Gold- and platinum-bismuth donor-acceptor interactions supported by an ambiphilic PBiP pincer ligand

Article abstract of DOI:10.1002/anie.201200848

Noble metals meet a heavyweight: A pincer ligand brings together bismuth with gold and platinum, so that metallophilic interactions are established. According to DFT calculations, these interactions contain dominant metal-bismuth contributions. Copyright

Full text of DOI:10.1002/anie.201200848

Angewandte
Chemie
DOI: 10.1002/anie.201200848
Metallophilic Interactions
Gold– and Platinum–Bismuth Donor–Acceptor Interactions Supported
by an Ambiphilic PBiP Pincer Ligand**
Carolin Tschersich, Christian Limberg,* Stefan Roggan, Christian Herwig, Nikolaus Ernsting,
Sergey Kovalenko, and Stefan Mebs
Dedicated to Professor Karl Wieghardt on the occasion of his 70th birthday
Compared to the other pnictogens, bismuth, the heaviest of all
stable elements, certainly has a unique character. Corre-
spondingly, also its chemistry in the oxidation state + III
frequently differs greatly from that of its lighter homologues.
Although some compounds have been isolated that show that
Scheme 1. Frameworks enabling electronic interactions of Lewis acidic
bismuthanes can principally act as donor ligands for transi-
tion-metal ions,[1] their number is rather limited. This is likely
boron (left) and bismuth centers (right) with electron-rich transition-
metal fragments d8 MLn (D=PR2, X=electronegative ligand).
due to the inert character of the 6s2 lone pair, which, because
it is stabilized by pronounced relativistic effects, does not
possess a donor strength comparable to that of phosphane
lone pairs for example. In contrast, BiIII compounds often
show distinct Lewis acidic properties, especially if electro-
negative ligands X are bound. This can be rationalized by the
metal!boron complexes may also be utilized to access
complexes in which bismuth(III) presents its Lewis acidic
nature in a bond to a late transition metal (Scheme 1, right).
The abovementioned properties of bismuth particularly
encourage corresponding investigations, both to gain funda-
mental insights and also with respect to potential applica-
tions: The possibility of influencing the reactivity and
catalytic activity (selectivity) of a late transition-metal com-
plex entity by Lewis acidic bismuth moieties, the properties of
which in turn can be tuned by the electronegativity of the
connected coligands, appears highly attractive. Nevertheless,
fact that binding of X to BiIII generates an antibonding s*(Bi
ꢀ
X) orbital directed towards the position trans to X, which acts
as an acceptor orbital for external ligands (“secondary
bonding”).[2] Lewis acidity combined with the large ionic
radius of Bi3+ and the low toxicity of its complexes has led to
an increasing popularity of Bi compounds, including as
catalysts in organic chemistry.[3]
The s-donor behavior of electron-rich transition-metal
ions towards electron deficient, Lewis acidic main-group
elements (for example of Group 13) was demonstrated some
time ago.[4] A general framework of systems that have allowed
for the successful establishment of metal–boron interactions
through tethering even in the absence of a trans-positioned s-
donor[4i] is shown in Scheme 1 on the left hand side. Very
recently, compounds were reported in which transition-metal
complex fragments act as donors even for saturated Lewis
acidic units containing SiIV and SnIV,[5a,b] as well as SbV
ꢀ
