121,898 research outputs found
Optoelectronic technologies to boost photobioreactors for algae production: from pulsed light sources to PV integrated net zero system
No full textMicro-Algae production has seen growth of interest as a renewable source of food, nutraceutical, and biofuels. In this work we studied the integration of light emitting diodes (LED) in photobioreactors (PBRs) to increase the algal production efficiency. A multiwavelength LED light source with selectable intensity able to operate under continuous wave irradiation (CW) or with high intensity, short pulses, has been developed. The efficiency of biomass production has been examined both for CW and pulsed operations. The efficiency obtained with the Photovoltaic (PV) + LED light source is then compared to that of the solar radiation to analyze the performances of an indoor and outdoor system
Conformational Preferences For N,n-dimethyl-2-haloacetamides (halo=f, Cl, Br And I) Through Theoretical And Experimental Studies: An Unexpected Orbital Interaction
No full textConformational preferences and orbital interactions of N,N-dimethyl-2- fluoroacetamide (1), N,N-dimethyl-2-chloroacetamide (2), N,N-dimethyl-2- bromoacetamide (3) and N,N-dimethyl-2-iodoacetamide (4) were analyzed using experimental infra-red data, theoretical calculations and NBO analysis. The conformational equilibria of compounds 1-4 can be represented by their cis and gauche rotamers. The gauche form of 1 is stable in the vapor phase and in a non-polar solvent, but the cis is predominant in a polar solvent. For 2-4 the gauche form is more stable than the cis, in both the vapor and liquid phases. These conformational preferences were attributed to the orbital interaction between two antibonding orbitals, π* C=O→σ*C-X. This unexpected interaction was possibly due to the high (0.3) electron density on π* C=O, which results from the interaction between one nitrogen lone pair and π*C=O. © 2005 Elsevier B.V. All rights reserved.7281-37984Vassilev, N.G., Dimitrov, S., (1999) J. Mol. Struct., 484, p. 39Lehninger, A.L., Nelson, D.L., Cox, M.M., (1993) Principles of Biochemistry, , Worth New YorkGreenberg Breneman, C.M.A., Liebman, J.F., (2002) The Amide Linkage: Structural Significance in Chemistry, Biochemistry and Materials Science, , Wiley New YorkWiberg, K.B., Breneman, C.M., (1992) J. Am. Chem. Soc., 114, p. 831Vargas, R., Garza, J., Dixon, D., Hay, B.P., (2001) J. Phys. Chem. a, 105, p. 774Sandrone, G., Dixon, D.A., Hay, B.P., (1999) J. Phys. Chem. a, 103, p. 893Rogers, M.T., Woodbrey, J.C., (1962) J. Phys. Chem., 66, p. 540Drakenberg, T., Dahlqvist, K., Forsen, S., (1972) J. Phys. Chem., 76, p. 2178Hobson, R.F., Reeves, L.W., (1973) J. Phys. Chem., 77, p. 419Wunderlich, M.D., Leung, L.K., Sandberg, J.A., Meyer, K.D., Yoder, C.H., (1978) J. Am. Chem. Soc., 100, p. 1500Ross, B.D., Wong, L.T., True, N.S., (1985) J. Phys. Chem., 89, p. 836Jackowski, K., Les, A., (1995) J. Mol. Struct., 331, p. 295Suarez, C., Tafazzoli, M., True, N.S., Gerrard, S., Lemaster, C.B., Lemaster, C.L., (1995) J. Phys. Chem., 99, p. 8170Yamada, S., (1996) J. Org. Chem., 61, p. 941Crawford, S.M.N., Taha, A.N., True, N.S., Lemaster, C.B., (1997) J. Phys. Chem., 101, p. 4699Basso, E.A., Pontes, R.M., (2002) J. Mol. Struct. (Theochem), 594, p. 199Briggs, R.S., O'Hagan, D., Howard, J.A.K., Yufit, D.S., (2003) J. Fluorine Chem., 119, p. 9Tormena, C.F., Rittner, R., Abraham, R.J., Basso, E.A., Pontes, R.M., (2000) J. Chem. Soc. Perkin