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Search for "density functional" in Full Text gives 297 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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

Graphical Abstract
  • high degree of freedom in the chemical structure of penoxsulam (I), the conformational analysis started with a Monte Carlo conformational search at the ωB97X-D/6-31G(d,p) [16][17] level of the density functional theory (DFT). The global energy minimum conformation was then re-optimized in a higher
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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

Graphical Abstract
  • series of new styryl-based organic chromophores containing a free amino group and the corresponding Schiff base derivatives. The photophysical, pH sensitivity, NLO properties, and thermal stabilities of all synthesized dyes were investigated. Density Functional Theory (DFT) calculations were also
  • were calculated by Density Functional Theory at the B3LYP/6-31+G(d,p) level of theory in the gas phase [64][65]. This method was also applied to study the nonlinear optic (NLO) properties of the dyes in their ground states. The theoretical absorption spectra in different solvents were calculated using
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Published 14 Sep 2020

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

  • Shakeel Alvi and
  • Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

Graphical Abstract
  • thermoelectric properties in addition to the onigiri-type core-shell assemblies have been reported for sumanene and its derivatives. More interestingly, its application in the absorption of small molecules such as NH3, CO2, CO, and H2 using density functional theory (DFT) calculations has also been revealed [25
  • /mol) transformation of 12 (syn) to 17, calculated by density functional theory (DFT) calculations. On the other hand, in 2008, Higashibayashi et al. reported the synthesis of first chiral C3-symmetric trimethylsumanene 28 starting from enantiopure norbornadiene (10) by employing a rational synthetic
  • an LED lamp at ca. 365 nm for 1 min in 2-methyltetrahydrofuran (mTHF) at 77 K gave 60 (Scheme 13) [45]. It was noticed from both experimental as well as theoretical studies that the ground state of the prepared carbene 60 is a triplet which was confirmed by ESR as well as density functional theory
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Review
Published 09 Sep 2020

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

  • Shahboz Yakubov and
  • Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

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  • (sp3)–H fluorination mechanistic studies: In order to unearth a greater understanding of their previously-reported photosensitized C(sp3)–H fluorination, Tan, Lu, Soo and co-workers employed a nanosecond-scale transient absorption (TA) spectroscopy and time-dependent density functional theory (TDDFT
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Review
Published 03 Sep 2020

Muyocopronones A and B: azaphilones from the endophytic fungus Muyocopron laterale

  • Ken-ichi Nakashima,
  • Junko Tomida,
  • Tomoe Tsuboi,
  • Yoshiaki Kawamura and
  • Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 2100–2107, doi:10.3762/bjoc.16.177

Graphical Abstract
  • ) [25]. After conformational analysis, geometry optimization was performed for two possible stereoisomers with the (7S,10R,11R)- and (7S,10S,11S)-configurations using density functional theory (DFT) at the CAM-B3LYP/6-311+G(d,p) level of theory. In addition, the ECD spectra of the DFT-optimized
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Published 28 Aug 2020

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and 6Li/13C NMR spectroscopic data

  • Jürgen Vollhardt,
  • Hans Jörg Lindner and
  • Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

Graphical Abstract
  • negative hyperconjugation. Density functional theory and natural bond order calculations of dilithio methandiides of type II [32][43] suggest that the two lone pairs at the dianionic carbon atom of (2a)4·(THF)6 and (2a)6·Li2O·(THF)6 are perhaps located in an sp2 hybridized orbital and p orbital. However
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Published 21 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

Graphical Abstract
  • advantageous: being a one-pot reaction with metal-free reagent, having shorter reaction times, good yields and a very simple purification method. Moreover, using the density functional theory (DFT) method at the M06-2X/6-31+G(d,p) level of theory the mechanism of the cycloaddition reactions has been elucidated
  • isocyanate; computational modeling; cyclic carbonates; density functional theory; oxazolidinone; Introduction Oxazolidinones (1), five-membered heterocyclic rings containing an ester group adjacent to a nitrogen atom, are important compounds in synthetic and pharmaceutical chemistry because of their
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Published 21 Jul 2020

