3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates

• Aneta M. Tomkiel,
• Adam Biedrzycki,
• Jolanta Płoszyńska,
• Dorota Naróg,
• Andrzej Sobkowiak and
• Jacek W. Morzycki

Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16

• oxidation currents are approximately equal to the half of oxidation current of 6d and also other investigated compounds. This is probably caused by the electrode blocking due to an adsorption of the oxidation products. The fact that the electrochemical oxidation of 6f and 6g starts at more negative

Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

• Malgorzata Adamkiewicz,
• David O’Hagan and
• Georg Hähner

Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307

• reported the formation of high quality vinyl-terminated SAMs generated from the vapour phase by adsorption of octadecyltrichlorosilanes onto silicon wafers [16]. With access to these SAMs it became an objective to explore functional group modification of the vinyl double bond. Carbon–carbon bond formation

Mono- and multilayers of molecular spoked carbazole wheels on graphite

• Stefan-S. Jester,
• A. Vikas Aggarwal,
• Daniel Kalle and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 2783–2788, doi:10.3762/bjoc.10.295

• behave as more or less rigid objects of certain sizes and shapes – depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs), where the first adlayer acts as a template for the commensurate adsorption of molecules in

• -intraannular alkoxy side chains fit (after adsorption) into the triangular cavity regions between each two spokes and the rim. Based on the observed intermolecular distances and an alignment of the alkoxy side chains along the HOPG main axis directions [10][11], an intermolecular side chain interdigitation

• octyloxy side chains are (most probably) adsorbed on the HOPG substrate in the intermolecular pores of the first layer. The results clearly indicate that not only the HOPG acts as a template for the organization of the first molecular adlayer, but the adsorption pattern is transferred to the second layer

Self-assembled monolayers of shape-persistent macrocycles on graphite: interior design and conformational polymorphism

• Joscha Vollmeyer,
• Friederike Eberhagen,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2014, 10, 2774–2782, doi:10.3762/bjoc.10.294

• . (c) Hexagonal pattern of molecular hexagons where all alkoxy side chains are adsorbed on the substrate along the six HOPG main axis directions, d1, d2, and d3, that are defined by the arrows in (a). Backbones are shown as bold black and grey lines, and the alkoxy side chains that after adsorption

• representative of the series of 1–3 that form the same patterns), its alterable side chain interaction schemes, and the resulting pattern geometries. (a) Eight alkoxy side chains are attached to four corners of the backbone. After adsorption, four side chains align along the crystallographic main axis direction

• substrate, whereas two side chains of each molecule point towards the solution phase (black dots). The arrows in (b) define the HOPG crystallographic main axis directions d1, d2, and d3. The backbones are shown as bold black and grey lines with alkoxy side chains that after adsorption align along d1 (thin

Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

• Juliana P. L. Gonçalves,
• Afnan Q. Shaikh,
• Manuela Reitzig,
• Daria A. Kovalenko,
• Jan Michael,
• René Beutner,
• Gianaurelio Cuniberti,
• Dieter Scharnweber and
• Jörg Opitz

Beilstein J. Org. Chem. 2014, 10, 2765–2773, doi:10.3762/bjoc.10.293

• modified titanium alloys surfaces by scanning and transmission electron microscopy. The process described shows an adsorption and immobilization of modified nanodiamonds on titanium; where aminosilanized nanodiamonds coupled with O-phosphorylethanolamine show a homogeneous interaction with the titanium

• alloy surface. Figure 4 shows the topological information of all nanodiamond entities immobilized onto Ti6Al7Nb surfaces either by adsorption to preformed anodic oxide layers (adDND), or by adsorption to air formed oxide layers followed by growth of the oxide layer by anodic polarization (anodDND

• functionalized with the phosphate group after the silanization process. These results indicate that the surface functionalization of DND is one important parameter for successful adsorption and immobilization on titanium alloy substrate. Another crucial parameter is to achieve a stable suspension of nanodiamonds

Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene

• Ludmilla Lumholdt,
• Sophie Fourmentin,
• Thorbjørn T. Nielsen and
• Kim L. Larsen

Beilstein J. Org. Chem. 2014, 10, 2743–2750, doi:10.3762/bjoc.10.290

• other words, coated PP pieces were fully submerged in the water phase for the entire experiment as opposed to non-coated PP pieces which were not wettable and, therefore, only partly submerged. This made the comparison between the adsorption of the VOCs by coated and non-coated PP problematic, as the