Trans., 2, p. 2054Tormena, C.F., Amadeu, N.S., Rittner, R., Abraham, R.J., (2002) J. Chem. Soc. Perkin Trans., 2, p. 773Olivato, P.R., Guerrero, S.A., Yreijo, M.H., Rittner, R., Tormena, C.F., (2002) J. Mol. Struct., 607, p. 87Martins, M.A.P., Rittner, R., Olivato, P.R., (1981) Spectrosc. Lett., p. 505Klapstein, D., Olivato, P.R., Oike, F., Martins, M.A.P., Rittner, R., (1988) Can. J. Spectrosc., 33, p. 161Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Zakrzewski, V.G., Pople, J.A., (1998) Gaussian 98, Revision A.7, , Gaussian, PittsburghPeterson, K.A., Figgen, D., Goll, E., Stoll, H., Dolg, M., (2003) J. Chem. Phys., 119, p. 11113Extensible Computational Chemistry Environment Basis Set Database, Version 02/25/04, , http://www.emsl.pnl.gov/forms/basisform.htmlGlendening, E.D., Reed, A.E., Carpenter, J.E., Weinhold, F., NBO Version 3.1, , (Included in the Gaussian 98 package of programsRef. [23])Brunck, T.K., Weinhold, F., (1979) J. Am. Chem. Soc., 101, p. 1700Goodman, L., Gu, H., Pophristic, V., (2005) J. Phys. Chem., 109, p. 1223Weinhold, F., (2001) Nature, 411, p. 539Tormena, C.F., Freitas, M.P., Rittner, R., Abraham, R.J., (2004) J. Phys. Chem. a, 108, p. 5161Freitas, M.P., Tormena, C.F., Rittner, R., Abraham, R.J., (2003) Spectrochim. Acta a, 59, p. 1783Bodot, H., Dicko, D.D., Gounelle, Y., (1967) Bull. Soc. Chim. Fr., p. 870Olivato, P.R., Rittner, R., (1996) Rev. Heteroat. Chem., 15, p. 11
Experimental And Theoretical Studies Of Intramolecular Hydrogen Bonding In 3-hydroxytetrahydropyran: Beyond Aim Analysis
No full textThe conformational preferences of 3-hydroxytetrahydropyran (1) were evaluated using infrared and nuclear magnetic resonance spectroscopic data in solvents of different polarities. Theoretical calculations in the isolated phase and including the solvent effect were performed, showing that the most stable conformations for compound 1 are those containing the substituent in the axial and equatorial orientations. The axial conformation is more stable in the isolated phase and in a nonpolar solvent, while the equatorial conformation is more stable than the axial in polar media. The occurrence of intramolecular hydrogen-bonded O-H⋯O in the axial conformer was detected from infrared spectra in a nonpolar solvent at different concentrations. Our attempt to evaluate this interaction using population natural bond orbital and topological quantum theory of atoms in molecules analyses failed, but topological noncovalent interaction analysis was capable of characterizing it. © 2014 American Chemical Society.1181527942800Eliel, E.L., Samuel, H.W., Doyle, M.P., (2001) Basic Organic Stereochemistry, , Wiley-Interscience: New YorkCortéz-Guzman, F., Hernández-Trujillo, J., Cuevas, G., The Nonexistence of Repulsive 1,3-diaxial Interactions in Monosubstituted Cyclohexanes (2003) J. Phys. Chem. A, 107, pp. 9253-9256Ribeiro, D.S., Rittner, R., The Role of Hyperconjugation in the Conformational Analysis of Methylcyclohexane and Methylheterocyclohexanes (2003) J. Org. Chem., 68, pp. 6780-6787Taddei, F., Kleinpeter, E., The Anomeric Effect in Substituted Cyclohexanes. I. The Role of Hyperconjugative Interactions and Steric Effect in Monosubstituted Cyclohexanes (2004) J. Mol. Struct.: THEOCHEM, 683, pp. 29-41Freitas, M.P., Tormena, C.F., Rittner, R., Interaction in trans-2-Halocyclohexanols-an Infraredand Theoretical Study (2001) J. Mol. Struct., 