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

• 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

• out TD-DFT calculations for conformer 2. Second, for the neutral species, the N=N–C–C dihedral angles in the optimized structures were manually set to 20° to generate new input files. Reoptimization yielded the same structures and free energies. The optimized geometries of all structures were

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

• photoswitching. Table 2 summarizes the theoretical excitation energy separation (in nm) between the characteristic n–π* and π–π* transitions in the ortho-substituted arylazopyrazoles under study. Theoretical TD-DFT calculations indicate that the family of ortho-substituted 4pzH-X presents well-separated n–π

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• photophysical studies (absorption and emission spectroscopy) and the studies on the electronic structure were accompanied by TD-DFT calculations for assigning the dominant longest-wavelength absorption bands. Results and Discussion Synthesis and tentative mechanism Recently, we reported a straightforward access

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

• the performance of different density functionals: B3LYP, CAM-B3LYP, LC-ωPBE, M06, M06-2X, and PBE1PBE. It was employed the 6-311+G(2d,p) basis set to simulate the excitation spectra of the BTDs. To comprise the solvent effects, the implicit PCM treatment was also included in the TD-DFT calculations

Small anion-assisted electrochemical potential splitting in a new series of bistriarylamine derivatives: organic mixed valency across a urea bridge and zwitterionization

• Keishiro Tahara,
• Tetsufumi Nakakita,
• Alyona A. Starikova,
• Takashi Ikeda,
• Masaaki Abe and
• Jun-ichi Kikuchi

Beilstein J. Org. Chem. 2019, 15, 2277–2286, doi:10.3762/bjoc.15.220

• broadness and intensity. Because any NIR absorption was not observed for the reference Ph1b+ (Figure 4b), this second band of 1b+ is assigned to an IVCT transition from the NAr3 unit to the NAr3•+ unit. Indeed, using time-dependent DFT (TD-DFT) calculations, an electronic transition from the β-HOMO to β

• . Vibrational frequencies were calculated to check the stability of the optimized structures and confirm that there are no imaginary frequencies. The TD-DFT calculations were also performed to predict electronic transitions with energies and oscillator strengths to obtain insight into UV–vis-NIR spectral data

Click chemistry towards thermally reversible photochromic 4,5-bisthiazolyl-1,2,3-triazoles

• Chenxia Zhang,
• Kaori Morinaka,
• Mahmut Kose,
• Takashi Ubukata and
• Yasushi Yokoyama

Beilstein J. Org. Chem. 2019, 15, 2161–2169, doi:10.3762/bjoc.15.213

• Supporting Information File 1). The absorption spectral properties are summarized in Table 1 together with their predicted absorption maxima obtained by TD DFT calculations in vacuum [35]. Although 1o and 2o showed substantial coloration, 3o showed only a slight coloration at room temperature. The solvent

• observation was well-reproduced by TD DFT calculations (Table 1 and chapter SI-4 in Supporting Information File 1). When the absorption maximum wavelength of 1c, whose central ethene moiety is triazole, is compared with those of the closely related 7c (cyclopentene) [37], 8c (hexafluorocyclopentene) [38], 9c

• about 740 nm. The thermal back reactions of these compounds proved that 3c with the electron-withdrawing cyano groups is the fastest while 2c with electron-donating methoxy groups was the slowest. DFT and TD DFT calculations supported these experimental results. The Cu(I)-catalyzed Huisgen reaction has

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• fluorescent. Minimum two Pekarian functions are needed to reproduce the band shape of the salts 6 in ethanol indicating that at least two electronic transitions are involved (Supporting Information File 1, Figure S3). TD DFT calculations interprets the longest wavelength absorption bands of 3 and 6 to be

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• functional theory (TD-DFT) calculations on the four representative molecules displayed in Figure 2: Dyes (1 and 3) vs (2 and 4) differ by the position (2,6 or 1,7) of the methyl groups on the BODIPY core, while dyes (1 and 2) vs (3 and 4) differ by the presence (or not) of a triphenylamine donor group on the

Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

• Ayato Yamada,
• Manabu Abe,
• Yoshinobu Nishimura,
• Shoji Ishizaka,
• Masashi Namba,
• Taku Nakashima,
• Kiyofumi Shimoji and
• Noboru Hattori

Beilstein J. Org. Chem. 2019, 15, 863–873, doi:10.3762/bjoc.15.84

• theory (TD-DFT) calculations for 5a at the CAM-B3LYP/6-31G(d) level of theory (Supporting Information File 1, Figure S2). The fluorescence quantum yields of caged-TEMPO 2a and 2b were found to be 2.9 and 2.2% in DMSO, which are much smaller than those of 5a and 5b, respectively, suggesting the chemical

Polysubstituted ferrocenes as tunable redox mediators

• Sven D. Waniek,
• Jan Klett,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

• II–IV are assigned to mainly d–d transitions [79]. TD-DFT calculations on the B3LYP, def2-TZVP, RIJCOSX, ZORA, CPCM (CH2Cl2) level do not give satisfactory results concerning energy, number of bands and oscillator strength of electronic transitions (Figures S32–S35, Supporting Information File 1

• model (CPCM) modeling dichloromethane was used in all calculations [97]. Geometry optimizations and TD-DFT calculations (50 vertical transitions) were performed using Ahlrichs’ split-valence triple-ξ basis set def2-TZVP which comprises polarization functions for all non-hydrogen atoms [98][99]. The

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

• -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

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

• 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

• emission data for pyrene–adenine conjugates 2–5 measured in diluted dichloromethane solution at ambient temperature. Selected lowest-energy vertical electronic transitions resulting from TD-DFT calculations for pyrene–adenine conjugates 3 and 5 in the ground state geometry at the B3LYP/6-311G(d,p) theory

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

• Srikala Pangannaya,
• Neethu Padinchare Purayil,
• Shweta Dabhi,
• Venu Mankad,
• Prafulla K. Jha,
• Satyam Shinde and
• Darshak R. Trivedi

Beilstein J. Org. Chem. 2017, 13, 222–238, doi:10.3762/bjoc.13.25

• a first order rate equation for the anion binding process. 1H NMR and TD-DFT calculations further confirmed the anion binding process of receptor R1 and R2 with F− and AcO− ions. The detection ability of Hg2+ and F− ions by receptor R1 allows its usage in molecular logic gate applications

Characterization of the synthetic cannabinoid MDMB-CHMCZCA

• Carina Weber,
• Stefan Pusch,
• Dieter Schollmeyer,
• Sascha Münster-Müller,
• Michael Pütz and
• Till Opatz

Beilstein J. Org. Chem. 2016, 12, 2808–2815, doi:10.3762/bjoc.12.279

• CO and/or a cyclohexyl radical or methylenecyclohexane. As MDMB-CHMCZCA bears a stereogenic center at C-1', the elucidation of the absolute configuration of the sample was attempted by ECD spectroscopy. While the UV spectra can be adequately predicted by TD-DFT calculations (time-dependent density

Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

• Lukas J. Patalag and
• Daniel B. Werz

Beilstein J. Org. Chem. 2016, 12, 2739–2747, doi:10.3762/bjoc.12.270

• (d,p)) reveal that the HOMO is predominantly located at the oligoene chain while the LUMO is rather spread over the BTD terminus (Figure 3). Indeed, further TD-DFT calculations (not shown) assign the longest wavelength absorptions of all three compounds to a high contribution of a HOMO–LUMO

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• -dependent DFT (TD-DFT) calculations were carried out on the optimized structures with PBE0/def2-TZVP level of theory based on our benchmark calculations (Supporting Information File 1, chapter S11). It is apparent in Figure 11 that as the BXR molecular materials increase in size the overlap of the HOMO and

New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

• Ze’en Xiao,
• Senhua Chen,
• Runlin Cai,
• Shao’e Lin,
• Kui Hong and
• Zhigang She

Beilstein J. Org. Chem. 2016, 12, 2077–2085, doi:10.3762/bjoc.12.196

• R1 values were 0.0350, ωR2 = 0.0899 (I > 2σ(I)). The goodness of fit on F2 was 1.067. CCDC number: 1458040. Calculation of ECD spectra. Molecular Merck force field (MMFF) and DFT/TD-DFT calculations were carried out with Spartan’ 14 software (Wavefunction Inc., Irvine, CA, USA) and Gaussian 09

