The core structure of TMC-95A is a promising lead for reversible proteasome inhibition.

Full text of DOI:10.1002/1521-3773(20020301)41:5<780::AID-ANIE780>3.0.CO;2-V

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[15] G. Zhu, Z. Chen, X. Zhang, J. Org. Chem. 1999, 64, 6907 6910.
[16] D. Heller, J. Holz, H.-J. Drexler, J. Lang, K. Drauz, H.-P. Krimmer, A.
Bˆrner, J. Org. Chem. 2001, 66, 6816 6817.
[17] The simultaneous increase in the selectivity can be explained easily
with the well-known pressure dependence of the enantioselectivity of
asymmetric hydrogenations.[13]
the product is obtained with 87.8% after only 4 min of
hydrogenation at normal pressure at 258C.[16] The lower
activity in toluene is a result of the ™induction periods∫[7] as
well as the formation of stable, blocking arene complexes, as
we have now shown quantitatively.[17]
In summary, we have shown that arene complexes of RhI
can have an unexpectedly large influence on the activity of
asymmetric hydrogenation reactions. A different interpreta-
tion is now possible for past investigations in which catalyst
activities were determined in alcohol/aromatic solvent mix-
tures or in aromatic solvents.[18] At the moment, we are
examining whether the inhibiting effect can also be induced
by P-ligands and by substrates with aromatic substituents, and
whether it is also relevant for other RhI-catalyzed reactions,
for example, hydroformylations.
[18] E. I. Klabunowski, Y. T. Struchkov, A. A. Voloboev, A. I. Yanovsky
V. A. Pavlov, J. Mol. Catal. 1988, 44, 217 243.
The Core Structure of TMC-95A Is a Promising
Lead for Reversible Proteasome Inhibition**
Markus Kaiser, Michael Groll, Christian Renner,
Robert Huber, and Luis Moroder*
Received: October 19, 2001 [Z18089]
The proteasome is an intracellular multicatalytic protease
complex which in combination with the ubiquitin pathway
plays a central role in major cellular processes, such as antigen
presentation, cell proliferation and differentiation, and apop-
tosis.[1] Proteolysis occurs in a barrel-shaped core structure
known as 20S proteasome, which consists of four stacked rings
arrayed in an a7b7b7a7 mode.[2a] In eukaryotic proteasome
three b-subunits of each b-ring are enzymatically active with
an N-terminal threonine residue as the active nucleophile
involved in proteolysis[2b] with three more or less distinct
substrate specificities, that is chymotrypsin-like (CL), trypsin-
like (TL), and peptidyl-glutamyl-peptide hydrolase (PGPH)
activities.[3]
À
[1] ™Hydrogenation of Functionalized Carbon Carbon double bonds∫:
J. M. Brown in Comprehensive Asymmetric Catalysis (Eds.: E. N.
Jacobsen, A. Pfaltz, H. Yamamoto), Springer, Berlin, 1999, Chap. 5.1,
pp. 121 182.
[2] M. J. Burk, C. S. Kalberg, A. Pizzano, J. Am. Chem. Soc. 1998, 120,
4345 4353.
[3] a) J. Halpern, D. P. Riley, A. S. C. Chan, J. S. Pluth, J. Am. Chem. Soc.
1977, 99, 8055 8057; b) C. R. Landis, J. Halpern, Organometallics
1983, 2, 840 842.
[4] J. M. Townsend, J. F. Blount, Inorg. Chem. 1981, 20, 269 271.
[5] P. H¸bler, J. Bargon, Angew. Chem. 2000, 112, 3849 3852; Angew.
Chem. Int. Ed. 2000, 39, 3701 3703, and references therein.
[6] a) I. D. Gridnev, N. Higashi, K. Asakura, T. Imamoto, J. Am. Chem.
Soc. 2000, 122, 7183 7194; b) I. D. Gridnev, M. Yasutake, N. Higashi,
T. Imamoto, J. Am. Chem. Soc. 2001, 123, 5268 5276.
Because of the physiological role of proteasome in critical
intracellular processes, this enzyme represents a promising
target for drug development in inflammatory and autoim-
mune diseases as well as in tumor therapy.[4] Correspondingly,
great attention has recently been paid to the discovery of
potent and selective proteasome inhibitors by structure-based
design or natural product screening approaches. Most of the
synthetic inhibitors consisting of peptide aldehydes, boro-
nates, and vinylsulfones, as well as the natural products
lactacystin and epoxymicins inhibit in a more or less selective
manner the proteasome by reaction with the N-terminal
threonine residue (for a recent review see ref. [5]). A notable
exception is the highly selective and competitive proteasome
inhibitor TMC-95A, which was isolated from the fermenta-
tion broth of Apiospora montagnei Sacc. TC 1093.[6]
[7] By hydrogenation of the diolefin, the cyclooctadiene precatalyst is
easily transferred into the solvent complex. a) H.-J. Drexler, W.
