Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• semiquinonate species were studied in solution by EPR spectroscopy (Figures S8–S25 in Supporting Information File 1); the parameters of their isotropic EPR spectra are tabulated in Table S4 in Supporting Information File 1. The measured values of the splitting constants were fitted using the computer simulation

Analysis of sesquiterpene hydrocarbons in grape berry exocarp (Vitis vinifera L.) using in vivo-labeling and comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS)

• Philipp P. Könen and
• Matthias Wüst

Beilstein J. Org. Chem. 2019, 15, 1945–1961, doi:10.3762/bjoc.15.190

• experiments with d3-MVL a maximum of 8 deuterium atoms are incorporated into α-ylangene, so that a molecular ion peak [M]+• with m/z = 212 is detected. After abstraction of the triple deuterated isopropyl group, the fragment ion is formed with m/z = 166. According to the computer simulation of Lodewyk, Gutta

New standards for collecting and fitting steady state kinetic data

• Kenneth A. Johnson

Beilstein J. Org. Chem. 2019, 15, 16–29, doi:10.3762/bjoc.15.2

• kcat/Km. Keywords: computer simulation; data fitting; enzyme catalysis; induced-fit; Michaelis constant; specificity constant; Review When Henri, Michaelis and Menten derived the equation for steady state enzyme turnover, they chose to define the rate in terms of Vmax and the substrate dissociation

• parameters rather than kcat and Km (Equation 1). To test this assertion, synthetic data were generated by computer simulation with kcat = 50 s−1 and Km = 20 μM. Data were generated at various concentrations of substrate (5, 10, 20, 30, and 40 μM), with a Gaussian distribution of random noise added to the

• limitations to conform to the approximations in defining the initial velocity of turnover before the substrate is consumed and product builds up, and it requires that the data be fit a second time in the form a plot of estimated rate versus concentration. Fitting by computer simulation overcomes these

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• processes like natural selection (and the in silico analogue) can couple synergistically with learning. This is a part of adaptation (generically named complex adaptive systems). The Baldwin effect describes the influence of learned behaviour on evolution. In 1987 Hinton and Nowlan used computer simulation

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

• was no mechanoanion in the fractured sample to a detectable extent. It was considered that a mechanoanion might promptly dissipate in the course of the mechanochemical reaction performed in a metallic vessel at room temperature. To gain an insight into the component radicals a systematic computer

• simulation was performed for the ESR spectra of Dx and Gly and the results are shown in Figure 3 in an interrelated manner. The simulated spectra shown in Figure 3, represented as dotted lines, satisfactorily reproduced the observed. Figure 6 shows the spectral components of the simulated spectra: one

Protonated paramagnetic redox forms of di-o-quinone bridged with p-phenylene-extended TTF: A EPR spectroscopy study

• Nikolay O. Chalkov,
• Vladimir K. Cherkasov,
• Gleb A. Abakumov,
• Andrey G. Starikov and
• Viacheslav A. Kuropatov

Beilstein J. Org. Chem. 2016, 12, 2450–2456, doi:10.3762/bjoc.12.238

• values of the p-phenylene protons. The value of the hyperfine coupling constant of the catechol hydroxy protons (0.09 G) was estimated by means of a computer simulation of an experimental EPR spectrum, once the other hyperfine coupling constants had been identified. The spin-density distribution in the

Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

• Giuseppina Raffaini,
• Antonino Mazzaglia and
• Fabio Ganazzoli

Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267

• recognize cells by exposing receptor-targeting groups on the surface of the nanoassembly [30]. Because of these promising results, we have begun to investigate the aggregation behaviour of an aCD model compound by atomistic computer simulation to clarify the early stages of self-assembly, in particular the

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• in scCO2 through a computer simulation technique, which also gives evidence for the production of stable IL droplets within a continuous CO2 phase through amphiphilic surfactant addition. This study suggests that microemulsion stability is dependent on ionic liquid anion-surfactant headgroup

Interplay of ortho- with spiro-cyclisation during iminyl radical closures onto arenes and heteroarenes

• Roy T. McBurney and
• John C. Walton

Beilstein J. Org. Chem. 2013, 9, 1083–1092, doi:10.3762/bjoc.9.120

• expected to be minimal. In view of this, no attempt was made to model the effect of the solvent computationally. O-Ethoxycarbonyl oximes prepared. EPR spectrum during photolysis of 1f in t-BuPh at 240 K. Top (black): experimental spectrum. Bottom (red): computer simulation. EPR spectrum during photolysis

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• solution was cooled down to 220 K, the well-resolved spectrum, Figure 1b, was obtained. The resolution improvement may be due to the fact that most of the polymer separates from the solution at the lower temperature. A good computer simulation was achieved by utilising the hyperfine splitting constants

• (hfs) listed in Table 1. A well-resolved EPR spectrum of 11b+•, generated from 2 with GaCl3, is shown in Figure 1c for comparison. Figure 1d shows the experimental spectrum obtained from treatment of 2 with InCl3, together with the corresponding computer simulation. Although the three EPR spectra

• gave a strong EPR spectrum and the hfs derived from the computer simulation are presented in Table 1. The comparatively large line width (~0.9 G) did not permit the resolution of small hfs from aromatic ring H-atoms. For the same reason, the hfs from the second N-atom were not resolved. However, it is