closed-shell M Bi interactions, with M representing a late
transition metal, are still virtually unexplored: Bismuthane
complexes are known mainly for the Groups 6–8,[1] and with
regard to the noble metals, only one precedent case of
ꢀ
a metallophilic M Bi interaction has been reported: in
[Au(C6F5)2]ꢀ[Bi(2-CH2NMe2C6H4)2]+ electrostatic effects
lead to a AuI···BiIII contact.[7]
To stabilize complexes displaying such metallic contacts
with pronounced M!Bi character, we have now developed
centers.[5c]
an ambiphilic ligand system in which a Lewis acidic Bi X unit
ꢀ
[6]
ꢀ
In the past we have been concerned with Bi M bonds,
and the background outlined above made us wonder whether
the concepts that have allowed for the synthesis of stable
is combined with two Lewis basic phosphane donor functions
ꢀ
that may serve to place the Bi X unit close to a transition-
metal center. Obvious choices for suitable complex metal
fragments are those containing metals with a d8 configuration
and thus a filled Lewis basic dz2 orbital (see Scheme 1). An
interesting candidate is also AuI, as it can be expected to lead
to large relativistic effects.[7] Having tailored a PBiP pincer
ligand for this purpose, we have therefore tested its potential
[*] Dipl.-Chem. C. Tschersich, Prof. Dr. C. Limberg, Dr. S. Roggan,
Dr. C. Herwig, Prof. Dr. N. Ernsting, Dr. S. Kovalenko, Dr. S. Mebs
Humboldt-Universitꢀt zu Berlin, Institut fꢁr Chemie
Brook-Taylor-Strasse 2, 12489 Berlin (Germany)
E-mail: christian.limberg@chemie.hu-berlin.de
Homepage: http/www.chemie.hu-berlin.de/aglimberg/
I
8
ꢀ
to establish M Bi interactions for Au and d -configurated
PtII. Herein we describe the results of our efforts that led to
complexes incorporating strong Au!Bi and Pt!Bi inter-
actions.
[**] We are grateful to the Deutsche Forschungsgemeinschaft, the
Fonds der Chemischen Industrie, and the Humboldt-Universitꢀt zu
Berlin for financial support. We also would like to thank Martin
Quick for support in femtosecond spectroscopy studies and Prof.
Martin Kaupp for helpful discussions.
To synthesize the envisaged ambiphilic ligand, two
equivalents of 1-bromo-2-diphenylphosphinobenzene were
reacted with nBuLi for a subsequent salt metathesis reaction
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201200848.
Angew. Chem. Int. Ed. 2012, 51, 1 – 5
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
These are not the final page numbers!

.
Angewandte
Communications
Scheme 2. Synthesis of ambiphilic Bi(o-PPh2-C6H4)2Cl (PBiP).
with BiCl3 (Scheme 2). After purification, Bi(o-PPh2-
C6H4)2Cl (PBiP) was isolated as a creamy white solid.
Single crystals of PBiP suitable for X-ray diffraction were
obtained by slow evaporation of the solvent from a saturated
solution in p-xylene, and Figure 1 shows the molecular
Scheme 3. Synthesis of heterometallic complexes 1 and 2. cod=1,5-
cyclooctadiene.
Figure 1. Molecular structure of Bi(o-PPh2-C6H4)2Cl (PBiP). Hydrogen
atoms are omitted for clarity. Selected bond lengths [ꢂ] and angles [8]:
Bi–Cl 2.5639(17); Cl-Bi-C1 90.91(18), Cl-Bi-C1’ 89.98(17), C1-Bi-C1’
95.4(2).
Figure 2. Molecular structure of [Au(PBiP)Cl] (1). One co-crystallized
acetone solvent molecule and hydrogen atoms are omitted for clarity.
Selected bond lengths [ꢂ] and angles [8]: Bi–Au 2.9979(3), Bi–Cl1
2.6183(16), Au–Cl2 2.5185(16), Au–P 2.3061(14), Au–P’ 2.3044(14);
Au-Bi-Cl1 171.42(4), Bi-Au-Cl2 162.25(4), P-Au-P’ 157.90(5), Bi-Au-P
79.26(4), Bi-Au-P’ 80.55(4), P-Au-Cl2 104.37(5), P’-Au-Cl2 97.60(5).
