Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• increases, and techniques develop at a rapid pace [10][11][52][53]. SAS techniques include small angle X-ray scattering (SAXS), small angle neutron scattering (SANS), and their wide angle (WAXS) and ultra-small angle (USAXS and USANS, respectively) analogues have various advantages and drawbacks compared to

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• azobenzene (Azo) or, more recently, arylazopyrazoles (AAPs), which change shape and polarity on photoisomerisation between the E and Z states, thus changing the self-assembled structure. Small-angle X-ray scattering (SAXS) is a powerful technique to probe the morphology of PS and can be used to measure the

• greater using low-energy X-rays (8 keV) due to their greater photoabsorption in water, thus leading the authors to conclude that higher energy (≈36 keV) should be used for future small-angle X-ray scattering (SAXS) experiments on photoswitchable systems. However, this may not always be achievable

Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches

• Tobias Klein,
• Franka V. Gruschwitz,
• Maren T. Kuchenbrod,
• Ivo Nischang,
• Stephanie Hoeppener and
• Johannes C. Brendel

Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175

• cross-section [19], and 28 nm for BTP by assuming a similar stacking distance and 2 molecules per cross-section [21]. Based on a fiber diameter of 12 nm (estimated from small-angle X-ray scattering experiments) [19][20], the resulting tensile strength for both compounds was approximately 16 to 17 MPa

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• medium. The ONCs have a thin rectangular shape, with an aspect ratio that is controlled by the content of the organic cosolvent (THF). The nanocrystals were characterized in solution by cryogenic transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering. The ONCs retain their structure

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

• flexible loop. Small angle X-ray scattering Small angle X-ray scattering is a universal technique whereby X-rays are recorded that have been elastically scattered at a low angle from samples in solution. Analysis of the scattered X-rays allows low-resolution structural information to be obtained, such as

• conformationally flexible sequence of 38 amino acids which was detrimental for crystallization. The respective crystal structures of the N- and C-domains could be solved separately and eventually used to establish the overall structure of the assembly by small-angle X-ray scattering (and further confirmed by

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• flexible nanofibres at 27 °C and further to small elongated micelles at 45 °C. Furthermore, the miscibility of the bolalipid with bilayer-forming phosphatidylcholines (DMPC, DPPC, and DSPC) was investigated by means of DSC, TEM, FTIR, and small angle X-ray scattering (SAXS). We could show that the PC

• investigated by FTIR and small angle X-ray scattering (SAXS). Results and Discussion Synthesis of PC-C18pPhC18-PC and its temperature-dependent aggregation behaviour Synthesis The phenylene-modified bolalipid 18,18’-(1,4-phenylene)bis{octadec-1-yl[2-(trimethylammonio)ethylphosphate]} (PC-C18pPhC18-PC) was

• , where q = 4π × sin(2θ)/λ and θ is the scattering angle. This was achieved using macros modified for the program IgorPro (version 6.34, WaveMetrics, Inc. 2013) from those macros written for the NIST Center for Neutron Research (Gaitherburg, USA) SANS instruments [60]. Small angle X-ray scattering (SAXS

Synthesis, structure, and mechanical properties of silica nanocomposite polyrotaxane gels

• Kazuaki Kato,
• Daisuke Matsui,
• Koichi Mayumi and
• Kohzo Ito

Beilstein J. Org. Chem. 2015, 11, 2194–2201, doi:10.3762/bjoc.11.238

• silica. Small-angle X-ray scattering revealed that the homogeneous distribution of silica nanoparticles in solution was maintained in the gel state. Such homogeneous nanocomposite gels were obtained with at least 30 wt % silica content, and the Young’s modulus increased with silica content. Gelation did

• modified to react with the surface of silica. The inner structure and the mechanical properties of the silica nanocomposite polyrotaxane gels were studied by small-angle X-ray scattering and viscoelastic measurements, respectively. Results and Discussion To achieve a covalent bond between the cyclic

• that the gelation was achieved mainly by the reaction between silica and TES-PR, with a parallel minor reaction occurring between the triethoxysilyl groups of different TES-PRs. To elucidate the dispersity of silica nanoparticles in the gels, small-angle X-ray scattering (SAXS) was carried out. Figure

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• at Lawrence Berkeley National Laboratory in the United States, we conducted solution-phase, small-angle X-ray scattering synchrotron experiments on the mixture of 33 and CB[8] in water (1:1.5, 3.0 mg/mL), which supported the periodicity of the 2D honeycomb SOF structures in solution. Liang Zhang

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• small-angle X-ray scattering (SAXS). ESR spectra of 48•+ and 483+ in CHCl3 at 23 °C showed 100% of spin for 48•+ and 33% of spin for 483+. Therefore, the spin–spin interaction in 48•+ is weak, whereas the spin–spin interaction in 483+ is strong. The monocation 48•+ClO4− easily formed a hexagonal fiber

TEMPO-derived spin labels linked to the nucleobases adenine and cytosine for probing local structural perturbations in DNA by EPR spectroscopy