Baumann, A. Spannenberg, C. Fischer, D. Heller, J. Organomet.
Chem. 2001, 621, 89 102; b) A. Bˆrner, D. Heller, Tetrahedron Lett.
2001, 42, 223 225; similar results for seven-membered chelates can be
found in: c) D. Heller, S. Borns, W. Baumann, R. Selke, Chem. Ber.
1996, 129, 85 89.
[8] 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-163839 (1) and -163840 (2). Copies of the data can be obtained
free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html (or on
application to CCDC, 12 Union Road, Cambridge CB21EZ, UK; fax:
(‡44)1223-336-033; e-mail: deposit@ccdc.cam.ac.uk). Further infor-
mation can be found in the Supporting Information.
¬
[9] a) R. Benn, A. Rufinska, Angew. Chem. 1986, 98, 851 871; Angew.
Chem. Int. Ed. 1986, 25, 861 881; b) W. von Philipsborn, Chem. Soc.
Rev. 1999, 28, 95 105.
[10] a) J. M. Ernsting, C. J. Elsevier, W. G. J. de Lange, K. Timmer, Magn.
Reson. Chem. 1991, 29, S118 S124; b) W. Leitner, M. B¸hl, R.
Fornika, C. Six, W. Baumann, E. Dinjus, M. Kessler, C. Kr¸ger, A.
This cyclic peptide metabolite consists of l-tyrosine, l-
asparagine, a highly oxidized l-tryptophane, and the (Z)-1-
¬
Rufinska, Organometallics 1999, 18, 1196 1206, and references
[*] Prof. L. Moroder, Dipl.-Chem. M. Kaiser, Dr. C. Renner
AG Biorganische Chemie
therein.
[11] a) B. E. Mann, Adv. Organomet. Chem. 1974, 12, 135 213; b) G. M.
Bodner, L. J. Todd, Inorg. Chem. 1974, 13, 360 363.
[12] The possible hydrogenation of aromatic compounds with similar
catalysts[3b] does not occur under these conditions. For example,
treatment of benzene (2.8 mmol) in methanol (7mL) with [Rh(Et-
DuPHOS)(cod)]BF4 (0.02 mmol) at 258C for 66 h and normal
pressure did not give rise to any products of benzene hydrogenation
(NMR spectroscopy).
Max-Planck Institut f¸r Biochemie
Am Klopferspitz 18A, 82152 Martinsried (Germany)
Fax : (‡49)89-8578-2847
E-mail: moroder@biochem.mpg.de
Dr. M. Groll, Prof. R. Huber
Abteilung Strukturforschung
Max-Planck Institut f¸r Biochemie
Am Klopferspitz 18A, 82152 Martinsried (Germany)
[13] C. R. Landis, J. Halpern, J. Am. Chem. Soc. 1987, 109, 1746 1754.
[14] D. Heller, R. Thede, D. Haberland, J. Mol. Catal. A 1997, 115, 27 3
281.
[**] This work was supported by the SFB 469 of the Ludwig-Maximilians-
Universit‰t M¸nchen and the SPP 1045.
780
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propenylamine and 3-methyloxopentanoic acid moities with a
phenyl/oxindole ring junction (structure A in Scheme 1).[7]
KOAc (Scheme 2). 7-Bromo-l-tryptophane was produced
from 7-bromoindole and l-serine by the use of tryptophane
synthetase following essentially known protocols[17] and then
A
similar biaryl moiety was so far encountered only in chloro-
peptin,[8] complestatin,[9] diazonamide,[10] and the kistami-
cins.[11] Because of the pharmacological interest of protea-
some inhibition and the distinct phenol/oxindole system the
synthesis of TMC-95A has attracted considerable interest.[12]
X-ray structural analysis of the complex of TMC-95A with
yeast proteasome clearly confirmed the noncovalent binding
of this low molecular weight cyclic peptide, with a network of
hydrogen bonds between the b-type extended peptide moiety
and the main chain of the protein[13] which contributes to the
high affinity for all three active sites.[6] From this crystal
structure the minimum structural elements of TMC-95A for
binding to the proteasome were derived (structure B in
Scheme 1). To validate our working assumption we selected
compound C (Scheme 1) as our first synthetic target; com-
pound C contains a propylamide residue as R1 for interaction
with the S1 pocket of the active sites, and the side chain of
asparagine, which is present in the natural product, as R3 for
occupancy of the S3 pocket. All other modifications at the
level of the core structure of TMC-95A were not expected to
significantly affect the binding affinity for proteasome. The
synthesis of this first TMC-95A analogue was accomplished
and its inhibitory potency fully confirmed our working
hypothesis.
