Journal of Physical Organic Chemistry

Cover image for Vol. 30 Issue 8

Early View (Online Version of Record published before inclusion in an issue)

Editor-in-Chief: Luis Echegoyen

Impact Factor: 1.336

ISI Journal Citation Reports © Ranking: 2016: 38/59 (Chemistry Organic); 109/145 (Chemistry Physical)

Online ISSN: 1099-1395

VIEW

  1. 1 - 70
  1. SPECIAL ISSUE ARTICLES

    1. New phthalimide-methionine dyad-based fluorescence probes for reactive oxygen species: Singlet oxygen, hydrogen peroxide, and hypochlorite

      Axel G. Griesbeck, Banu Öngel and Murat Atar

      Version of Record online: 14 JUL 2017 | DOI: 10.1002/poc.3741

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      New fluorescent molecular probes for reactive oxygen species were composed of prefluorescent phthalimide reporters and fluorescence-quenching methionine-derived receptors. The sulfoxides that are the sole primary oxidation products show strong fluorescence in the blue-green (430-540 nm) spectral region, whereas the probes are nearly nonfluorescent due to rapid intramolecular electron-transfer quenching of the excited molecules. All probes can be switched on with singlet oxygen, hydrogen peroxide, and hypochlorite as oxidants with different efficiencies.

    2. QM/MM calculations combined with the dimer approach on the static disorder at organic-organic interfaces of thin-film organic solar cells composed of small molecules

      Charlotte Brückner, Matthias Stolte, Frank Würthner, Jens Pflaum and Bernd Engels

      Version of Record online: 13 JUL 2017 | DOI: 10.1002/poc.3740

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      A QM/MM approach using ωB97X-D combined with AMOEBA calculations was used to analyze the energetic disorder in the vicinity of interfaces in amorphous organic heterostructures. Distributions of ground-, excited-, and cationic-state energies as well as of ionization potentials and excitation energies, all being relevant quantities for the charge and exciton transport properties of thin films, were calculated. Similar to amorphous bulk phases, local densities of states at molecular interfaces possess Gaussian-shaped profiles with a significant amount of disorder.

    3. Development of an electrochromic device triggered by the macrocell current in chloride-induced corrosion of steel-reinforced concrete

      Thomas Juraschek and Oliver Weichold

      Version of Record online: 13 JUL 2017 | DOI: 10.1002/poc.3739

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      An electrochromic device is presented in which the colour change is successfully triggered by the weak electrical currents occurring during steel corrosion in reinforced concrete. The device consists of diheptyl viologen in a LiClO4-poly(ethylene glycol) electrolyte sandwiched between an ITO-coated PET sheet and a copper plate. It is simple, easy to construct, and requires little to no service or maintenance throughout the service life. As part of corrosion monitoring systems, it is therefore an ideal component of a sustainable infrastructural development.

    4. Evaluating brominated thioxanthones as organo-photocatalysts

      Akila Iyer, Anthony Clay, Steffen Jockusch and J. Sivaguru

      Version of Record online: 13 JUL 2017 | DOI: 10.1002/poc.3738

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      Bromination of the widely used triplet sensitizer thioxanthone extends the absorption spectrum into the visible range with only minor loss of lowest triplet state energy (3 kcal/mol for di-bromination). The di-brominated derivative was effective as organo-photocatalyst in performing [2+2] cross photocycloaddition of acrylimide-based compounds under visible light irradiation.

    5. Photooxygenation of oxygen-substituted naphthalenes

      Marcel Bauch, Angela Krtitschka and Torsten Linker

      Version of Record online: 13 JUL 2017 | DOI: 10.1002/poc.3734

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      Various naphthalenes 1 are smoothly photooxygenated to afford endoperoxides 2 quantitatively. Important is the low temperature of –78°C and the proper solvent to handle and isolate such labile species. Reactivities nicely correlate with the HOMO energies of naphthalenes 1. The endoperoxides 2 reconvert quantitatively to the parent naphthalenes 1 under release of singlet oxygen even at –20°C, making them to superior organic sources of this reactive species under very mild conditions.

    6. Dynamic effects in the didehydro-Diels-Alder (DDDA) reaction of enyne-ketoenes: 50% stepwise bond formation in spite of concerted transition state

      Anup Rana, Indrajit Paul and Michael Schmittel

      Version of Record online: 12 JUL 2017 | DOI: 10.1002/poc.3732

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      The mechanism of the didehydro-Diels-Alder reaction of (E)-3-phenyl-1-(2-(phenylethynyl)phenyl)prop-2-en-1-one is investigated experimentally as well as computationally. As all experiments to trap an intermediate failed, a detailed computational study was instigated. Molecular dynamics simulation revealed that the concerted transition state acts as a common bottleneck for both the concerted and stepwise paths.

    7. New methods for the synthesis of 4H-dithieno[3,2-b:2′,3′-d]pyrrole

      Sebastian Förtsch, Astrid Vogt and Peter Bäuerle

      Version of Record online: 11 JUL 2017 | DOI: 10.1002/poc.3743

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      Six alternative methods for the synthesis of 4H-dithieno[3,2-b:2′,3′-d]pyrrole (DTP) are presented involving Cadogan, Ullmann-type, or Buchwald-Hartwig–type reactions. The use of ammonia surrogates afforded the fused target heteroacene in overall yields of 33% to 63%, and the corresponding methods are applicable on large scale.

  2. RESEARCH ARTICLES

    1. Effect of the tether length upon Truce-Smiles rearrangement reactions

      David Fuss, Yu Qi Wu, Michael R. Grossi, Joshua W. Hollett and Tabitha E. Wood

      Version of Record online: 7 JUL 2017 | DOI: 10.1002/poc.3742

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      A study of the effect of tether length in the Truce-Smiles rearrangement, an intramolecular nucleophilic aromatic substitution reaction, is presented. Experimental results are supported by computational modelling of reaction pathway potential energy surfaces.