• former was an expression of aqueous adsorption, while the latter was of gaseous adsorption. Furthermore, it has been shown that the ACD coating is equally distributed along the PP fibres [22]. Hence, it could be argued that no crude PP fibres are present in a coated PP sample and, therefore, no

• adsorption by the untreated PP itself. For these reasons, it was decided to view the adsorption of the coated PP samples as a combination of the adsorption caused by the coating together with the potential, possible adsorption of crude PP fibres (if present), and accordingly no direct comparisons were made

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• samples carrying amino groups count among these) is prone to unspecific adsorption of organic molecules via hydrogen bonding and other interactions [29]. Therefore it seems reasonable to assume that the rather low amounts of hydrindantin formed upon the addition of KCN can be adsorbed on the diamond

• can be used for other nanoparticles with similar adsorption properties as well and represents a useful addition to the wet-chemical analysis of functional groups on nanomaterials. Experimental General chemicals and methods Detonation diamond has been purchased from Gansu Lingyun Corp. (Lanzhou, China

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• /polyacrylonitrile/copper nanorods composite fibers by adsorption and reduction. The composite fibers were fully characterized by FTIR, SEM, TEM, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The results indicated that the copper nanorods were not only successfully synthesized on the surface

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• higher adsorption strength on the cathode surface. This suggests that dienes undergo carboxylation according to mechanism II while adsorbed on the surface, combined with mechanism I (Scheme 7). Moreover it was shown that diene configuration has a strong stereoelectronic effect on the rate of the

Molecular ordering at electrified interfaces: Template and potential effects

• Thanh Hai Phan and
• Klaus Wandelt

Beilstein J. Org. Chem. 2014, 10, 2243–2254, doi:10.3762/bjoc.10.233

• adsorption and phase transition of 1,1’-dibenzyl-4,4’-bipyridinium molecules (abbreviated as DBV2+) on a chloride-modified Cu(111) electrode surface. The cyclic voltammogram (CV) of the Cu(111) electrode exposed to a mixture of 10 mM HCl and 0.1 mM DBVCl2 shows three distinguishable pairs of current waves P1

• intermediate potentials, two peaks are seen which are due to chloride desorption/adsorption at −360 mV and −80 mV, respectively. Compared to this CV in pure hydrochloric acid, drastic changes are found in the cyclic voltamogram of the Cu(111) electrode in contact with the electrolyte containing 0.1 mM DBV2

• /P1’ and P3/P3’) [5][6][7][13][14][15][16], as well as to an order/disorder phase transition due to chloride desorption/adsorption [17]. As mentioned in the Introduction, the viologen dication (DBV2+) is known to undergo two successive one-electron transfer steps in the electrochemical environment

Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100) surface investigated by scanning tunneling microscopy and low energy electron diffraction

• Stefan Gärtner,
• Benjamin Fiedler,
• Oliver Bauer,
• Antonela Marele and
• Moritz M. Sokolowski

Beilstein J. Org. Chem. 2014, 10, 2055–2064, doi:10.3762/bjoc.10.213

• , 76131 Karlsruhe, Germany Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain 10.3762/bjoc.10.213 Abstract We have investigated the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) on the clean and on the oxygen pre-covered Cu(100

• et al., we have no indication for a dissociation of the PTCDA upon adsorption, and we propose a detailed structure model with two intact PTCDA molecules within the unit cell. Domains of high lateral order are obtained, if the deposition is performed at 400 K. For deposition at room temperature, a

• light-emitting diodes [2]. In order to obtain a fundamental understanding of the interactions at these interfaces, the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) on single crystal surfaces of noble metals has been studied intensively as a model system [3]. On the coinage

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• like dried silica to prevent moisture adsorption from the environment [73]. Thermal degradation of riboflavin RF is a heat stable compound and little information is available regarding its thermal degradation in aqueous solution. However, some degradation pathways and products have been reported for

Theoretical study of the adsorption of benzene on coinage metals

• Werner Reckien,
• Melanie Eggers and
• Thomas Bredow

Beilstein J. Org. Chem. 2014, 10, 1775–1784, doi:10.3762/bjoc.10.185

• Werner Reckien Melanie Eggers Thomas Bredow Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstr. 4, 53115 Bonn, Germany 10.3762/bjoc.10.185 Abstract The adsorption of benzene on the M(111), M(100) and M(110) surfaces of the coinage metals copper (M

