Direct access to parent amido complexes of rhodium and iridium through N-H activation of ammonia

Article abstract of DOI:10.1002/anie.201104745

Simplicity! A direct entry to amido rhodium and iridium complexes was easily achieved by reaction of gaseous ammonia with alkoxo-bridged precursors under very mild conditions. This new approach allowed the high-yield access for the first time to elusive [Rh-NH₂] complexes. Copyright

Full text of DOI:10.1002/anie.201104745

DOI: 10.1002/anie.201104745
Amido Complexes
Direct Access to Parent Amido Complexes of Rhodium and Iridium
ꢀ
through N H Activation of Ammonia**
Inmaculada Mena, Miguel A. Casado,* Pilar Garcꢀa-OrduÇa, Vꢀctor Polo, Fernando J. Lahoz,
Atif Fazal, and Luis A. Oro*
ꢀ
Ammonia is a low-cost and potentially valuable building
block for almost every nitrogen-containing compound
required by industry. There is an obvious interest in utilizing
this chemical as feedstock in catalytic organic transformations
to produce higher-value products, an issue that has began to
be explored with some degree of success.[1] However, most of
late transition metal catalyzed reactions do not occur with
ammonia. Several factors have been invoked to explain this
the formation of M NH2 bonds, circumventing the formation
of Werner adducts, should rely on an appropriate design of
organometallic precursors. Herein we report on a synthetic
protocol that uses gaseous ammonia as “NH2” source to
generate stable novel parent bridging and terminal amido RhI
and IrI complexes under very mild conditions.
We chose as metallic precursors dinuclear complexes
bearing alkoxo-bridging ligands, well suited to induce N H
ꢀ
lack of reactivity:[2] 1) The high strength of the N H bond of
activation.[7] In this way, treatment of the methoxo-bridged
compounds [{M(m-OMe)(tfbb)}2] (M = Rh, Ir; tfbb = tetra-
fluorobenzobarrelene) with gaseous ammonia in diethyl ether
at atmospheric pressure rapidly afforded the parent amido-
bridged trinuclear complexes [{M(m2-NH2)(tfbb)}3] (M = Rh
(1), Ir (2)) which were isolated in good yields. On the other
hand, reactions of the cod complexes [{M(m-OMe)(cod)}2]
(cod = 1,5-cycloctadiene) with gaseous ammonia yielded
dinuclear amido-bridged complexes [{M(m-NH2)(cod)}2]
(M = Rh (3), Ir (4)) in excellent yields (Scheme 1). All the
ꢀ
ammonia (107 kcalmolꢀ1) makes its activation very difficult
to achieve by metal centers; 2) the catalyst often deactivates
!
through the formation of stable Werner ammine (M NH3)
adducts; and 3) the low acidity of ammonia prevents its
participation in proton exchange reactions that could lead to
ꢀ
N H activation.
In order to achieve a metal-mediated functionalization of
ammonia, an imperative requisite should be the formation of
ꢀ
M NH2 bonds directly from ammonia (i.e. rather than
!
leading to stable M NH3 adducts).[3] So far, only few early
examples involving interaction of NH3 with iridium com-
plexes followed an oxidative addition profile.[4] This concept
was elegantly illustrated by Hartwig et al., who reported on
the formal oxidative addition of ammonia to an electron-rich
IrI pincer system, leading to the first structurally characterized
terminal amido hydrido IrIII complex.[5] In spite of the efficacy
ꢀ
of this N H activation, uptake and homolytic breakage of
ammonia by late transition metal complexes still remains a
difficult goal.[6] We assumed that a good approach to induce
[*] Dipl.-Chem. I. Mena, Dr. M. A. Casado, Dr. P. Garcꢀa-OrduÇa,
Prof. F. J. Lahoz, Prof. L. A. Oro
Instituto de Sꢀntesis Quꢀmica y Catꢁlisis Homogꢂnea ISQCH
Universidad de Zaragoza-CSIC
Pl. San Francisco s/n, 50009 Zaragoza (Spain)
E-mail: mcasado@unizar.es
Scheme 1. Synthesis of parent amido-bridged complexes [{M(m-NH2)-
(tfbb)}3] (1, 2) and [{M(m-NH2)(cod)}2] (3, 4) (M=Rh, Ir).
