A peptidic hydrogel that may behave as a “Trojan Horse”

• Nicola Castellucci,
• Giorgio Sartor,
• Natalia Calonghi,
• Carola Parolin,
• Giuseppe Falini and
• Claudia Tomasini

Beilstein J. Org. Chem. 2013, 9, 417–424, doi:10.3762/bjoc.9.44

• 10.3762/bjoc.9.44 Abstract A physical hydrogel prepared with the low-molecular-weight hydrogelator (LMWHG) CH2(C3H6CO-L-Phe-D-Oxd-OH)2 and water/ethanol mixture was applied as a potential “Trojan Horse” carrier into cells. By SEM and XRD analysis we could demonstrate that a fibrous structure is present in

• , were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Hydrogel 1 is a strong and thermoreversible gel (Figure 1a) with its melting point at 45 °C. The XRD pattern from the hydrogel 1, collected at 100 K, is characterized by the presence of diffraction rings at low angle

• (indicated in Figure 2b) having periodicities of 2.2 nm, 1.7 nm, 1.4 nm and 0.54 nm. The additional high-angle diffraction rings not listed are due to the presence of ice [27]. Any attempt to collect XRD data at room temperature, or at 100 K in the presence of cryoprotectants, to avoid the formation of ice

Iron-containing mesoporous aluminosilicate catalyzed direct alkenylation of phenols: Facile synthesis of 1,1-diarylalkenes

• Satyajit Haldar and
• Subratanath Koner

Beilstein J. Org. Chem. 2013, 9, 49–55, doi:10.3762/bjoc.9.6

• established from the small-angle XRD patterns (see Supporting Information File 1). The BET surface area and the pore width of Fe-Al-MCM-41 were found to be 753 m2/g and 25.83 Å, respectively. The aluminium and iron contents of the Fe-Al-MCM-41 catalyst were estimated by AAS method and found to be 5.5 wt % and

• hydrolysis [48]. The disintegration of the mesoporous structure was achieved by boiling Fe-Al-MCM-41 with millipore water. The liquid-to-sample ratio was fixed at 1 Lg−1. After 12 h of heating, the sample was filtered and dried in an oven for 2 h at 398 K. The XRD patterns of the dried sample revealed that

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

• /Zn and the MHM prepared by using Fe-Ni/Zn and βCD (Fe-Ni/Zn/βCD) were synthesized by adapting a method previously described in the literature [7]. These magnetic materials were characterized in the solid state by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and

Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

• Govindaswamy Shanker,
• Marko Prehm and
• Carsten Tschierske

Beilstein J. Org. Chem. 2012, 8, 472–485, doi:10.3762/bjoc.8.54

• studied by optical polarizing microscopy (PM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). All dimesogens exhibit broad ranges of cybotactic nematic phases (NcybA and NcybC), in some cases accompanied by additional mesophases (CybA or SmC) at lower temperature. The combination of

• bent-core mesogens are of special interest for achieving biaxial nematic phases of the orthorhombic type. The orthogonal (NcybA) and skewed (NcybC) cybotactic nematic phases were distinguished by XRD and optical observations. Keywords: bent-core mesogens; cybotactic nematic phases; dimesogen; liquid

• differential scanning calorimetry (DSC, DSC-7, Perkin-Elmer). The assignment of the mesophases is based on the combined results of optical textures and X-ray diffraction (XRD) studies. XRD investigations on aligned samples were performed by using a 2D wire detector (HI-Star, Siemens AG). Alignment was achieved

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

• investigations into the integration of bent-core mesogens into new NP hybrids have been reported. An early report investigated the grafting of bent-core ligands 1410,10 and 1412,11 (Figure 18) to hexanethiol coated Au NPs with diameters of 2.8 ± 0.6 and 2.5 ± 0.5 nm by TEM (3.9 ± 1.5 nm and 2.4 ± 0.8 nm by XRD

Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

• Alicja Schlange,
• Antonio Rodolfo dos Santos,
• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165

• has much higher dispersion. Powder X-ray diffraction analysis was performed to investigate the crystalline structure of the prepared catalysts and the support material. XRD spectra are given in Figure 5. For pristine carbon nanotubes the diffraction peaks at 30.0° and 50.4° can be attributed to the

• with ethanol, then separated by means of a centrifuge at 4000 rpm and finally dried in a furnace at 60 °C under air flow. Characterization methods The crystalline structures of the support material and electrocatalysts were analyzed by X-ray diffraction (XRD) with a Siemens D5000/Kristalloflex

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• in ethanol (Scheme 1). The as-prepared Cell–OPPh2–Pd0 catalyst was characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analyses (TGA), scanning electron microscopy (SEM) and

