Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• crystallinity [25]. The far-infrared spectrum exhibited a plateau in the lower wavenumber region around 12 cm−1, suggesting that a significant amount of DWCNTs have effective lengths (CNT channels consisted of some condutive paths affected by defects or kinks) longer than 4 μm (Supporting Information File 1

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• currently at the forefront and delivering great PCE, unfused electron acceptors have continued to garner considerable attention. Chang and co-workers focused on enhancing the aggregation and crystallinity of unfused Qx acceptors, Qx17 and Qx18, containing a Qx core and different halogenated end groups. Both

• chlorination effects on the Qx20 series, resulting in four new NFAs, i.e., Qx22–Qx25 (Figure 4). The research revealed the strategic balance between molecular crystallinity, packing, and optical properties. Qx24 and Qx25, with lower steric hindrance in the alkyl side chains, showed slightly decreased

• crystallinity and optical absorption but a shorter π–π stacking distance. OSC devices based on Qx23 and Qx25 achieved the highest PCE (10.67 and 12.19%, respectively) compared to Qx22 and Qx24 (6.94 and 8.01%, respectively) [35]. Xiao and fellows studied the impact of side chains on molecular packing and

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• similarity of the two spectra may have been due to the low content of nickel in the catalyst. To understand the crystallinity of the material, we carried out a powder XRD (PXRD) analysis (Figure 2). Chitosan, in general, gives rise to a characteristic, partially crystalline phase by virtue of intramolecular

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• of the glycosidic bond. In this system, the SEE was hydrolytically inactive and the acid catalysis activated the C-1 at the reducing end efficiently to promote chain-elongation. Immobilized catalysis provided cellulose analogues with very high crystallinity. A synthetic mutant enzyme of endoglucanase

• II [75] was cross-linked by bis-nitrilotriacetic acid yielding fibrous cellulose [76]. Cross-linked enzymes are believed to arrange their catalytic core domains and promote the formation of cellulose with high crystallinity. A similar principle was also demonstrated on a self-assembled monolayer [77

• , fluorine, and carboxymethyl groups, prevented the formation of insoluble aggregates by disrupting hydrogen-bond networks. Dramatic differences in the conformation (e.g., radius of gyration and glycosidic bond conformation) and aggregation behaviour (i.e., crystallinity and solubility) were observed for

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• polymer and increases the degree of crystallinity, which consequently increases μe. At the same time, the polymer containing two fluorine atoms on the dithiophene unit and one in position 7 exhibited balanced ambipolar properties, having the currently best ratio of μh/μe = 6.41 cm2⋅V−1⋅s−1/6.46 cm2⋅V−1⋅s

Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• -crystals as more and more of the DCM evaporated. Changes in the content of guest molecules without loss of macroscopically visible crystallinity have been observed before [13]. Independent of what the pathway to co-crystallization was in the present case, the slow crystallization with solvent, as compared

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• crystallinity, reduced chain mobility and hydrophobicity of polymers [114][115], which makes biodegradation often ineffective and time-consuming, particularly for polyolefins, such as polyethylene, polyvinyl chloride (PVC), polystyrene or PET [116][117]. Thus, abiotic pretreatments may be required, including UV

• chirality of lactic acid, three forms of PLA (ʟ, PLLA; ᴅ, PDLA; ᴅʟ, PDLLA) with slightly different properties (crystallinity, Tg 60–65 °C, Tm 130–180 °C) exist [256]. PLA is soluble in benzene, tetrahydrofuran, ethyl acetate, propylene carbonate and dioxane [257], and it is biodegradable [258][259]. Because

Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding

• Subrata Nath,
• Alexander Kappelt,
• Matthias Spengler,
• Bibhisan Roy,
• Jens Voskuhl and
• Michael Giese

Beilstein J. Org. Chem. 2021, 17, 124–131, doi:10.3762/bjoc.17.13

• fluorine substitution of the aromatic halogen bond donor on the liquid crystallinity and the photo-response of halogen-bonded liquid crystals [12]. However, all reported halogen-bonded liquid crystals rely on the halogen-bond-acceptor capability of pyridyl units and so far, no study on the fluorescence