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• first-order rate-law with a Gibbs free energy of activation of ΔG‡298K = 112 kJ mol−1. Three proposed mechanistic pathways are taken into account and supported by detailed (time-dependent) densitiy functional theory [(TD)-DFT] calculations. The preferred pathway is initiated by an irreversible CO

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• using TD-DFT calculations [21]. Thus, the intensive Cotton effect is associated with the exciton coupling of the two chromophores of the iodobenzene units. In the ECD spectrum of (+)-9, the mirror image of the trend lines of (−)-9 was found. The UV–vis absorption spectrum of 3 exhibits absorption maxima

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

• Yunfei Wang and
• Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

• -dependent density functional theory (TD-DFT) calculations (see the Supporting Information File 1 for details). The UV–vis data indicates that the degrees of π-delocalization for the TTFVs and DTF compounds are quite similar. This result is congruous with the fact that diphenyl-TTFVs generally prefer a

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• trifluoromethyl-substituted TFF derivatives are lightly orange colored, while the ester and cyano TTFs are dark red compounds. In order to rationalize these evolutions, we have performed TD-DFT calculations on the model molecules TTF, TTF-CF3, TTF-CO2Me and TTF-CN. The results are shown in Figure 2 and collected

• initial geometry optimization calculations. Final geometries are given in Supporting Information File 1. Representation of frontier orbitals included in Figure 2 were generated with Molekel 4.3 [57]. TD-DFT calculations were performed at the B3LYP/6-311G** level of theory, on the previously converged

• optical transitions deduced from TD-DFT calculations (see Table 3). View of the 2ac molecule. Thermal ellipsoids are shown at the 50% probability level. View of the 2bc molecule. Thermal ellipsoids are shown at the 50% probability level. View of the two crystallographically independent 4bc molecules

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• which has previously and incorrectly been described as an n→π* transition [16][20]; however, TD-DFT calculations predict this to be π→π* (Figure 3) [27][28]. The n→π* transition was calculated to have a slightly higher energy transition with an oscillator strength of 0; thus, it should not be visible in

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• maximum of 1 was evidently red-shifted relative to those of 3 and pyrene. The 355 nm absorption band of 1 was assigned to the HOMO–LUMO transition by TD-DFT calculations (ωB97XD/6-31G(d)). DFT calculations also demonstrated that the HOMO and LUMO of 1 are primarily located on the pyrene moiety (Figure 4

Photoionisation of the tropyl radical

• Kathrin H. Fischer,
• Patrick Hemberger,
• Andras Bodi and
• Ingo Fischer

Beilstein J. Org. Chem. 2013, 9, 681–688, doi:10.3762/bjoc.9.77

• calculated the EOM-CCSD/cc-pVTZ excitation energies for the triplet states, using QChem 4 [44] at the DFT-optimised ground state tropyl ion geometry, to be 3.82 and 4.00 eV, corresponding to 10.05 and 10.23 eV photon energies. TD-DFT calculations yield 9.70, 10.05 eV (B3LYP/6-311++G(d,p)); 9.86, 10.25 (M06

• by a 1 eV gap to the next electronic excited state. EOM-CCSD vertical-excitation-energy calculations predict that the next higher lying state is a triplet at 12.48 eV followed by two more triplet states in ca. 100 meV intervals as well as several singlet states around 12.8 eV. TD-DFT calculations, on

Toward unidirectional switches: 2-(2-Hydroxyphenyl)pyridine and 2-(2-methoxyphenyl)pyridine derivatives as pH-triggered pivots

• Christina Tepper and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2012, 8, 977–985, doi:10.3762/bjoc.8.110

• (TD-DFT) with B3LYP as a functional and by employing the 6-31G* basis set (Figure 6b). TD-DFT calculations were performed at the optimized ground-state geometries of (M)-13 and (P)-13, calculating the energy, oscillator strength and rotatory strength for each of the 200 lowest singlet excitations. The