oro@unizar.es
reactions leading to complexes 1–4 were found to be
reversible. For example, monitoring by NMR spectroscopy
the reaction of 3 with MeOH in a 1:1 ratio in [D6]benzene
showed upon 10 min, when the equilibrium was considered to
be reached, the presence of unchanged 3, the original
methoxo-bridged complex [{Rh(m-OMe)(cod)}2] and the
mixed amido-alkoxo species [{Rh(cod)}2(m-OMe)(m-NH2)]
in a 0.4:0.3:1 ratio along with released ammonia (see
Supporting Information). Excess of substrates (i.e. NH3 or
MeOH) are required to drive the reactions to completion
either way, as observed experimentally.
Dr. V. Polo
Departamento de Quꢀmica Fꢀsica, Universidad de Zaragoza
50009 Zaragoza (Spain)
Dr. A. Fazal, Prof. L. A. Oro
Center for Refining & Petrochemicals
King Fahd University of Petroleum & Minerals
Dhahran 31261 (Saudi Arabia)
[**] Financial support from CONSOLIDER INGENIO-2010 program
under the projects MULTICAT (CSD2009-00050) and Factorꢀa de
Cristalizaciꢃn (CSD2006-0015). P.G.O. acknowledges financial
support from the CSIC “JAE-Doc” program. L.A.O. is a Visiting
Professor at the King Fahd University of Petroleum & Minerals.
Complexes 1–4 have been fully characterized by elemen-
tal analysis, spectrometric techniques, and multinuclear NMR
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201104745.
Angew. Chem. Int. Ed. 2011, 50, 11735 –11738
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
11735

Communications
(1H, 13C{1H}, and bidimensional g-HMQC 1H-15N) data.
Additionally, an X-ray structural analysis has been carried
out for complexes 1, 2, and 3 (Figures 1 and 2).[8] The most
striking structural feature of these complexes relies on the
Calculations at the DFT level have been carried for amido
di- and trinuclear complexes of Rh and Ir bearing tfbb and
cod as ancillary ligands. The obtained gas-phase optimized
geometries of structures 1–4 are in good agreement with X-
ray values. Stationary points on the potential energy surfaces
have been found for the experimentally unobserved trinu-
clear complexes of Rh and Ir bearing the cod ligand. These
structures show a distortion from the C3v symmetry due to
short hydrogen–hydrogen contacts (1.966 ꢀ) between neigh-
boring cod units, pointing out a destabilization of trinuclear
cod complexes due to steric repulsion. In contrast, such steric
hindrance is reduced for trinuclear tfbb complexes due to the
smaller size of the ligand (See Supporting Information).
Complexes 1–4 showed a temperature-dependent behav-
ior in solution. At room temperature, both the 1H and 13C{1H}
NMR spectra of 1 and 2 showed two signals for the tfbb
=
ligands (CH and CH, respectively), indicating an averaged
Figure 1. Molecular diagram of complex 1. Selected bond lengths [ꢄ]
and angles [8]: Rh1–N1 2.058(2), Rh1–N3 2.075(3), Rh2–N1 2.089(2),
Rh2–N2 2.066(3), Rh3–N2 2.084(3), Rh3–N3 2.068(3), mean Rh–Ct
2.001(3); N1-Rh1-N3 86.9(1), N1-Rh2-N2 88.1(1), N2-Rh3-N3 88.4(1)8.
Ct represents the midpoints of the olefinic bonds.
D3h symmetry, and a resonance due to the NH2 moiety at 0.35
(1) and 2.67 ppm (2) (15N NMR: 5.5 ppm (1); ꢀ1.73 ppm (2)).