• (D3 and D3(BJ)) are compared. PBE-D3, PBE-D3(BJ) and RPBE-D3 give similar results which exhibit a good agreement with experimental data. RevPBE-D3 and RevPBE-D3(BJ) tend to overestimate adsorption energies. The inclusion of three-center terms (PBE-D3(ABC)) leads to a slightly better agreement with the

• experiment in most cases. Vertical adsorbate–substrate distances are calculated and compared to previous theoretical results. The observed trends for the surfaces and metals are consistent with the calculated adsorption energies. Keywords: adsorption; benzene; coinage metals; density functional theory

Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

• Ulrike Groenhagen,
• Michael Maczka,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2014, 10, 1421–1432, doi:10.3762/bjoc.10.146

• the production of other, usually less volatile secondary metabolites and whether different compounds can be detected by headspace analysis [7] compared to commonly used solvent extraction or adsorption/extraction procedures. Strain FORM5 has been reported to produce the tetrahydrocyclopenta[b]pyridine

• streptopyridines also under these conditions. The liquid cultures were either extracted with ethyl acetate (E-extract) or filtered over Oasis adsorption material. The latter was than extracted with ethyl acetate (O-extract). These extracts were analyzed by GC–MS. While the E-extract did not show the presence of

Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

• Melanie Rauschenberg,
• Eva-Corrina Fritz,
• Christian Schulz,
• Tobias Kaufmann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 1354–1364, doi:10.3762/bjoc.10.138

• -specific protein adsorption, the arrays were incubated with a 3% bovine serum albumin (BSA) solution in PBS buffer (pH 7.5, 0.1% Tween 20) for 30 min and washed two times with PBS buffer prior to lectin screening. The surfaces of the carbohydrate arrays were covered by a solution of 1 mM FITC HisHis and 1

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

• Fabrizio Chiodo,
• Marco Marradi,
• Javier Calvo,
• Eloisa Yuste and
• Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

• corresponding ester prodrug candidates with a free thiol-ending group fundamental for their gold chemo-adsorption (Figure 1 and Supporting Information File 1). Abacavir (ABC) and lamivudine (3TC) were functionalized at the primary hydroxy groups through an ester bond that will be cleaved by cellular esterase

From porphyrin benzylphosphoramidate conjugates to the catalytic hydrogenation of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin

• Marcos C. de Souza,
• Leandro F. Pedrosa,
• Géssica S. Cazagrande,
• Vitor F. Ferreira,
• Maria G. P. M. S. Neves and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2014, 10, 628–633, doi:10.3762/bjoc.10.54

• favor the conversion of the porphyrin into isobacteriochlorin, probably by binding more efficiently the chlorin intermediate onto the catalyst surface influencing not only the stationary function of the catalyst, but also the adsorption–desorption equilibrium at that surface thus facilitating the

• CHCl3, CH2Cl2 and THF, because a hydrogenation reaction did not take place. In ethanol and its combinations with NEt3 and DMF the dynamic adsorption–desorption between the catalyst and the substrates was established in an adequate extension. The balance between the solubility of the porphyrin and its

• various reduced counterparts and the adsorption on the catalytic palladium surface is of great importance for the conversion to the desired TPCF20 and TPIF20. Conclusion Three new porphyrin aminoalkyl dibenzylphosphoramidates 1a–c derived from 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF20) were

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• more places for adsorption on/in the film. This behavior of anti,anti,syn-8 is exclusively observed for the aromatic analytes. Our triptycene-based cage compound 19 exhibits only moderate affinities, which is in accordance with the calculated collapsed structure (Figure 8). For protic analytes, anti

• compared (Figure 11). While the adsorption of aromatic analytes is dominated by the cavity size, the nature of the protection group dominates the adsorption of the protic analytes via hydrogen bonding [72]. A clear dependency on the number of nitro groups in the molecule, ascending from 8 with no nitro

Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

• Christian Dollendorf,
• Martin Hetzer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 1652–1662, doi:10.3762/bjoc.9.189

• -linked polycationic hydrogel when investigating the swelling–deswelling behavior and the absorbency of organic substances [12]. Positively charged polymeric systems show an increased adsorption to negatively charged cell membranes, a higher retention time within tumor tissue [13][14][15] and the ability

