Synthesis of purines and adenines containing the hexafluoroisopropyl group

• Viacheslav Petrov,
• Rebecca J. Dooley,
• Alexander A. Marchione,
• Elizabeth L. Diaz,
• Brittany S. Clem and
• William Marshall

Beilstein J. Org. Chem. 2020, 16, 2739–2748, doi:10.3762/bjoc.16.224

• of the material was confirmed by powder diffraction data and compared to simulated powder diffraction data from the single crystal diffraction experiment. The reaction conditions, mass spectrometry, and NMR data are given in Table 1 and Table 3. Crystal structure of 2a, with the thermal ellipsoids

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• (Table 1). As expected, an increase in the SSA was observed upon grinding because of the reduction of the β-CD particle size. XRD analysis X-ray diffraction data give additional evidence for the crystallinity variation of the β-CD particles upon grinding. Figure 3 shows a series of X-ray powder

• diffraction patterns recorded after various grinding times, and establish the extent of the amorphization of the reaction mixture during mechanochemical milling. The peaks corresponding to pure β-CD crystals decrease over time. Clearly, the polycrystalline β-CD powder becomes amorphous over time. The

• every 3 cycles to limit agglomeration of the powder. The resulting powder was purified by flash chromatography on silica gel using acetonitrile/water 9:1 to 8:2 (v/v) as mobile phase. Isolated yield 21% (364 mg). All runs were performed at least twice in order to ensure reproducibility. X-ray powder

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• before the crystallization, as confirmed by powder diffraction data collected at room temperature for the white precipitate obtained from the mixed water solutions of TAPM and NDS. Space group P21/c, a = 20.9609(10) Å, b = 19.7563(9) Å, c = 22.6642(10) Å, β = 92.694(3)°, cell volume = 9375.1(8) Å3. When

• F-1 was submitted to vacuum drying at 100 °C for several hours, a sample F-1b was obtained. X-ray powder diffraction showed that F-1b contained a mixture of unknown phases (Figure S3, Supporting Information File 1). However, after a few hours of being exposed to air, it reverted into the phase F-1a

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• single crystal structure analysis were compared to the X-ray powder diffraction spectra (Figures S10, S11 and S12, in Supporting Information File 1). Whereas no correlation of the main peaks was found for DTT 1, DTS 2 showed a better relationship between the powder and single crystal derived powder

Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation

• Sebastian Haferkamp,
• Andrea Paul,
• Adam A. L. Michalchuk and
• Franziska Emmerling

Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110

• real time, using in situ techniques [12][13]. The first in situ and real time study was performed by X-ray powder diffraction (XRPD) to monitor transformations during a milling process [12]. In situ studies allow novel insight into the mechanism of a mechanochemical process, without changing the

• in the main text. The final products were characterized by XRPD. X-ray powder diffraction (XRPD): All samples were characterized by XRPD analysis using a Bruker D8 diffractometer with Cu-Kα1 radiation (λ = 1.54106 Å) in a range of 5.0° ≤ 2 θ ≤ 40°. The data were obtained in transmission mode with a

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• equimolar quantities of 9-methyladenine and 1-methylthymine in an amalgam mill gave powder diffraction patterns consistent with the formation of Hoogsteen-type base-pairing (Scheme 16) [81]. No co-crystal formation was observed using 1-methylcytosine with 9-ethylguanine or other combinations which did not

The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy

• Patrick A. Julien,
• Ivani Malvestiti and
• Tomislav Friščić

Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216

• mechanochemical reactions. A significant recent advance in mechanistic studies of mechanochemical reaction mechanisms was the introduction of techniques for in situ, real-time monitoring of ball milling processes [27], first through synchrotron X-ray powder diffraction (XRPD) [28][29], and later by Raman

• Bruker Vertex 70 FT-IR Platinum ATR, while X-ray powder diffraction patterns were collected on a Proto Manufacturing AXRD Benchtop Powder Diffractometer using Ni-filtered Cu Kα radiation. The conversion for each solid-state reaction was evaluated after milling using 1H NMR spectroscopy conducted in CDCl3

Mechanochemical Knoevenagel condensation investigated in situ

• Sebastian Haferkamp,
• Franziska Fischer,
• Werner Kraus and
• Franziska Emmerling

Beilstein J. Org. Chem. 2017, 13, 2010–2014, doi:10.3762/bjoc.13.197

• Perspex grinding jar, allowing to monitor the course of the reaction simultaneously. A detailed description of the experimental setup can be found elsewhere [24]. Figure 2 shows the X-ray powder diffraction (XRPD) patterns and the Raman spectra of the in situ investigation, monitored in a time-span of 60

• single crystal determination. The crystal structure could be solved, matching the parameters described in the literature [26]. Conclusion Using an in situ tandem approach combining synchrotron X-ray powder diffraction and Raman spectroscopy, we investigated the mechanochemical Knoevenagel condensation of