Cooling the solutions of 1 and 2 led to the freezing of the
fluxional motions, and single species with C3v symmetry were
observed, according with the solid-state structure found for
both complexes. For instance, at ꢀ508C the 1H NMR
=
spectrum of 1 showed the CH and CH protons as sets of
two resonances, while the amido protons were observed as
two resonances at 0.23 and 0.44 ppm. This dynamic behavior
responds to a fast exchange between the two possible
conformers (cone and partial cone), which show approxi-
mately C3v and C2 symmetries, respectively. Line-shape NMR
variable-temperature analysis allowed an estimation of the
activation energy for the envelope flipping motions, which
were 42.1 and 52.3 kJmolꢀ1 for complexes 1 and 2, respec-
tively. These results are supported by gas-phase calculations
(see Supporting Information). Partial cone structures of 1 and
2 have been found, being 17.1 and 20.0 kJmolꢀ1 less stable
than the respective cone conformer. Transition structures
have been found for the fluxional motion, yielding activation
energies of 40.4 and 44.9 kJmolꢀ1 for 1 and 2, respectively, in
good agreement with experimental values. On the other hand,
Figure 2. ORTEP diagram of complex 3. Selected bonds lengths [ꢄ]
and angles [8] (only data for one independent molecule is given here):
Rh1–N1 2.092(2), Rh1–N2 2.078(3), Rh2–N1 2.088(2), Rh2–N2
2.064(2), mean Rh–Ct 2.003(5); N1-Rh1-N2 76.64(9), N1-Rh2-N2
76.95(10). Ct represents the midpoints of olefinic bonds.
1
the pattern of the H and 13C{1H} NMR spectra of both cod
different nuclearity of the tfbb compounds 1 and 2 in
comparison to the cod complex 3, apparently only induced
by the nature of the diolefin. Complexes 1 and 2 are trinuclear
and isostructural, and exhibit three square-planar metal
centers bridged by three m2-NH2 groups, forming a Rh3N3
six-membered metallacycle with a cone disposition.[9] Inter-
metallic distances fall in the range 3.2043(3)–3.3981(2) ꢀ (1)
and 3.2135(4)–3.4222(4) ꢀ (2), all of them excluding clear
metal–metal interactions.
On the contrary, complex 3 is dinuclear, and crystallizes
with two crystallographically independent but chemically
identical molecules in the unit cell. The rhodium atoms lie on
slightly distorted square-planar geometries and are held
together by two amido bridging groups; the whole structure
complexes 3 and 4 at room temperature were similar to each
other, indicating a dynamic motion which could not be frozen
at ꢀ908C in [D8]toluene. The D2h symmetry detected, in
contrast to the expected C2v symmetry observed in the solid
state, responded to a four-membered “MNMN” metallacycle
inversion,[10] which is fast on the NMR time scale therefore
producing averaged NMR signals that reflected a planar
conformation.
Access to terminal parent amido complexes of RhI was
straightforward by splitting the amido bridges of complex 1
with donor ligands, like dimethylphenylphosphane and the N-
heterocyclic carbene 1,3-bis(2,6-diisopropylphenyl)imidazol-
2-ylidene (IPr). Treatment of 1 with PMe2Ph in a 1:3 molar
ratio gave [Rh(tfbb)(NH2)(PMe2Ph)] (5) in 61% yield. In a
similar way, addition of IPr to 1 in a 3:1 molar ratio led to the
formation of mononuclear complex [Rh(tfbb)(IPr)(NH2)] (6)
ꢀ
is folded around the N N vector with dihedral angles of
68.36(6)8 and 58.45(7)8 between the two metal coordination
planes of each molecule. The intermetallic separations
(2.7785(3) and 2.8603(3) ꢀ) are much shorter than those
observed in the tfbb analogs.
in 44% yield (Scheme 2). Complexes 5 and 6 featured an
I
ꢀ
unprecedented Rh NH2 moiety, which was confirmed by
15N-1H HMQC spectroscopy (d(1H) = ꢀ0.54 (5), 1.23 ppm
11736 www.angewandte.org
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2011, 50, 11735 –11738

ꢀ
unknown Rh NH2 complexes, and 2) this protocol is not
limited to a specific system, but on the contrary, it may be
extended to other metals bearing alkoxo bridging ligands.