structure.[8] The Bi C and Bi Cl distances in PBiP do not
significantly differ from those in other Bi(aryl)2Cl com-
pounds,[9] and the sum of angles around the bismuth atom
(276.298) is also characteristic for this metal in its oxidation
ꢀ
ꢀ
state + III.[10] The two Bi P/P’ distances in the molecule differ
from each other (3.1695(18) and 3.4071(18) ꢀ), both being
shorter than the sum of the Bi and P van der Waals radii
(3.87 ꢀ).[11]
C6H4)2Ph}Cl][4c] and it documents the unusual character of
these ligand systems. The Bi/B-Au-Cl and P-Au-P’ angles are
quite similar for both complexes. Obviously, the most
ꢀ
ꢀ
important structural parameter of [Au(PBiP)Cl] is the Au
Bi distance. To our knowledge, only one compound so far
For the complexation of AuI, a mixture of the two
colorless compounds [Au(PPh3)Cl] and PBiP was dissolved in
dichloromethane, which led to an immediate coloration to
yellow. The 31P{1H} NMR spectrum of the corresponding
yellow solid dissolved in CD2Cl2 showed a single resonance at
d = 25.8 ppm, which a chemical shift typical for aryl phos-
phane units coordinated to AuI,[5c,12] thus suggesting the
complex [Au(PBiP)Cl] (1) as the product (Scheme 3).
By diffusion of hexane into a saturated solution of 1 in
acetone, crystals could be grown that where suitable for an X-
ray diffraction analysis;[8] the corresponding molecular struc-
ture is depicted in Figure 2. The AuI center in 1 is located in
a distorted square-planar coordination sphere composed of
the bismuth(III) atom, the two phosphane moieties, and the
chloride ligand. This is noteworthy, as a four-coordinate
gold(I) atom should favor a tetrahedral surrounding.[13]
However, the same observation has been made by Bourissou
et al. in case of the gold–boron system [Au{B(o-PPh2-
exists in the literature that may be compared with 1 in this
ꢀ
respect: In 2007, Fernꢁndez et al. reported a Au Bi inter-
action in [Au(C6F5)2]ꢀ[Bi(2-CH2NMe2C6H4)2]+.[7a] In this
I
III
ꢀ
complex, the Au Bi distance of 3.7284(5) ꢀ is still as long
as the sum of the corresponding van der Waals radii that can
formally be assigned (3.728 ꢀ),[11] but naturally in case of such
large atoms the latter are somewhat ill-defined, as even the
homometallic element–element distances vary substantially
in different compounds. DFT and ab initio calculations have
revealed that in [Au(C6F5)2]ꢀ[Bi(2-CH2NMe2C6H4)2]+, the
Au–Bi contact mainly arises from electrostatic interactions
(80%), complemented by some dispersion-type interactions
(20%).
ꢀ
The Au Bi distance is much shorter in 1 (2.9979(3) ꢀ). To
clarify which kind of orbitals are involved in bonding, density
functional calculations were performed (B3LYP/Def2-
TZVP), and an NBO analysis revealed one dominating
2
www.angewandte.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2012, 51, 1 – 5
These are not the final page numbers!

Angewandte
Chemie
donor–acceptor interaction between atomic orbitals of the
two metal atoms: Au(5dx2ꢀy2)!Bi(6py), which stabilizes the
Lewis structure by an energy of 12.3 kcalmolꢀ1. Some back-
donation Bi(6s)!Au(6s) does occur, but comparison of the
corresponding stabilizing energy of 4.9 kcalmolꢀ1 shows that
its contribution to the bonding is minor (see the Supporting
Information). The orbitals mainly contributing to the donor–
acceptor interactions are shown in Figure 3.
With a 0.43 ps time constant, the emission shifts to the red
region and broadens significantly. This process could reflect
the reorganization of the structure and solvent shell. There-
after, the emission disappears with 1.76 ps time constant. All
spectra and their analysis are reported in the Supporting
Information.
The complexation behavior of PBiP with regard to Lewis
basic d8 transition-metal complex fragments was investigated
in the reaction of PBiP with [Pt(cod)Cl2] in dichloromethane,
which led to the formation of [Pt(PBiP)Cl2] (2; Scheme 3).
