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Search for "density functional theory" in Full Text gives 272 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

The phenyl vinyl ether–methanol complex: a model system for quantum chemistry benchmarking

  • Dominic Bernhard,
  • Fabian Dietrich,
  • Mariyam Fatima,
  • Cristóbal Pérez,
  • Hannes C. Gottschalk,
  • Axel Wuttke,
  • Ricardo A. Mata,
  • Martin A. Suhm,
  • Melanie Schnell and
  • Markus Gerhards

Beilstein J. Org. Chem. 2018, 14, 1642–1654, doi:10.3762/bjoc.14.140

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  • -corrected density functional theory (DFT-D3) [44][45], spin-component-scaled approximated coupled cluster-singles-doubles (SCS-CC2) [46] as well as explicitly correlated local coupled cluster theory (LCCSD(T0)-F12) [47] calculations, the latter allowing for a quantification and visualization of London
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Published 02 Jul 2018

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

  • Eric Detmar,
  • Valentin Müller,
  • Daniel Zell,
  • Lutz Ackermann and
  • Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

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  • Abstract Carboxylate-assisted cobalt(III)-catalyzed C–H cyanations are highly efficient processes for the synthesis of (hetero)aromatic nitriles. We have now analyzed the cyanation of differently substituted 2-phenylpyridines in detail computationally by density functional theory and also experimentally
  • intermediates and transition states. Keywords: catalysis; C–H activation; density functional theory; London dispersion; reaction mechanisms; Introduction For a long time, large and bulky substituents have intuitively been considered to act through unfavorable steric interactions, although London dispersion
  • ligand dissociation process within the Pd(PPh3)4 system [25]. Furthermore, only the results obtained from dispersion-corrected density functional theory [28][29] were in agreement with the experimental observations and dispersion reduces the activation free energies by up to 30 kcal mol–1 [27]. Currently
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Published 25 Jun 2018

Steric “attraction”: not by dispersion alone

  • Ganna Gryn’ova and
  • Clémence Corminboeuf

Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125

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  • functional theory [39], post-Hartree–Fock [40][41], symmetry adapted perturbation theory (SAPT) [42][43][44][45][46] data or to a combination of the latter two (e.g., the monomer electron density force field, MEDFF) [47]. The latter approach has been subsequently exploited in the machine learning
  • describing intermolecular interactions. Effective fragment potential (EFP) methods estimate it by adding a damping term to their classical multipolar expansion [36][37]. To account for this effect, quantum mechanically derived force fields (FFs) are fitted to semi-empirical [38], dispersion-corrected density
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Published 19 Jun 2018

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

  • Claudia Lar,
  • Adrian Woiczechowski-Pop,
  • Attila Bende,
  • Ioana Georgeta Grosu,
  • Natalia Miklášová,
  • Elena Bogdan,
  • Niculina Daniela Hădade,
  • Anamaria Terec and
  • Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

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  • , anthracene and 1,5-dihydroxynaphthalene have been obtained at density functional theory level, using the M11 [42] exchange-correlation functional and the def2-TZVP [43] basis set implemented in the Gaussian 09 program package [44]. In order to take into account the solvent effect induced by the DMSO solvent
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Published 06 Jun 2018

London dispersion as important factor for the stabilization of (Z)-azobenzenes in the presence of hydrogen bonding

  • Andreas H. Heindl,
  • Raffael C. Wende and
  • Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 1238–1243, doi:10.3762/bjoc.14.106

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  • density functional theory (DFT) computations, attractive LD forces were identified as the origin of this stability trend. Based on this study, LD interactions represent a valuable tool for the design of novel azobenzene photoswitches [24]. Herein we provide further evidence for the importance of LD as
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Published 29 May 2018

Are dispersion corrections accurate outside equilibrium? A case study on benzene

  • Tim Gould,
  • Erin R. Johnson and
  • Sherif Abdulkader Tawfik

Beilstein J. Org. Chem. 2018, 14, 1181–1191, doi:10.3762/bjoc.14.99

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  • interest in how to accurately model them. Multiple families of approaches for including dispersion forces in quantum chemical simulations now exist, mostly based around the principle of improving density functional theory (DFT) calculations (see, e.g., some key and recent summaries [3][5][13][14]) through
  • polarisability tensor. Summary of modern dispersion methods Over the last decade, a number of new approaches have been developed that explicitly introduce dispersion forces into electronic structure theory methods – typically density functional theory (DFT). These approaches seek to overcome the fundamental lack
  • quite poor, however, further reflecting their poorer treatment of dispersion energies and forces away from equilibrium. Conclusion In this work we used benchmark results for several configurations of the benzene dimer to test the ability of dispersion-corrected density functional theory to obtain
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Published 23 May 2018

