Journal of Physical Organic Chemistry

Cover image for Vol. 24 Issue 6

June 2011

Volume 24, Issue 6

Pages 439–528

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. Synthesis and nonlinear optical properties of branched pyrroline chromophores (pages 439–444)

      Jialei Liu, Wenjun Hou, Shuwen Feng, Ling Qiu, Xinhou Liu and Zhen Zhen

      Article first published online: 24 AUG 2010 | DOI: 10.1002/poc.1772

      Thumbnail image of graphical abstract

      Modification of the TCP chromophore with bulky groups provides reduction of dipole–dipole interactions, thus great improvement of the macroscopic electro-optic (EO) response was achieved by incorporating these chromophores as a guest into amorphous polycarbonate (APC). Furthermore, the modificated chromophore possesses good processability and exhibits high thermal decomposition temperature.

    2. Fundamental properties of N-alkenylaziridines—implications for the design of new reactions and organocatalysts (pages 445–449)

      Matthew R. Siebert and Dean J. Tantillo

      Article first published online: 18 OCT 2010 | DOI: 10.1002/poc.1776

      Thumbnail image of graphical abstract

      Quantum chemical calculations reveal that N-alkenylaziridines are less basic/nucleophilic at their (β)-carbon than are corresponding systems that lack an aziridine ring and their derived iminium ions are more susceptible to attack by nucleophiles.

    3. Photostability of DπA nonlinear optical chromophores containing a benzothiazolium acceptor (pages 450–459)

      Marek Cigáň, Anton Gáplovský, Ivica Sigmundová, Pavol Zahradník, Roman Dĕdic and Magdaléna Hromadová

      Article first published online: 28 SEP 2010 | DOI: 10.1002/poc.1782

      Thumbnail image of graphical abstract

      The photochemical stability of seven DπA benzothiazolium push–pull molecules with different length of conjugated bridge and different acceptor strength was investigated. Both structural modifications (extension of conjugated bridge and an additional acceptor group bonded to heterocycle) resulting in an increase of NLO response led to a decrease in photostability due to the self-sensitized 1O2 photooxygenative attack. Thus a compromise should be found between an increase in NLO response and a decrease in photostability to make a choice of studied compounds for practical applications.

    4. Application of activation hardness in perturbed pericyclic reactions: a case study involving electrocyclic ring opening reactions of heterocyclobutenes (pages 460–465)

      M. Jaccob, I. Sheeba Jem, Santanab Giri, P. Venuvanalingam and P. K. Chattaraj

      Article first published online: 28 SEP 2010 | DOI: 10.1002/poc.1785

      Thumbnail image of graphical abstract

      The activation hardness (Δη) based on the HOMO, LUMO, HOMO-1, and LUMO+1 levels are newly defined and the second activation hardness value explains reactivity trend in the isomerization of heterocyclobutenes in a better way.

    5. Reactions of O-aryl S-aryl dithiocarbonates with secondary alicyclic amines in aqueous ethanol. Kinetics and mechanism (pages 466–473)

      Enrique A. Castro, Marcela Gazitúa and José G. Santos

      Article first published online: 28 SEP 2010 | DOI: 10.1002/poc.1787

      Thumbnail image of graphical abstract

      For the reactions of these dithiocarbonates with sec alicyclic amines, two tetrahedral intermediates (one zwitterionic and the other anionic) are formed.

    6. Kinetics and mechanism of the pyridinolysis of N-aryl-P,P-diphenyl phosphinic amides in dimethyl sulfoxide (pages 474–479)

      Arun Kanti Guha, Chan Kyung Kim and Hai Whang Lee

      Article first published online: 4 OCT 2010 | DOI: 10.1002/poc.1788

      Thumbnail image of graphical abstract

      The Hammett plots for substituent Z variations are anomalously biphasic concave upwards with a break point at Z=H, indicating frontside and backside nucleophilic attack for electron-donating and -withdrawing substituents Z, respectively.