The main difficulty in the synthesis of compound C was
expected from cyclization to the constraint ring structure.
Based on previous experiences reported for the synthesis of
the chloropeptin ring,[14] a first synthetic route by acid-
catalyzed ring contraction of an 18-membered macrolactame
precursor was attempted. This foresees a Suzuki cross-
reaction for the preparation of the biaryl system followed by
lactamization of the linear precursor. As meanwhile also
reported by Estiarte et al.,[15] cyclization of the 18-membered
precursor failed. Thus, the compound C was synthesized
according Scheme 2 and 3 by formation of the ™correct∫ biaryl
junction at the level of the linear precursor followed by
cyclization.
O
OH
O
Z
O
B
I
I
O
O
a) - c)
d)
O
O
O
O
OH
NH
NH2
NH
Z
1
2
3
H
HO
N
O
O
e)
NH2
f) - g)
NH
Boc
N
H
Br
N
N
H
H
Br
Br
4
5
6
Scheme 2. Synthesis of 3 and 6: a) SOCl2, MeOH; b) Z-OSu; c) K2CO3
(10 equiv), MeI (5 equiv); d) B2O4C12H24 (1.1 equiv), [Pd(dppf)Cl2] ¥
CH2Cl2 (5 mol%), KOAc (3 equiv); e) l-serine, tryptophane-synthetase,
PLP, 378C; f) Boc2O; g) nPrNH2, EDCI, HOBt. Z-OSu ˆ Na-(benzyloxy-
carbonyloxy)succinimide, dppf ˆ Ph2PC5H4FeC5H4PPh, PLP ˆ pyridoxal
5'-phosphate, Boc ˆ tert-butoxycarbonyl, EDCI ˆ N'-(3-dimethylamino-
propyl)-N-ethylcarbodiimide,
DME ˆ dimethoxyethane.
HOBt ˆ 1-hydroxy-1H-benzotriazole,
converted into the related Na-Boc propylamide derivative 6
(Scheme 2). The derivatives 3 and 6 were coupled under
standard conditions of the Suzuki cross-reaction[18] to gen-
erate the key intermediate 7 in 80% yield after flash
chromatography (Scheme 3). Upon C-terminal extension of
the peptide chain with the asparagine tert-butyl ester, the
linear precursor 8 was oxidized at the indole moiety by
standard procedures with DMSO/concentrated HCl[19] (40%
yield) prior to peptide cyclization with PyBOP/HOBt/DIEA.
After HPLC purification the desired compound C (10) was
isolated in about 40% yield as a homogeneous product
(Scheme 3). NMR analysis confirmed the correct ring struc-
ture including the S configuration at the C3 atom of the
oxindole.[20] Apparently only this
For this synthetic route 3-iodo-l-tyrosine was converted
into the suitably protected derivative 2 which was then
transformed to the aryl boronate 3 by the Miyauri Suzuki
reaction[16] using bis(pinacolato)diboron, [PdCl2(dppf)], and
configuration allows cyclization of
the precursor into the highly re-
R1
O
NH
NH
O
HO
NH
NH
stricted ring. From distance and
dihedral angle constraints derived
from 2D NMR spectra a spatial
structure of compound C was cal-
culated which is superimposable to
that of TMC-95A determined by
X-ray analysis of its complex with
the proteasome (Figure 1).
O
NH
H
HO
H
NH
O
O
N
H
O
N
O
O
O
H
O
N
H
O
CONH2
CONH2
O
R3
NH
NH
O
HO
O
NH
NH
Z
N
H
O
In the context of the structural
analysis of the TMC-95A/yeast pro-
teasome complex the natural prod-
uct was found to inhibit the three
proteolytic activites of yeast and
A
B
C
Scheme 1. Structure of TMC-95A (A), the minimal skeleton (B) for binding to the proteasome as derived
from the X-ray structure of the TMC-95A/proteasome complex, and the analogue (C) with propylamide as
R1 and the side chain of asparagine as R3 residue. Compound C was synthesized for the validation of the
design concept.
