Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations

• Adriana K. Slavova-Kazakova,
• Silvia E. Angelova,
• Timur L. Veprintsev,
• Petko Denev,
• Davide Fabbri,
• Maria Antonietta Dettori,
• Maria Kratchanova,
• Vladimir V. Naumov,
• Aleksei V. Trofimov,
• Rostislav F. Vasil’ev,
• Giovanna Delogu and
• Vessela D. Kancheva

Beilstein J. Org. Chem. 2015, 11, 1398–1411, doi:10.3762/bjoc.11.151

• 4 – density functional theory (DFT) calculations at UB3LYP/6-31+G(d,p) level, applied to explain the structure–activity relationship. Dimers showed 2–2.5-fold higher values of kA than their monomers. Model 2 gives information about the effects of the side chains and revealed much higher antioxidant

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• that occurs in ligand L2 leading to a resonance structure that involves the C=N hydrazone bond as it can be seen in (Figure S2, Supporting Information File 1). Theoretical calculations Theoretical calculations based on density functional theory (DFT) methods have been performed with the Gaussian 09

Surprisingly facile CO₂ insertion into cobalt alkoxide bonds: A theoretical investigation

• Willem K. Offermans,
• Claudia Bizzarri,
• Walter Leitner and
• Thomas E. Müller

Beilstein J. Org. Chem. 2015, 11, 1340–1351, doi:10.3762/bjoc.11.144

• density functional theory (DFT) were performed by using the DMol3 program [57][58]. The Perdew–Burke–Ernzerhof functional to account for the exchange correlation of the electrons was applied [59]. A double numerical basis set plus a polarization d-function on all non-hydrogen atoms and a polarization p

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene: the effect of planarisation on charge transport properties

• Rupert G. D. Taylor,
• Joseph Cameron,
• Iain A. Wright,
• Neil Thomson,
• Olena Avramchenko,
• Alexander L. Kanibolotsky,
• Anto R. Inigo,
• Tell Tuttle and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1148–1154, doi:10.3762/bjoc.11.129

• and electrochemical properties of compounds 1 and 2 have been measured by UV–vis spectroscopy and cyclic voltammetry and the results compared with density functional theory (DFT) calculations to confirm the observed properties. Organic field effect transistor (OFET) devices fabricated from 1 and 2

New tris- and pentakis-fused donors containing extended tetrathiafulvalenes: New positive electrode materials for rechargeable batteries

• Shintaro Iwamoto,
• Yuu Inatomi,
• Daisuke Ogi,
• Satoshi Shibayama,
• Yukiko Murakami,
• Minami Kato,
• Kazuyuki Takahashi,
• Kazuyoshi Tanaka,
• Nobuhiko Hojo and
• Yohji Misaki

Beilstein J. Org. Chem. 2015, 11, 1136–1147, doi:10.3762/bjoc.11.128

• obtained as stable solids. Theoretical calculations We performed theoretical calculations of 5A, 6Aa and 7Aa by using the Gaussian 09 program based on the density functional theory (DFT) at the B3LYP/6-31G(d) level [27]. Their HOMO and HOMO–n (n = 1–2 and 1–4) of the trans isomers of 5a, 6a and 8a are

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• experimental resolution, based on the value we measure for the CT complex. Ab initio calculations To gain insight into the conduction mechanism of compound 5, we performed theoretical calculations based on a combination of density functional theory (DFT) and Green’s functions techniques within the framework of

First principle investigation of the linker length effects on the thermodynamics of divalent pseudorotaxanes

• Andreas J. Achazi,
• Doreen Mollenhauer and
• Beate Paulus

Beilstein J. Org. Chem. 2015, 11, 687–692, doi:10.3762/bjoc.11.78

• linker shows an enhanced binding strength due to electronic effects, namely the dispersion interaction between the linkers from the guest and the host. For the longer linkers this ideal packing is not possible due to steric hindrance. Keywords: density functional theory (DFT); dispersion correction

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

• Andrey S. Mereshchenko,
• Alexey V. Ivanov,
• Viktor I. Baranovskii,
• Grzegorz Mloston,
• Ludmila L. Rodina and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

• -thioxocyclobutanone (2b) as dipolarophiles (Figure 1). The calculations were performed at the density functional theory (DFT) level using the 6-31G(d) basis set. For reactions of diazo compounds 1a–f with thiobenzophenone (2a), the solvent was simulated using the polarizable continuum model (PCM) [22], and for the

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• acylphosphonites, (3) conversion of these compounds to phosphorothioates, (4) evidence that acylphosphonites, unlike their phosphine analogs, do not undergo facile inversion, and (5) confirmation of this observation by density functional theory (DFT) calculations. Results and Discussion Synthesis of

Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

• Bodee Nutho,
• Wasinee Khuntawee,
• Chompoonut Rungnim,
• Piamsook Pongsawasdi,
• Peter Wolschann,
• Alfred Karpfen,
• Nawee Kungwan and
• Thanyada Rungrotmongkol

Beilstein J. Org. Chem. 2014, 10, 2789–2799, doi:10.3762/bjoc.10.296

• binding free energies were also corrected with quantum mechanics energy (∆EQM) by replacing the MM energy (∆EMM) in Equation 3 with density functional theory (DFT) calculation using the M06-2X functional with 6-31G(d,p) level of basis set. Besides, the full optimization in gas phase and PCM water model of

Theoretical study of the adsorption of benzene on coinage metals

• Werner Reckien,
• Melanie Eggers and
• Thomas Bredow

Beilstein J. Org. Chem. 2014, 10, 1775–1784, doi:10.3762/bjoc.10.185

• = Cu), silver (M = Ag) and gold (M = Au) is studied on the basis of density functional theory (DFT) calculations with an empirical dispersion correction (D3). Variants of the Perdew–Burke–Ernzerhof functionals (PBE, RPBE and RevPBE) in combination with different versions of the dispersion correction

• interactions. Density functional theory (DFT) is established as a standard method for quantum-chemical solid-state calculations [12]. However, DFT has the well known shortcoming that it fails to describe dispersion effects. Consequently, standard DFT methods are not suitable for the calculation of the

Proton transfers in the Strecker reaction revealed by DFT calculations

• Shinichi Yamabe,
• Guixiang Zeng,
• Wei Guan and
• Shigeyoshi Sakaki

Beilstein J. Org. Chem. 2014, 10, 1765–1774, doi:10.3762/bjoc.10.184

• . Methods of calculation Geometry optimizations were performed by density functional theory (DFT) with the B3LYP [17][18] functional. The basis set 6-311+G(d,p) was employed for all the atoms in the calculations. The solution (water) effect was considered by the Polarizable Continuum Model (PCM) [19][20][21

Substitution effect and effect of axle’s flexibility at (pseudo-)rotaxanes

• Friedrich Malberg,
• Jan Gerit Brandenburg,
• Werner Reckien,
• Oldamur Hollóczki,
• Stefan Grimme and
• Barbara Kirchner

Beilstein J. Org. Chem. 2014, 10, 1299–1307, doi:10.3762/bjoc.10.131

• =O stretch mode [27]. Different density functionals, including one functional with an empirical correction for dispersion interaction, for the treatment of such rotaxane complexes were studied. We compared these density functional theory (DFT) results with Møller–Plesset second-order perturbation

• different functional groups and by changing the degree of molecular flexibility. Computational methodologies The structures of all compounds were fully optimized without any symmetry constraints. Density functional theory (DFT) with the gradient-corrected meta-functional TPSS combined with the resolution of

Dimerisation, rhodium complex formation and rearrangements of N-heterocyclic carbenes of indazoles

• Zong Guan,
• Jan C. Namyslo,
• Martin H. H. Drafz,
• Martin Nieger and
• Andreas Schmidt

Beilstein J. Org. Chem. 2014, 10, 832–840, doi:10.3762/bjoc.10.79

• yield (85%) than in the literature (40%) [29]. All density-functional theory (DFT)-calculations were carried out by using the Jaguar 7.7.107 software running on Linux 2.6.18-238.el5 SMP (x86_64) on two AMD Phenom II X6 1090T processor workstations (Beowulf-cluster) parallelized with OpenMPI 1.3.4. MM2

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• . Transition structures were optimized with quasi-Newton–Raphson methods by using the Powell update algorithm for hessian matrix approximation (subsequent analytical frequency calculation). Calculating hydrogen-bonding interactions, density functional theory (DFT) is frequently employed. The B3LYP functional

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• enantioselectivity of the β-(N-acylamino)aryl thioether (up to 92% ee), with only 1 mol % of chiral guanidine OC-46 as a catalyst. Based on density functional theory (DFT) calculations, a plausible mechanism indicated that the hydrogen-bonding interaction between the chiral guanidine and the carbonyl group in meso-N

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

• Robert J. Perkins,
• Hai-Chao Xu,
• John M. Campbell and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

• to initial formation of N-localized radical 6. Depending on the reaction conditions, the experiment favoured either a sulfonamide or alcohol based cyclization. Density functional theory (DFT) calculations suggested that sulfonamide based cyclizations proceed by addition of the N-localized radical to

