9; [C5H5RhCPh2] ), 247 ꢀ4.8; [C5H5RhSe] ),
‡
‡
‡
0.12 mmol) in pentane ꢀ10 mL) was treated at À788C with PhN3 ꢀ56 mL,
0.48 mmol). After the reaction mixture was warmed to room temperature,
it was stirred for 45 min. A change of color from blue to red-brown,
accompanied by the precipitation of a solid, occurred. The solvent was
removed in vacuo, the residue was dissolved in a small quantity of diethyl
ether, and the solution was chromatographed on Al2O3 ꢀneutral, activity
grade V, height of column 5.0 cm). With diethyl ether, a red fraction was
eluted, from which after removal of the solvent a red solid was obtained.
This was washed three times with small quantities of pentane and dried;
yield 30 mg ꢀ68%).
245 ꢀ11; [SeCPh2] ), 196 ꢀ4.5; [C5H5RhCO] ), 168 ꢀ19; [RhC5H5] ); IR
ꢀKBr): nÄ ˆ 2001 cmÀ1 ꢀCO); 1H NMR ꢀC6D6, 200 MHz): d ˆ 7.78 ± 7.64 ꢀm,
4H; ortho-H of C6H5), 7.14 ± 6.84 ꢀm, 6H; meta- and para-H of C6H5), 4.58
ꢀd, JꢀRh,H) ˆ 0.7 Hz, 5H; C5H5); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 187.0 ꢀd,
JꢀRh,C) ˆ 82.2 Hz; RhCO), 154.1, 153.6 ꢀboth s; ipso-C of C6H5), 132.7,
127.9, 127.7, 127.2, 126.5, 125.6 ꢀall s; ortho-, meta- and para-C of C6H5), 96.3
ꢀd, JꢀRh,C) ˆ 19.2 Hz; RhCPh2), 92.3 ꢀd, JꢀRh,C) ˆ 3.9 Hz; C5H5); ele-
mental analysis for C19H15ORhSe ꢀ441.2): calcd: C 51.73, H 3.43, Rh 23.32;
found: C 52.01, H 3.35, Rh 23.35.
[7h5-C5H5)Rh7k2-SCPh2)7PMe3)] 723): A solution of 4 ꢀ63 mg, 0.15 mmol)
in benzene ꢀ5 mL) was treated with small portions of sulfur ꢀ4.9 mg,
0.15 mmol) and stirred for 15 min at room temperature. A gradual change
of color from violet to brown occurred. The solvent was removed in vacuo,
and the residue was washed several times with small quantities of pentane
ꢀÀ408C). The remaining light brown solid was dried in vacuo; yield 63 mg
b) A solution of 2c ꢀ59 mg, 0.12 mmol) in pentane ꢀ10 mL) was treated at
À788C with PhN3 ꢀ56 mL, 0.48 mmol). After warming to room temper-
ature, the reaction mixture was worked up as described for a); yield 30 mg
‡
ꢀ68%); m.p. 2248C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 378 ꢀ30; [M ]), 350 ꢀ26;
‡
‡
‡
[M À N2]), 259 ꢀ100; [C5H5RhNPh] ), 168 ꢀ91; [RhC5H5] ); 1H NMR