Angew. Chem. Int. Ed. 2002, 41, No. 5
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Table 1. Inhibition of proteasome (IC50 [mm]) by compound C, TMC-95A,
H
H
N
O
and Ac-Leu-Leu-Nle-H in absence of SDS.[21]
N
O
CL activity
TL activity
PGPH activity
NH
Boc
NH
Boc
compound C
8.0[a]
1.9[b]
10.6[a]
3.7[b]
7.4[a]
1.8[b]
a)
b)
6
N
H
O
N
H
O
TMC-95A[6]
Ac-Leu-Leu-Nle-H
0.012[b]
35.4[a]
1.5[b]
6.7[b]
O
O
H
N
142.5[a]
88.0[a]
O
O
OH
OtBu
NH2
[a] Yeast proteasome. [b] Human proteasome.
NH
Z
NH
Z
TL and PGPH activities, but it is significantly less potent
against the CL activity. This may well be attributed to the
exchange of the (Z)-1-propenylamide with the more flexible
propylamide as P1 residue for occupancy of the specificity
subsite S1 of the enzyme. Full retainment of affinity of
compound C for the two other active sites of the proteasome
confirms that the N-terminal acyl residue as well as the
tyrosine hydroxy group are not critically involved in the
interaction with the protein counterpart, whilst the biaryl
moiety restricts the peptide backbone into the extended b-
strand conformation for optimal hydrogen bonding to the
active site clefts. The data also confirm that the degree of
oxidation of the tryptophane residue can be reduced and that
the oxindole group is sufficient for the additional hydrogen
bond to the protein backbone to be established.
In conclusion, the inhibitory potencies of compound C
confirm the correctness of our inhibitor design based on
minimization of the TMC-95A skeleton, and clearly indicate
that by optimization of the R1 and R3 residues both selectivity
and affinity for the three active sites may significantly be
improved. These results also suggest that not all of the
complex structural elements of the natural product are
required for inhibition of proteasome, thus markedly facili-
tating the synthesis of TMC-95A related compounds.
7
8
H
H
N
N
O
O
NH2
O
O
c)
d)
N
H
O
N
H
O
O
O
NH
H
N
H
N
O
O
OH
NH2
O
NH2
NH
Z
NH
Z
O
9
10
Scheme 3. Synthesis of 10. a) 3 (1.1 equiv), [Pd(dppf)Cl2] ¥ CH2Cl2
(5 mol%), K2CO3 (3 equiv), DME/H2O (7:1), 70 8C; b) H-Asn-OtBu,
EDCI, HOBt; c) DMSO (20 equiv), AcOH/HCl (4:1); d) PyBOP
(4 equiv), HOBt (4 equiv), DIEA (6 equiv). PyBOP ˆ benzotriazol-1-
yloxytripyrrolidinophosphonium hexafluorophosphate, DIEA ˆ diisopro-
pylethylamine.
Received: November 13, 2001 [Z18212]
[1] a) O. Coux, K. Tanaka, A. L. Goldberg, Annu. Rev. Biochem. 1996, 65,
801 847; b) M. Groettrup, A. Soza, U. Kuckelkorn, P. M. Kloetzel,
Immunol. Today 1996, 17, 429 435; c) D. Voges, P. Zwickl, W.
Baumeister, Annu. Rev. Biochem. 1999, 8, 1015 1068; d) M. Bochtler,
L. Ditzel, M. Groll, C. Hartmann, R. Huber, Annu. Rev. Biophys.
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Science 1995, 268, 533 539; b) M. Groll, L. Ditzel, J. Lˆwe, D. Stock,
M. Bochtler, H. D. Bartunik, R. Huber, Nature 1997, 386, 463 471.
[3] M. Orlowski, S. Wilk, Arch. Biochem. Biophys. 2000, 383, 1 16.
[4] a) Q. P. Dou, S. Nam, Expert Opin. Ther. Pat. 2000, 10, 1263 1272;
b) J. Adams, V. J. Palombella, P. J. Elliott, Invest. New Drugs 2000, 18,
Figure 1. Conformation of compound C determined by NMR spectros-
copy (20 lowest energy structures; gray) superimposed on the three-
dimensional structure of TMC-95A as determined by X-ray analysis of its
complex with yeast proteasome (black); for better visualization the
N-terminal phenyl group is omitted.
¬
109 121; c) C. Wojcik, Drug Discovery Today 1999, 4, 188.
