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Search for "theoretical calculations" in Full Text gives 134 result(s) in Beilstein Journal of Organic Chemistry.

Molecular and macromolecular electrochemistry: synthesis, mechanism, and redox properties

  • Shinsuke Inagi and
  • Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 1505–1506, doi:10.3762/bjoc.18.158

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  • , polymer electrolyte membrane electrolysis technology, and new methods coupled with photoredox catalysts or transition metal catalysis, resulting in remarkable progress in organic electrosynthetic processes. Theoretical calculations have also led to a better understanding of the electron transfer behavior
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Published 26 Oct 2022

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

  • Kaiyue Ye,
  • Liyuan Cao,
  • Davita M. E. van Raamsdonk,
  • Zhijia Wang,
  • Jianzhang Zhao,
  • Daniel Escudero and
  • Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

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  • the dyads were studied with steady-state and time-resolved spectroscopic methods, as well as theoretical calculations. Results and Discussion Molecular design and structure confirmation In order to study the effect of conformational flexibility on TADF, NI-PTZ was designed (Scheme 1). As dicussed
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Published 11 Oct 2022

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

  • Michael Keppler,
  • Sandra Moser,
  • Henning J. Jessen,
  • Christoph Held and
  • Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

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  • , we analysed a set of well-known PPK enzymes regarding the thermodynamic equilibrium of ATP synthesis and compared the experimental results obtained with theoretical calculations. The theoretical calculations addressed the equilibrium position of the considered reactions as function of the substrate
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Published 20 Sep 2022

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

  • Tomoya Imai,
  • Ryuhei Akasaka,
  • Naruhiro Yoshida,
  • Toru Amaya and
  • Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

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  • on DFT calculations. Theoretical calculations DFT calculations were performed to clarify the reasons for the oxidation potentials [52][54][56]. To investigate the effects of the torsion of the naphthalene moiety and the conformation of the MeO group on the oxidation potential of these materials
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Published 03 Aug 2022

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

  • Maxime Pypec,
  • Laurent Jouffret,
  • Claude Taillefumier and
  • Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

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  • studied in detail. Computational studies For the theoretical calculations, acetyl N-(methylamino)dimethylamide model peptoids (Ac-N(NMe)n-NMe2) were used instead of the corresponding synthesized benzyl esters. The model structures were generated using the coordinates extracted from the single crystal X
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Published 14 Jul 2022

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

  • Virginija Jakubkiene,
  • Gabrielius Ernis Valiulis,
  • Markus Schweipert,
  • Asta Zubriene,
  • Daumantas Matulis,
  • Franz-Josef Meyer-Almes and
  • Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

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  • °C (Scheme 2). It is known that there are two possible tautomeric forms of each hydroxamic acid: the keto and enol tautomer. Furthemore, each tautomer can adopt an E or Z conformation (Figure 2) [32][33][34][35][36]. The results of NMR spectra and theoretical calculations showed that hydroxamic acids
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Published 13 Jul 2022

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

  • Saika Izumi,
  • Prasannamani Govindharaj,
  • Anna Drewniak,
  • Paola Zimmermann Crocomo,
  • Satoshi Minakata,
  • Leonardo Evaristo de Sousa,
  • Piotr de Silva,
  • Przemyslaw Data and
  • Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

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  • efficiency (EQE) exceeds the theoretical maximum of those with prompt fluorescent emitters. Most importantly, comparative study of the D–A molecule and its D–A–D counterpart from the viewpoints of the experiments and theoretical calculations revealed the effect of the number of the electron donor on the
  • on the physicochemical properties of the DBPHZ-cored D–A system, the properties of D–A compound 1 were compared with those of POZ-DBPHZ. Theoretical calculations further support the impact of the donor numbers in the DBPHZ-cored D–A system. Results and Discussion Synthesis of materials To synthesize
  • ], indicating a dominant non-radiative decay of the excited state for the D–A type compound, which was supported by the theoretical calculations (vide infra). In the solid state, the D–A compound 1 showed an emission at around λem = 560 nm with a very low ΦPL (<0.1) (Figure S1 in Supporting Information File 1
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Published 25 Apr 2022

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

  • Ettore Crovini,
  • Zhen Zhang,
  • Yu Kusakabe,
  • Yongxia Ren,
  • Yoshimasa Wada,
  • Bilal A. Naqvi,
  • Prakhar Sahay,
  • Tomas Matulaitis,
  • Stefan Diesing,
  • Ifor D. W. Samuel,
  • Wolfgang Brütting,
  • Katsuaki Suzuki,
  • Hironori Kaji,
  • Stefan Bräse and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

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  • DICzTRZ were determined by a combination of NMR spectroscopy, mass spectrometry, and IR spectroscopy. Theoretical calculations Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations in the gas phase at the PBE0/6-31G(d,p) level reveal the potential of DICzTRZ as a TADF material. The
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Published 08 Dec 2021