Compound 2 was isolated as a light-yellow solid, and crystals
that were suitable for X-ray diffraction analysis could be
obtained by the same procedure as described above for 1; the
molecular structure of 2 is shown in Figure 4.[8] The plati-
num(II) center is found in a square-pyramidal coordination
Figure 3. Superposition of the donor and acceptor orbitals according
to NBO analysis, which contribute mainly to the metal–bismuth
interactions in 1 (above) and 2 (below); s character Bi6s 87%, Au6s
96%.
Figure 4. a) Molecular structure of [Pt(PBiP)Cl2] (2). One co-crystal-
lized acetone solvent molecule and hydrogen atoms are omitted for
clarity. Selected bond lengths [ꢂ] and angles [8]: Bi–Pt 2.9009(5), Bi–Cl1
2.6197(19), Pt–Cl2 2.4195(17), Pt–Cl3 2.4193(17), Pt–P’ 2.268(2), Pt–P
2.266(2); Pt-Bi-Cl1 178.67(6), Bi-Pt-Cl3 93.95(4), Bi-Pt-P’ 87.46(6), Cl2-
Metallophilic interactions involving gold are of interest
not only principally and theoretically but also for photo-
physical chemistry: Luminescence of gold(I) complexes has
been observed depending on the nature and geometry of the
chosen ligands and on the strength of intermolecular auro-
philic interactions.[14] A new development in this area is the
synthesis of complexes, which contain a second metal
component through heterometallic interactions.[14] The latter
can modify the frontier orbital situation of gold and thus
influence the photophysical properties.
ꢀ
Pt-Cl3 87.54(6), P-Pt-P’ 97.96(9); b) View onto Cl1 along the Bi Pt
axis.
sphere, where the two phosphane donor functions of the
ambiphilic ligand are in cis configuration to each other. The
two chloride ligands complement the square base, and owing
to the geometry of the PBiP ligand, the bismuth atom forms
the top of the pyramid. In this position, the Lewis acidic
ꢀ
Indeed, the combination of [Au(PPh3)Cl] and PBiP results
in a new absorption band for 1 that is not inherent to the
starting materials. The optical absorption of [Au(PBiP)Cl] in
dichloromethane has its maximum at 377 nm. As static
fluorescence measurements did not show emission, the fate
of photoexcited complex 1 was investigated in more detail by
femtosecond transient absorption spectroscopy.[15] Excitation
was performed with short pulses at 403 nm, which is on the
red flank of the absorption band. After a variable time delay,
induced absorption spectra were measured (90 fs time
resolution) with white-light continuum pulses. Characteristic
spectral changes at early times, between 430–630 nm, can be
attributed to stimulated emission (SE). The initial SE band at
around 460 nm mirrors the absorption band and also its
oscillator strength is similar. It is assigned to the Franck–
Condon region on the excited-state potential energy surface.
s*(Bi Cl) orbital is ideally oriented for an interaction with
the filled dz2 orbital of the PtII ion (Scheme 1), and to
maximize this interaction the Pt-Bi-Cl unit adopts an almost
linear arrangement (Pt-Bi-Cl angle 1788), as often found in
case of efficient secondary bonding.[1,2] The Pt Bi distance in
ꢀ
2 amounts to 2.9009(5) ꢀ; therefore, the ratio between the
metal–metal distance and the sum of the van der Waals radii is
even smaller (0.76) than in the case of the gold–bismuth
complex 1 (0.80).[10] If the structure of 2 is divided by the plane
ꢀ
including the Pt Bi axis and the P-Pt-P angle bisector, it
becomes obvious that the two P atoms of 2 experience
somewhat different environments (Figure 4b), and if this
structure was preserved in solution, different resonances
should be expected for the two P donor functions in the NMR
spectra of the complex. Indeed at ꢀ808C, the 31P{1H} NMR
spectrum of 2 dissolved in [D8]THF displays two doublets
Angew. Chem. Int. Ed. 2012, 51, 1 – 5
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3
These are not the final page numbers!