• , the reaction mixture was milled in stainless steel jars at 50 Hz for 45 minutes. The final products were characterized by XRPD. X-ray powder diffraction: All samples were characterised by XRPD analysis using a Bruker D8 diffractometer: Cu Kα1 radiation (λ = 1.54106 Å), 5.0° ≤ 2 θ ≤ 60°. All data were

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• hydrolases; glycosyl transferases; kinetic crystallography; lectins; polysaccharides; powder diffraction; small-angle X-ray scattering; starch; synchrotron radiation; transporters; X-ray crystallography; Introduction Over the last decade, glycoscience has greatly benefited from the development of structural

• hydrated unit cell (Figure 4) [12]. Polycrystalline material Powder diffraction is a standard technique in material science that is used to investigate polycrystalline materials as many micrometer-sized crystals instead of a large single crystal. A powder diffraction pattern captures all possible crystal

• orientations simultaneously. The development of synchrotron radiation instrumentation dedicated to powder diffraction [13] allows to perform the experiments that were considered to be impractical before. When using high quality data in conjunction with advanced computational methods, it is possible to solve

Adsorption of RNA on mineral surfaces and mineral precipitates

• Elisa Biondi,
• Yoshihiro Furukawa,
• Jun Kawai and
• Steven A. Benner

Beilstein J. Org. Chem. 2017, 13, 393–404, doi:10.3762/bjoc.13.42

• clean tubes and radioactive counts in each slide were read at the scintillation counter with the Cherenkov method. Feigl’s staining and X-ray powder diffraction Feigl’s stain [29] is a solution of silver and manganese sulfates. The stain colors orthorhombic and hexagonal carbonates black, but does not

• % formamide gel loading buffer for denaturing PAGE analysis (18%, 7 M urea). Gels were dried for 30 min at 80 °C before being exposed to a phosphorimager screen for quantitative autoradiography. Mineral identification with X-ray powder diffraction Identification of synthetic minerals was conducted with a

• : Feigl’s stain of CaCO3 precipitate formed by double decomposition of 1 M CaCl2 + 1 M Na2CO3 in the absence (upper tube) or presence (lower tube) of RNA. B: X-ray powder diffraction of samples prepared the same way showing a net increase in vaterite versus calcite. RNA adsorbed on aragonite is resistant to

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• of the stereocenters of compounds 4 are 2’R*, 3aS*, 3’R*, 4’R*, 9aR*. The homogeneity of compounds 4b–d,f–i,l–n was additionally confirmed by powder X-ray diffraction. The analysis of the experimental powder diffraction patterns of compounds 4b–d,f–i,l–n show that the investigated samples were single

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• use this technique for routine analysis [48]. Finally the binding constant of the host-guest inclusion complex was reported at 690 ± 140 M−1. Pesticides bearing a non-aromatic group X-ray powder diffraction analysis and DSC validated the formation of a complex between (diethoxyphosphinoximino

• guest might weaken the hydration water binding, as revealed in DSC experiments by the lower endothermic fusion peak, specific to a dehydration process. X-ray powder diffraction analysis finally confirmed the complex formation. All these studies proved that organophosphorus pesticides are able to

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• and to decrease with increase in PEG concentration consistent with the threading of varying numbers of α-CD onto the PEG. It was also observed that X-ray powder diffraction patterns of the powdered frozen hydrogel were consistent with the formation of localized regions where the α-CD/PEG pseudo

• -polyrotaxanes crystallized to form interchain links within the hydrogel. Similar conclusions were reached from another X-ray powder diffraction study of frozen α-CD/PEG hydrogels formed with PEG of 8, 20 and 600 kDa molecular weights [87]. The accompanying rheological and differential scanning calorimetric

Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time ¹³C CP-MAS solid-state NMR characterization

• Isabelle Mallard,
• Davy Baudelet,
• Franca Castiglione,
• Monica Ferro,
• Walter Panzeri,
• Enzio Ragg and
• Andrea Mele

Beilstein J. Org. Chem. 2015, 11, 2785–2794, doi:10.3762/bjoc.11.299

• D1, D2 and D3 were in agreement with the results obtained by Orpecio and Evans [37] for β-cyclodextrin–epichlorohydrin polymers. Powder X-ray diffraction spectra The starting monomer, CRYSMEB and all polymers D1, D2 and D3 were analyzed by X-ray powder diffraction. Figure 2 shows, as an example, the

• X-ray powder diffraction (XRPD) profiles of CRYSMEB and polymer D1. The upper trace clearly displays the typical halos of the amorphous material. This finding was indeed unexpected, as the starting material was supposed to show non-negligible crystallinity. Similar patterns are observed for D1, as

• aqueous phase was analyzed by UV–vis spectroscopy (Perkin-Elmer lambda 2S spectrophotometer). X-ray powder diffraction in the 2θ range of 4.7–40° (step size 0.02°; time per step 0.04 s, slits 0.6–8 mm, 30 KV × 10 mA, PSD 3) were collected on a Bruker AXS D2 Phaser diffractometer equipped with LinxEye

Ru complexes of Hoveyda–Grubbs type immobilized on lamellar zeolites: activity in olefin metathesis reactions