• narrower and liquid crystallinity is induced starting with NO2-C9∙∙∙F4Az (see Figure 3). The reduced performance of the azo series compared to the stilbazole series is in line with previous reports and can be attributed to the repulsion of the free electron pairs of the azo group [7]. Interestingly

• induction of liquid crystallinity in our assemblies, we synthesised a series of azo compounds with decreasing fluorination degree at the halogen bond donating iodobenzene [12]. Reducing the number of the fluorine atoms at the halogen bond donating moiety lowers the polarisation of the iodine atom and thus

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

• crystallinity (well-defined spots) and identical spacings in all systems. Image analysis revealed 0.96 ± 0.10 nm dark-contrast stripes separated by 0.69 ± 0.12 nm light-contrast stripes in all cases. The molecular model that best fits the cryo-TEM and TEM data is a bilayer, where pairs of PDI cores are coupled

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

Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• nanomaterials. Specifically, the deacetylation of ChNC into ChsNC led to a decrease in crystallinity in the nanomaterial. Indeed, this can be seen in the FTIR with the broadening of the N–H and O–H stretches from 3000–3500 cm−1. This was more notable in the powder X-ray diffraction (PXRD) spectra of ChNCs and

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• )cellulose such as the acidity, the crystallinity and the particle size of cellulose as well as the nature of the feedstocks. This review highlights all these parameters and all the strategies employed to produce isosorbide from (ligno)cellulose in a one-pot process. Keywords: catalysis; cellulose

• wheat straw pulp led to 63% of isosorbide, corresponding to a productivity of 40 g·L−1·h−1 with 72% of purity. This high yield can be ascribed to several parameters such as small particle diameter, large surface area/porosity and lower crystallinity. For the particle size, cellulose fiber diameters are

• 2 µm and 50 µm of respectively pre-treated wheat straw and microcrystalline Avicel PH-101, that can explain the higher yield of isosorbide from CIMV-delignified wheat straw pulp. The crystallinity and the particle size effects were confirmed by starting from a ball-milled Avicel PH-101 cellulose. A

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• in Figure 4. The differences between inorganic and organic semiconductors are primarily the transport of charge within the material, which arise from the drastically different properties and various degrees of crystallinity of organic semiconductors, which we will now briefly discuss. In amorphous

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• phosphorous species in the carbons could be responsible for the examined difference [130]. X-ray diffraction (XRD): X-ray diffraction gives information on the crystallinity or amorphicity of activated carbons. Comparison of resulting XRD patterns with the crystallographic databases clarify that partially

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• . Electron transport was not detected for the tested samples by TOF experiments. TOF photocurrent transients with well-visible transit times for the samples 3, 5, and 6 were not observed apparently due to either strong crystallinity of thick films or strongly dispersive transport of charges. Therefore, the

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes

• Zeguo Fang,
• Nawaf Al-Maharik,
• Peer Kirsch,
• Matthias Bremer,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65

• phases. The smectic phase of LC 8 was maintained over a broad temperature range (54–84 °C), whereas that for 10 and 11a only showed a melting point and these compounds did not display any obvious liquid crystallinity (Table 1). Therefore, any development of these latter materials would require extended

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

• microcrystalline powders of all derivatives (Supporting Information File 1, Figure S9). At first glance, the stronger intensity of the signals for DTT 1 and DST 3 clearly evidences a higher crystallinity compared to triacenes DTS 2 and DSS 4. XRD plots of heterotriacenes 1 to 3 obtained from the corresponding

• smaller with 52 nm. The lack of correlation between the spectra for DTT 1 (Figure S10 in Supporting Information File 1) accounts for a completely different crystalline phase in the XRD vs the multicrystalline powder spectrum. Nevertheless, the high crystallinity observed in XRD measurements of

Mechanochemical amorphization of chitin: impact of apparatus material on performance and contamination