570, pp. 175-180Freitas, M.P., Tormena, C.F., Oliveira, P.R., Rittner, R., Halogenated Six-Membered Rings: A Theoretical Approach for Substituent Effects in Conformational Analysis (2002) J. Mol. Struct.: THEOCHEM, 589-590, pp. 147-151Freitas, M.P., Tormena, C.F., Luizar, C., Ferreira, M.M.C., Rittner, R., Substituent Interactions in trans -2-Substituted Methoxycyclohexanes: An Explanation to the Conformational Behaviour in a Chemometric and Theoretical View (2002) J. Mol. Struct. THEOCHEM, 618, pp. 219-224Freitas, M.P., Tormena, C.F., Rittner, R., Abraham, R.J., Conformational Analysis of trans -2-Halocyclohexanols and their Methyl Ethers: A 1H NMR, Theoretical and Solvation Approach (2003) J. Phys. Org. Chem., 16, pp. 27-33Freitas, M.P., Tormena, C.F., Rittner, R., Abraham, R.J., Conformational Properties of trans -2-Halo-acetoxycyclohexanes: 1H NMR, Solvation and Theoretical Investigation (2005) J. Mol. Struct., 734, pp. 211-217Freitas, M.P., Rittner, R., Tormena, C.F., Abraham, R.J., Conformational Analysis and Stereoelectronic Effects in trans -1,2-Dihalocyclohexanes: 1H NMR and Theoretical Investigation (2005) Spectrochim. Acta, Part A, 61, pp. 1771-1776Bocca, C.C., Basso, E.A., Fiorin, B.C., Tormena, C.F., Dos Santos, F.P., Conformational Behavior of cis -2-Methoxy, cis -2-Methylthio, and cis -2-Methylselenocyclohexanol: A Theoretical and Experimental Investigation (2006) J. Phys. Chem. A, 110, pp. 9438-9442Cedran, J.C., Dos Santos, F.P., Basso, E.A., Tormena, C.F., Conformational Preferences of 2-Methoxy, 2-Methylthio, and 2-Methylselenocyclohexyl- N, N -dimethylcarbamate: A Theoretical and Experimental Investigation (2007) J. Phys. Chem. A, 111, pp. 11701-11705Basso, E.A., Abiko, L.A., Gauze, G.F., Pontes, R.M., Conformational Analysis of cis -2-HalocyclohexanolsSolvent Effects by NMR and Theoretical Calculations (2011) J. Org. Chem., 76, pp. 145-153Silla, J.M., Cormanich, R.A., Duarte, C.J., Freitas, M.P., Ramalho, T.C., Barbosa, T.M., Santos, F.P., Rittner, R., Alkyl Group Effect on the Conformational Isomerism of trans -2-Bromoalkoxycyclohexanes Analyzed by NMR Spectroscopy and Theoretical Calculation (2011) J. Phys. Chem. A, 115, pp. 10122-10127Basso, E.A., Kaiser, C., Rittner, R., Lambert, J.B., Axial Equatorial Proportions for 2-Substituted Cyclohexanones (1993) J. Org. Chem., 58, pp. 7865-7869Freitas, M.P., Rittner, R., Tormena, C.F., Abraham, R.J., Conformational Analysis of 2-Bromocyclohexanone. A Combined NMR, IR, Solvation and Theoretical Approach (2001) J. Phys. Org. Chem., 14, pp. 317-322Yoshinaga, F., Tormena, C.F., Freitas, M.P., Rittner, R., Abraham, R.J., Conformational Analysis of 2-Halocyclohexanones: An NMR, Theoretical and Solvation Study (2002) J. Chem. Soc., Perkin Trans.2, pp. 1494-1498Freitas, M.P., Tormena, C.F., Garcia, J.C., Rittner, R., Abraham, R.J., Basso, E.A., Santos, F.P., Cedran, J.C., NMR, Solvation and Theoretical Investigations of Conformational Isomerism in 2-X-cyclohexanones (X=NMe2, OMe, SMe and SeMe) (2003) J. Phys. Org. Chem., 16, pp. 833-838Coelho, J.V., Freitas, M.P., Tormena, C.F., Rittner, R., On the4 JHH Long-range Coupling in 2-Bromocyclohexanone: Conformational Insights (2009) Magn. Reson. Chem., 47, pp. 348-351Coelho, J.V., Freitas, M.P., Ramalho, T.C., Martins, C.R., Bitencourt, M., Carmanich, R.A., Tormena, C.F., Rittner, R., The Case of Infrared Carbonyl Stretching Intensities of 2-Bromocyclohexanone: Conformational and