[5] A. F. Kisselev, A. L. Goldberg, Chem. Biol. 2001, 8, 739 758.
[6] Y. Koguchi, J. Kohno, M. Nishio, K. Takahashi, T. Okuda, T. Ohnuki,
S. Komatsubara, J. Antibiot. 2000, 53, 105 109.
[7] J. Kohno, Y. Koguchi, M. Nishio, K. Nakao, M. Kuroda, R. Shimizu, T.
Ohnuki, S. Komatsubara, J. Org. Chem. 2000, 65, 990 995.
[8] M. Matsuzaki, H. Ikeda, T. Ogino, A. Matsumoto, H. B. Woodruff, H.
Tanaka, S. Omura, J. Antibiot. 1994, 47, 1173 1174.
[9] I. Kaneko, K. Kamoshida, S. Takahashi, J. Antibiot. 1989, 42, 236 241.
[10] N. Lindquist, W. Fenical, G. D. Van Duyne, J. Clardy, J. Am. Chem.
Soc. 1991, 113, 2303 2304.
[11] a) N. Naruse, O. Tenmyo, S. Kobaru, M. Hatori, K. Tomita, Y.
Hamagishi, T. Oki, J. Careofokumura, J. Antibiot. 1993, 46, 1804
1811; b) N. Naruse, M. Oka, M. Konishi, T. Oki, J. Antibiot. 1993, 46,
1812 1818.
human proteasome with similar potencies[13] as previously
reported for human proteasome.[6] The inhibitory effects of
compound C are reported in Table 1, and compared with
those of TMC-95A and the calpain inhibitor I, that is Ac-Leu-
Leu-Nle-H. Despite the difficult quantitative comparison of
IC50 values obtained with different proteasome preparations
and assay conditions, the synthetic TMC-95A analogue was
found to inhibit all three proteolytic activities more efficiently
than the tripeptide aldehyde. Compared to the natural
product, compound C retains almost full inhibition of the
782
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[12] a) S. Lin, S. J. Danishefsky, Angew. Chem. 2001, 113, 2020 2024;
Angew. Chem. Int. Ed. 2001, 40, 1967 1970; b) D. Ma, Q. Wu,
Tetrahedron Lett. 2001, 42, 5279 5281; c) D. Ma, Q. Wu, Tetrahedron
Lett. 2000, 41, 9089 9093; d) B. K. Albrecht, R. M. Williams, Tetra-
hedron Lett. 2001, 42, 2755 2757; e) M. Inoue, H. Furuyama, H.
Sakazaki, M. Hirama, Org. Lett. 2001, 3, 2863 2865; see also: f) S.
Lin, S. J. Danishefsky, Angew. Chem. 2002, 114, 530 533; Angew.
Chem. Int. Ed. 2002, 41, 512 515.
[13] M. Groll, Y. Koguchi, R. Huber, J. Kohno, J. Mol. Biol. 2001, 311,
543 548.
[14] A. M. Elder, D. H. Rich, Org. Lett. 1999, 1, 1443 1446.
[15] M. A. Estiarte, A. M. Elder, D. H. Rich, 17th Am. Peptide Symp. (San
Diego, USA) 2001, Poster P412.
well as one-dimensional (1D) and two-dimensional (2D)
polymers.
The coordination chemistry of Pn ligand complexes[3]
towards cationic metal centers (excluding cationic organo-
metallic complex moieties[4]) has to date been limited to the
use of cyclo-P3 ligand complexes, such as [(triphos)M(h3-P3)]
(M ˆ Co, Rh, or Ir; triphos ˆ 1,1,1-tris(diphenylphosphanyl-
methyl)ethane), which react with CuI, AgI, or AuI to form
metal-bridged dimers.[5] In the reaction of the Co compound
with CuBr, a multidecker complex of Co containing a (CuBr)6
middle deck was obtained.[6] To generate definite polymers,
P2-ligand complexes seem to be the starting material of
choice. From our experience with the chromium complex
[{CpCr(CO)2}2(m,h2-P2)][7] (Cp ˆ C5H5) we know that this
starting material readily undergoes fragmentation reactions;[8]
thus, we decided to use the more stable Mo analogue 1.[9]
Herein we report the synthesis of a molecular cationic
complex of AgI containing different and novel coordination
modes of the P2-ligand complex as well as the formation of the
first 1D chain polymers of AgI and CuI containing P2-ligand
complexes.