.
Angewandte
Communications
(d = 23.8 and 16.8 ppm with 195Pt satellites), which at room
temperature are broadened into the baseline, presumably
through a dynamic process. At low temperatures, the two
Krummenacher, J. Meyer, F. Armbruster, F. Breher, Dalton
Trans. 2008, 5836 – 5865; i) S. Bontemps, M. Sircoglou, G.
Bouhadir, H. Puschmann, J. A. K. Howard, P. W. Dyer, K.
Miqueu, D. Bourissou, Chem. Eur. J. 2008, 14, 731 – 740;
j) Ref [4d]; k) M. Sircoglou, M. Mercy, N. Saffon, Y. Coppel,
G. Bouhadir, L. Maron, D. Bourissou, Angew. Chem. 2009, 121,
3506 – 3509; Angew. Chem. Int. Ed. 2009, 48, 3454 – 3457; l) H.
Braunschweig, K. Gruss, K. Radacki, Angew. Chem. 2009, 121,
4303 – 4305; Angew. Chem. Int. Ed. 2009, 48, 4239 – 4241;
m) I. R. Crossley, A. F. Hill, A. C. Willis, Organometallics 2010,
29, 326 – 336 and references therein; n) J. Bauer, H. Braunsch-
weig, P. Brenner, K. Kraft, K. Radacki, K. Schwab, Chem. Eur. J.
2010, 16, 11985 – 11992; o) G. Bouhadir, A. Amgoune, D.
Bourissou, Adv. Organomet. Chem. 2010, 58, 1 – 107; p) A.
Amgoune, D. Bourissou, Chem. Commun. 2011, 47, 859 – 871.
[5] a) J. Wagler, E. Brendler, Angew. Chem. 2010, 122, 634 – 637;
Angew. Chem. Int. Ed. 2010, 49, 624 – 627; L. A. Truflandier, E.
Brendler, J. Wagler, J. Autschbach, Angew. Chem. 2011, 123,
269 – 273; Angew. Chem. Int. Ed. 2011, 50, 255 – 259; b) J.
Wagler, A. F. Hill, T. Heine, Eur. J. Inorg. Chem. 2008, 4225 –
4229; P. Gualco, T.-P. Lin, M. Sircoglou, M. Mercy, S. Ladeira, G.
Bouhadir, L. M. Pꢂrez, A. Amgoune, L. Maron, F. P. Gabbaꢃ, D.
Bourissou, Angew. Chem. 2009, 121, 10076 – 10079; Angew.
Chem. Int. Ed. 2009, 48, 9892 – 9895; P. Gualco, M. Mercy, S.
Ladeira, Y. Coppel, L. Maron, A. Amgoune, D. Bourissou,
Chem. Eur. J. 2010, 16, 10808 – 10817; c) T.-P. Lin, C. R. Wade,
L. M. Pꢂrez, F. P. Gabbaꢃ, Angew. Chem. 2010, 122, 6501 – 6504;
Angew. Chem. Int. Ed. 2010, 49, 6357 – 6360; C. R. Wade, F. P.
Gabbaꢃ, Angew. Chem. 2011, 123, 7507 – 7510; Angew. Chem.
Int. Ed. 2011, 50, 7369 – 7372.
1
donor moities of the ligand can also be distinguished by H
and 13C{1H} NMR spectroscopic analysis.
Calculations were also carried out for 2, and an NBO
analysis revealed again one dominating metal–metal inter-
action, namely Pt(5d)!Bi(6p) with a stabilizing energy of
24.4 kcalmolꢀ1 (see Figure 3 and Supporting Information).