ꢀ
Finally, we believe that the ability to generate M NH2
complexes directly from ammonia follows the right direction
towards the discovering of new catalytic processes involving
the functionalization of ammonia, a highly desirable and
valuable target that we are currently exploring.
Experimental Section
1: Gaseous ammonia was bubbled through a yellow suspension of
[{Rh(m-OMe)(tfbb)}2] (0.25 g, 0.35 mmol) in diethyl ether (20 mL) at
ꢀ158C, giving rise to the crystallization of an orange microcrystalline
solid within 5 min. The bubbling of ammonia was continued for
30 min and the solid was collected by filtration via cannula, washed
with hexanes and then vacuum-dried (0.21 g, 88%). 1H NMR
(300 MHz, [D6]benzene, 258C, TMS): d = 5.41 (m, 6H; CH), 2.83
Scheme 2. Synthesis of complexes 5 and 6. a) 3 equiv PMe2Ph,
toluene, ꢀ158C; b) 3 equiv IPr, toluene, RT.
(6); d(15N) = ꢀ11.8 (5), 67.6 ppm (6)). The diolefins appeared
(m, 12H; CH) (tfbb), 0.35 ppm (br s, 6H; NH2); 1H NMR
=
1
as a set of three resonances in their H NMR spectra, which
(300 MHz, CD2Cl2, ꢀ508C, TMS): d = 5.89 (m, 3H), 5.35 (m, 3H)
=
indicated the presence of
a
mirror plane, while the
(CH), 3.38 (m, 6H), 3.20 (m, 6H) ( CH) (tfbb), 0.44 (br s, 3H),
0.23 ppm (br s, 3H) (NH2); 13C{1H} NMR (75 MHz, [D6]benzene,
tfbb:NH2:L (L = PMe2Ph, IPr) ratio was 1:1:1 in both cases.
In 6, the presence of a sole septuplet for the iPr protons is
explained taking into account the added effects of a rotational
process that exchanges unsymmetrical isopropyl groups, and
the mirror plane that bisects the imidazol ring of IPr and
contains the Rh, N, and the C-carbenic atoms.[11]
In general, access to parent amido low-valent late
transition metal complexes is rather limited, perhaps due to
the absence of aromatic substituents at nitrogen, which adds
stabilization to the system by electronic delocalization.[12]
There are synthetic routes towards these compounds mainly
based on salt metathesis reactions,[13–15] however they need
strong bases and do not use ammonia directly for their
formation. Only few examples of these elusive species have
been recently reported to be prepared from ammonia without
change of the redox state of the metals; they are based on
1
1
258C, TMS): d = 139.2 (dm, J(C,F) = 248 Hz), 138.2 (dm, J(C,F) =
255 Hz) (CF), 127.8 (m, Cq), 52.3 (d, 1J(C,Rh) = 10 Hz; = CH),
40.2 ppm (d, J(C,Rh) = 4 Hz; CH) (tfbb); 19F{1H} NMR (282 MHz,
2
[D6]benzene): d = ꢀ147.9 (d, 3J(F,F) = 25 Hz), ꢀ160.5 ppm (d, 3J-
(F,F) = 25 Hz); 15N-1H HMQC (40 MHz, [D6]benzene, 258C, NH3):
d = 5.5 (br s; NH2); MS (m-TOF+): m/z 369.9 [M+/3+Na+H];
elemental analysis calcd (%) for C36H24F12N3Rh3: C 41.77, H 2.34, F
22.02, N 4.06; found: C 41.65, H 2.23, F 21.95, N 4.01.