ꢀC6D6, 200 MHz): d ˆ 8.04 ꢀm, 4H; ortho-H of C6H5), 7.65 ± 7.45 ꢀm, 6H;
meta- and para-H of C6H5), 5.41 ꢀd, JꢀRh,H) ˆ 0.7 Hz, 5H; C5H5); 13C NMR
ꢀC6D6, 100.6 MHz): d ˆ 157.3 ꢀs; ipso-C of C6H5), 128.9, 124.8, 121.3 ꢀall s;
‡
ꢀ95%); m.p. 778C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 442 ꢀ53; [M ]), 410 ꢀ16;
‡
‡
‡
[M À S]), 366 ꢀ84; [M À PMe3]), 334 ꢀ3.7; [C5H5RhCPh2] ), 301 ꢀ28;
‡
‡
‡
[RhSCPh2] ), 269 ꢀ3.0; [RhCPh2] ), 198 ꢀ20; [SCPh2] ), 168 ꢀ24;
4468
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000 0947-6539/00/0624-4468 $ 17.50+.50/0 Chem. Eur. J. 2000, 6, No. 24

Half-Sandwich-Type Carbenerhodium Complexes
4461±4470
‡
[RhC5H5] ); 1H NMR ꢀC6D6, 200 MHz): d ˆ 7.99 ꢀm, 4H; ortho-H of
violet solid was obtained. This was washed several times with small
C6H5), 7.09 ꢀm, 2H; para-H of C6H5), 6.96 ꢀm, 4H; meta-H of C6H5), 4.65
ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.7 Hz, 5H; C5H5), 0.54 ꢀdd, JꢀP,H) ˆ 10.0,
JꢀRh,H) ˆ 0.9 Hz, 9H; PCH3); 13C NMR ꢀC6D6, 50.3 MHz): d ˆ 154.0,
152.1 ꢀboth s; ipso-C of C6H5), 133.6, 130.2, 127.5, 126.9, 125.4, 124.2 ꢀall s;
ortho-, meta-, and para-C of C6H5), 89.6 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ 3.5 Hz;
C5H5), 79.1 ꢀdd, JꢀRh,C) ˆ 20.8, JꢀP,C) ˆ 3.7 Hz; RhCPh2), 18.8 ꢀd,
JꢀP,C) ˆ 30.8 Hz; PCH3); 31P NMR ꢀC6D6, 81.0 MHz): d ˆ 1.0 ꢀd,
JꢀRh,P) ˆ 183.1 Hz); elemental analysis for C21H24PRhS ꢀ442.4): calcd: C
57.02, H 5.47; found: C 57.23, H 5.63.
quantities of pentane ꢀÀ208C) and dried; yield 48 mg ꢀ78%); m.p. 1108C
‡
‡
ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 491 ꢀ1.2; [M ]), 168 ꢀ16; [RhC5H5] ), 128
ꢀ4.5; [CuC5H5] ); IR ꢀKBr): nÄ ˆ 1974 cmÀ1 ꢀCO); 1H NMR ꢀCDCl3,
‡
400 MHz): d ˆ 7.17 ꢀm, 4H; ortho-H of C6H5), 7.02 ꢀm, 2H; para-H of
C6H5), 6.92 ꢀm, 4H; meta-H of C6H5), 5.76 ꢀs, 5H; CuC5H5) 4.97 ꢀd,
JꢀRh,H) ˆ 0.5 Hz, 5H; RhC5H5); 13C NMR ꢀCDCl3, 100.6 MHz): d ˆ 206.3
ꢀd, JꢀRh,C) ˆ 36.7 Hz; RhCPh2), 190.0 ꢀd, JꢀRh,C) ˆ 86.2 Hz; RhCO),
163.4, 159.6 ꢀboth s; ipso-C of C6H5), 130.5, 127.8, 126.7, 126.6, 126.4, 126.2
ꢀall s; ortho-, meta-, and para-C of C6H5), 99.7 ꢀs; CuC5H5), 90.3 ꢀd,
JꢀRh,C) ˆ 3.7 Hz; RhC5H5); elemental analysis for C24H20CuORh ꢀ490.9):
calcd: C 58.72, H 4.11; found: C 59.06, H 3.79.