  3. SPECIAL ISSUE ARTICLES

    1. Optical differentiation between quadruplex DNA and duplex DNA with a [2.2.2]heptamethinecyanine dye

      Heiko Ihmels, Mohamed M.A. Mahmoud and Brian O. Patrick

      Version of Record online: 6 JUL 2017 | DOI: 10.1002/poc.3736

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      The trinuclear [2.2.2.]heptamethine cyanine enables the discrimination between quadruplex and duplex DNA based on the different developments of absorption and emission properties upon ligand-DNA association.

  4. REVIEWS

    1. Solvated proton as the main reagent and a catalyst in the single-stage aromatic sulfonation and protodesulfonation of sulfonic acids

      Vladimir A. Kozlov, Sergey N. Ivanov and Oskar I. Koifman

      Version of Record online: 5 JUL 2017 | DOI: 10.1002/poc.3715

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      The hydrated proton environment plays the determining role in the formation of a cyclic transition state of electrophilic aromatic substitution (EAS), ie, reversible arene sulfonation and hydrolysis (protodesulfonation) of arenesulfonic acids. The mechanism of these processes is realized as single stage and occurring in an acidic water medium via the same transition state, but an alternative 2-stage mechanism of EAS, that proceed via π- and σ-complexes, is logically and energetically should be considered less reasonable.

  5. SPECIAL ISSUE ARTICLES

    1. Synthesis, structure, and photoreactions of fluorinated 2,11-diaza[32]paracyclophane: Photochemical formation of cage-diene type benzene dimer

      Hideki Okamoto, Tetsuya Kozai, Zenji Okabayashi, Teruo Shinmyozu, Hiromi Ota, Kiichi Amimoto and Kyosuke Satake

      Version of Record online: 5 JUL 2017 | DOI: 10.1002/poc.3726

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      Fluorinated azacyclophane was synthesized, and its photoreaction was investigated. Upon photolysis, the 2 benzene cores of the azacyclophane dimerized to produce a cage diene benzene dimer. The structure and photo- and thermal behavior of the cage diene isomer were also revealed.

  6. RESEARCH ARTICLES

    1. The mechanism of the reaction between an aziridine and carbon dioxide with no added catalyst

      Chau Phung, Dean J. Tantillo, Jason E. Hein and Allan R. Pinhas

      Version of Record online: 4 JUL 2017 | DOI: 10.1002/poc.3735

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      The mechanism of the reaction between a 2-alkyl aziridine and CO2 to generate an oxazolidinone has been studied. Calculations suggest that this reaction should not proceed at room temperature in the absence of a catalyst. Kinetic studies show that the reaction displays a zero-order dependence with respect to aziridine, indicating that free aziridine is not involved in the rate-determining step. A small amount of an ammonium salt generated in situ acts as a catalyst.

  7. SPECIAL ISSUE ARTICLES

    1. Exploring the utility of coumarins-based luminescent spectra converters

      Viktoryia A. Lapina, Tatiyana A. Pavich, Piotr P. Pershukevich, Aleksei V. Trofimov, Natalia N. Trofimova, Yurii B. Tsaplev and Pavel P. Zak

      Version of Record online: 29 JUN 2017 | DOI: 10.1002/poc.3731

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      The use of the coumarins-based luminescent spectral converters allows to transform the emission spectrum of the primary light-emitting diode source into a spectrum, which mimics that of the natural daylight. The fine control of the emission spectra of the coumarins in polymeric matrices of the spectral converters is achieved by introducing therein the nonionic detergents.

  8. RESEARCH ARTICLES

    1. Mixed micellization study of ibuprofen (sodium salt) and cationic surfactant (conventional as well as gemini)

      Dileep Kumar, Malik Abdul Rub, Naved Azum and Abdullah M. Asiri

      Version of Record online: 29 JUN 2017 | DOI: 10.1002/poc.3730

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      The interaction between cationic surfactant (conventional as well as Gemini surfactant) and sodium salt of ibuprofen drug have evaluated. The means of the interaction of drugs by added foreign materials is of paramount importance in the drug delivery. The packing parameters of amphiphiles in the micelles (P), volume contribution of the hydrophobic chain (V0), and its effective length (lc) have also been calculated. The ΔGom and ΔGoads values for all systems were found out to be negative. Protocol for the synthesis of 14-4-14 Gemini surfactant.

    2. Kinetics and thermochemistry of the unusual [2π + 2σ + 2σ]-cycloaddition of quadricyclane with some dienophiles

      Vladimir D. Kiselev, Dmitry A. Kornilov, Oleg V. Anikin, Igor A. Sedov and Alexander I. Konovalov

      Version of Record online: 28 JUN 2017 | DOI: 10.1002/poc.3737

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      Rate constants and reaction enthalpies at 25°C of the [2π + 2σ + 2σ]-cycloaddition reactions of quadricyclane with tetracyanoethylene (120 L mol−1 s−1; −236.5 kJ mol−1), 4-phenyl-1,2,4-triazoline-3,5-dione (0.282; −255.1), N-phenylmaleimide (3.7·10−7; -), and diethyl azodicarboxylate (2.8·10−6; -) are determined experimentally.

  9. SPECIAL ISSUE ARTICLES

    1. Container Chemistry: Manipulating excited state behavior of organic guests within cavitands that form capsules in water

      Pradeepkumar Jagadesan, Shampa R. Samanta, Rajib Choudhury and Vaidhyanathan Ramamurthy

      Version of Record online: 27 JUN 2017 | DOI: 10.1002/poc.3728

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      Two new cavitands reported here possess internal cavity similar to that of octa acid. They encapsulate molecules such anthracene, dibenzyl ketone, and coumarin in water by forming a capsular assembly. These hosts provide a hydrophobic “molecular laboratory” in an aqueous environment. Inclusion of organic molecules within these hosts in water is favored by enthalpy and entropy. Of the 2 hosts, only the one with benzoate group at the periphery acts as the triplet sensitizer.