5: To a solution of 1 (0.12 g, 0.12 mmol) in toluene (4 mL) kept at
ꢀ158C, pure dimethylphenylphosphane (0.05 g, 52 mL, 0.36 mmol)
was added slowly via syringe. The resulting orange solution was
stirred for 15 min and then the volume was evaporated to dryness by
reduced pressure. The resulting orange solid was washed with
hexanes, filtered via cannula and dried under vacuum (0.11 g,
61%). 1H NMR (400 MHz, [D8]toluene, 258C, TMS): d = 8.00 (m,
2H; Ho Ph), 7.10 (m, 3H; Hm + Hp Ph) (PMe2Ph), 5.49 (s, 2H; CH),
=
3.12 (m, 4H; CH) (tfbb), 1.12 (m, 6H; Me), ꢀ0.54 ppm (br s, 2H;
NH2); 1H NMR (400 MHz, [D8]toluene, 258C, TMS): d = 8.05 (m,
ꢀ
deprotonative N H cleavage by a m3-oxo triruthenium
2H; Ho Ph), 7.14 (m, 3H; Hm + Hp Ph) (PMe2Ph), 5.57 (s, 2H; CH),
cluster[16] and by a diaryl Fe complex.[17] Furthermore, it has
been shown how ammonia is activated by bifunctional
iridium[18] or ruthenium[19] complexes through metal–ligand
cooperation. The reactions described herein proceed as well
=
=
3.18 (m, 2H; CH), 3.02 (m, 2H; CH) (tfbb), 1.21 (m, 6H; Me),
ꢀ0.36 ppm (br s, 2H; NH2); 31P{1H} NMR (121 MHz, [D6]benzene,
258C): d = ꢀ13.6 ppm (d, 1J(P,Rh) = 170 Hz); 13C{1H}-APT NMR
plus HSQC (100.6 MHz, [D8]toluene, ꢀ208C, TMS): d = 142.1 (dd,
1J(C,P) = 18 Hz, 2J(C,Rh) = 17 Hz; Cipso Ph), 139.9 (dm, 1J(C,F) =
242 Hz), 138.2 (dm, 1J(C,F) = 269 Hz) (CF tfbb), 131.63 (dd, 2J-
ꢀ
through an N H heterolytic cleavage of ammonia, assisted
intramolecularly by a methoxo basic ligand attached to the
metal. Once the amido complexes are formed, no exchange
with ND3 was observed. Under mild conditions, no reaction of
the terminal amido Rh complexes with olefins was detected.
However, with terminal acetylenes, clear evidence of alkynyl
complexes along with polymer formation was observed. We
anticipate that diolefin amido rhodium complexes described
herein catalyze very efficiently the homogeneous polymeri-
zation of phenylacetylene, being the trinuclear tfbb complex 1
much more active than the dinuclear cod complex 2.
3
3
(C,P) = 6 Hz, J(C,Rh) = 6 Hz; Co), 128.7 (s, Cp), 127.6 (d, J(C,P) =
4 Hz; Cm) (Ph), 48.5 (d, 1J(C,Rh) = 10 Hz; CH), 40.3 ppm (d,
=
2J(C,Rh) = 3 Hz; CH) (tfbb); 19F{1H} NMR (282 MHz, [D6]benzene):
d = ꢀ144.4 (d, 3J(F,F) = 23 Hz), ꢀ157.1 ppm (d, 3J(F,F) = 25 Hz); 15N-
1H HMQC (40 MHz, [D6]benzene, 258C, NH3): d = ꢀ11.8 ppm; MS
(m-TOF+): m/z 467.0 [M+ꢀNH2]; elemental analysis calcd (%) for
C20H19F4NPRh: C 49.71, H 3.96, N 2.90; found: C 49.68, H 3.89, N
2.81.
Received: July 8, 2011
Revised: September 5, 2011
Published online: October 12, 2011
In conclusion, we have developed a method that allows
the high-yield access to RhI and IrI parent amido complexes
directly from gaseous ammonia, creating a unique platform
where to explore the reactivity and catalytic performance of
these rare and relevant species.[20] Two important points
should be underlined about the synthetic strategy we
enlighten here: 1) it provides a direct entry into previously
Keywords: amido complexes · ammonia · iridium ·
.