[7h5-C5H5)Rh7k2-SeCPh2)7PMe3)] 724): Compound 24 was prepared as
described for 22, from 4 ꢀ61 mg, 0.15 mmol) and red selenium ꢀ11.7 mg,
0.15 mmol) in benzene ꢀ10 mL); yield 61 mg ꢀ83%). Orange-yellowsolid;
X-ray structure determination of compounds 3 and 22: Single crystals of 3
were grown from a saturated solution in hexane ꢀ608C), which was cooled
to room temperature under an atmosphere of CO, and those of 22 from a
saturated solution in hexane/toluene ꢀ4/1, 608C). Crystal data collection
parameters are summarized in Table 1. Intensity data were corrected for
Lorentz and polarization effects and an empirical absorption correction
was applied ꢀy scans). The structures were solved by direct methods
ꢀSHELXS-97).[31] Atomic coordinates and anisotropic thermal parameters
of the non-hydrogen atoms were refined by the full-matrix least-squares
method ꢀSHELXL-97).[32] The positions of all hydrogen atoms were
‡
‡
m.p. 658C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 489 ꢀ58; [M ]), 413 ꢀ90; [M À
‡
‡
PMe3]), 410 ꢀ20; [M À Se]), 348 ꢀ25; [RhSeCPh2] ), 334 ꢀ4.6;
‡
‡
‡
[C5H5RhCPh2] ), 269 ꢀ2.7; [RhCPh2] ), 245 ꢀ21; [SeCPh2] ), 168 ꢀ20;
‡
[RhC5H5] ); 1H NMR ꢀC6D6, 400 MHz): d ˆ 7.95 ꢀm, 4H; ortho-H of
C6H5), 7.01 ꢀm, 2H; para-H of C6H5), 6.86 ꢀm, 4H; meta-H of C6H5), 4.65
ꢀdd, JꢀRh,H) ˆ JꢀP,H) ˆ 0.9 Hz, 5H; C5H5), 0.59 ꢀdd, JꢀP,H) ˆ 10.0,
JꢀRh,H) ˆ 0.7 Hz, 9H; PCH3); 13C NMR ꢀC6D6, 100.6 MHz): d ˆ 156.5,
154.6 ꢀboth s; ipso-C of C6H5), 134.0, 128.0, 127.8, 127.7, 125.5, 124.0 ꢀall s;
ortho-, meta-, and para-C of C6H5), 89.6 ꢀdd, JꢀRh,C) ˆ JꢀP,C) ˆ 3.8 Hz;
C5H5), 85.1 ꢀdd, JꢀRh,C) ˆ 22.3, JꢀP,C) ˆ 4.1 Hz; RhCPh2), 19.4 ꢀd,
JꢀP,C) ˆ 31.7 Hz; PCH3); 31P NMR ꢀC6D6, 81.0 MHz): d ˆ 0.6 ꢀd,
JꢀRh,P) ˆ 179.9 Hz); elemental analysis for C21H24PRhSe ꢀ489.3): calcd:
C 51.55, H 4.94; found: C 51.73, H 5.09.
À
calculated according to ideal geometry ꢀdistance C H ˆ 0.95 Š) and used
only in structure factor calculation.[33]
[7h5-C5H5)7CO)Rh7m-CPh2)7CuCl)2] 725):
A solution of 3 ꢀ51 mg,
Acknowledgements
0.14 mmol) in benzene ꢀ10 mL) was treated with small portions of CuCl
ꢀ27.0 mg, 0.28 mmol) and stirred for 2 h at room temperature. The reaction
mixture was filtered, and the filtrate was concentrated to about 1 mL in
vacuo. The solution was then chromatographed on Al2O3 ꢀneutral, activity
grade V, height of column 3 cm). With benzene, a red fraction was eluted,
from which after removal of the solvent a deep red solid was obtained. This
was washed several times with 5 mL portions of pentane and dried; yield
We thank the Deutsche Forschungsgemeinschaft ꢀSFB 347) and the Fonds
der Chemischen Industrie for financial support, the Fonds in particular for
a Doktorandenstipendium ꢀto P. S.). Moreover, we acknowledge support by
Mrs. I. Geiter ꢀtechnical assistance), Mrs. R. Schedl and Mr. C. P. Kneis
ꢀelemental analysis and DTA), Mrs. M. L. Schäfer and Dr. W. Buchner
ꢀNMR spectra), Dr. G. Lange and Mr. F. Dadrich ꢀmass spectra), and
Degussa AG for gifts of chemicals.
‡
69 mg ꢀ87%); m.p. 1268C ꢀdecomp); MS ꢀ70 eV): m/z ꢀIr): 560 ꢀ6.4; [M ]),
‡
‡
532 ꢀ0.3; [M À CO), 433 ꢀ0.3; [M À
CO À CuCl), 334 ꢀ100; [C5H5Rh-
‡
‡
Table 1. Crystal structure data of compounds 3 and 22.