    2. Singlet oxygen production and in vitro phototoxicity studies on fenofibrate, mycophenolate mofetil, trifusal, and their active metabolites

      Oscar Molins-Molina, Roger Bresolí-Obach, Guillermo Garcia-Lainez, Inmaculada Andreu, Santi Nonell, Miguel A. Miranda and M. Consuelo Jiménez

      Version of Record online: 21 JUN 2017 | DOI: 10.1002/poc.3722

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      Time-resolved near-infrared emission measurements and 3T3 neutral red uptake assays have been performed for the title compounds.

  10. RESEARCH ARTICLES

    1. Computational design of tetrazolone-based high-energy density energetic materials: Property prediction and decomposition mechanism

      Ying Shi

      Version of Record online: 20 JUN 2017 | DOI: 10.1002/poc.3733

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      The fascinating tetrazolone-based compounds and their energetic properties as well as decomposition mechanisms have been reported firstly, and they may be very promising candidates of green high-energy density materials.

    2. A natural bond orbital analysis of aryl-substituted polyfluorinated carbanions: negative hyperconjugation

      Masahiko Suenaga, Kazuhide Nakata, José-Luis M. Abboud and Masaaki Mishima

      Version of Record online: 20 JUN 2017 | DOI: 10.1002/poc.3721

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      Aryl-substituted polyfluorinated carbanions, ArCHRf where Rf = CF3 (1), C2F5 (2), i-C3F7 (3), and t-C4F9 (4) were analyzed by means of the natural bond orbital (NBO) theory. The donor/acceptor NBO interaction energies, E(2), for π(Cα-C1)[RIGHTWARDS ARROW]σ*(Cβ-F) or σ*(Cβ-Cγ) were related to negative hyperconjugation of the Cβ-F and Cβ-Cγ bonds.

    3. Solvent controlling excited state proton transfer reaction in quinoline/isoquinoline-pyrazole isomer QP-I: A theoretical study

      Dapeng Yang, Guang Yang, Jinfeng Zhao, Nahong Song, Rui Zheng and Yusheng Wang

      Version of Record online: 19 JUN 2017 | DOI: 10.1002/poc.3729

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      The strengthened hydrogen bond provides the tendency of excited state intramolecular protontransfer (ESIPT) reaction.The redistribution of charge in both acetonitrile and cyclohexanereveals the ESIPT process. Solvent polarity could control and regulate the ESIPT reaction for QP-I system.

    4. An effective tridental molecular clip for fullerenes

      Pablo A. Denis, Michael Kramer, Catherine Lee and Michael Yanney

      Version of Record online: 19 JUN 2017 | DOI: 10.1002/poc.3727

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      The construction of fullerene receptors featuring 3 corannulene pincers is challenging because they tend to form intramolecular pi-stacked structures. Here, we present a tridental structure, which according to first principle calculations, is expected to bind C60 with unprecedented affinity.

  11. SPECIAL ISSUE REVIEWS

    1. Four-membered cyclic peroxides: Carriers of chemical energy

      Erick Leite Bastos, Pooria Farahani, Etelvino J.H. Bechara and Wilhelm Josef Baader

      Version of Record online: 19 JUN 2017 | DOI: 10.1002/poc.3725

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      Four-membered cyclic peroxides are high-energy compounds often associated to cold light emission, but whose chemical and biological roles are still matters of debate. This review gives some insight on the synthesis, chemiluminescence mechanism, and biological relevance of 1,2-dioxetanes, 1,2-dioxetanones, and 1,2-dioxetanedione and provides practical protocols for those interested in engaging this field.

  12. RESEARCH ARTICLES

    1. Photochromism of new unsymmetrical diarylethenes with a quinoline moiety

      Peng Liu, Hongliang Liu, Gang Liu, Zhihui Zhang, Fen Xu and Shouzhi Pu

      Version of Record online: 16 JUN 2017 | DOI: 10.1002/poc.3716

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      Three unsymmetrical diarylethenes with a 6-membered quinoline moiety were synthesized, and the substituent effects on their photochromic properties were studied systematically.

  13. SPECIAL ISSUE ARTICLES

    1. Computational study on 1,3-disilacyclobutane-1,3-diylidene disilylenes: A synthetic strategy for cis-bent disilenes

      Yoshiki Fujita and Manabu Abe

      Version of Record online: 13 JUN 2017 | DOI: 10.1002/poc.3724

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      The cis-bent disilene with an R2Si═SiR2 double-bonding structure was found to be the most energetically stable structure for the 2,2,4,4-tetrafluoro-substituted compound. In contrast, the singlet disilylene structures (R2Si:) with a 4-membered ring geometry were calculated to be more energetically stable than the disilene structures for 1,3-disilacyclobutane-1,3-diylidene disilylenes with electron-donating substituents such as H and SiH3.

  14. RESEARCH ARTICLES

    1. Simple method for determining of the isokinetic temperature value for the SNAr reactions in solution

      Vladislav M. Vlasov

      Version of Record online: 13 JUN 2017 | DOI: 10.1002/poc.3723

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      The simple isokinetic relationship was found for SNAr reactions: δ∆Gexp = (0.12 ± 0.41) + (0.97 ± 0.02) (Tiso − Texp) δ∆S r = 0.998, s = 1.43, n = 13 where Tiso and Texp are the isokinetic and experimental temperatures, respectively. The δ∆Gexp and δ∆S values are the changes of the free energy of activation and activation entropy, respectively.

  15. SPECIAL ISSUE ARTICLES

    1. Functionalization of oxabenzonorbornadiene: Manganese(III)-mediated oxidative addition of dimedone

      Raşit Çalışkan, Ozlem Sari and Metin Balci

      Version of Record online: 5 JUN 2017 | DOI: 10.1002/poc.3720

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      The reaction of oxabenzonorborna-diene with dimedone and Mn(OAc)3 in the presence of HCl gave an adduct that was submitted to the ring-opening reactions. The BBr3-supported ring-opening reaction of the adduct gave a five-membered ring, however, reaction with formed a bicyclic system.

