Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

• Ryo Takishima,
• Yuji Nishii,
• Tomoaki Hinoue,
• Yoshitane Imai and
• Masahiro Miura

Beilstein J. Org. Chem. 2020, 16, 325–336, doi:10.3762/bjoc.16.32

• Cotton signals characteristic to axially chiral molecules. In all cases, the (S)- and (R)-enantiomers were evidently mirror images of each other while the anisotropy factors gabs are relatively small and in the range of 10−4 to 10−7. The spectral shapes of 3a–c and 4a–c were respectively comparable

Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

• Afef Mabrouki,
• Malek Fouzai,
• Armand Soldera,
• Abdelkader Kriaa and
• Ahmed Hedhli

Beilstein J. Org. Chem. 2020, 16, 149–158, doi:10.3762/bjoc.16.17

• the fluorine atom leads to a subtle modification of properties such as melting point, mesophase morphology, transition temperatures, optical anisotropy, dielectric anisotropy, and visco-elasticity [5][6][7][8][9][10]. Therefore, many fluorinated liquid crystals have been prepared, and the fluoro

• lead on a deep study in order to investigate other parameters such as response time, viscosity and dielectric anisotropy. DSC thermograms of fluorinated compounds 2b, 4a and 4b recorded at 5 °C/mn at heating (down traces) and cooling (top traces) cycles. Optical texture (×10) of liquid crystal phase

Unexpected one-pot formation of the 1H-6a,8a-epiminotricyclopenta[a,c,e][8]annulene system from cyclopentanone, ammonia and dimethyl fumarate. Synthesis of highly strained polycyclic nitroxide and EPR study

• Sergey A. Dobrynin,
• Igor A. Kirilyuk,
• Yuri V. Gatilov,
• Andrey A. Kuzhelev,
• Olesya A. Krumkacheva,
• Matvey V. Fedin,
• Michael K. Bowman and
• Elena G. Bagryanskaya

Beilstein J. Org. Chem. 2019, 15, 2664–2670, doi:10.3762/bjoc.15.259

• interaction (hfi) anisotropy of the NO group by librational motion, and (ii) modulation of the hfi with other nuclei in the radical by rotation of the groups containing those nuclei (e.g., rotation of methyl groups). The temperature dependence of spin relaxation reveals the relevant mechanism. For comparison

• thermally activated rotation of their methyl groups becomes rapid. Above 140 K this rotation is rapid enough to average the hfi anisotropy and to cause some decrease in the phase relaxation rates. Finally, at T > 220 K the librational motion of the NO group dominates phase relaxation and causes the

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• molecules on Au(111)) [34][35]. In addition to 1a, we studied 1b carrying (long) hexadecyloxy (OC16H33) and (short) hexyloxy (OC6H13) side chains, so that the anisotropy of the molecule is slightly increased as compared to 1a. Compound 1b assembles (at a concentration of 5 × 10−7 M) into an oblique pattern

Reversible end-to-end assembly of selectively functionalized gold nanorods by light-responsive arylazopyrazole–cyclodextrin interaction

• Maximilian Niehues,
• Patricia Tegeder and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2019, 15, 1407–1415, doi:10.3762/bjoc.15.140

• , shape and chemical environment giving rise to different SPR band wavelengths [6][7][8]. Especially gold nanorods (AuNR) are of interest because of their good synthetic availability and their unique optical properties. Due to their anisotropy AuNR possess a transversal SPR (TSPR) band in the visible and

Design of a double-decker coordination cage revisited to make new cages and exemplify ligand isomerism

• Sagarika Samantray,
• Sreenivasulu Bandi and
• Dillip K. Chand

Beilstein J. Org. Chem. 2019, 15, 1129–1140, doi:10.3762/bjoc.15.109

• respective signals of 1a. The observed downfield shift of the Hf signal in 2a is complexation-induced and found to have a unique position. The downfield shift of the Hg signal in 2a could not be induced by complexation and is best described by considering an anisotropy effect of the nearby carbonyl groups

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

• Fangfang Pan,
• Mohadeseh Dashti,
• Michael R. Reynolds,
• Kari Rissanen,
• John F. Trant and
• Ngong Kodiah Beyeh