No significant contribution of a Bi!Pt back-donation was
found, so the situation depicted in Scheme 1 is realized in 2 in
an ideal way. This explains how the Pt!Bi stabilization
energy is almost twice as high as the Au!Bi stabilization
energy in 1, indicating a stronger interaction between the
metal atoms in 2, which is consistent with the above findings
ꢀ
regarding the Pt Bi distance.
These results clearly indicate the feasibility of the concept
illustrated in an idealized way in Scheme 1 and the potential
of Bi(o-PPh2-C6H4)2Cl in the establishment of metallophilic
interactions involving bismuth and M!Bi bonds. In future
work, the influence of the Bi functions and their modification
(by variation of X) on the reactivity/selectivity of platinum
and also palladium complex fragments, for instance in
catalytic applications, will be investigated. A cooperative
reactivity of late-metal and bismuth centers in substrate
activation is also conceivable.
[6] S. Roggan, C. Limberg, B. Ziemer, M. Brandt, Angew. Chem.
2004, 116, 2906 – 2910; Angew. Chem. Int. Ed. 2004, 43, 2846 –
2849; S. Roggan, C. Limberg, G. Schnakenburg, S. Sandhçffner,
H. Pritzkow, B. Ziemer, Chem. Eur. J. 2005, 11, 225 – 234; C.
Knispel, C. Limberg, M. Mehring, Organometallics 2009, 28,
646 – 651; R. Schiwon, C. Knispel, C. Limberg, Organometallics
2010, 29, 1670 – 1674; C. Knispel, C. Limberg, C. Tschersich,
Chem. Commun. 2011, 47, 10794 – 10796.
[7] a) E. J. Fernꢁndez, A. Laguna, J. M. Lꢄpez-de-Luzuriaga, M.
Monge, M. Nema, M. E. Olmos, J. Pꢂrez, C. Silvestru, Chem.
Commun. 2007, 571 – 573; b) O. Schuster, A. Schier, H. Schmid-
baur, Organometallics 2003, 22, 4079 – 4083.
Received: January 31, 2012
Published online: && &&, &&&&
Keywords: ambiphilic ligands · bismuth · gold ·
.
metallophilic interactions · platinum
[1] a) S. Roggan, C. Limberg, Inorg. Chim. Acta 2006, 359, 4698 –
4722; b) H. Braunschweig, P. Cogswell, K. Schwab, Coord.
Chem. Rev. 2011, 255, 101 – 117.
[2] a) A. E. Reed, P. v. R. Schleyer, J. Am. Chem. Soc. 1990, 112,
1434 – 1445; b) W. Clegg, R. J. Errington, G. A. Fisher, D. C. R.
Hockless, N. C. Norman, A. G. Orpen, S. E. Stratford, J. Chem.
Soc. Dalton Trans. 1992, 1967 – 1974.
[8] For crystallographic data of PBiP, 1, and 2, see the Supporting
Information.
[9] a) K. H. Whitmire, D. Labahn, H. W. Roesky, M. Noltemeyer, J.
Organomet. Chem. 1991, 402, 55 – 66; b) Y. Matano, H. Kurata,
T. Murafuji, N. Azuma, H. Suzuki, Organometallics 1998, 17,
4049 – 4059; c) N. J. Hardman, B. Twamley, P. P. Power, Angew.
Chem. 2000, 112, 2884 – 2886; Angew. Chem. Int. Ed. 2000, 39,
2771 – 2773; d) A. P. Soran, C. Silvestru, H. J. Breunig, G. Balꢁzs,
J. C. Green, Organometallics 2007, 26, 1196 – 1203.
[10] a) E. Shustorovich, P. A. Dobosh, J. Am. Chem. Soc. 1979, 101,
4090 – 4095; b) P. Pyykkç, J. P. Desclaux, Acc. Chem. Res. 1979,
12, 276 – 281; c) C. Silvestru, H. J. Breunig, H. Althaus, Chem.
Rev. 1999, 99, 3277 – 3327.