  16. RESEARCH ARTICLES

    1. Introducing boranorcaradienes with more stability than their corresponding borepins: Reversal of tautomerization via substituents at theoretical levels

      M. Koohi, M. Shariati and B.N. Haerizade

      Version of Record online: 5 JUN 2017 | DOI: 10.1002/poc.3714

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      Typical borepins (a) appear nearly 40.0 kcalmol−1 more stable than their corresponding tautomeric boranorcaradienes (b). Here, we discuss substituent effects on thermodynamic and kinetic parameters involved in tautomerization of 14 bimolecular systems [(1a to 14a) ⇌ (1b to 14b)] involving mono-, di-, tri-, and tetra-aza substituted 6H-dibenzo[c,e]borepins as well as 1a,2,7b-tetrahydro-1H-indeceno[4,5-b]borirenes, at B3LYP/AUG-cc-pVTZ, MP2/AUG-cc-pVTZ and HF/AUG-cc-pVTZ levels. Among them, 2 new boranorcaradienes are found, which appear more stable than their respective borepins. They are namely, 1a,9b-dihydro-1H-borireno[2,3-h]pyridazino[4,3-f]cinnoline (6b) and 1a,9b-dihydro-1H-borireno[2,3-h]pyrimido[5,4-f]quinazoline) (7b).

    2. Nucleophile-electrophile interactions in the reaction of oxiranes with carboxylic acids in the presence of tertiary amines

      Stanislav Bakhtin, Elena Shved and Yuliia Bespal'ko

      Version of Record online: 5 JUN 2017 | DOI: 10.1002/poc.3717

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      The nucleophile-electrophile interactions in the reaction system “N,N-dimethylaniline – acetic acid – epichlorohydrin” have been investigated using kinetic methods. The behavior of the initial (amine) and intermediate (carboxylate) nucleophiles has been detailed in reaction pathway. Amine reacts with oxirane activated by acidic reagent while carboxylate-anion—with both activated and non-activated epichlorohydrin.

    3. Design and interaction mechanism of ligand targeted with folate receptor α and β

      C. Wang, Y. Jiang, X. Fei and Y. Gu

      Version of Record online: 31 MAY 2017 | DOI: 10.1002/poc.3719

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      The variety of interaction models between ligands and FRα or FRβ was studied. By the difference between FRα and FRβ complexes, a novel compound with high selectively with FRα was designed, which will improve the recognition accuracy of the tumor cell and the efficiency of targeted drug delivery systems.

    4. The importance of orientation of exocyclic groups in a naphthoxyloside: A specific rotation calculation study

      Paula N. Goulart, Clarissa O. da Silva and Göran Widmalm

      Version of Record online: 31 MAY 2017 | DOI: 10.1002/poc.3708

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      Most abundant conformations found for 2-naphthyl β-d-xylopyranoside in methanol solution: alternating hydrogen bond directionality and aglycone orientation.

    5. DFT study on abstraction reaction mechanism of oh radical with 2-methoxyphenol

      Angappan Mano Priya and Senthilkumar Lakshmipathi

      Version of Record online: 25 MAY 2017 | DOI: 10.1002/poc.3713

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      The hydrogen abstraction of 2-methoxyphenol (2MP) with OH radical from methoxy group is found to be the dominant reaction channel. Also, time-dependent density functional theory calculations have been performed using same level of theory, and the results reveal that the reactions occur in ground state than the excited state. The atmospheric lifetime of 2MP with respect to OH radicals is 2.27 hours, which implies that OH radical plays an important role in the degradation of 2MP.

    6. Photocatalytic degradation of methylene blue solution by diphenylanthrazoline compounds

      Tianchu Zhao, Rui Liu, Jiapeng Lu, Xiaolin Zhu, Xuhong Zhu, Keping Lu and Hongjun Zhu

      Version of Record online: 23 MAY 2017 | DOI: 10.1002/poc.3712

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      The photocatalytic degradation of methylene blue solution by 8 diphenylanthrazoline compounds was investigated. The removal rate for CODCr in methylene blue solution at 12 hours was ~54.1% to 96.3%. These pure organic semiconductor materials displayed comparative photocatalytic properties to the inorganic semiconductor materials.

    7. A DFT-based mechanistic study on the formation of oximes

      Serdal Kirmizialtin, Banu Sizirici Yildiz and Ibrahim Yildiz

      Version of Record online: 5 MAY 2017 | DOI: 10.1002/poc.3711

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      In this computational study, we analyzed the proposed oxime formation mechanism on model systems using DFT calculations including a solvation model. The energetics of the reaction steps in neutral and acidic conditions as well as in the presence of aniline were performed. Explicit water molecules were included in the calculations to study the energetics of solvent-assisted proton transfer steps.

    8. Reaction of glycine with glyoxylate: Competing transaminations, aldol reactions, and decarboxylations

      Mark Conley, Mike Mojica, Fiaz Mohammed, Ke Chen, Jonathan W. Napoline, Pamela Pollet, Jing Wang, Ramanarayanan Krishnamurthy and Charles L. Liotta

      Version of Record online: 5 MAY 2017 | DOI: 10.1002/poc.3709

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      The aqueous reaction of 13C-labeled glycine with unlabeled glyoxylate undergoes a transamination process to produce 13C-labeled glyoxylate and unlabeled glycine. A competing aldol process produces 2-amino-3-hydroxysuccinate, which promotes the decarboxylation of glyoxylate.