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• significantly compared with the N-alkylated compound. Density functional theory (DFT) calculations, at the B3YLP-61G*(d,p) level of theory using the Gaussian ‘09 suite of programs [28], result in the observation of a polar distribution of the calculated molecular orbital densities for 2, as expected from the

An aniline dication-like transition state in the Bamberger rearrangement

• Shinichi Yamabe,
• Guixiang Zeng,
• Wei Guan and
• Shigeyoshi Sakaki

Beilstein J. Org. Chem. 2013, 9, 1073–1082, doi:10.3762/bjoc.9.119

• rearrangement. Theoretical calculations The reacting systems were investigated by density functional theory (DFT) calculations. The B3LYP [8][9] method was used to trace the reaction path. The basis sets employed were 6-31G(d) and 6-311+G(d,p), where the latter was adopted for the key (OH transfer) steps. For

Synthesis, photophysical and electrochemical characterization of terpyridine-functionalized dendritic oligothiophenes and their Ru(II) complexes

• Amaresh Mishra,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2013, 9, 866–876, doi:10.3762/bjoc.9.100

• nonemissive [Ru(tpy)2]2+ center of the metallodendrimer. Quantum chemical calculations. In order to gain insight into the structural properties, the electron density distribution of the frontier orbitals of both complexes was analyzed by density functional theory (DFT) using the B3LYP/LANL2DZ basis set

• platinum wire, and the reference electrode was an Ag/AgCl secondary electrode. All potentials were internally referenced to the ferrocene/ferricenium couple. Calculations. Full geometry optimizations were performed in the gas phase by using density functional theory (DFT) calculations based on the B3LYP

• oligothienylene-ethynylene dendrons and their corresponding terpyridine-based ligands. Their complexation with Ru(II) led to interesting novel metallodendrimers with rich spectroscopic properties. All new compounds were fully characterized by 1H and 13C NMR, as well as MALDI–TOF mass spectra. Density functional

Gold-catalyzed oxycyclization of allenic carbamates: expeditious synthesis of 1,3-oxazin-2-ones

• Benito Alcaide,
• Pedro Almendros,
• M. Teresa Quirós and
• Israel Fernández

Beilstein J. Org. Chem. 2013, 9, 818–826, doi:10.3762/bjoc.9.93

• the gold to the distal allenic double bond leading to complex 9, followed by a 6-exo-dig oxyauration is likely for the achievement of 1,3-oxazin-2-ones 4 from allenic carbamates 2 (Scheme 4, right-hand catalytic cycle). Density functional theory (DFT) calculations (see Supporting Information File 1

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• interaction. Hence, density functional theory (DFT) calculations also indicate that the tautomer 8y is relatively more stable than 8x and 8z (Figure 2). Further, in order to generalize the reaction, attempts were made for the alkenylation of indolin-2-one with 6-aryl-4-sec-amino-2H-pyran-2-one-3-carbonitriles

• 1.053, largest difference peak and hole 0.455 and −0.644 e·Å−3. Computational details Geometric characterization of all of the three tautomers of 8yc was performed at the level of density functional theory (DFT) using the B3LYP functional [48][49]. For all the atoms 6-31G** basis sets were used. All

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

• chose a (7,7) active space and employed a 6-31G(d) basis set. For the cation the input parameters were calculated by density functional theory (DFT) with the Gaussian 09 suite of programs [35], employing the B3LYP functional and a 6-31G(d) basis set. For a closed-shell molecule without vibronic

Complete σ* intramolecular aromatic hydroxylation mechanism through O₂ activation by a Schiff base macrocyclic dicopper(I) complex

• Albert Poater and
• Miquel Solà

Beilstein J. Org. Chem. 2013, 9, 585–593, doi:10.3762/bjoc.9.63

• was not possible to trap or detect any intermediate in the path from a + O2 → g. Here, by means of density functional theory (DFT) calculations, we search for the whole reaction pathway (Figure 1). The results are compared with those obtained in a similar previous study in which the hexaazamacrocyclic

A new family of four-ring bent-core nematic liquid crystals with highly polar transverse and end groups

• Kalpana Upadhyaya,
• Venkatesh Gude,
• Golam Mohiuddin and
• Rao V. S. Nandiraju

Beilstein J. Org. Chem. 2013, 9, 26–35, doi:10.3762/bjoc.9.4

• to possibly weakened lateral interactions and increased intermolecular spacing between molecules. Density functional theory calculations The quantum mechanical calculations of molecular properties in the gas phase were performed by using density functional theory (DFT) [58] employing the combination