[3] a) S. Shimada, O. Yamazaki, T. Tanaka, M. L. N. Rao, Y. Suzuki,
M. Tanaka, Angew. Chem. 2003, 115, 1889 – 1892; Angew. Chem.
Int. Ed. 2003, 42, 1845 – 1848; b) H. Gaspard-Iloughmane, C.
Le Roux, Eur. J. Org. Chem. 2004, 2517 – 2532; c) H. Qin, N.
Yamagiwa, S. Matsunaga, M. Shibasaki, J. Am. Chem. Soc. 2006,
128, 1611 – 1614; d) R. M. Hua, Curr. Org. Synth. 2008, 5, 1 – 27.
[4] a) A. F. Hill, G. R. Owen, A. J. P. White, D. J. Williams, Angew.
Chem. 1999, 111, 2920 – 2923; Angew. Chem. Int. Ed. 1999, 38,
2759 – 2761; b) H. Braunschweig, K. Gruss, K. Radacki, Angew.
Chem. 2007, 119, 7929 – 7931; Angew. Chem. Int. Ed. 2007, 46,
7782 – 7784; c) M. Sircoglou, S. Bontemps, M. Mercy, N. Saffon,
M. Takahashi, G. Bouhadir, L. Maron, D. Bourissou, Angew.
Chem. 2007, 119, 8737 – 8740; Angew. Chem. Int. Ed. 2007, 46,
8583 – 8586; d) H. Braunschweig, K. Gruss, K. Radacki, Inorg.
Chem. 2008, 47, 8595 – 8597; e) S. Bontemps, G. Bouhadir, W.
Gu, M. Mercy, C.-H. Chen, B. M. Foxman, L. Maron, O. V.
Ozerov, D. Bourissou, Angew. Chem. 2008, 120, 1503 – 1506;
Angew. Chem. Int. Ed. 2008, 47, 1481 – 1484; f) M. Sircoglou, G.
Bouhadir, N. Saffon, K. Miqueu, D. Bourissou, Organometallics
2008, 27, 1675 – 1678; g) F.-G. Fontaine, J. Boudreau, M.-H.
Thibault, Eur. J. Inorg. Chem. 2008, 5439 – 5454; h) I. Kuzu, I.
[11] a) A. Bondi, J. Phys. Chem. 1964, 68, 441 – 451; b) M. Mantina,
A. C. Chamberlin, R. Valero, C. J. Cramer, D. G. Truhlar, J.
Phys. Chem. A 2009, 113, 5806 – 5812.
[12] The 31P{1H} NMR chemical shift of [Au(PPh3)Cl] for comparison
(121.5 MHz, CD2Cl2): d = 33.7 ppm.
[13] M. A. Carvajal, J. J. Novoa, S. Alvarez, J. Am. Chem. Soc. 2004,
126, 1465 – 1477.
[14] E. J. Fernꢁndez, A. Laguna, J. M. Lꢄpez-de-Luzuriaga, Dalton
Trans. 2007, 20, 1969 – 1981 and references therein.
[15] S. A. Kovalenko, A. L. Dobryakov, N. P. Ernsting, Rev. Sci.
Instrum. 2011, 82, 063102.
4
www.angewandte.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2012, 51, 1 – 5
These are not the final page numbers!

Angewandte
Chemie
Communications
Metallophilic Interactions
Noble metals meet a heavyweight: A
pincer ligand brings together bismuth
with gold and platinum, so that metal-
lophilic interactions are established.
According to DFT calculations, these
interactions contain dominant metal!
bismuth contributions.
C. Tschersich, C. Limberg,* S. Roggan,
C. Herwig, N. Ernsting, S. Kovalenko,
S. Mebs
&&&& — &&&&
Gold– and Platinum–Bismuth Donor–
Acceptor Interactions Supported by an
Ambiphilic PBiP Pincer Ligand
Angew. Chem. Int. Ed. 2012, 51, 1 – 5
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5
These are not the final page numbers!