Models of necessity

  • Timothy Clark and
  • Martin G. Hicks

Beilstein J. Org. Chem. 2020, 16, 1649–1661, doi:10.3762/bjoc.16.137

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  • , which is difficult to reconcile with requirement 2 above. A possible solution would be to use computationally very efficient quantum mechanics such as, for instance, semiempirical molecular-orbital theory or tight-binding density-functional theory. As outlined above, these techniques are fast enough to
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Commentary
Published 13 Jul 2020

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

  • Csilla Hargitai,
  • Györgyi Koványi-Lax,
  • Tamás Nagy,
  • Péter Ábrányi-Balogh,
  • András Dancsó,
  • Gábor Tóth,
  • Judit Halász,
  • Angéla Pandur,
  • Gyula Simig and
  • Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

Graphical Abstract
  • reaction described in Scheme 1 to further o-(pivaloylaminomethyl)benzaldehydes and to support the results by density functional theory (DFT) calculations, single-crystal X-ray measurements and comprehensive NMR studies. Results and Discussion Acid-catalyzed transformations of compounds 1a–d First we kept
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Published 13 Jul 2020

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

Graphical Abstract
  • measurements, TRPL spectroscopy, and density functional theory (DFT) calculations. They found that the HER efficiency correlated to the excited state lifetime and exciton binding energy. The FSO-BP and FSO-FSz hindered the charge transfer and mobility due to the phenyl–phenyl dihedral angle or sharp bends in
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Review
Published 26 Jun 2020

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

  • Liwei Cao,
  • Mikhail Kabeshov,
  • Steven V. Ley and
  • Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

Graphical Abstract
  • automated reaction planning, as well as a starting point for microkinetic modelling. Keywords: C–H activation; density functional theory; reaction prediction; Introduction Periodically, our knowledge of chemistry is enriched with new transformations that provide significant breakthroughs by enabling new
  • the mechanistic models based on accurate quantum chemical methods, such as the density functional theory (DFT) methods, decreases. Automation of DFT, as well as using results of DFT to develop less expensive predictive models, are the two approaches that may offer the alternatives to the fully data
  • transition metal coordination sphere; the energy of a new M–C bond formed and the thermodynamic stability of organometallic product. With new developments in computational chemistry, mechanistic studies using density functional theory (DFT) provide valuable insights into the reactivity of organometallic
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Published 25 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

Graphical Abstract
  • -deficient fluorinated aromatic ring. To confirm the electron-withdrawing effect of this fluorinated aromatic ring, the electronic charge at the adjacent C≡C bond was calculated by density functional theory (DFT) using the Gaussian 16 (Revision B.01) software package [35]. As typical examples, the molecular
  • derivatives previously developed by our group and (B) phosphorescent molecular structures intended for this work. Mulliken charge distributions of fluorinated 1a and nonfluorinated 1c obtained from density functional theory calculations [CAM-B3LYP/6-31+G(d) level]. Absorption and photoluminescence (PL
  • molecular orbitals (isosurface value: 0.04 a.u.) involved in vertical electronic transitions in 2a and 3a calculated using density functional theory (DFT) and time-dependent DFT at the CAM-B3LYP/6-31+G(d) level (HOMO: highest occupied molecular orbital, LUMO: lowest unoccupied molecular orbital). Synthetic
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Published 29 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

Graphical Abstract
  • . 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
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Published 13 May 2020

Cation-induced ring-opening and oxidation reaction of photoreluctant spirooxazine–quinolizinium conjugates

  • Phil M. Pithan,
  • Sören Steup and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2020, 16, 904–916, doi:10.3762/bjoc.16.82

Graphical Abstract
  • discussed in the literature whether metal cations are coordinated in a monodentate fashion to the phenolate oxygen atom or rather in a bidentate fashion both to the phenolate oxygen and the imine nitrogen atoms of the open merocyanine form [25][28]. Furthermore, density functional theory (DFT) calculations
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Published 05 May 2020