    9. Steric interactions controlling the syn diastereofacial selectivity in the [3 + 2] cycloaddition reaction between acetonitrile oxide and 7-oxanorborn-5-en-2-ones: A molecular electron density theory study

      A. I. Adjieufack, I.M. Ndassa, J. Ketcha Mbadcam, M. Ríos-Gutiérrez and L.R. Domingo

      Version of Record online: 5 MAY 2017 | DOI: 10.1002/poc.3710

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      The zw-type [3 + 2] cycloaddition reactions between acetonitrile oxide and 7-oxanorborn-5-en-2-ones present low para regio and complete syn diastereofacial selectivities. The nonpolar character of these zw-type [3 + 2] cycloaddition reactions accounts for the high activation energies and low para regioselectivity, while the steric hindrance found along the anti approach mode is responsible for the complete syn diastereofacial selectivity.

    10. Theoretical studies and antibacterial activity for Schiff base complexes

      Wail Al Zoubi, Abbas Ali Salih Al-Hamdani, I Putu Widiantara, Rehab Ghalib Hamoodah and Young Gun Ko

      Version of Record online: 5 MAY 2017 | DOI: 10.1002/poc.3707

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      Complexes of this ligand [VO(II)(HL)(SO4)], [Pt(IV)(L)Cl3], [Re(V)(L)Cl3]Cl, and [M(II)(L)Cl] (M═Pd(II), Ni(II), Cu(II)) were synthesized. The resulted compounds were characterized by IR, NMR (1H and 13C), mass spectrometry, element analysis, and UV-Vis spectroscopy.

    11. Antimicrobial and antitumor activities of 1,2,4-triazoles/polypyrrole chitosan core shell nanoparticles

      Nehal Salahuddin, Ahmed A. Elbarbary, Mohamed L. Salem and Samar Elksass

      Version of Record online: 27 APR 2017 | DOI: 10.1002/poc.3702

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      The polypyrrole chitosan (PPC) nanoparticles have been prepared by in situ oxidative polymerization of pyrrole in chitosan solution using FeCl3 as an oxidant. 1,2,4-Triazole derivatives (I-IV) were loaded into PPC nanoparticles (PPCI, PPCII, PPCIII, and PPCIV). The antitumor activity of PPC nanoparticles loaded 1,2,4-triazoles was examined against Ehrlich ascites carcinoma cells and breast cancer cell line (MCF7). PPCIV nanoparticles showed high efficacy against Ehrlich ascites carcinoma tumor cells in vitro.

    12. Topological aspects of chemical reactivity. Destiny of electron pairs in allowed and forbidden pericyclic reactions

      Robert Ponec

      Version of Record online: 26 APR 2017 | DOI: 10.1002/poc.3706

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      The proposed approach relies on the idea to characterize the extent to which the electron pairs are conserved or broken by the probability of finding the pair of electrons of opposite spin at a given point of space. This probability is given by the αβ component of the pair density Παβ(r, r), and monitoring of this quantity in the form of snapshots for different points along the reaction path brings new insights into the destiny of electron pairs in chemical reactions.

    13. Influence of the methyl group at C=C bridging bond of stilbene on the longest wavelength maximum in ultraviolet absorption spectra

      Yanxiu Zhang, Chao-Tun Cao, Jingyuan Zhang and Chenzhong Cao

      Version of Record online: 17 APR 2017 | DOI: 10.1002/poc.3705

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      Compared with the λmax of UV spectra of compounds XSBY, the λmax of compounds XSMBY have blue shift in case of the same couple of groups X and Y. This blue shift is results from the side-group CH3 at the bridging group C(CH3)=CH in XSMBY molecule. The specific cross-interaction between X and Y has important effect on the λmax of XSMBY, whereas it has little effect on the λmax of XSBY.

    14. Some dielectric properties of novel nano-s-triazine derivatives

      Amal M. Abdel-Karim, A.H. Salama, Fatma A. El-Samahy, Mervat El-Sedik and Fayez H. Osman

      Version of Record online: 17 APR 2017 | DOI: 10.1002/poc.3703

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      We succeed in preparation of s-triazine derivatives in nano range provided by XRD and SEM. This work includes the study of dielectric properties and ac-electrical conductivity of the prepared compounds. The dielectric constant increases with the increase of both temperature and frequency. Moreover, from the measured dielectric loss ε″, we found that there are different types of electric energy losses in the presence of an ac field from which we calculate the entropy ΔS and the enthalpy change ΔH of the dielectric relaxation for each sample. The dielectric relaxation was attributed to the phase transition of the s-triazine derivatives. Analysis of ac conductivity data indicates that the correlated barrier hopping (CBH) model is the most suitable mechanism for the ac-conductance behavior.

    15. Theoretical insights on a series of difluoramino group–based energetic molecules

      Xinghui Jin, Jianhua Zhou, Bingcheng Hu and Congming Ma

      Version of Record online: 12 APR 2017 | DOI: 10.1002/poc.3704

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      A series of difluoramino group-based energetic molecules was designed and the relative properties such as detonation properties, impact sensitivities, electronic density, frontier molecular orbital, electrostatic potential on the surface and thermal dynamic parameters were predicted theoretically.

    16. A comparative study on the hydrolysis of acetic anhydride and N,N-dimethylformamide: Kinetic isotope effect, transition-state structure, polarity, and solvent effect

      William C. Cooper, Abhinay Chilukoorie, Suhesh Polam, Dane Scott and Floyd Wiseman

      Version of Record online: 4 APR 2017 | DOI: 10.1002/poc.3701

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      Proton inventory techniques play a crucial role in elucidating mechanisms by identifying the number and types of hydrogens involved in the transition state structures. The transition state structure in simple acetic anhydride hydrolysis has 4 protons; whereas, acetate catalyzed hydrolysis has 2. This study also shows an inverse kinetic isotope effect (kOH-/kOD- = 0.51 ± 0.03 at 25°C and an hydroxide concentration of 2.0M) for the hydroxide reaction with DMF. In the case of acetic anhydride, sodium chloride had a negative effect on the rate of hydrolysis and the charge of ions involved in the formation of activated complex is

      0.378 e.