[16] T. Ishiyama, M. Murata, N. Miyaura, J. Org. Chem. 1995, 60, 7508
7510.
[17] M. Lee, R. S. Phillips, Biorg. Med. Chem. Lett. 1992, 2, 1563 1564.
[18] N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457 2483.
[19] W. E. Savige, A. Fontana, Int. J. Pept. Protein Res. 1980, 15, 285 297.
[20] NMR experiments were performed at 228C in [D6]DMSO at 500 MHz
(Bruker DRX500 spectrometer). 2D-1H DQF-COSY, TOCSY (70 ms
mixing) and ROESY (200 ms mixing) spectra were acquired for
resonance assignment and conformational analysis. Forty five distance
constraints and three F dihedral angle constraints were extracted
from ROESY and 1D-1H spectra, respectively.
independent structures were generated by distance geometry
A total of 100
a
algorithm, refined by two steps with a simulated annealing molecular
dynamics (MD-SA; coarse ‡ fine) protocol and sorted according to
final energies. No significant violations of experimental constraints
occurred for any of the calculated structures.
[Cp2Mo2(CO)4(m,h2-P2)]
1
[Ag2h{Cp2Mo2(CO)4(m,h2:h2-P2)}2i
[21] The IC50 values for yeast and human 20S proteasome were determined
at 378C in the absence of SDS using the fluorogenic substrates Suc-
Leu-Leu-Val-Tyr-AMC, Bz-Thr-Val-Arg-AMC and Z-Leu-Leu-Glu-
bNa to assay the CT, TL, and PGPH activities following essentially
protocols reported previously (G. Loidl, H.-J. Musiol, M. Groll, R.
Huber, L. Moroder, J. Pept. Sci. 2000, 6, 36 46).
h{Cp2Mo2(CO)4(m,h2:h1:h1-P2)}2i][(CF3SO3)2]
2
4
[{Re(CO)3Br}2h{Cp2Mo2(CO)4(m,h2:h1:h1-P2)}2i]
3
[Ag2{Cp2Mo2(CO)4(m,h2:h1:h1-P2)}3(m,h1:h1-NO3)]1 [NO3]n
[Cu(m-Br){Cp2Mo2(CO)4(m,h2:h1:h1-P2)}]1
5
The reaction of Ag(CF3SO3) with 1 in CH3CN leads to the
quantitative formation of 2, in which the tetrahedral Mo2P2
ligand coordinates to two Ag(i) centers in a bridging as well as
in a novel chelating coordination mode. Whereas the coordi-
nation of M2P2 tetrahedral complexes to one (type A) and two
(type B) organometallic moieties is known, such as, in the
type B situation where coordination to [Re(CO)3Br] frag-
ments forms a central six-membered ring moiety in complex
3,[10] the side-on coordination mode of an M2P2 complex at one
metal center (type C), as found in complex 2, is unique for a
P2-ligand complex.[3]
P2-Ligand Complexes as Building Blocks for
the Formation of One-DimensionalPolymers**
Junfeng Bai, Eva Leiner, and Manfred Scheer*
Dedicated to Professor Eckhard Herrmann
on the occasion of his 65th birthday
Self-organisation of discrete units to form supramolecular
aggregates and networks of inorganic coordination com-
pounds is a prominent field in contemporary chemistry.[1]
Within this field coordination polymers are of interest with
regard to their physical, electronic, catalytic, and structural
properties.[2] Usual approaches in this area make use of
N-donor containing ligands and heterocycles to connect
different metal centers together. However, our goal in this
field is to use Pn ligand complexes as connecting moieties
between metal cations to form well-oriented assemblies as
If the counterions at the AgI centers are noncoordinating,
complexes similar to 2 are obtained.[11] However, we found a
different coordination behavior if the counterion is incorpo-
rated into the coordination sphere of the AgI atom. Thus, the
reaction of 1 with AgNO3 leads to the quantitative formation
of a novel polymeric AgI compound 4, where one of the NO3
counterions is now incorporated into the coordination sphere
of the AgI atoms to form a waved 1D polymeric chain.
[*] Prof. Dr. M. Scheer, Dr. J. Bai, E. Leiner
Institut f¸r Anorganische Chemie
Universit‰t Karlsruhe
76128 Karlsruhe (Germany)
Fax : (‡49)721-608-7021
E-mail: mascheer@chemie.uni-karlsruhe.de
[**] This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie.
Angew. Chem. Int. Ed. 2002, 41, No. 5
¹ WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002
1433-7851/02/4105-0783 $ 17.50+.50/0
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