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

  • Najeh Tka,
  • Mohamed Adnene Hadj Ayed,
  • Mourad Ben Braiek,
  • Mahjoub Jabli and
  • Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

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  • a PGSTAT30 Autolab potentiostat. Theoretical calculations The theoretical studies were realized in vacuum with the Gaussian 09 program [70]. The geometry of the equilibrium conformer at the ground state was first found at AM1 level. Then, further optimization through density functional theory (DFT
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Published 20 Sep 2021

Development of N-F fluorinating agents and their fluorinations: Historical perspective

  • Teruo Umemoto,
  • Yuhao Yang and
  • Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

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Published 27 Jul 2021

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

  • Najeh Tka,
  • Mohamed Adnene Hadj Ayed,
  • Mourad Ben Braiek,
  • Mahjoub Jabli,
  • Noureddine Chaaben,
  • Kamel Alimi,
  • Stefan Jopp and
  • Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

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  • were recorded on a Shimadzu 2401 PC spectrophotometer in quartz cuvettes with a path length of 1 cm. Emission spectra were recorded on a Perkin-Elmer LS50B spectrofluorimeter. Theoretical calculations Theoretical studies were realized in vacuum with Gaussian 09 program [72]. The geometry of the
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Published 16 Jul 2021

Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

  • Asha Budakoti,
  • Pradip Kumar Mondal,
  • Prachi Verma and
  • Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

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  • -trimethylsilylalkenyl cation 242 formed by the Grob-type fragmentation (Scheme 57), which was trapped by the subsequent attack of the halide anion, leading to the formation of Prins product 244. On the basis of theoretical calculations, the authors could conclude factors controlling the alkyne Prins cyclization over
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Published 29 Apr 2021

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

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  • induces the formation of nematic mesophases with broad temperature ranges, the temperature range of the mesophase of the azobenzene-based assemblies is significant narrower. Theoretical calculations and the modular use of halogen bond donors with changing fluorination degree reveal that at least three
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Published 14 Jan 2021

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

  • Giovanna Zanella,
  • Martina Petrović,
  • Dina Scarpi,
  • Ernesto G. Occhiato and
  • Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

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  • theoretical calculations predict that the position of the propargylic acetate substituent has a great impact on the reactivity. In contrast to our previous successful cyclization of the 2-substituted substrates, where the nitrogen favors the formation of the cyclized final product, the substitution at
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Published 15 Dec 2020

Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

  • Daniela Rodrigues Silva,
  • Joyce K. Daré and
  • Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

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  • conformers (II, VI, and VII), and with a rotatable C–C(F) bond that generates different conformers (I). The μ values for all herbicides were computed through theoretical calculations (see computational details section) and are presented in Table 2 along with their respective experimental log P data
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Published 05 Oct 2020

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

  • Anka Utama Putra,
  • Deniz Çakmaz,
  • Nurgül Seferoğlu,
  • Alberto Barsella and
  • Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

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  • little effect on the shift for dye 3 (6 nm). In case of the Schiff bases 8–11, similar bathochromic shifts were observed. In addition, experimentally, there was no solvatochromic behavior observed for dyes 7 and 12 as was predicted by theoretical calculations. Based on theoretical calculations, the main
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Published 14 Sep 2020

Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA

  • Annike Weißenstein,
  • Myroslav O. Vysotsky,
  • Ivo Piantanida and
  • Frank Würthner

Beilstein J. Org. Chem. 2020, 16, 2032–2045, doi:10.3762/bjoc.16.170

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  • with significant Stokes shifts (+60 nm) and quantum yields of 10–32% (Table 1). Theoretical calculations To get insight into the electronic and optical properties of the 2-amino-6-chloro-substituted NDIs, we carried out computational investigations by using the Gaussian 09 program suite [32]. In
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Published 19 Aug 2020

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

  • Esra Demir,
  • Ozlem Sari,
  • Yasin Çetinkaya,
  • Ufuk Atmaca,
  • Safiye Sağ Erdem and
  • Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

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  • reaction of CSI with epoxides in different solvents under mild conditions and compared the reaction mechanism with previously proposed mechanisms using theoretical calculations. Keshava Murthy and Dhar [41] postulated a mechanism involving a zwitterionic intermediate. C–O bond cleavage in this unstable and
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Published 21 Jul 2020

Recent synthesis of thietanes

  • Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

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  • diradicals as intermediates. To explain the regioselectivity, theoretical calculations were performed with thiochalcone and acrylonitrile as model substrates. For the frontier molecular orbital treatment, the largest coefficients in both HOMO and LUMO of thiochalcone existed on the sulfur atom, while the
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Published 22 Jun 2020

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

  • Carlos H. Escalante,
  • Eder I. Martínez-Mora,
  • Carlos Espinoza-Hicks,
  • Alejandro A. Camacho-Dávila,
  • Fernando R. Ramos-Morales,
  • Francisco Delgado and
  • Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