Intermolecular Interaction Insights (2010) Chem. Phys. Lett., 494, pp. 26-30Anizelli, P.R., Vilcachagua, J.D., Cunha Neto, A., Tormena, C.F., Stereoelectronic Interaction and Their Effects on Conformational Preference for 2-Substituted Methylenecyclohexane: An Experimental and Theoretical Investigation (2008) J. Phys. Chem. A, 112, pp. 8785-8789Alabugin, I.V., Gilmore, K.M., Peterson, P.W., Hyperconjugation (2011) Wiley Interdiscip. Rev.: Comput. Mol. Sci., 1, pp. 109-141Ha, S., Gao, J., Tidor, B., Brady, J.W., Karplus, M., Solvent Effect on the Anomeric Equilibrium in D-glucose: A Free Energy Simulation Analysis (1991) J. Am. Chem. Soc., 113, pp. 1553-1557Cramer, C.J., Anomeric and Reverse Anomeric Effects in the Gas Phase and Aqueous Solution (1992) J. Org. Chem., 57, pp. 7034-7043Mo, Y., Computational Evidence that Hyperconjugative Interactions are not Responsible for the Anomeric Effect (2010) Nat. Chem., 2, pp. 666-671Huang, Y., Zhong, A.-G., Yang, Q., Liu, S., Origin of Anomeric Effect: A Density Functional of Steric Analysis (2011) J. Chem. Phys., 134, pp. 84103-84109Bauerfeldt, G.F., Cardozo, T.M., Pereira, M.S., Da Silva, C.O., The Anomeric Effect: The Dominance of Exchange Effects in Closed-Shell Systems (2013) Org. Biomol. Chem., 11, pp. 299-308Cocinero, E.J., Çarçabal, P., Vaden, T.D., Simons, J.P., Davis, B.G., Sensing the Anomeric Effect in a Solvent-Free Environment (2011) Nature, 469, pp. 76-80Freitas, M.P., Simultaneous Gauche and Anomeric Effects in α-Substituted Sulfoxides (2012) J. Org. Chem., 77, pp. 7607-7611Freitas, M.P., The Anomeric Effect on the Basis of Natural Bond Orbital Analysis (2013) Org. Biomol. Chem., 11, pp. 2885-2890Sugai, T., Lkeda, H., Ohta, H., Biocatalytic Approaches to Both Enantiomers of (2R*,3S*)-2- Allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol (1996) Tetrahedron, 52, pp. 8123-8134Kosjek, B., Nti-Gyabaah, J., Telari, K., Dunne, L., Moore, J.C., Preparative Asymmetric Synthesis of 4,4-Dimethoxytetrahydro-2 H -pyran-3-ol with a Ketone Reductase and in Situ Cofactor Recycling using Glucose Dehydrogenase (2008) Org. Process Res. Dev., 12, pp. 584-588Sugawara, K., Imanishi, Y., Hashiyama, T., Efficient and Practical Synthesis of both Enantiomers of 6-Silyloxy-3-pyranone Derivatives (2000) Tetrahedron: Asymmetry, 11, pp. 4529-4535Chan, W.N., Evans, J.M., Hadley, M.S., Morgan, H.K.A., Stean, T.O., Thompson, M., Upton, N., Vong, A.K., Synthesis of Novel trans -4-(Substitutedbenzamido)-3,4-dihydro-2 H -benzo[ b ]-pyran-3-ol Derivatives as Potential Anticonvulsant Agents with a Distinctive Binding Profile (1996) J. Med. Chem., 39, pp. 4537-4539Sasaerila, Y., Gries, R., Gries, G., Khaskin, G., King, S., Takács, S., Hardi, Sex Pheromone Components of Male Tirathabamundella (Lepidoptera: Pyralidae) (2003) Chemoecology, 13, pp. 89-93Barker, S.A., Brimacombe, J.S., Foster, A.B., Whiffen, D.H., Zweifel, G., Intramolecular Hydrogen Bonding in some Monohydroxy Derivatives of Tetrahydrofuran, Tetrahydropyran and 1,3-dioxan (1959) Tetrahedron, 7, pp. 10-18Møller, C., Plesset, M.S., Note on an approximation treatment for many-electron systems (1934) Phys. Rev., 46, pp. 618-622Head-Gordon, M., Pople, J.A., Frisch, M.J., MP2 energy evaluation by direct methods (1988) Chem. Phys. Lett., 153, pp. 503-506Purvis III, G.D., Bartlett, R.J., A full coupled-cluster singles and doubles model: The inclusion of disconnected triples (1982) J. Chem. Phys., 76, pp. 