• the Cell–OPPh2–Pd0, indicating coordination of the phosphine atom with the palladium and further confirming the formation of a palladium complex on the surface of the polymer. Figure 1 shows the XRD pattern of the cellulose-supported palladium catalyst and the Cell–OPPh2 matrix. The Cell–OPPh2

• ) lattice planes of the face-centered cubic crystalline structure of the Pd nanoparticles are correspondingly clearly seen from the XRD pattern of Cell–OPPh2–Pd0 catalyst. The thermal stability of Cell–OPPh2–Pd0 has a great effect on its catalytic activity and recyclability because the Suzuki–Miyaura

Amphiphilic dendritic peptides: Synthesis and behavior as an organogelator and liquid crystal

• Baoxiang Gao,
• Hongxia Li,
• Defang Xia,
• Sufang Sun and
• Xinwu Ba

Beilstein J. Org. Chem. 2011, 7, 198–203, doi:10.3762/bjoc.7.26

• organogels assembled from G3 formed thin fibres that underwent further aggregation to form fibre bundles. These fibre bundles constitute a highly developed entangled network. Figure 2 shows the XRD scan of organogelator G3 and liquid crystal G3. Being different from the liquid crystal, the XRD of

• crystalline behavior Thermotropic behavior of ADPs was investigated by a combination of differential scanning calorimetry (DSC), polarization optical microscopy (POM) and X-ray diffraction (XRD) experiments. Figure 4 shows DSC curves of amphiphilic dendritic peptides. In the DSC scan from −60 °C to 200 °C, G1

• characteristic of hexagonal columnar liquid crystals. The conic fan-shaped textures of G3 grow (Figure 6B), and no longer change at 50 °C (Figure 6C). Figure 7 shows the XRD scan for the birefringent phase of G3 at 50 °C. The birefringent phases of G3 were further confirmed as a hexagonal columnar liquid crystal

Thermal rearrangement of tert-butylsulfinamide

• Veera Reddy Arava,
• Laxminarasimhulu Gorentla and
• Pramod Kumar Dubey

Beilstein J. Org. Chem. 2011, 7, 9–12, doi:10.3762/bjoc.7.2

• 1. From the spectral data, structure 3 was assigned to the product shown in Figure 2. The structure of 3 was confirmed by chemical synthesis (Scheme 2) and finally by XRD [4] (Figure 3). Both tert-butylsulfanyl chloride 4 (Scheme 3) and tert-butylsulfonamide 5 (Scheme 4) were prepared by known

ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering

• Franziska Weichelt,
• Solvig Lenz,
• Stefanie Tiede,
• Ingrid Reinhardt,
• Bernhard Frerich and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, 1199–1205, doi:10.3762/bjoc.6.137

• (SEM) images of the powders showed agglomerates of nanoparticles (~50–100 nm) and a rhombohedral calcite crystal structure was detected both by X-ray diffraction (XRD) and Raman measurements. Nano-sized platelets with a thickness <20 nm were formed in the synthesis of HAp and exhibited a calcium

• phosphate hydroxide crystal structure again from XRD and Raman measurements (Figure 1). Preparation and characterization of monolithic materials Monolithic hybrid materials were then prepared via ROMP from cis-5-cyclooctene-trans-1,2-diol (COE), a 7-oxanorborn-2-ene-derived cross-linker (CL) and up to 12 wt

• monoliths. Powder X-ray diffraction (XRD) was performed on a Philips X’Pert wide-angle diffractometer with slit optics, Cu Kα radiation (λ = 154 nm) and Ni Kβ filter. The powder was applied to the specimen holder using double faced-adhesive tape and the upper site was covered with a thin layer of the powder

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

• Sayanti Brahmachari,
• Sisir Debnath,
• Sounak Dutta and
• Prasanta Kumar Das

Beilstein J. Org. Chem. 2010, 6, 859–868, doi:10.3762/bjoc.6.101

• microscopy (FESEM), atomic force microscopy (AFM), photoluminescence, FTIR studies, X-ray diffraction (XRD) and 2D NOESY experiments were carried out to elucidate the different non-covalent interactions responsible for the self-assembled gelation. The formation of three-dimensional supramolecular aggregates

• amphiphiles such as the aliphatic chain length and the polar head group was systematically carried out to understand their influence on the self-assembled hydrogelation. The various factors involved in the formation of supramolecular aggregates leading to hydrogelation were studied using FTIR, XRD and

• which is in accord with the absence of any kind of intermolecular interaction in the non-gelated state of the amphiphile. To investigate the molecular packing and orientation of the gelator molecules in the supramolecular self-assembled state, the xerogel of 2 was examined by X-ray diffraction (XRD). A