A³-Coupling catalyzed by robust Au nanoparticles covalently bonded to HS-functionalized cellulose nanocrystalline films

• Jian-Lin Huang,
• Derek G. Gray and
• Chao-Jun Li

Beilstein J. Org. Chem. 2013, 9, 1388–1396, doi:10.3762/bjoc.9.155

• show lower catalytic activities compared with homogeneous catalysts, which may be caused by blocking the diffusion and adsorption of organic reactant molecules and products or the poor dispersion of active sites [22][23]. Cellulose nanocrystals (CNCs) have emerged as a new class of nanomaterials owing

Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

• Rahat Javaid,
• Shin-ichiro Kawasaki,
• Akira Suzuki and
• Toshishige M. Suzuki

Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129

• carrier gas, whereas a Porapak–Q column (3 mm × 3 m) was used coupled with helium as the carrier gas for CO2 analysis. The specific surface area and pore diameter of the porous Pd were determined volumetrically (N2 adsorption) by using Belsorp MAX. Samples were degassed at 250 °C under vacuum prior to the

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

Self-assembled organic–inorganic magnetic hybrid adsorbent ferrite based on cyclodextrin nanoparticles

• Ângelo M. L. Denadai,
• Frederico B. De Sousa,
• Joel J. Passos,
• Fernando C. Guatimosim,
• Kirla D. Barbosa,
• Ana E. Burgos,
• Fernando Castro de Oliveira,
• Jeann C. da Silva,
• Bernardo R. A. Neves,
• Nelcy D. S. Mohallem and
• Rubén D. Sinisterra

Beilstein J. Org. Chem. 2012, 8, 1867–1876, doi:10.3762/bjoc.8.215

• -assembled material based on ferrite associated with β-cyclodextrin (Fe-Ni/Zn/βCD) at the nanoscale level. This MHM and pure ferrite (Fe-Ni/Zn) were used as an adsorbent system for Cr3+ and Cr2O72− ions in aqueous solutions. Prior to the adsorption studies, both ferrites were characterized in order to

• available binding sites, to bond or interact through intermolecular forces with the inorganic matrix, and high surface area, which is important to improve the MHM adsorption and adhesion properties. In order to design a MHM based on Fe-Ni/Zn with adsorption properties for environmental use, cyclodextrins

• . These hydroxy groups could improve the adsorption properties of the MHM by including guest molecules in CD cavities or also by allowing the assembly process. Recently, adsorption materials have become one of the most versatile and widely used technologies to remove heavy metals from industrial

Antifreeze glycopeptide diastereomers

• Lilly Nagel,
• Carsten Budke,
• Axel Dreyer,
• Thomas Koop and
• Norbert Sewald

Beilstein J. Org. Chem. 2012, 8, 1657–1667, doi:10.3762/bjoc.8.190

• –55 tripeptide units -Ala-Ala-Thr- glycosylated at the threonine side chains. Despite the structural homology among all the fish species, divergence regarding the composition of the amino acids occurs in peptides from natural sources. Although AFGPs were discovered in the early 1960s, the adsorption

• of sequential mutations on the adsorption of such synthetic AFGP analogues onto ice surfaces, and to corroborate the molecular mechanism of antifreeze activity. Recently, we published the synthesis of monosaccharide-based AFGP analogues containing glycine, proline and serine instead of alanine

• position for adsorption to the ice surface; a similar situation applies to the retro-inverso peptide 7. Moreover, these conformational changes may possibly also alter the water hydration shell around the peptide, which has been suggested to be essential for the antifreeze activity of AFGPs and AFGP

Cyclodextrin nanosponge-sensitized enantiodifferentiating photoisomerization of cyclooctene and 1,3-cyclooctadiene

• Wenting Liang,
• Cheng Yang,
• Masaki Nishijima,
• Gaku Fukuhara,
• Tadashi Mori,
• Andrea Mele,
• Franca Castiglione,
• Fabrizio Caldera,
• Francesco Trotta and
• Yoshihisa Inoue

Beilstein J. Org. Chem. 2012, 8, 1305–1311, doi:10.3762/bjoc.8.149

• spectra shifting to higher wavenumbers. On the other hand, the stiffness of the polymeric network of CDNSs is more affected by the PMA/CD ratio, rather than the type of CD used. The adsorption, absorption and inclusion properties of these new materials have been demonstrated for a large variety of