    17. Strategy of improving the stability and detonation performance for energetic material by introducing the boron atoms

      Wen-Jie Wu, Wei-Jie Chi, Quan-Song Li, Jian-Nan Ji and Ze-Sheng Li

      Version of Record online: 24 MAR 2017 | DOI: 10.1002/poc.3699

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      Boron-containing energetic compound DANB was investigated by theoretical calculation. It possesses more superior detonation performance and thermodynamic stability than those of CL-20, HMX, RDX, and FOX-7. Our results show that DANB is a promising candidate for stable and powerful energetic material.

    18. Synthesis, spectroscopic, and computational studies of charge-transfer complexation between benzidine with 2,3-dichloro-5,6-dicyano-p-benzoquinone and chloronil

      Arunapriya Lakkadi, Naveen Baindla, Srimai Vuppala and Parthasarathy Tigulla

      Version of Record online: 22 MAR 2017 | DOI: 10.1002/poc.3700

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      In this work, the charge-transfer complexes were prepared and characterized by different techniques such as UV-Vis, FTIR, and 1HNMR. The experimental studies were well supported by quantum chemical simulations by using density functional theory; molecular geometry, Mulliken charges, and molecular electrostatic potential surfaces of reactants and complexes.

      These are helpful in assigning the CT route. The results reveal that the charge transfer takes place from donor to acceptor.

    19. Mechanistic insights into C-C cross coupling activities of Pd/Ni-doped heterofullerenes

      Manjusha C. Padole and Parag A. Deshpande

      Version of Record online: 22 MAR 2017 | DOI: 10.1002/poc.3696

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      Density functional theory calculations were implemented to test the C-C couplings activities of Pd- and Ni-doped heterofullerenes. The compounds were found to be active for catalyzing Suzuki-Miyaura and Heck coupling reactions.

    20. Tert-butyl hydroperoxide-promoted guanylation of amines with benzoylthioureas: Mechanistic insights by HRMS and 1H NMR

      Henrique Esteves, Tiago Oliveira Brito, Renato Ribeiro-Viana, Ângelo de Fátima and Fernando Macedo Jr.

      Version of Record online: 22 MAR 2017 | DOI: 10.1002/poc.3698

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      A mechanistic study of tert-butyl hydroperoxide-promoted guanylation of thioureas by monitoring short lifetime intermediaries using ESI-Q-TOF HRMS is presented. 1H nuclear magnetic resonance data furnished access to kinetic parameters, which allied to the HRMS results, suggested that an addition/elimination mechanism involving the aminoiminomethanesulphinic acid and the nucleophilic amine is the main pathway to yield the guanidine. Noteworthy, benzoylthiourea consumption rate presented a nonlinear kinetic behaviour, while tBuOOH and BnNH2 consumptions were found to follow second-order kinetics.

    21. Nondoped blue fluorescent OLED based on cyanophenanthrimidazole-styryl-triphenylamine/carbazole materials

      Thanikachalam Venugopal, Jeeva Palanivel and Jayabharathi Jayaraman

      Version of Record online: 10 MAR 2017 | DOI: 10.1002/poc.3695

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      Experimental details, computational details, molecular design, solvatochromic experiments, charge transfer indexes, photophysical properties, solvatochromic effects, thermal properties and lifetime decay, EL performances, figures of natural transition orbitals, computed hole and particle distribution, transition density matrix and tables of photophysical constants, and computational parameters are provided as the supporting materials.

    22. A quantum chemical study on the OH radical quenching by natural antioxidant fisetin

      Ahmad Bayat and Alireza Fattahi

      Version of Record online: 2 MAR 2017 | DOI: 10.1002/poc.3692

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      In this work, the antioxidant ability of fisetin was explored toward hydroxyl (•OH) radical in aqueous and lipid solution using density functional level of theory. Results show that the reactivity of fisetin toward hydroxyl (OH) radical takes place almost exclusively by radical adduct formation regardless of the polarity of the environment. Also, the single-electron transfer process seems to be thermodynamically unfavorable in both media.

    23. The reactivity of the 5-formylcytosine with hydroxyl radical: A theoretical perspective

      Lingxia Jin, Mengdan Lü, Caibin Zhao, Suotian Min, Tianlei Zhang and Qiang Zhang

      Version of Record online: 2 MAR 2017 | DOI: 10.1002/poc.3691

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      The addition of •OH to C5═C6 double bond of 5-fCyt is more favourable than other paths. The ∆Gs≠ of C6 channel is a little higher than C5 route, indicating some amount of regioselectivity, which is in agreement with the conclusions of •OH-mediated cytosine reaction reported experimentally and theoretically.

    24. Olefinic vs aromatic way of substituent effects: The case of 3- and 4-substituted cyclohexa-1,3-dienamine derivatives

      Halina Szatylowicz, Tomasz Siodla and Tadeusz M. Krygowski

      Version of Record online: 28 FEB 2017 | DOI: 10.1002/poc.3694

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      Both classical and reverse substituent effects acting from para-position are always stronger in olefinic systems than in aromatic ones. Moreover, for 1-4 interactions the substituent effect on π-electron delocalization in diene systems is opposite to that observed in aromatic ones—an increase of the electron-attracting power of the substituent increases π-electron delocalization in the olefinic series, whereas decreases it in the aromatic ones.

    25. Structural and thermochemical studies on CH3SCH2CHO, CH3CH2SCHO, CH3SC(═O)CH3, and radicals corresponding to loss of H atom

      Guanghui Song and Joseph W. Bozzelli

      Version of Record online: 24 FEB 2017 | DOI: 10.1002/poc.3688

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      Thermochemical properties (ΔHf°, S°, and Cp(T)), lowest energy structures, internal rotor potentials, and C─H bond dissociation energies of CH3SCH2CHO, CH3CH2SCHO, and CH3SC(═O)CH3, and their radicals formed after loss of a hydrogen atom were determined using density functional theory computations. Group additivity values are developed for estimating properties of structurally similar, larger sulfur-containing compounds. Such data are of value in understanding the mechanism and kinetics of methyl ethyl sulfide oxidation under varied temperatures and pressures.

