Heterochiral self-sorting into only one stereoisomer is observed when metallo-supramolecular squares self-assemble from amino acid-substituted, dynamically interconverting bipyridine stereoisomers and dpppM(OTf)(2) corners (M = Pd, Pt).

A preferred choice: Prochiral 3,3′,5,5′-tetramethyl-4,4′-bipyridine can be converted into two types of axially chiral 4,4′-bipyridine compounds, separable into enantiomers by chiral HPLC. The obtained enantiopure bipyridines were sufficiently stable in solution to be used in the self-assembly of chiral metallo-supramolecular squares, which reveal a remarkable preference for one of ten possible structures (shown here). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2111/2008/z800113_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

It is found that 4,4'-bipyridines functionalized in their 3,3'-positions with Fréchet dendrons of 0th to 3rd generation self-assemble with (dppp)M(II) triflates (dppp: bis-(diphenylphosphino)propane; M = Pd, Pt) into metallo-supramolecular squares. They bear a nanometer-sized cavity inside an unpolar dendritic shell. A total of eight amide groups decorate the rims of the cavity connecting the dendrons to the square. Evidence for their formation up to the third generation comes from ESI-FTICR mass spectrometry and NMR experiments. Based on these results, the presence of significant amounts of other polygons or open-chain oligomers can be excluded. Exchange processes have been studied by variable-temperature NMR spectroscopy and by following the ligand exchanges between different squares by mass spectrometry. The ligand exchange is much slower for the Pt(II) squares as compared to their Pd(II) analogs. Visualization of films of these dendrimers using atomic force microscopy (AFM) provides information on their molecular dimensions. After deposition of a square monolayer on the surface, a slow reorganization within this layer is observed which leads to the formation of "tower-like" aggregates and multi-layer formation. The interplay of interactions between the dendrimers and the surface and interactions between different dendrimers are invoked to rationalize the observations.

Doppelt ist besser: Eine doppelte Metalltemplatstrategie wurde genutzt, um ein „π-konjugiertes Catenan“ aus zwei ineinandergreifenden Makrocyclen mit Oligothienyl- und Phenanthrolineinheiten aufzubauen (siehe berechnete Struktur). Die optischen und Redoxeigenschaften belegen ebenso wie die Struktur- und Konformationsanalysen eindeutig, dass sich die beiden Makrocyclen im Catenan durch Donor-Acceptor-Wechselwirkungen durch den Raum beeinflussen.

The self-assembly reactions between the fluorinated ditopic ligand 1,4-bis(4-pyridyl)tetrafluorobenzene (A) and different nitrogen-protected palladium(II) and platinum(II) complexes have been investigated. While dynamic equilibria between molecular triangles and squares were observed when the diimine compounds 4,4'-R2bipy (bipy = 2,2'-bipyridine; R = H, Me, t-Bu) were employed as ancillary ligands, only square species were obtained from ethylenediamine (en) derivatives. Characterization of the obtained metallomacrocycles was accomplished by 1H and 19F NMR spectroscopy in combination with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR). Molecular dynamics simulations (UFF) have been performed to interpret the influence of the fluorinated ring on the square/triangle relative stability. Density functional calculations using the GIAO method have been employed for the interpretation of the chemical shift assignments. The study of the ability of these compounds to act as hosts of electron-rich aromatic guests has shown that the palladium ethylenediamine square is capable of establishing this type of intermolecular interaction exclusively in aqueous media. The host-guest stoichiometry and association constants have been determinated by 1H NMR spectroscopy.

Ein „π‐konjugiertes Catenan“ oder, besser gesagt, ein aus zwei ineinander verschlungenen konjugierten Makrocyclen gebildetes Catenan wurde durch eine doppelte Metalltemplatstrategie synthetisiert. Auffälliges Merkmal dieses Systems ist eine durch den Raum wirkende elektronische Wechselwirkung der Donoreinheiten (Oligothiophene, metallische Farbe) mit der Acceptorkomponente des anderen Rings (Phenanthrolin, blau). Einzelheiten finden Sie in der Zuschrift von P. Bäuerle et al. auf S. 367ff.