• Dnyaneshwar B. Gophane and
• Snorri Th. Sigurdsson

Beilstein J. Org. Chem. 2015, 11, 219–227, doi:10.3762/bjoc.11.24

• biologically relevant conditions through the determination of intermediate to long-range distances [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. EPR spectroscopy can also give information about the relative orientation of two rigid spin labels [31][32][33][34][35]. Small angle X-ray

• scattering is also frequently used to study global structures of large molecules and molecular assemblies [36][37][38][39]. Local structural perturbations in nucleic acids can be studied with some of the aforementioned techniques. For example, NMR has been used to study hydrogen-bonding interactions [11][40

The search for new amphiphiles: synthesis of a modular, high-throughput library

• George C. Feast,
• Thomas Lepitre,
• Xavier Mulet,
• Charlotte E. Conn,
• Oliver E. Hutt,
• G. Paul Savage and
• Calum J. Drummond

Beilstein J. Org. Chem. 2014, 10, 1578–1588, doi:10.3762/bjoc.10.163

• boundary (confirmed by a dark image when viewed with crossed polarisers) indicating the presence of either a cubic or micellar phase. By contrast the lactose amphiphile 70 (Figure 7) shows a birefringent texture corresponding to a lamellar phase. Preliminary small-angle X-ray scattering data for these

• amphiphile library (that form normal phases) [30], we are able to achieve lyotropic phases ranging across the structural landscape of normal to inverse micelles. Upon completion of the comprehensive phase behaviour analysis of this second library, using high-throughput small-angle X-ray scattering (SAXS) at

• -angle X-ray scattering (SSAXS), to determine the liquid-crystalline phases of the individual compounds. These amphiphiles were found to form normal phases that have interfaces that curve away from water (Figure 2). For the majority of biomedical applications, inverse phase-forming amphiphiles (with

Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

• Alexej Bubnov,
• Miroslav Kašpar,
• Věra Hamplová,
• Ute Dawin and
• Frank Giesselmann

Beilstein J. Org. Chem. 2013, 9, 425–436, doi:10.3762/bjoc.9.45

• . The temperature was calibrated from extrapolated onsets of the melting points of water, indium and zinc. The enthalpy change was calibrated based on the enthalpies of melting of water, indium and zinc. The small-angle X-ray scattering studies have been performed with Ni-filtered Cu Kα radiation

Formation of smectic phases in binary liquid crystal mixtures with a huge length ratio

• Nadia Kapernaum,
• Friederike Knecht,
• C. Scott Hartley,
• Jeffrey C. Roberts,
• Robert P. Lemieux and
• Frank Giesselmann

Beilstein J. Org. Chem. 2012, 8, 1118–1125, doi:10.3762/bjoc.8.124

• mole fraction of x16 = 0.6 is reached. Over a broad range of temperatures and concentrations, SmA is the dominant phase in the diagram. Small-angle X-ray scattering (SAXS) measurements were performed for all mixtures. As shown in Figure 4, the layer spacing d measured at T = Tc varies linearly with the

• other peaks. In Figure 11a the pseudohexagon is marked with white lines. Precise measurements of the smectic layer spacing d were obtained by small-angle X-ray scattering (SAXS). Figure 12a shows the smectic layer spacing d of the SmC and the SmF phases of PhP16. At the phase transition, we observe a

• procedures and showed the expected physical and spectral properties. The liquid-crystalline compound 2PhP was purchased from a commercial source. A Kratky compact camera from Anton Paar was used to perform small-angle X-ray scattering (Ni-filtered Cu Kα radiation with wavelength λ = 1.5418 Å). The unaligned

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

• cybotactic nematic phases Usually the two distinct types of cybotactic nematic phases, NcybC and NcybA, can be distinguished by analyzing the shape of the diffuse small-angle X-ray scattering of magnetically aligned samples, which is split into two maxima beside the meridian for NcybC phases (Figure 8a and

Low temperature enantiotropic nematic phases from V-shaped, shape-persistent molecules

• Matthias Lehmann and
• Jens Seltmann

Beilstein J. Org. Chem. 2009, 5, No. 73, doi:10.3762/bjoc.5.73

• illustrated in Figure 6B, the sulfur atoms are then separated throughout the sample on average by 9–10 Å. The fact that with small angle X-ray scattering no reflection corresponding to the overall molecular length could be found is not fully understood. The correlation lengths ξ/d are all in the range of 3–5

Molecular length distribution and the formation of smectic phases

• Nadia Kapernaum,
• C. Scott Hartley,
• Jeffrey C. Roberts,
• Robert P. Lemieux and
• Frank Giesselmann

Beilstein J. Org. Chem. 2009, 5, No. 65, doi:10.3762/bjoc.5.65

• mesomorphism in homologous series where nematic is the dominating mesophase for short-length homologues, SmA for medium-length homologues and SmC for longer homologues (see e.g. [1]). For all mixtures small angle X-ray scattering (SAXS) measurements were performed. Figure 4 shows the layer spacing in the SmA