• Hynek Balcar,
• Naděžda Žilková,
• Martin Kubů,
• Michal Mazur,
• Zdeněk Bastl and
• Jiří Čejka

Beilstein J. Org. Chem. 2015, 11, 2087–2096, doi:10.3762/bjoc.11.225

• samples were degassed on a Micromeritics FlowPrep060 instrument under helium at 110 °C for 6 h. X-ray powder diffraction (XRD) data were obtained on a Bruker AXS D8 Advance diffractometer with a graphite monochromator and a Vantec-1 position sensitive detector using Cu Kα radiation (at 40 kV and 30 mA) in

Copper ion salts of arylthiotetrathiafulvalenes: synthesis, structure diversity and magnetic properties

• Longfei Ma,
• Jibin Sun,
• Xiaofeng Lu,
• Shangxi Zhang,
• Hui Qi,
• Lei Liu,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 850–859, doi:10.3762/bjoc.11.95

• powder diffraction (XRPD) pattern was recorded on X’Pert PRO (PANalytical). The temperature dependence of the magnetic susceptibility was measured on a SQUID magnetometer of Quantum Design MPMS-XL applying a magnetic field of 1 kOe. The data were corrected for core diamagnetism estimated from the sum of

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials

• Valeria C. Edelsztein,
• Andrea S. Mac Cormack,
• Matías Ciarlantini and
• Pablo H. Di Chenna

Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213

• spectrometer in a demountable liquid cell with two NaBr disks, 32 mm in diameter and a 0.5 mm thick Teflon spacer. For the dichloromethane gel, a warm solution of 1 (0.25 wt %) was injected into the cell and allowed to cool down for 10 min at room temperature before measuring the spectra. X-ray powder

• diffraction measurements: Diffraction patterns were obtained by using a Siemens D5000 diffractometer with Cu Kα radiation (λ = 1.54056 Å), the stepsize was 0.025° with a measurement time of 6 s per step. Scanning electron microscopy: SEM measurements were performed in a similar manner as described in [25

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

• coating procedure. X-ray powder diffraction analysis: As described in [22], X-ray powder diffraction patterns were collected by using a PanAnalytical X’Pert Pro equipped with an X’Celerator detector powder diffractometer using Cu Kα radiation generated at 40 kV and 40 mA. The diffraction patterns were

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

• that the determination of crystal structure at various temperatures around the ST temperature T1/2 is highly desirable in studies of ST phenomena in solids. Even temperature-dependent X-ray powder diffraction data from temperature-dependent studies can be extremely useful in the characterization of the

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

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• ) complex [56]. The structure was dimeric; each macrocycle was present as the trianion bound to the titanium by all three oxygens and pulled slightly into the cavity by iPrO−. The paper also reported the result of a reaction between the lithium salt of 3b and vanadyl chloride (VOCl3). Based on powder

• diffraction and 51V NMR data it was proposed that the VO group bound within the macrocyclic cavity, by analogy to the Ti(IV) complex, and that these units formed linear aggregates held together by V=O···V=O interactions. Ten years later, Redshaw was able to prove Hampton’s assertion regarding the structure by

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• reaction of di- and trihaloaryls with arylboronic acida. Supporting Information Scanning electron microscope image, X-ray photoemission spectrum, X-ray powder diffraction pattern, catalytic activity of different loading of palladium over NiFe2O4, catalyst recycling studies and 1H and 13C NMR for the

Insights into the mechanical properties of a silicone oil gel with a ‘latent’ gelator, 1-octadecylamine, and CO₂ as an ‘activator’

• Emiliano Carretti,
• Mathew George and
• Richard G. Weiss

Beilstein J. Org. Chem. 2010, 6, 984–991, doi:10.3762/bjoc.6.111

• fibers [14] because the powder diffraction patterns of the neat ODA-C powder and the SAFIN structures in the gel are the same (i.e., the ODA-C molecules pack in the same morph in the absence and presence of silicone oil). Flow curves. The rheological behavior of the gels was explored over a torque range

Oxalyl retro-peptide gelators. Synthesis, gelation properties and stereochemical effects

• Janja Makarević,
• Milan Jokić,
• Leo Frkanec,
• Vesna Čaplar,
• Nataša Šijaković Vujičić and
• Mladen Žinić

Beilstein J. Org. Chem. 2010, 6, 945–959, doi:10.3762/bjoc.6.106

• chirality as observed for some other gels of the chiral gelators. XRPD, molecular modeling and packing model The X-ray powder diffraction (XRPD) pattern of (S,S)-1b xerogel showed strong peaks corresponding to periodic distance d of 16.1 and 13.4 Å and a weaker peaks corresponding to d’s of 15.1 and 8.6 Å

• )-arrangements of i-Bu groups in the latter. Schematic presentation of the proposed (S,S)-1b and (S,R)-1b basic packing model based on XRPD, 1H NMR, FTIR and molecular modeling results. X-ray powder diffraction (XRPD) diagram of (S,R)-1a water/DMSO xerogel. Oxalyl retro-dipetide gelators; each b to a, (a) LiOH