Beilstein J. Org. Chem. 2019, 15, 947–954, doi:10.3762/bjoc.15.91

• anisotropy influence from the host’s aromatic rings, increasing the shielding. Conclusion In conclusion, we present XB assemblies between Hex-NARBr and Cy-NARCl as tetravalent XB acceptors, a divalent XB donor DIOFB, and small organic guest solvents (MeOH, MeCN and water). In the assemblies, both XB and HB

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• consequent local magnetic anisotropy effects on the β-CD protons induced by the tosyl group confined in the β-CD cavity. The strategy for NMR resonance assignment and glucopyranose sequence analysis is discussed in detail in Supporting Information File 1. Briefly, the well-resolved anomeric resonances

Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

• Krzysztof M. Zwoliński and
• Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

• no diamagnetic ring current characteristic for porphyrins, the remarkable chemical shift differentiation observed for the crown strap shall be rationalized by its close spatial proximity to anisotropy cones spanning from aromatic substituent’s. Moreover, vicinal coupling constants 3JH-H found for the

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

• from the higher periods, than between atoms with hard electron densities [22][23]. For molecules, one has to consider the anisotropy of molecular polarizabilities, which is strongly pronounced for molecules with delocalized pi-electron densities, the polarizability component along the molecular axis

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• the peptide-binding pocket of the β-clamp, they carried out a fluorescence anisotropy titration screening of the Rockefeller University chemical library containing 30,600 polar organic compounds which led to the discovery of RU7 (9, Figure 3) with an inhibition constant of 10 μM. Pleasingly, it was

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• the shifts of the methylene protons α-situated vs the piperazine P-1 Nsp2 nitrogen involved in p→π LP(N)→π(C=N, s-triazine; C=O, amide) conjugation (3.78–3.91 ppm). To conclude, except the well-documented deshielding promoted by the magnetic anisotropy of π-delocalised systems, such as s-triazines and

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

• (Δδ = 0.3 ppm) of C-43* was caused by the anisotropy of the aromatic ring, which requires a reorientation of the amide part of the hemiaminal in isomer 2. The macrolactone ring of lanyamycin 1/2 was found to be related to those characterizing the bafilomycins (Figure 3) [10][11]. The obvious

Gram-scale preparation of negative-type liquid crystals with a CF₂CF₂-carbocycle unit via an improved short-step synthetic protocol

• Tatsuya Kumon,
• Shohei Hashishita,
• Takumi Kida,
• Shigeyuki Yamada,
• Takashi Ishihara and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 148–154, doi:10.3762/bjoc.14.10

• discovery of fluorinated liquid-crystalline (LC) molecules [10][11] led to the rational molecular design and synthesis of a family of novel fluorinated LC molecules that possess large negative dielectric anisotropy (Δε). In fact, as shown in Figure 1, tricyclic molecules containing a CF2CF2 carbocycle, e.g

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• with the electric field gradients associated with the orientated media, creating anisotropy and resolving into two sets of doublets. If there is sufficient resolution between these quadrupolar couplings, then the enantiomeric ratio can be recorded. We have used poly-γ-benzyl-L-glutamate (PBLG

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• ][36]. The simulation program included the effect of anisotropy in the g-factor and/or α-hydrogen hyperfine tensor on the line shape of powder spectra, according to Kneubuhl’s [37] and Cochran’s [38] equations, respectively. An anisotropic interaction of β-hydrogens is usually small (less than 0.3 mT

Membrane properties of hydroxycholesterols related to the brain cholesterol metabolism

• Malte Hilsch,
• Ivan Haralampiev,
• Peter Müller,
• Daniel Huster and
• Holger A. Scheidt

Beilstein J. Org. Chem. 2017, 13, 720–727, doi:10.3762/bjoc.13.71

• 2H NMR measurements, only a very small increase of acyl chain order was observed in the presence of 24S-HC [8]. Surprisingly, in the same study, 24S-HC and 27-HC exhibited a comparable effect on the acyl chain order compared to endogenous cholesterol measuring the diphenylhexatriene (DPH) anisotropy

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu²⁺

• Rahman Hosseinzadeh,
• Mohammad Nemati,
• Reza Zadmard and
• Maryam Mohadjerani

Beilstein J. Org. Chem. 2016, 12, 1749–1757, doi:10.3762/bjoc.12.163

• example, the peaks of the tert-butyl groups of receptor L resonated at 1.29 (Hh1) and 1.22 ppm (Hh2) turned to one signal at 1.20 ppm during the titration. All these observations might be attributed to the changes in electron density, the anisotropy effect and the changes in the conformation of receptor L