One hundred years of benzotropone chemistry

  • Arif Dastan,
  • Haydar Kilic and
  • Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

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Published 23 May 2018

Correlation effects and many-body interactions in water clusters

  • Andreas Heßelmann

Beilstein J. Org. Chem. 2018, 14, 979–991, doi:10.3762/bjoc.14.83

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  • enhance the induction energy. In a recent work by Hapka et al. it was shown that also standard density functional theory methods are able to describe nonadditive effects to the interaction energy quite well for hydrogen-bonded clusters, yet, fail to do so for dispersion bound complexes [31]. The common
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Published 02 May 2018

Local energy decomposition analysis of hydrogen-bonded dimers within a domain-based pair natural orbital coupled cluster study

  • Ahmet Altun,
  • Frank Neese and
  • Giovanni Bistoni

Beilstein J. Org. Chem. 2018, 14, 919–929, doi:10.3762/bjoc.14.79

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  • ]. They are typically carried out at the Hartree–Fock (HF) or density functional theory (DFT) level. In these schemes, the interacting system is treated as a supermolecule and the overall interaction energy is decomposed into various terms such as electrostatic interaction, charge transfer, polarization
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Published 25 Apr 2018

Phosphodiester models for cleavage of nucleic acids

  • Satu Mikkola,
  • Tuomas Lönnberg and
  • Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

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Published 10 Apr 2018

An uracil-linked hydroxyflavone probe for the recognition of ATP

  • Márton Bojtár,
  • Péter Zoltán Janzsó-Berend,
  • Dávid Mester,
  • Dóra Hessz,
  • Mihály Kállay,
  • Miklós Kubinyi and
  • István Bitter

Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63

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  • complex were computed. Foremost, a molecular mechanical (MM) conformation analysis was performed for the individual molecules using the MMFF force field [47]. The stable conformers were optimized further at the density functional theory (DFT) level using the PBE functional [48][49] with D3BJ dispersion
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Published 03 Apr 2018

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

  • Lin Gan,
  • Xianglong Li,
  • Xinyi Cai,
  • Kunkun Liu,
  • Wei Li and
  • Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

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  • energy levels, are calculated from Ered and Eox. Compounds 1 and 2 have similar HOMO and LUMO energy levels due to the same donor and acceptor in the molecules (Table 1). The molecular geometry of 1 and 2 in the ground state and excited state were simulated by density functional theory (DFT) and time
  • -dependent density functional theory (TD-DFT) calculations, respectively. The ground state (S0) geometries were optimized on B3LYP/6-31G* level in gas phase, while the lowest triplet excited state (T1) energy levels and the singlet excited state (S1) geometries of those molecules were optimized by TD-DFT on
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Published 22 Mar 2018

Terahertz spectroscopy of 2,4,6-trinitrotoluene molecular solids from first principles

  • Ido Azuri,
  • Anna Hirsch,
  • Anthony M. Reilly,
  • Alexandre Tkatchenko,
  • Shai Kendler,
  • Oded Hod and
  • Leeor Kronik

Beilstein J. Org. Chem. 2018, 14, 381–388, doi:10.3762/bjoc.14.26

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  • . Keywords: density functional theory; THz spectroscopy; Introduction The transparency of many non-conductive materials in the terahertz range (0.1 to 10 THz) of the electromagnetic spectrum has led to the development of several potential applications of terahertz radiation [1]. Terahertz spectroscopy of
  • yield reliable simulated spectra for complex materials is density functional theory (DFT) [23]. A significant complication, however, is that conventionally used exchange–correlation energy functionals in DFT do not describe the intermolecular dispersion interactions well. Therefore, early calculations
  • Science, Tel Aviv University, Tel Aviv 6997801, Israel 10.3762/bjoc.14.26 Abstract We present a computational analysis of the terahertz spectra of the monoclinic and the orthorhombic polymorphs of 2,4,6-trinitrotoluene. Very good agreement with experimental data is found when using density functional
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Published 09 Feb 2018