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  • ]. Theoretical calculations The Diels–Alder reaction of vinylpyrroles 8b, 8c and 8g with maleimides 7b and 7c resulted in a highly diastereoselective cycloaddition leading to the mixture of endo/exo cycloadducts 9/10, where the endo product 9 was the major one (Scheme 3 and Table 2). Considering the synthetic
  • pyrrolizine-containing polycycles, including isoindolo[2,1-a]indole-based tetrahydro and fully aromatic pentacycles. These findings reveal the synthetic value of 2-formylpyrrole (13a) for the diastereo- and regioselective construction of isoindolo- and pyrrolo-fused polycyclic indoles. Theoretical
  • calculations suggest that the greater stability of the endo TSs in the Diels–Alder cycloadditions is associated with NCIs between the N-substituents of both cycloaddends. These interactions are also involved in the case of pyrrolo[2,1-a]isoindole 18a with dienophile 7c. Fused aza-hetero polycyclic frames and
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Published 17 Jun 2020

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

  • Shigeyuki Yamada,
  • Takuya Higashida,
  • Yizhou Wang,
  • Masato Morita,
  • Takuya Hosokai,
  • Kaveendra Maduwantha,
  • Kaveenga Rasika Koswattage and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

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  • corresponding bis-oxidized bisbenzil derivatives. Based on theoretical calculations, the selective formation of the fluorinated analogues stemmed from the slight modulation of the charge distribution at the alkyne moiety of the reactant induced by the electron-withdrawing fluorine atoms. Evaluation of the
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Published 29 May 2020

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

  • Rasa Keruckiene,
  • Simona Vekteryte,
  • Ervinas Urbonas,
  • Matas Guzauskas,
  • Eigirdas Skuodis,
  • Dmytro Volyniuk and
  • Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

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  • compounds, based on theoretical calculations and experimental measurements, as well as the electrochemical and thermal properties, are discussed. The synthesized compounds form glasses with glass-transition temperatures ranging from 116 °C to 123 °C. The ionization potentials estimated by cyclic voltammetry
  • [15]. Theoretical calculations and electrochemical properties DFT calculations were employed to gain insight into the structure–property relationships of the quinazoline-based derivatives 1–3. The compounds have phenyl spacers between the donor and acceptor units (Figure 2). Therefore, the dihedral
  • results of theoretical calculations which revealed that the HOMO and LUMO orbitals of the carbazole-substituted quinazoline compound 1 overlap. Photophysical and electronic properties Figure 4 shows the theoretical UV spectra and experimental absorption spectra of dilute THF solutions of compounds 1–3
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Published 28 May 2020

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

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  • . Theoretical calculations The optimized structures of 3–6 were obtained by density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level of theory (Figure 1). The dihedral angles between the acridanyl and phenyl moieties in compound 3 (37.0 and 36.3°) are comparable with the dihedral angles
  • earlier [34]. 1H NMR and 13C NMR spectra were obtained using a Varian Unity Inova (300 MHz (1H) and 75 MHz (13C)). Absorption and photoluminescence (PL) spectra of dilute solutions and of the films were recorded as described previously [35]. Theoretical calculations were carried out using Gaussian 16 [29
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Published 13 May 2020

Synthesis and properties of tetrathiafulvalenes bearing 6-aryl-1,4-dithiafulvenes

  • Aya Yoshimura,
  • Hitoshi Kimura,
  • Kohei Kagawa,
  • Mayuka Yoshioka,
  • Toshiki Itou,
  • Dhananjayan Vasu,
  • Takashi Shirahata,
  • Hideki Yorimitsu and
  • Yohji Misaki

Beilstein J. Org. Chem. 2020, 16, 974–981, doi:10.3762/bjoc.16.86

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  • ; one was the palladium-catalyzed C–H arylation of TTF with bromide 12 (Scheme 2a) and the other was the Vilsmeier–Haack reaction of 1a, followed by triethyl phosphite-mediated cross coupling with 11 (Scheme 2b). Theoretical calculations The DFT calculations of compounds 1a, 3a, and 4 have been carried
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Published 12 May 2020

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

  • Ji Ma,
  • Yubin Fu,
  • Junzhi Liu and
  • Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

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  • exhibits a narrow energy gap (1.78 eV) and a lower LUMO energy level than the parent peropyrene without the fusion of the five-membered rings. In addition, the effects of the peri-fused pentagons on the aromaticity and molecular orbitals of 1 were evaluated by theoretical calculations. This work presents
  • -diphenylethyne, Pd2(dba)3, P(o-tol)3, KOAc, LiCl, DMF, 130 °C, microwave, 6 h, 5%. Supporting Information Supporting Information File 276: Experimental details, synthetic procedures, single crystal X-ray data for 1, detailed theoretical calculations, and analytical data for the compounds. Acknowledgements We
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Published 20 Apr 2020
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