• Thomas Di Nardo and
• Audrey Moores

Beilstein J. Org. Chem. 2019, 15, 1217–1225, doi:10.3762/bjoc.15.119

• mechanochemical amorphization of chitin. We measured the crystallinity index of chitin after milling it in a vibration mill in an apparatus made of copper, aluminum, brass, tungsten carbide, zirconia, stainless steel, polytetrafluoroethylene (PTFE), or poly(methyl methacrylate) (PMMA). These materials offer a

• have been considered and showed an effect on the yield [29][30][31], to the best of our knowledge, there are no larger studies comparing several materials, especially with consideration to biomass amorphization and contamination. Amorphization is a common process whereby the crystallinity of a material

• combination of balls, size and apparatus materials can help to optimize the energy input while allowing the desired loss of crystallinity for hard milling or maintaining crystallinity for soft milling techniques. In order to better understand the role of the milling medium on polymer reactivity, we launched a

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• nanofibers are 63.57 J/g and 47.09 J/g, respectively. In the case of PCL/CB[7] nanofibers, the enthalpies decreased obviously for both heating and cooling process. The degree of crystallinity of PCL chains can be calculated from the melting enthalpy from DSC curves using Equation 1. where χc is the degree of

• crystallinity of the samples, ΔHm is the experimental melting enthalpy of PCL chains and is the theoretical melting enthalpy of a reference PCL with 100% crystallinity. Herein, is taken as 135.6 J/g [12][15]. As shown in Table S2 (Supporting Information File 1), the degree of crystallinity of neat electrospun

• PCL nanofibers is 46.9%, roughly as high as that of PCL nanofibers reported in the literature [17]. Due to the doped PCL chains in the nanofibers, the PCL/CB[7] nanofibers show a lower crystallinity compared with that of neat PCL nanofibers. The degree of crystallinity (χc) gradually increases from

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• NMR [97]. It is curious that the resulting multiblock copolymers reveal some crystallinity, whereas the parent PNB and PCOE(OH) are fully amorphous. It can be explained if we recall that hydrogenated PNB is a semicrystalline polymer [100]. The Pd/Al2O3 catalyst was used to promote the hydrogenation of

• crystallinity and melting temperature are higher for the copolymers with longer COE blocks. Copolymer crystallinity can be studied in detail by combining WAXD and DSC methods, including recently emerged technique of thermal fractionation by successive self-nucleation and annealing [84][92][102][103]. It was

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• , photophysical properties and OLED performances, Chi, Kim and co-workers analyzed the X-ray structures of Pt(fppz)2 (13) and other related platinum(II) complexes 14 and 15 in both single crystal and thin film samples (Figure 7) [13]. They observed different degrees of crystallinity as a function of the

• crystallinity and molecular orientation are key parameters that can make great differences for the resulting thin-film optoelectronic performances. Apart from display applications, general lighting efficiency currently constitutes a main concern of our society and white-emitting OLEDs (WOLEDs) represent a

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

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

• molecular structure rather than its crystallinity, offering a powerful tool for in situ studies of mechanochemical organic reactions that often proceed through amorphous or eutectic intermediates. We now report a Raman spectroscopy study of the effect of ball milling frequency on the course of a model

• reaction component xn (Figure 3). It is important to note that the herein presented approach to data analysis assumes that the Raman spectra of individual reactants or products are not significantly affected by the degree of crystallinity or changes in the composition of the reaction mixture. While Raman

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

• Joana M. Pais,
• Maria João Barroca,
• Maria Paula M. Marques,
• Filipe A. Almeida Paz and
• Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

• method. Nonetheless, the crystallinity is easily regained by subjecting the bulk material, at ambient temperature, to a water-saturated atmosphere during ca. 16 hours (for details, see the experimental section). The PXRD of the rehydrated sample reveals the presence of a new phase which contains no

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

• the Raman spectra indicates the completion of the reaction after 50 minutes. In the following, the Raman bands become narrower, signifying an increasing crystallinity of the product. Since the in situ data reveal an onset of the reaction after 36 min, we investigated in further experiments whether