    26. Density functional theoretical studies on photoswitching and charge migration dynamics of thio and selenoureidopeptides

      Sherin Joy, Vommina V Sureshbabu and Ganga Periyasamy

      Version of Record online: 22 FEB 2017 | DOI: 10.1002/poc.3693

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      The photoswitching ability of various thio/seleno ureidopeptide models pertaining to an n to π* transition and the charge migration dynamics from ureido end to carboxylate end of the peptidomimetics have been explored.

    27. The influence of steric effects on the kinetics and mechanism of SNAr reactions of 1-phenoxy-nitrobenzenes with aliphatic primary amines in acetonitrile

      Chukwuemeka Isanbor

      Version of Record online: 20 FEB 2017 | DOI: 10.1002/poc.3687

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      Specific steric effects of ortho-CF3 group leads to rate retardation and base catalysis due to increase in k−1 coupled with a decrease in kAm as the proton transfer from zwitterionic intermediates, 6, to catalysing amine becomes less thermodynamically favourable.

    28. Trans-2-Aminocyclohexanol derivatives as pH-triggered conformational switches

      Vyacheslav V. Samoshin, Yu Zheng and Xin Liu

      Version of Record online: 17 FEB 2017 | DOI: 10.1002/poc.3689

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      Trans-2-aminocyclohexanols have been explored as powerful conformational pH triggers by 1H nuclear magnetic resonance spectroscopy titration. The change of relative conformational stability on protonation in some models exceeded 20 kJ/mol resulting in conformational flip and forcing all substituents to change their orientation. The pKa values of protonated compounds varied from 2.6 to 8.5 (in d4-methanol) depending on the structure of amino group.

    29. Is it possible to use the 31P chemical shifts of phosphines to measure hydrogen bond acidities (HBA)? A comparative study with the use of the 15N chemical shifts of amines for measuring HBA

      Ibon Alkorta and José Elguero

      Version of Record online: 7 FEB 2017 | DOI: 10.1002/poc.3690

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      The nuclear magnetic resonance chemical shifts of 15 hydrogen-bonded complexes of trimethylphosphine, trimethylamine, and trimethylphosphine oxide have been calculated at B3LYP/6-311++G(d,p) level. The results show that the determination of hydrogen bond acidities is more reliable with Me3PO than Me3N and Me3P. A model that explains the chemical shift variations on the basis of the deformation and electronic effect of the hydrogen bond is proposed.

    30. Comparative charge transfer studies in nonmetallated and metallated porphyrin fullerene dyads

      Neha Gupta, Samya Naqvi, Mukesh Jewariya, Suresh Chand and Rachana Kumar

      Version of Record online: 3 FEB 2017 | DOI: 10.1002/poc.3685

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      Important study of charge carrier generation and separation dynamics in metallated and nonmetallated porphyrin-fullerene dyad is discussed in this work. The time-resolved data shows ultrafast charge separation and slow charge recombination in our dyads as desired for optimal solar cells performance. The metal-free porphyrin-fullerene dyad (H2P-C60) shows even better performance in ultrafast charge separation and formation of long-lived charge-separated state than metallated porphyrin-fullerene dayd (ZnP-C60).

    31. Approaching an experimental electron density model of the biologically active trans-epoxysuccinyl amide group—Substituent effects vs. crystal packing

      Ming W. Shi, Scott G. Stewart, Alexandre N. Sobolev, Birger Dittrich, Tanja Schirmeister, Peter Luger, Malte Hesse, Yu-Sheng Chen, Peter R. Spackman, Mark A. Spackman and Simon Grabowsky

      Version of Record online: 24 JAN 2017 | DOI: 10.1002/poc.3683

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      New syntheses, electron-density determinations and model-energy analyses of model compounds bearing the biologically relevant trans-epoxysuccinyl amide group in comparison with the drugs loxistatin acid (E64c) and loxistatin (E64d) give insight about the varying importance of different functional groups for binding in the enzyme and the crystal.

    32. Chitosan loaded with silver nanoparticles, CS-AgNPs, using thymus syriacus, wild mint, and rosemary essential oil extracts as reducing and capping agents

      Fadi AL-Shnani, Thanaa Al-Haddad, Francois Karabet and Abdul Wahab Allaf

      Version of Record online: 23 JAN 2017 | DOI: 10.1002/poc.3680

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      Herein, we describe a green procedure to prepare silver nanoparticles (AgNPs) integrated in chitosan using essential oils as reducing and capping agents. Scanning electron microscopy images were analyzed to count and calculate the area of integrated AgNPs in the structure of chitosan. Chitosan loaded with silver nanoparticles colloidal samples have 83% of AgNPs with 62 nm diameter when thymus syriacus (T) is used. While for wild mint (M) and rosemary (R) essential oils, 75% of AgNPs have 62 nm in diameter.

    33. A theoretical assignment on excited-state intramolecular proton transfer mechanism for quercetin

      Dapeng Yang, Guang Yang, Jinfeng Zhao, Rui Zheng, Yusheng Wang and Jian Lv

      Version of Record online: 13 JAN 2017 | DOI: 10.1002/poc.3684

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      Both hydrogen bonds of quercetin are strengthened in the S1 state. Frontier molecular orbitals support the ESIPT process. The ESIPT reaction should occur along hydrogen bond of 6-membered ring-like structure rather than the 5-membered one.