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

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  • maintaining a large optical bandgap. In fact, dihedral angles of 49.9, 86.8, 71.4 and 82.4° were determined by density functional theory (DFT) calculations between the donor plane and the acceptor plane for T20–T23, respectively. Due to its lesser twisted structure and based on the design rule previously
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Published 30 Jan 2018

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

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  • fluoride substrates (Figure 1), producing the corresponding substituted products in moderate to good yields. The water/isopropanol system was also shown to be amenable to phenolate and thiolate nucleophiles [3]. Previously, Paquin et al. undertook density functional theory (DFT) studies on the mechanism of
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Published 09 Jan 2018

Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

  • Tamara Šmidlehner,
  • Ivo Piantanida and
  • Gennaro Pescitelli

Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5

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  • richer in bands than a typical ECD spectrum (just like IR spectra vs UV–vis spectra) [1][4][36]. Nowadays, density functional theory (DFT) allows a calculation of the VCD spectrum of a chiral molecule, which then can be compared with the measured VCD spectrum and by this the absolute configuration (AC
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Published 08 Jan 2018

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

  • Aleksey A. Vasilev,
  • Meglena I. Kandinska,
  • Stanimir S. Stoyanov,
  • Stanislava B. Yordanova,
  • David Sucunza,
  • Juan J. Vaquero,
  • Obis D. Castaño,
  • Stanislav Baluschev and
  • Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

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  • position) are presented in Figure 5 with the respective atom color scheme. The electronic reorganizations upon excitation were probed using time-dependent density functional theory (TDDFT) calculations. TDPBE0 (time-dependent density functional theory calculations using Perdew–Burke–Ernzerhof exchange
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Published 28 Dec 2017

15N-Labelling and structure determination of adamantylated azolo-azines in solution

  • Sergey L. Deev,
  • Alexander S. Paramonov,
  • Tatyana S. Shestakova,
  • Igor A. Khalymbadzha,
  • Oleg N. Chupakhin,
  • Julia O. Subbotina,
  • Oleg S. Eltsov,
  • Pavel A. Slepukhin,
  • Vladimir L. Rusinov,
  • Alexander S. Arseniev and
  • Zakhar O. Shenkarev

Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250

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  • analysis in the 1D 13С spectra acquired with selective 15N decoupling, respectively. Additional spin–spin interactions were detected in the 15N-HMBC spectra. NMR data and DFT (density functional theory) calculations permitted to suggest a possible mechanism of isomerization for the adamantylated products
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Published 29 Nov 2017

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

  • Artur Jabłoński,
  • Yannic Fritz,
  • Hans-Achim Wagenknecht,
  • Rafał Czerwieniec,
  • Tytus Bernaś,
  • Damian Trzybiński,
  • Krzysztof Woźniak and
  • Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

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  • using the density functional theory (DFT) with the hybrid gradient corrected correlation functional B3LYP [38] and Gaussian-type basis functions 6-311G(d,p) [39]. TD-DFT calculations were performed in the optimized ground state geometry using the same B3LYP functional and basis sets. Five lowest singlet
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Published 28 Nov 2017

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

  • Tathagata Mukherjee,
  • Soumik Biswas,
  • Andreas Ehnbom,
  • Subrata K. Ghosh,
  • Ibrahim El-Zoghbi,
  • Nattamai Bhuvanesh,
  • Hassan S. Bazzi and
  • John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

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  • ][67][68]. Calculations. Computations were performed with the Gaussian09 program package, employing the ultrafine grid (99,590) to enhance accuracy [69]. Geometries were optimized using density functional theory (DFT). The B3LYP [70][71][72] functional was employed with an all-electron 6-311+G(d,p) [73
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Published 23 Nov 2017

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

  • Elisandra Scapin,
  • Paulo R. S. Salbego,
  • Caroline R. Bender,
  • Alexandre R. Meyer,
  • Anderson B. Pagliari,
  • Tainára Orlando,
  • Geórgia C. Zimmer,
  • Clarissa P. Frizzo,
  • Helio G. Bonacorso,
  • Nilo Zanatta and
  • Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

