Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• shape, through poly(host–guest)-interactions, was found. Furthermore, we were able to show the collapse of the supramolecular polymers upon addition of potassium adamantane-1-carboxylate. Experimental General remarks All reagents used were commercially available (Sigma-Aldrich, Acros Organics) and used

• , Humboldtstr. 10, 07743 Jena, Germany 10.3762/bjoc.9.94 Abstract Mono-(6-azido-6-deoxy)-β-cyclodextrin (CD) was covalently attached to an alkyne-modified 5-methyl-2-(pyridin-2-yl)thiazol-4-ol yielding a fluorophore containing CD in a click-type reaction. Intermolecular complexes were formed by poly(host–guest

• )-interactions. The supramolecular structures were characterized by 1H NMR-ROESY spectroscopy, dynamic light scattering, UV–vis spectroscopy, fluorescence spectroscopy, and asymmetric flow field-flow fractionation. By adding potassium adamantane-1-carboxylate, the thiazol dye is displaced from the CD-cavity and

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Influence of cyclodextrin on the solubility and the polymerization of (meth)acrylated Triton^® X-100

• Melanie Kemnitz and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2176–2183, doi:10.3762/bjoc.8.245

• –guest interactions. The successful polymerization of 10–13 was demonstrated, e.g., by 1H NMR spectroscopy. The signals of the olefinic protons between 5.5 and 6.2 ppm vanished; whereas the signals of the polymer backbone at 0.67 ppm were clearly visible. As expected, the signals of the protons of the

• possible after the complexation of (meth)acrylated Triton® X-100 (2 and 3) with RAMEB-CD (Scheme 3). The polymers 10 and 12 complexed with 1 equiv of RAMEB-CD precipitated during the polymerization, whereas the double complexed polymers 11 and 13 did not precipitate, as a consequence of the stronger host

Mannose-decorated cyclodextrin vesicles: The interplay of multivalency and surface density in lectin–carbohydrate recognition

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2012, 8, 1543–1551, doi:10.3762/bjoc.8.175

• be modified by host–guest interactions with functional guest molecules. In this article, we investigate the multivalent interaction of the lectin concanavalin A (ConA) with cyclodextrin vesicles decorated with mannose–adamantane conjugates with one, two or three adamantane units as well as one or two

• in Table 1. According to a quantitative treatment of multivalent host–guest interactions at surfaces, it may be expected that for a 1:1 monovalent interaction with a binding constant of ≈104 M−1, a divalent interaction can have an apparent binding constant of ≈107 M−1 and a trivalent interaction can

Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

• Nina Gonsior,
• Fabian Mohr and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 390–397, doi:10.3762/bjoc.8.42

• relatively low values of the formation constant calculated for both a 1:1 complex (K1 = 1.6 × 102 M−1) and a 1:2 complex (K2 = 0.2 × 102 M−1) indicates only weak host/guest interactions and therefore only a slight increase of solubility in water was achieved. However, the value of K1 is in good agreement

Supramolecular chemistry II

• Christoph A. Schalley

Beilstein J. Org. Chem. 2011, 7, 1541–1542, doi:10.3762/bjoc.7.181

• devoted to quantifying host–guest interactions, aiming at a more profound understanding of the subtle entropic and enthalpic effects that govern the interactions between host and guest. A first Thematic Series devoted to supramolecular chemistry was assembled about two years ago and published by the

Fluorometric recognition of both dihydrogen phosphate and iodide by a new flexible anthracene linked benzimidazolium-based receptor

• Kumaresh Ghosh and
• Debasis Kar

Beilstein J. Org. Chem. 2011, 7, 254–264, doi:10.3762/bjoc.7.34

• the polar C+–H bond of benzimidazolium motif and reduces the possibility of host–guest interactions [46]. This is clearly reflected in the binding constant values in Table 1. Due to the presence of a minimum amount of CH3CN in CHCl3 the binding constant values for the selected anions are greater in

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• water-soluble polymer is obtained due to the host guest interactions. Those polymeric complexes are stable in water up to about 90 °C. Above this temperature the polymer precipitates due to decomplexation. The complex was investigated by 1H NMR spectrometry, dynamic light scattering (DLS), differential

Synthesis of deep- cavity fluorous calix[4]arenes as molecular recognition scaffolds

• Maksim Osipov,
• Qianli Chu,
• Steven J. Geib,
• Dennis P. Curran and
• Stephen G. Weber

Beilstein J. Org. Chem. 2008, 4, No. 36, doi:10.3762/bjoc.4.36

• enhance the formation of a single conformer [12]. Of the four possible conformations, the cone is the most desirable for molecular recognition and sensing applications because it has the largest available surface area for host-guest interactions [10]. With appropriate functionality and conformation, the

• , thus limiting the scope of possible host-guest interactions. Increasing the depth of the cavity by coupling 5 with aromatic rings to give 9 allows for host-guest interactions involving larger substrates. This modification increases the versatility of the scaffold and the variety of host-guest

• interactions that can occur in ion binding [8] and capsule formation [34]. Likewise, introduction of hydrogen bonding groups like those of 9 are crucial for achieving interactions with various substrates [35][36]. Coupling an aromatic ring onto the upper-rim of the fluorous calixarene led to an increase in

Molecular recognition. 1. Crystal structures of hexaazamacrocyclic amines containing p-xylylene spacers and their adducts with acids

• Teresa Borowiak,
• Grzegorz Dutkiewicz,
• Maciej Kubicki,
• Marek Pietraszkiewicz,
• Agnieszka Gil and
• Rainer Mattes

Beilstein J. Org. Chem. 2005, 1, No. 16, doi:10.1186/1860-5397-1-16

• hexaprotonated cation is produced.[6][13] The supramolecular assemblies which are formed between the receptor 1 and the anionic guests under participation of solvent molecules are kept together by two main types of interactions: Coulombic forces and hydrogen bonding. Host-guest interactions depend also strongly