Experimental and theoretical insights in the alkene–arene intramolecular π-stacking interaction

• Valeria Corne,
• Ariel M. Sarotti,
• Carmen Ramirez de Arellano,
• Rolando A. Spanevello and
• Alejandra G. Suárez

Beilstein J. Org. Chem. 2016, 12, 1616–1623, doi:10.3762/bjoc.12.158

• range of a previous reported acrylate with a pendant phenoxy group 6c (6.14–5.41 ppm) [16]. This effect is interpreted in terms of the anisotropy phenomena caused by the proximity of the aromatic ring to the double bond. Another salient observation is the broadening of the vinylic signals that can be

Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

• Vito Rizzi,
• Sergio Matera,
• Paola Semeraro,
• Paola Fini and
• Pinalysa Cosma

Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54

• ]. In particular, the magnetic anisotropy effect can be taken in consideration to explain this behavior [55]. But also when an aliphatic moiety enters the hydrophobic cavity, an influence on H3 and H5 protons can be expected as reported in [56]. After this assessment, for the sake of comparison with

• produced by the inclusion. Moreover, it is known [9], that signals of protons located outside the cavity of CDs exhibit an upfield shift, attributable to the C–C bond anisotropy effect. Interesting results were obtained when the 7-CH3 protons of S4TdR were considered. In fact, as shown by the empty black

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• an anisotropy effect of the DMB ring. Conclusion In summary, synthesis protocols for a series of methyl-protected hydroquinone-pyrrole dyads with good overall yields have been devised. DFT calculations allow insight into the electronic properties and conjugation within these compounds, with good

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• be attributed to magnetic anisotropy effects due to their location near to the aromatic ring of the guests which is rich in π-electrons [43]. The protons of 1 and 2 were also affected by the presence of β-CD (Table 3 and Table 4). A progressive upfield shift of the aromatic protons (Ha, Hb and Hc) of

Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case

• Karina Mroczyńska,
• Małgorzata Kaczorowska,
• Erkki Kolehmainen,
• Ireneusz Grubecki,
• Marek Pietrzak and
• Borys Ośmiałowski

Beilstein J. Org. Chem. 2015, 11, 2105–2116, doi:10.3762/bjoc.11.227

• explained by the alternative binding of 9 with 1e form as shown in Figure 5. The following may be concluded based on unnatural behavior of the titration curve: a) within hydrogen-bonded forms present in solution for at least one magnetic anisotropy is important to chemical shift, b) two alternate hydrogen

• structures of 1 and VT 1H NMR spectra (from +25 to −40 °C, low temperatures at bottom, CDCl3). The proposed structure explaining unusual behavior of the titration curve for 1∙∙∙9 titration and anisotropy influence on methylene chemical shift. Collective titration curves (H1/H7 and H3/H5 chemical shifts

Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes

• Sara J. Krivickas,
• Chiho Hashimoto,
• Junya Yoshida,
• Akira Ueda,
• Kazuyuki Takahashi,
• John D. Wallis and
• Hatsumi Mori

Beilstein J. Org. Chem. 2015, 11, 1561–1569, doi:10.3762/bjoc.11.172

• magneto-electrical phenomena such as piezoelectricity, pyroelectricity, ferroelectricity and electrical magnetochiral anisotropy. Rikken et al. observed magneto-chiral dichroism in a europium complex [2][3] and also electrical magneto-chiral anisotropy in carbon nanotubes where small changes in the

• )methyloxazoline)2X, (52X, X = AsF6 [7], PF6 [8]) where disorder within the racemic salt leads to lower conductivity. Recently, Pop et al., have also reported electrical magnetochiral anisotropy in chiral molecular conductors, (R,R)- and (S,S)-[dimethyl-(ethylenedithio)tetrathiafulvalene]2ClO4 (62ClO4) [9][10

Cathodic hydrodimerization of nitroolefins

• Michael Weßling and
• Hans J. Schäfer

Beilstein J. Org. Chem. 2015, 11, 1163–1174, doi:10.3762/bjoc.11.131

• shifts. This also holds for significant differences in the chemical shifts for formally identical protons in 2b/e. The considerable differences probably result from the anisotropy effect of the aromatic ring and the nitro group. For the nitro group a similar anisotropic cone as for the carbonyl group is