Direct borylation of terrylene and quaterrylene

  • Haruka Kano,
  • Keiji Uehara,
  • Kyohei Matsuo,
  • Hironobu Hayashi,
  • Hiroko Yamada and
  • Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

Graphical Abstract
  • fluorescence at 576 nm with a quantum yield of ΦF = 0.86 at 298 K (Figure 3). Both peaks are slightly red-shifted relative to those of intact terrylene (λabs = 560 nm and λem = 571 nm with ΦF = 0.82 in toluene). We employed density functional theory (DFT) and time-dependent (TD)-DFT calculations, both of them
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Published 06 Apr 2020

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

  • Takahide Shimada,
  • Shigeki Mori,
  • Masatoshi Ishida and
  • Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

Graphical Abstract
  • , density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d) level of theory. The a2-symmetry of the HOMOs and b2-symmetry of the LUMOs of each, the α- and β-ethynyl-substituted BODIPYs are almost identical to those of the unsubstituted compound 1a (Figure S24, Supporting Information
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Published 01 Apr 2020

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

  • Mai Nagase,
  • Kenta Kato,
  • Akiko Yagi,
  • Yasutomo Segawa and
  • Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

Graphical Abstract
  • -catalyzed six-fold C–H borylation of HBC was successfully achieved by screening solvents. The crystal structure of hexaborylated HBC was confirmed via X-ray crystallography. Optoelectronic properties of the thus-obtained hexaborylated HBC were analyzed with the support of density functional theory
  • hexaborylated HBC 1. The structure of thus-obtained 1 was confirmed by X-ray crystallography, and the electronic effects of the boryl groups were investigated through optoelectronic measurements and density functional theory (DFT) calculations. Results and Discussion We have examined the conditions for C–H
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Published 13 Mar 2020

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

  • Panagiotis S. Gritzapis,
  • Panayiotis C. Varras,
  • Nikolaos-Panagiotis Andreou,
  • Katerina R. Katsani,
  • Konstantinos Dafnopoulos,
  • George Psomas,
  • Zisis V. Peitsinis,
  • Alexandros E. Koumbis and
  • Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

Graphical Abstract
  • factor of 1.43 [11]. Theoretical calculations Calculations for the photodegradation of carbamates The structures, properties and the basic photochemistry of compounds 11 and 12 was studied using the density functional theory (DFT) method [86][87][88][89] and the functional B3PW91 along with the 6-31 G(d
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Published 09 Mar 2020

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

  • Narasimhamurthy Rajeev,
  • Toreshettahally R. Swaroop,
  • Ahmad I. Alrawashdeh,
  • Shofiur Rahman,
  • Abdullah Alodhayb,
  • Seegehalli M. Anil,
  • Kuppalli R. Kiran,
  • Chandra,
  • Paris E. Georghiou,
  • Kanchugarakoppal S. Rangappa and
  • Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

Graphical Abstract
  • reactions, a mechanism is proposed in which the key steps are supported by quantum chemical calculations. Keywords: benzylamines; carbamothioates; density functional theory; intrinsic reaction coordinate analysis; isocyanides; sodium hydride; xanthate esters; Introduction Carbamothioates (thiocarbamates
  • , however, carbamothioates 4a–l were instead obtained in 76–88% yield (Scheme 1). Herein, we report on this intriguing finding and show several examples, including a single crystal X-ray structure of one of the products so obtained. A plausible mechanism to explain the reaction using density functional
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Published 03 Feb 2020

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

  • David Martínez-López,
  • Amirhossein Babalhavaeji,
  • Diego Sampedro and
  • G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

Graphical Abstract
  • of intramolecular H-bond formation, we wished to retain at least one methoxy group. To reduce the rate of thermal reversion, only derivatives with substituents in all four ortho-positions were considered. Time-dependent density functional theory (TD-DFT) calculations were used to predict the
  • absorption wavelengths of possible derivatives. Based on these considerations, we carried out the synthesis and photochemical characterization of compounds 4 and 5. Results and Discussion Computational chemistry Calculations were performed using density functional theory (DFT) methods (B3LYP/6-31+G**) to
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Published 30 Dec 2019