ꢀ
N H activation · rhodium
Angew. Chem. Int. Ed. 2011, 50, 11735 –11738
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org 11737

Communications
[9] B. Lippert, P. J. Sanz Miguel, Chem. Soc. Rev. 2011, 40, 4475 –
4482.
[10] C. Tejel, M. A. Ciriano, M. Bordonaba, J. A. Lꢂpez, F. J. Lahoz,
L. A. Oro, Chem. Eur. J. 2002, 8, 3128 – 3138.
[1] a) J. I. van der Vlugt, Chem. Soc. Rev. 2010, 39, 2302 – 2322; b) Y.
Aubin, C. Fischmeister, C. M. Thomas, J. L. Renaud, Chem. Soc.
Rev. 2010, 39, 4130 – 4145.
[2] J. L. Klinkenberg, J. F. Hartwig, Angew. Chem. 2011, 123, 88 – 98;
Angew. Chem. Int. Ed. 2011, 50, 86 – 95.
[3] T. Braun, Angew. Chem. 2005, 117, 5138 – 5140; Angew. Chem.
Int. Ed. 2005, 44, 5012 – 5014.
[4] a) A. L. Casalnuovo, J. C. Calabrese, D. Milstein, Inorg. Chem.
1987, 26, 971 – 973; b) R. Koelliker, D. Milstein, Angew. Chem.
1991, 103, 724 – 726; Angew. Chem. Int. Ed. Engl. 1991, 30, 707 –
709; c) M. Schulz, D. Milstein, J. Chem. Soc. Chem. Commun.
1993, 318 – 319; d) R. Koelliker, D. Milstein, J. Am. Chem. Soc.
1991, 113, 8524 – 8525.
[11] a) S. Ragone, A. Poater, L. Cavallo, J. Am. Chem. Soc. 2010, 132,
4249 – 4258; b) C. L. Vꢃlez, P. R. L. Markwick, R. L. Holland,
A. G. DiPasquale, A. L. Rheingold, J. M. OꢄConnor, Organo-
metallics 2010, 29, 6695 – 6702; c) V. Ritleng, C. Barth, E.
Brenner, S. Milosevik, M. J. Chetcuti, Organometallics 2008,
27, 4223 – 4228.
[12] a) J. R. Fulton, A. W. Holland, D. J. Fox, R. G. Bergman, Acc.
Chem. Res. 2002, 35, 44 – 56; b) M. Rahim, C. White, A. L.
Rheingold, K. J. Ahmed, Organometallics 1993, 12, 2401 – 2403;
c) M. K. Kolel-Veetil, M. Rahim, A. J. Edwards, A. L. Rhein-
gold, K. J. Ahmed, Inorg. Chem. 1992, 31, 3877 – 3878.
[13] a) J. L. Klinkenberg, J. F. Hartwig, J. Am. Chem. Soc. 2010, 132,
11830 – 11833; b) D. J. Fox, R. G. Bergman, Organometallics
2004, 23, 1656 – 1670; c) J. Cꢅmpora, P. Palma, D. del Rꢆo, M. M.
Conejo, E. ꢇlvarez, Organometallics 2004, 23, 5653 – 5655;
d) D. J. Fox, R. G. Bergman, J. Am. Chem. Soc. 2003, 125,
8984 – 898; e) A. W. Kaplan, J. C. M. Ritter, R. G. Bergman, J.
Am. Chem. Soc. 1998, 120, 6828 – 6829.
[14] M. Kanzelberger, X. Zhang, T. J. Emge, A. S. Goldman, J. Zhao,
C. Incarvito, J. F. Hartwig, J. Am. Chem. Soc. 2003, 125, 13644 –
13645.
[15] a) D. Conner, K. N. Jayaprakash, T. R. Cundari, T. B. Gunnoe,
Organometallics 2004, 23, 2724 – 2733; b) A. W. Holland, R. G.