CPh2] ), 196 ꢀ5.7; [C5H5RhCO] ),
168 ꢀ51; [RhC5H5] ); IR ꢀKBr): nÄ ˆ
‡
3
22
1989 cmÀ1 ꢀCO); 1H NMR ꢀCDCl3,
200 MHz): d ˆ 7.43 ꢀm, 4H; ortho-H of
C6H5), 7.27 ± 7.17 ꢀm, 4H; meta-H of
C6H5), 7.11 ꢀm, 2H; para-H of C6H5),
5.18 ꢀbr s, 5H; C5H5); 13C NMR
ꢀCDCl3, 50.3 MHz): d ˆ 217.0 ꢀd,
JꢀRh,C) ˆ 45.8 Hz; RhCPh2), 189.9
ꢀd, JꢀRh,C) ˆ 86.7 Hz; RhCO), 162.9,
157.4 ꢀboth s; ipso-C of C6H5), 129.7,
128.0, 127.6, 127.4, 127.1, 127.0 ꢀall s;
ortho-, meta-, and para-C of C6H5),
91.0 ꢀd, JꢀRh,C) ˆ 3.6 Hz; C5H5); ele-
mental analysis for C19H15Cl2Cu2ORh
ꢀ560.2): calcd: C 40.74, H 2.70, Rh
18.37; found: C 40.57, H 2.40, Rh 18.33.
formula
mol. mass
cryst. size [mm]
cryst. system
space group
a [Š]
b [Š]
c [Š]
a [8]
b [8]
C19H15ORh
362.22
C19H15ORhSe
441.18
0.3 Â 0.3 Â 0.2
monoclinic
P21/n ꢀno. 14)
8.678ꢀ8)
11.136ꢀ1)
16.00ꢀ1)
90.0
97.57ꢀ4)
90.0
1532.7ꢀ14)
4
0.38 Â 0.33 Â 0.25
orthorhombic
Pca21 ꢀno. 29)
15.289ꢀ2)
6.551ꢀ2)
16.496ꢀ4)
90.0
90.0
90.0
1652.2ꢀ7)
4
1.774
Enraf-Nonius CAD 4
MoKa ꢀ0.71073 Š)
293ꢀ2)
3.235
74.27
w/q
61.90
2949
2948
g [8]
V [Š3]
Z
1calcd [g cmÀ1
]
1.570
diffractometer
radiation ꢀgraphite-monochromated)
Enraf-Nonius CAD 4
MoKa ꢀ0.71073 Š)
223ꢀ2)
1.109
80.72
w/q
47.96
2401
2400
1907
[I > 2sꢀI)]
190
0.0236
0.0646
1.041
12.63
‡ 0.464/ À 0.380
[7h5-C5H5)7CO)Rh7m-CPh2)Cu7h5-
C5H5)] 726): A solution of 25 ꢀ71 mg,
0.13 mmol) in THF ꢀ10 mL) was treat-
T [K]
m [mmÀ1
]
ed with
a suspension of NaC5H5
transmission min. [%]
scan method
2q ꢀmax) [8]
total reflections
unique reflections
observed reflections
ꢀ57.0 mg, 0.65 mmol) in THF ꢀ5 mL)
and stirred for 30 min at room temper-
ature. A gradual change of color from
deep red to violet occurred. The
solvent was removed in vacuo, the oily
residue was extracted with benzene
ꢀ10 mL), and the extract was concen-
trated to about 1 mL in vacuo. The
solution was chromatographed on
Al2O3 ꢀneutral, activity grade V, height
of column 4.0 cm). With benzene, a
violet fraction was eluted, from which
after removal of the solvent a red-
1979
[I >2sꢀI)]
199
0.0384
0.0914
1.067
14.81
‡ 0.605/ À 0.441
parameters refined
R1
wR2
GOF
reflection/parameter ratio
residual electron density [e Š
À3
]
Chem. Eur. J. 2000, 6, No. 24
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0624-4469 $ 17.50+.50/0
4469

H. Werner et al.
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[33] Crystallographic data ꢀexcluding structure factors) for the structures
reported in this paper have been deposited with the Cambridge
Crystallographic Data Centre as supplementary publication nos.
CCDC-146602 and CCDC-146603. Copies of the data can be obtained
free of charge on application to CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK ꢀfax: ꢀ‡44)1223-336-033; e-mail: deposit@ccdc.cam.
ac.uk).
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Received: June 30, 2000 [F2578]
4470
ꢁ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0624-4470 $ 17.50+.50/0
Chem. Eur. J. 2000, 6, No. 24