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

  • Soleiman E. Helaly,
  • Wilawan Kuephadungphan,
  • Patima Phainuphong,
  • Mahmoud A. A. Ibrahim,
  • Kanoksri Tasanathai,
  • Suchada Mongkolsamrit,
  • Janet Jennifer Luangsa-ard,
  • Souwalak Phongpaichit,
  • Vatcharin Rukachaisirikul and
  • Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

Graphical Abstract
  • ) were not elucidated previously. Therefore, electronic circular dichroism (ECD) measurements combined with time-dependent density functional theory (TDDFT) calculations of ECD data of compound 1 in MeOH at the B3LYP/6-311+G* level of theory were carried out. The CD spectrum of 1 showed strong Cotton
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Published 16 Dec 2019

Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

  • Daniel R. Sutherland,
  • Nidhi Sharma,
  • Georgina M. Rosair,
  • Ifor D. W. Samuel,
  • Ai-Lan Lee and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285

Graphical Abstract
  • carbazoles with respect to the bridging benzene of ca. 44° in both 3 and 4 (Figure 2). Theoretical properties Density functional theory (DFT) calculations were performed in the gas phase to assess the electronic structures of 2–5 (see Supporting Information File 1 for details). The S1 and T1 excited states
  • were calculated from the optimized ground-state structure using the Tamm Dancoff approximation (TDA) to time-dependent density functional theory (TD-DFT) [30][31]. In all derivatives, the LUMO is mainly localized on the strongly electron-accepting BQ moiety (Figure 3). The HOMO is mainly located on the
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Published 04 Dec 2019

Carbazole-functionalized hyper-cross-linked polymers for CO2 uptake based on Friedel–Crafts polymerization on 9-phenylcarbazole

  • Dandan Fang,
  • Xiaodong Li,
  • Meishuai Zou,
  • Xiaoyan Guo and
  • Aijuan Zhang

Beilstein J. Org. Chem. 2019, 15, 2856–2863, doi:10.3762/bjoc.15.279

Graphical Abstract
  • from the adsorption branches using nonlocal density functional theory (NLDFT) methods. P2–P5 exhibited narrow pore size distribution in the micropore scopes (<2 nm), while P1 showed a wide pore size distribution. The surface areas of P1–P5 ranged from 350 to 769 m2 g−1 (Table 2). The lowest specific
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Published 26 Nov 2019

A combinatorial approach to improving the performance of azoarene photoswitches

  • Joaquin Calbo,
  • Aditya R. Thawani,
  • Rosina S. L. Gibson,
  • Andrew J. P. White and
  • Matthew J. Fuchter

Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266

Graphical Abstract
  • performance: o-F [13][14], o-Cl [8][29][30], o-OMe [10][29][31], or o-Pyr [32]. For the sake of comparison, both mono- and di-ortho-substitutions were considered. Theoretical half-lives (t1/2) were calculated within the density functional theory (DFT) framework, according to the protocol reported in our prior
  • ground state geometries of both Z- and E-isomers were computed under the time-dependent density functional theory (TDDFT) approach [41][42]. The 20 lowest-lying singlet excited states were calculated in all conformers at the TD-PBE0/6-31G** level of theory in the gas phase. Solvent effects in
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Published 14 Nov 2019

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

  • Pedro H. P. R. Carvalho,
  • Jose R. Correa,
  • Karen L. R. Paiva,
  • Daniel F. S. Machado,
  • Jackson D. Scholten and
  • Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

Graphical Abstract
  • density functional theory (TD-DFT). In practice, when applying DFT calculations, there is no “universal” exchange correlation functional (XCF), thus the performance of different XCFs in simulating the absorption spectra of BTD-4APTEG had to be assessed. We aimed at describing the maxima absorption peak
  • were carried out with the long-range corrected density functional CAM-B3LYP with 6-31G(d) Pople’s split basis set. Harmonic frequency calculations were performed to verify that a genuine energetic minimum was achieved. Solvent effects on the BTD-4APTEG geometries were assessed using the polarizable
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Published 06 Nov 2019
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