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  • , using ionic liquids and water as solvents, and short reaction times. In addition, 5-substituted isomers have proved to be excellent models in carrying out a thorough investigation of the azide–tetrazole equilibrium mechanism by density functional theory (DFT) and various experimental methods (e.g., NMR
  • (R in the 4-position of the ring), which was attributed to an equilibrium of azide–tetrazole. In the solid state, all compounds were found as 2-azidopyrimidines. The regiochemistry of the reaction and the stability of the products are discussed on the basis of the data obtained by density functional
  • theory (DFT) for energetic and molecular orbital (MO) calculations. Keywords: 5-aminotetrazol; azide–tetrazole equilibrium; 2-azidopyrimidine; β-enaminones; tetrazolo[1,5-a]pyrimidine; trifluoromethylatedtetrazolo[1,5-a]pyrimidines; Introduction Tetrazolo[1,5-a]pyrimidines have attracted attention in
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Published 10 Nov 2017

Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives

  • Mio Matsumura,
  • Mizuki Yamada,
  • Atsuya Muranaka,
  • Misae Kanai,
  • Naoki Kakusawa,
  • Daisuke Hashizume,
  • Masanobu Uchiyama and
  • Shuji Yasuike

Beilstein J. Org. Chem. 2017, 13, 2304–2309, doi:10.3762/bjoc.13.226

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  • corresponding vibronic band was seen in the absorption spectrum at 330–340 nm. Density functional theory (DFT) calculations [38] were carried out at the B3LYP/LanL2DZ level of theory. The HOMO and LUMO energies of the selected compounds are given in Table 3. For fluorescent compounds 3, 4, 7, and 9, the HOMO
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Published 30 Oct 2017

Are boat transition states likely to occur in Cope rearrangements? A DFT study of the biogenesis of germacranes

  • José Enrique Barquera-Lozada and
  • Gabriel Cuevas

Beilstein J. Org. Chem. 2017, 13, 1969–1976, doi:10.3762/bjoc.13.192

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  • elemanschkuhriolide, but this transition state is questionable due to its high energy. The possible mechanisms of this transformation were studied in the density functional theory frame. The mechanistic differences between the transformation of (Z,E)-germacranes and (E,E)-germacranes were also studied. We found that
  • stable elemanolide that is even more stable than its (Z,E)-germacrane. Keywords: biogenesis; density functional theory; reaction mechanism; sigmatropic rearrangement; terpenes; Introduction Germacranes are biogenetic precursors of elemanes [1][2][3][4], because germacranes can be easily transformed
  • , stabilizing the transition state, or destabilizing the ground states energy of the reactants. An antibody-catalyzed oxy-Cope reaction has already been described [42] as well as a proposed reaction mechanism [43]. In the study presented in this paper, we performed density functional theory (DFT) calculations
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Published 19 Sep 2017

Theoretical simulation of the infrared signature of mechanically stressed polymer solids

  • Matthew S. Sammon,
  • Milan Ončák and
  • Martin K. Beyer

Beilstein J. Org. Chem. 2017, 13, 1710–1716, doi:10.3762/bjoc.13.165

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  • and widening of bond angles, which changes the infrared spectrum. Here, the infrared spectrum of solid polymer samples exposed to mechanical stress is simulated by density functional theory calculations. Mechanical stress is described with the external force explicitly included (EFEI) method. The
  • infrared bands is not a shift of the peak position, but rather peak broadening and a characteristic change in the relative intensities of the strongest bands, which may serve for the identification and quantification of mechanical stress in polymer solids. Keywords: density functional theory; infrared
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Published 17 Aug 2017

Correction: Dynamic behavior of rearranging carbocations – implications for terpene biosynthesis

  • Stephanie R. Hare and
  • Dean J. Tantillo

Beilstein J. Org. Chem. 2017, 13, 1669–1669, doi:10.3762/bjoc.13.161

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  • Stephanie R. Hare Dean J. Tantillo Department of Chemistry, University of California–Davis, 1 Shields Avenue, Davis, CA 95616, USA 10.3762/bjoc.13.161 Keywords: carbocation; density functional theory; dynamics; mechanism; terpene; The originally published Figure 6 had several mis-drawn
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Published 15 Aug 2017
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