    7. Concerted SN2 mechanism for the hydrolysis of acid chlorides: comparisons of reactivities calculated by the density functional theory with experimental data (pages 480–491)

      Ferenc Ruff and Ödön Farkas

      Article first published online: 11 NOV 2010 | DOI: 10.1002/poc.1790

      Thumbnail image of graphical abstract

      Acid chlorides hydrolyze via concerted, general base and general acid catalyzed SN2 mechanism. The structure of the tetrahedral TS changes with substituents and solvent. Late/early TSs are formed if the attacking reagent is poorer/better nucleophile than the leaving group, and loose/tight TSs are formed for substrates bearing electron-donating /electron-withdrawing substituents.

    8. A DFT-GIAO and DFT-NBO study of polar substituent effects on NMR 17O chemical shifts in some rigid polycyclic alkanes (pages 492–498)

      William Adcock

      Article first published online: 8 NOV 2010 | DOI: 10.1002/poc.1791

      Thumbnail image of graphical abstract

      17O NMR shieldings of several polcyclic alkanes (Y=OH and O) covering a wide range of electronic substituent effects were calculated at the B3LYP/6-311+G(2d, p) level of theory using the DFT-GIAO theoretical model. The relationship between the calculated 17O SCS and substituent constants (σF, σR, and σχ) as well as NBO molecular parameters was explored by regression analysis.

    9. Theoretical studies on aromaticity of selected hydroxypyrones. Part 3#. Chelatoaromaticity phenomenon in metalcomplexes of hydroxypyrones (pages 499–506)

      Krzysztof K. Zborowski, Miquel Solà, Jordi Poater and Leonard M. Proniewicz

      Article first published online: 18 OCT 2010 | DOI: 10.1002/poc.1794

      Thumbnail image of graphical abstract

      Chelatoaromaticity phenomenon is studied in complexes of pyromeconic acid, maltol, and ethylmaltol with aluminum, gallium, and indium cations. Calculated values of aromaticity indices show a significant increase of ligands aromaticity during complexation. This effect (effect of chelatoaromaticity) stabilizes formed chelatocomplexes.

    10. CO2 production in the bromate-1,4-cyclohexanedione oscillatory reaction (pages 507–512)

      Jiamin Feng, James R. Green, Samuel A Johnson and Jichang Wang

      Article first published online: 8 NOV 2010 | DOI: 10.1002/poc.1795

      Thumbnail image of graphical abstract

      The oscillatory bromate-1,4-cyclohexanedione reaction gives loss of CO2 and the ring-opening products 5-(dibromomethylene)-2(5H)-furanone, (E)-5,5,5-tribromo-4-oxo-2-pentenoic acid, and dibromoacetic acid, particularly ≥60°C.

    11. Calculated polar substituent effects on the stability of 4-substituted(X) - cub-1-yl and -bicyclo[2.2.2]oct-1-yl cations: a DFT study (pages 513–516)

      William Adcock

      Article first published online: 4 NOV 2010 | DOI: 10.1002/poc.1796

      Thumbnail image of graphical abstract

      Relative hydride affinities (ΔE, kcal/mol)for the appropriate isodesmic reactions of the two cations covering a wide range of electronic substituent effects were calculated within the framework of DFT theory at the B3LYP/6-311+G(2d,p) level. The relationship between the ΔE values and polar substituent constants (σF and σχ) was explored by regression analysis.

    12. Modulation of color change and photocyclization of diarylethene with metal complex (pages 517–521)

      Huan-Huan Liu and Yi Chen

      Article first published online: 22 OCT 2010 | DOI: 10.1002/poc.1798

      Thumbnail image of graphical abstract

      Modulation of color change and photocyclization of diarylethene with metal complex has been demonstrated. Diarylethene–metal complex generates not only marked color change but also significant promotion in photocyclization, which may provide a simple and convenient way to modulate the color and the photocyclization of diarylethene system.

    13. Pulse radiolysis studies of 2- and 3-hydroxybenzyl alcohols: inhibition of dehydration of ·OH-(hydroxybenzyl alcohols) adducts by H2PO4 ions (pages 522–528)

      Surajdevprakash B. Dhiman and Devidas B. Naik

      Article first published online: 8 NOV 2010 | DOI: 10.1002/poc.1803

      Thumbnail image of graphical abstract

      Though (OH-HBAs) adducts decay to give phenoxyl radicals in the presence of HPOmath image ions, the same is inhibited strongly in the presence of added H2POmath image ions.

SEARCH

SEARCH BY CITATION