Mass spectrometry has played a significant role in dendrimer chemistry, because it serves as an excellent analytical means to determine the purity and analyze the nature of defects even for higher generations. However, a mass spectrometer can also be used as a laboratory to study isolated dendrimer molecules in the gas phase or their host-guest complexes. Since the properties of molecules under environment-free conditions are often quite different from those in solution, their gas-phase chemistry provides valuable new insight into properties which cannot easily be studied in solution. This article summarizes some of our work on characterizing self-assembling metallo-supramolecular dendrimers, on analyzing ionization artifacts, on the differentiation between several, sometimes even isomeric defects through tandem MS experiments, and finally on the analysis of a surprisingly clear dendritic effect occurring in the fragmentation of dendritic host-guest complexes. Copyright (c) 2006 John Wiley & Sons, Ltd.

Infrared multi-photon dissociation (IRMPD) spectra of mass-selected, self-assembled supramolecular squares and their gas-phase fragments have been recorded in a Fourier-transform ion-cyclotron resonance (FT-ICR) mass spectrometer. The squares have been transferred into the gas phase by electrospray ionization (ESI) under very soft ionization conditions resulting in a series of signals for intact squares in different charge states by stripping off two or more counter ions. The fragmentation patterns of the squares strongly depend on the parent ion's charge state. For species with a lower number of charges, expulsions of edge ligands prevail, whereas charge separation pathways dominate the dissociation pathways of more highly charged species.

The interlocked oligothiophene macrocycle 1 was synthesized via a heteroleptic template approach, with the help of a platina-macrocycle intermediate; the corresponding homoleptic approach to the synthesis of 1 resulted in relatively poor yields of the desired product. The structure of the isolated copper(I) catenate was confirmed by ESI-FT-ICR and tandem mass spectrometry.

For the first time, the real-time gravimetric detection of the light-weight analyte ethene with quartz microbalance sensors becomes possible in the range of 3–600ppm, when metallo-supramolecular macrocycles are used as sensor-active layers. Thermodynamic and kinetic measurements as well as theoretical simulations indicate a weak and reversible binding of ethene at the metal centers.

A method for the synthesis of interlocked pi-conjugated macrocycles is described, Starting from 2,9-bis(oligothienyl)[1,10]phenanthrolines, (trimethylsilyl) acetylene groups were introduced at the terminal thiophene rings by selective iodination and subsequent Sonogashira-Hagihara coupling. Subsequently, we applied our recently developed metal-template approach to macrocyclization reactions by treating the deprotected acetylenes with cis-[Pt(dppp)Cl-2] to yield a platina-macrocycle. Based on this synthetic knowledge, by a

The controlled formation of supramolecular architectures on chloride pre-covered Cu(1 0 0) has been studied by means of in situ scanning tunneling microscopy (STM) in an electrochemical environment. On top of the c(2 x 2)-Cl layer, ordered arrays of supramolecular cavitand structures could be obtained either by a surface assisted assent 1 of monomer building-blocks (1, 1'-dibenzyl-4,4'-bipyridinium molecules) or by a direct adsorption of supramolecular assemblies (metallo-supramolecular squares) from the solution phase. Besides the omnipresent vane der-Waals-like interactions additional electrostatic interactions between the anionic chloride layer and the positively charged (metallo)-organic molecules are supposed to have strong impact on the 2D phase behavior in both cases.The obtained supramolecular entities with their cavities oriented towards the solution phase can be, regarded as potential host Assemblies for the specific inclusion of guest molecules. (C) 2005 Elsevier Ltd. All rights reserved.

Die Antwort liegt darunter: Metallosupramolekulare Kationen adsorbieren geordnet auf einer Kupferoberfläche, die zuvor mit einer Schicht aus Chloridionen modifiziert wurde. Diese Anionenschicht wirkt als Templat zweiter Ordnung, dessen Wechselwirkungen mit dem Kationen den Adsorptionsprozess bestimmen (siehe Schema).

Die Antwort liegt darunter: Metallosupramolekulare Kationen adsorbieren geordnet auf einer Kupferoberfläche, die zuvor mit einer Schicht aus Chloridionen modifiziert wurde. Diese Anionenschicht wirkt als Templat zweiter Ordnung, dessen Wechselwirkungen mit dem Kationen den Adsorptionsprozess bestimmen (siehe Schema).