C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions

• Mazaahir Kidwai,
• Saurav Bhardwaj and
• Roona Poddar

Beilstein J. Org. Chem. 2010, 6, No. 35, doi:10.3762/bjoc.6.35

• differences which have been shown in the TEM image. The number of reactive sites on the surface is small in the case of larger crystallites and considerably greater in the case of smaller crystallites (Figure 1). To investigate further the surface morphology of CuO-nanoparticles, powder XRD and TEM images

• were taken. Figure 1 shows the XRD pattern of CuO-nanoparticles in which diffraction peaks can be indexed to a monoclinic structure. The intense diffraction peak at an angle 38.4 shows index plane (111) which contains more basic sites with higher density as compared to bulk CuO. During optimization of

• of the reaction mixture and washed thoroughly with ethyl acetate. The resulting nanoparticles could be reused for several cycles without any significant loss of activity. In our study, we used same nanoparticles three times and the results are summarized below (Table 5). The TEM and XRD analysis of

Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al₂O₃ under inspection

• Franziska Bernhardt,
• Ronald Trotzki,
• Tony Szuppa,
• Achim Stolle and
• Bernd Ondruschka

Beilstein J. Org. Chem. 2010, 6, No. 7, doi:10.3762/bjoc.6.7

• Table 2 resulted from XRD analyses (cf. Supporting Information File 1) and specific surface areas AS were determined using 6-point-BET measurements. γ-Al2O3 SRS1 and SRS3 differ in their surface characteristics. SRS1 possesses a neutral surface, whereas SRS3 shows a higher basicity that was verified by

• surface [72]. However, the authors were not able to prove the change in alumina modification as the XRD results only point out the formation of K3AlF6 phases, but not the proposed phase transformation. The main difference between our present study and the recently published study is the fact that

• , according to the previous study, the formation of K3AlF6 and KOH (Equation 1) [30][61][73][74] was reported to take place during calcination, whereas, in our study, this reaction occurs already in the solution. This was indicated by XRD measurements of the freshly prepared KF-loaded aluminas (cf. Supporting

Influence of spacer chain lengths and polar terminal groups on the mesomorphic properties of tethered 5-phenylpyrimidines

• Gundula F. Starkulla,
• Elisabeth Kapatsina,
• Angelika Baro,
• Frank Giesselmann,
• Stefan Tussetschläger,
• Martin Kaller and
• Sabine Laschat

Beilstein J. Org. Chem. 2009, 5, No. 63, doi:10.3762/bjoc.5.63

• confirmed by XRD experiments (see the Supporting Information). It should be noted that the allyloxy-substituted byproduct 9 showed a smectic mesophase between 50 °C and 67 °C as well. In contrast, the corresponding 4-allyloxy-4′-octylbiphenyl 11 showed only isotropic melting at 92 °C. The DSC results of

• crystallization peak at 42 °C were observed. POM investigation displayed fan-shaped and focal conic textures, as exemplified in Figure 4. XRD experiments proved the smectic phase. In contrast to the bromides 3 and chlorides 4, the hydroxy and azide derivatives 5a,b and 7b–e were non mesomorphic and showed only

• values obtained from the X-ray experiments fit with the molecular lengths derived from simple molecular modelling (Chem3D) [13]. For example, the XRD pattern of the azide derivative 6c results in a layer distance of 25.5 Å, whereas the calculated length of the molecule for the most elongated conformation

Saddle-shaped tetraphenylenes with peripheral gallic esters displaying columnar mesophases

• Eugen Wuckert,
• Constanze Hägele,
• Frank Giesselmann,
• Angelika Baro and
• Sabine Laschat

Beilstein J. Org. Chem. 2009, 5, No. 57, doi:10.3762/bjoc.5.57

• , clear evidence was possible only by XRD data, which are summarized in Table 2. While rectangular columnar mesophases were observed for tetraphenylenes 2e–i with shorter chains (n = 9–13) (shown for 2f in Figure S1 in the Supporting Information), hexagonal columnar mesophases were found for the long

• mesophases with increasing chain lengths has been also observed in other columnar systems [32][33] and has been attributed to the enhanced core–core interaction necessary for the formation of the Colr phases [34]. According to molecular modelling [35] and comparison with the XRD data each disk within the

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• general stability order to be I−< BF4− ≈ PF6−< CF3SO3−< (CF3SO2)2N− (Figure 4). For all the compounds, the mesomorphic behaviour and phase transition temperatures were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC), and powder X-ray diffractometry (XRD). To

• confirmed by XRD. The X-ray pattern (Figure 6) of the Smectic A form recorded at 120 °C contains a diffuse band at 4.6 Å (wide angle), which shows clearly that the alkyl chains have a liquid-like structure and are segregated from the aromatic cores. The layer thickness in the Smectic A phase was determined