Bergman, J. Am. Chem. Soc. 2002, 124, 14684 – 14695; c) K. N.
Jayaprakash, D. Conner, T. B. Gunnoe, Organometallics 2001,
20, 5254 – 5256; d) F. L. Joslin, M. P. Johnson, J. T. Mague, D. M.
Roundhill, Organometallics 1991, 10, 2781 – 2794.
[5] J. Zhao, A. S. Goldman, J. F. Hartwig, Science 2005, 307, 1080 –
1082.
[6] a) E. Morgan, D. F. MacLean, R. McDonald, L. Turculet, J. Am.
Chem. Soc. 2009, 131, 14234 – 14236; b) M. A. Salomon, A. K.
Jungton, T. Braun, Dalton Trans. 2009, 7669 – 7677; c) C. M.
Fafard, D. Adhikari, B. M. Foxman, D. J. Mindiola, O. V. Ozerov,
J. Am. Chem. Soc. 2007, 129, 10318 – 10319; d) P. Klꢁring, S. Pahl,
T. Braun, A. Penner, Dalton Trans. 2011, 40, 6785 – 6791.
[7] a) C. Tejel, M. A. Ciriano, M. Bordonaba, J. A. Lꢂpez, F. J.
Lahoz, L. A. Oro, Inorg. Chem. 2002, 41, 2348 – 2355; b) J. J. Li,
W. Li, A. J. James, T. Holbert, T. P. Sharp, P. R. Sharp, Inorg.
Chem. 1999, 38, 1563 – 1572.
[8] Data for 1: C36H24F12N3Rh3·C6H14, M = 1121.48, space group P21/
n, a = 13.5763(8), b = 13.3187(8), c = 21.4824(13) ꢀ; b =
99.062(2)8; V= 3835.9(4) ꢀ3; Z = 4; R1 = 0.0344, 9620 reflec-
tions, I > 2s(I); wR(F2) = 0.0880, GoF = 1.033 (10940 unique).
Data for 2: C36H24F12N3Ir3·C6H14, M = 1389.42, space group P21/
n, a = 13.5872(6), b = 13.3741(6), c = 21.3459(10) ꢀ; b =
98.951(1)8; V= 3831.7(3) ꢀ3; Z = 4; R1 = 0.0262, 8669 reflec-
tions, I > 2s(I); wR(F2) = 0.0680, GoF = 1.019 (9967 unique).
[16] Y. Nakajima, H. Kameo, H. Suzuki, Angew. Chem. 2006, 118,
964 – 966; Angew. Chem. Int. Ed. 2006, 45, 950 – 952.
[17] C. Ni, H. Lei, P. P. Power, Organometallics 2010, 29, 1988 – 1991.
[18] T. Kimura, N. Koiso, K. Ishiwata, S. Kuwata, T. Ikariya, J. Am.
Chem. Soc. 2011, 133, 8880 – 8883.
[19] E. Khaskin, M. A. Iron, L. J. W. Shimon, J. Zhang, D. Milstein, J.
Am. Chem. Soc. 2010, 132, 8542 – 8543.
[20] a) J. F. Hartwig, Nature 2008, 455, 314 – 322; b) T. E. Mꢈller,
K. C. Hultzsch, M. Yus, F. Foubelo, M. Tada, Chem. Rev. 2008,
108, 3795 – 3892.
ꢀ
Data for 3: C16H28N2Rh2, M = 454.22, space group P1, a =
6.9014(4), b = 11.6776(7), c = 21.2575(13) ꢀ; a = 104.3290(10),
b = 98.7070(10); g = 90.4370(10)8, V= 1638.9(2) ꢀ3; Z = 4; R1 =
0.0208, 7277 reflections, I > 2s(I); wR(F2) = 0.0706, GoF = 1.002
(8225 unique). CCDC 831649 (1), 831650 (2), and 831651 (3)
contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
11738 www.angewandte.org
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2011, 50, 11735 –11738