Angewandte Chemie International EditionVolume 43, Issue 10 p. 1291-1294 Communication Second-Order Templation: Ordered Deposition of Supramolecular Squares on a Chloride-Covered Cu(100) Surface† Caroline Safarowsky Dipl.-Chem., Caroline Safarowsky Dipl.-Chem. Institut für Physikalische und Theoretische Chemie der Universität, Wegelerstrasse 12, 53115 Bonn, Germany, Fax: (+49) 228-732-551Search for more papers by this authorLeo Merz Dipl.-Chem., Leo Merz Dipl.-Chem. Institut für Physik der Universität, Klingelbergstrasse 82, 4056 Basel, SwitzerlandSearch for more papers by this authorAlexander Rang Dipl.-Chem., Alexander Rang Dipl.-Chem. Kekulé-Institut für Organische Chemie und Biochemie der Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany, Fax: (+49) 228-735-662Search for more papers by this authorPeter Broekmann Dr., Peter Broekmann Dr. broekman@thch.uni-bonn.de Institut für Physikalische und Theoretische Chemie der Universität, Wegelerstrasse 12, 53115 Bonn, Germany, Fax: (+49) 228-732-551Search for more papers by this authorB. A. Hermann Prof. Dr., B. A. Hermann Prof. Dr. b.hermann@cens.de Institut für Physik der Universität, Klingelbergstrasse 82, 4056 Basel, Switzerland Present address: Walther-Meissner-Institut für Tieftemperaturforschung der Bayerischen Akademie der Wissenschaften und Fakultät für Physik/Center for Nano Science (CeNS) der LMU München, Walther-Meissner-Strasse 8, 85748 Garching, Germany, Fax: (+49) 89-289-14206Search for more papers by this authorChristoph A. Schalley Dr., Christoph A. Schalley Dr. c.schalley@uni-bonn.de Kekulé-Institut für Organische Chemie und Biochemie der Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany, Fax: (+49) 228-735-662Search for more papers by this author Caroline Safarowsky Dipl.-Chem., Caroline Safarowsky Dipl.-Chem. Institut für Physikalische und Theoretische Chemie der Universität, Wegelerstrasse 12, 53115 Bonn, Germany, Fax: (+49) 228-732-551Search for more papers by this authorLeo Merz Dipl.-Chem., Leo Merz Dipl.-Chem. Institut für Physik der Universität, Klingelbergstrasse 82, 4056 Basel, SwitzerlandSearch for more papers by this authorAlexander Rang Dipl.-Chem., Alexander Rang Dipl.-Chem. Kekulé-Institut für Organische Chemie und Biochemie der Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany, Fax: (+49) 228-735-662Search for more papers by this authorPeter Broekmann Dr., Peter Broekmann Dr. broekman@thch.uni-bonn.de Institut für Physikalische und Theoretische Chemie der Universität, Wegelerstrasse 12, 53115 Bonn, Germany, Fax: (+49) 228-732-551Search for more papers by this authorB. A. Hermann Prof. Dr., B. A. Hermann Prof. Dr. b.hermann@cens.de Institut für Physik der Universität, Klingelbergstrasse 82, 4056 Basel, Switzerland Present address: Walther-Meissner-Institut für Tieftemperaturforschung der Bayerischen Akademie der Wissenschaften und Fakultät für Physik/Center for Nano Science (CeNS) der LMU München, Walther-Meissner-Strasse 8, 85748 Garching, Germany, Fax: (+49) 89-289-14206Search for more papers by this authorChristoph A. Schalley Dr., Christoph A. Schalley Dr. c.schalley@uni-bonn.de Kekulé-Institut für Organische Chemie und Biochemie der Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany, Fax: (+49) 228-735-662Search for more papers by this author First published: 25 February 2004 https://doi.org/10.1002/anie.200352968Citations: 65 † This work was supported by the SFB 624 of the Deutsche Forschungsgemeinschaft and the NRP 47 of the Swiss National Science Foundation. C.A.S. and B.A.H. gratefully acknowledge the Fonds der Chemischen Industrie and the BMBF for financial support. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Beneath the surface lies the answer: Metallosupramolecular cations are deposited in an ordered manner on a copper surface, which had previously been covered with chloride ions. The anion layer acts as a second-order template, whose interactions with the cation determine the adsorption process (see scheme). Citing Literature Volume43, Issue10February 27, 2004Pages 1291-1294 RelatedInformation