    34. Alkylperoxyl spin adducts of pyrroline-N-oxide spin traps: Experimental and theoretical CASSCF study of the unimolecular decomposition in organic solvent, potential applications in water

      Sergiu Lescic, Hakim Karoui, Micaël Hardy, Laurence Charles, Paul Tordo, Olivier Ouari, Anouk Gaudel-Siri and Didier Siri

      Version of Record online: 12 JAN 2017 | DOI: 10.1002/poc.3677

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      We investigated at the MRMP2//CASSCF level of theory the mechanism of decay of methylperoxyl and tert-butylperoxyl spin adducts formed with various cyclic nitrones. We showed that no transition state can be located for the O─O homolytic cleavage that yields an intermediate biradical with the following sequence O─N─C─O. Then, homolytic cleavage of the N─C bond yields a nitrosoaldehyde, through an early transition state with a very low activation energy.

    35. Substituent effect on structure, stability, and aromaticity of novel BnNmC20–(n+m) heterofullerenes

      Maryam Koohi, Somayeh Soleimani Amiri and Bibi Narjes Haerizade

      Version of Record online: 10 JAN 2017 | DOI: 10.1002/poc.3682

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      A flow chart for examination of the stability of fullerene C20 and some of its scrutinized novel BnNmC20─(n+m) heterofullerene analogues, at DFT levels.

    36. Anilinolysis of O-butyl phenyl phosphonochloridothioate in acetonitrile: Synthesis, characterization, kinetic study, and reaction mechanism

      Hasi Rani Barai, Ji-hoon Kim and Sang Woo Joo

      Version of Record online: 5 JAN 2017 | DOI: 10.1002/poc.3679

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      The kinetics of the nucleophilic substitution reactions of O-butyl phenyl phosphonochloridothioate with XC6H4NH2(D)2 are investigated in MeCN at 55.0°C. This study examines the synthesis, characterization, kinetic study, the substituent effects, deuterium kinetic isotope effects, and mechanism of the thiophosphoryl transfer reactions. A concerted SN2 mechanism with predominant backside nucleophilic attack involving in-line-type TSb was proposed on the basis of the selectivity parameters and variation trend of the deuterium kinetic isotope effects with X.

    37. A comparative study on the Ge6C14 heterofullerene nanocages: a density functional survey

      M. Koohi, M. Shariati and S. Soleimani Amiri

      Version of Record online: 5 JAN 2017 | DOI: 10.1002/poc.3678

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      A density functional theory study on stability, structural, and electronic properties of the isolated-pentagon Ge6C14 isomers.

    38. Surface, micellar, and thermodynamic properties of antidepressant drug nortriptyline hydrochloride with TX-114 in aqueous/urea solutions

      Malik Abdul Rub, Naved Azum, Farah Khan and Abdullah M. Asiri

      Version of Record online: 20 DEC 2016 | DOI: 10.1002/poc.3676

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      Herein, we study the mixed micellization and adsorption behavior of mixed systems enclosing an antidepressant drug nortriptyline hydrochloride (NOT) and Triton X-114 in aqueous/urea solutions. The NOT is used for cure of depression. Different theoretical models like Clint, Rubingh, and Rosen were used to get information about the nature of interaction between the components. Because of the occurrence of urea increase in the surface charge of the micelles was obtained resulting delay of the micelles formation. Different thermodynamic parameters have calculated.

    39. Synthesis, physicochemical, and biological activities of novel N-acyl tyrosine monomeric and Gemini surfactants in single and SDS/CTAB–mixed micellar system

      Nausheen Joondan, Sabina Jhaumeer-Laulloo, Prakashanand Caumul and Matthew Akerman

      Version of Record online: 16 DEC 2016 | DOI: 10.1002/poc.3675

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      N-acyl Gemini surfactant with mole ratio 0.4 to 0.6 in CTAB binary mixture showed optimum antibacterial activity and displayed the lowest ocular irritation index.

    40. Visible absorbing symmetrical squaraine and croconine dye derivatives: A comparative computational study

      Anuj Tripathi, Promila and Chetti Prabhakar

      Version of Record online: 12 DEC 2016 | DOI: 10.1002/poc.3673

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      C–N bonding croconine molecules are having approximately 100-nm red shifted absorption than its corresponding squaraines. This red shifted absorption in croconines is due to the variation in central C–C–C angle (replacement of central 4-membered ring with 5-membered ring) and presence of some diradical character (squaraines are showing zero diradical character, and croconines are found with some diradical character, ranging from 18% to 25%). Enhanced optical absorption was also observed in same series of molecules (either in squaraines or in croconines) with increase in conjugation at donor group.

    41. Computational design and screening of promising energetic materials: Novel azobis(tetrazoles) with ten catenated nitrogen atoms chain

      Piao He, Jian-Guo Zhang, Le Wu, Jin-Ting Wu and Tong-Lai Zhang

      Version of Record online: 6 DEC 2016 | DOI: 10.1002/poc.3674

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      The fascinating azobis(tetrazoles) compounds with ten catenated nitrogen atoms chain have been reported firstly, and may be very promising candidates of high energy density materials (HEDM).

    42. Abnormal effect of hydroxyl on the longest wavelength maximum in ultraviolet absorption spectra for bis-aryl Schiff bases

      Chao-Tun Cao, Wei Zhou and Chenzhong Cao

      Version of Record online: 2 DEC 2016 | DOI: 10.1002/poc.3672

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      There is an abnormal effect of hydroxyl (OH) on the longest wavelength maximum of ultraviolet absorption spectra for bis-aryl Schiff bases (XArCH=NArY); the OH distributing on the 4′-position (4′-OH) and 2′-position (2′-OH) of benzene rings has abnormal performance: the 4′-OH increases the λmax, whereas the 2′-9OH decreases the λmax.

    43. Synthesis of hydroxyoligophenylenes containing electron-donating, electron-accepting groups, or π-deficient aromatic ring and their solvatochromic behavior

      Isao Yamaguchi and Ryosuke Yamaji

      Version of Record online: 25 NOV 2016 | DOI: 10.1002/poc.3671

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      Solvatochromic behavior of hydroxyoligophenylenes containing dimenthylamino, nitro groups, or pyridine ring before and after the deprotonation of the OH group was investigated.

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