1910-1918Weinhold, F., Natural Bond Orbital Analysis: A Critical Overview of Relationships to Alternative Bonding Perspectives (2012) J. Comput. Chem., 33, pp. 2363-2379Bader, R.F.W., (1990) Atoms in Molecules: A Quantum Theory, , Clarendon: Oxford, U.KJohnson, E.R., Keinan, S., Mori-Sánchez, P., Contreras-García, J., Cohen, A.J., Yang, W., Revealing Noncovalent Interactions (2010) J. Am. Chem. Soc., 132, pp. 6498-6506Frisch, M.J., (2009) Gaussian 09, , revision D.01Gaussian, Inc. Wallingford, CTGeertsen, J., Oddershede, J., 2nd-Order Polarization Propagator Calculations of Indirect Nuclear Spin-Spin Coupling Tensors in the Water Molecule (1984) Chem. Phys., 90, pp. 301-311Enevoldsen, T., Oddershede, J., Sauer, S.P.A., Correlated Calculations of Indirect Nuclear Spin-Spin Coupling Constants using Second-Order Polarization Propagator Approximations: SOPPA and SOPPA(CCSD) (1998) Theor. Chem. Acc., 100, pp. 275-284Sauer, S.P.A., Second-Order Polarization Propagator Approximation with Coupled-Cluster Singles and Doubles Amplitudes-SOPPA(CCSD): The Polarizability and Pyperpolarizability of Li- (1997) J. Phys. B: At., Mol. Opt. Phys., 30, pp. 3773-3780(2011), http://daltonprogram.org, Dalton2011, A Molecular Electronic Structure ProgramBarone, V., (1996) Recent Advances in Density Functional Methods, Part i, , Chong, D. P. World Scientific Publ. Co. SingaporeGlendening, E.D., Badenhoop, J.K., Reed, A.E., Carpenter, J.E., Bohmann, J.A., Morales, C.M., Landis, C.R., Weinhold, F., (2013) NBO 6.0, , Theoretical Chemistry Institute, University of Wisconsin, Madison: Madison, WI, Program implemented in the Gaussian 09 packageKeith, T.A., (2011) AIMALL, , aim.tkgristmill.comh, version 11.10.16TK Gristmill Software: Overland Park, KSContreras-García, J., Johnson, E.R., Keinan, S., Chaudret, R., Piquemal, J.-P., Beratan, D.N., Yang, W., NCIPLOT: A Program for Plotting Noncovalent Interaction Regions (2011) J. Chem. Theory Comput., 7, pp. 625-632Zweifel, G., Plamondon, J., Hydroboration of Dihydropyrans and Dihydrofurans (1970) J. Org. Chem., 35, pp. 898-902Marenich, A.V., Cramer, C.J., Truhlar, D.G., Universal Solvation Model Based on Solute Electron Density and on a Continuum Model of the Solvent Defined by the Bulk Dielectric Constant and Atomic Surface Tensions (2009) J. Phys. Chem. B, 113, pp. 6378-6396Abraham, R.J., Jones, A.D., Warne, M.A., Rittner, R., Tormena, C.F., Conformational Analysis. Part 27. NMR, Solvation and Theoretical Investigation of Conformational Isomerism in Fluoro- and l,l-difluoro-acetone (1996) J. Chem. Soc., Perkin Trans 2, pp. 533-539Helgaker, T., Jaszuński, M., Pecul, M., The Quantum-Chemical Calculation of NMR Indirect Spin-Spin Coupling Constants (2008) Prog. Nucl. Magn. Reson. Spectrosc., 53, pp. 249-268Conley, R.T., (1972) Infrared Spectroscopy, pp. 129-131. , 2 nd ed. Allyn and Bacon: BostonLane, J.R., Contreras-García, J., Piquemal, J.-P., Miller, B.J., Kjaergaard, H.G., Are Bond Critical Points Really Critical for Hydrogen Bonding? (2013) J. Chem. Theory Comput., 9, pp. 3263-3266Grabowski, S.J., What Is the Covalency of Hydrogen Bonding? (2011) Chem. Rev., 111, pp. 2597-262
Effect Of Sulfur Oxidation On The Transmission Mechanism Of4jhh Nmr Coupling Constants In 1,3-dithiane
No full textLong-range 4JHH couplings in 1,3-dithiane derivatives are rationalized in terms of the effects of hyperconjugative interactions involving the S=0 group. Theoretical and experimental studies of 4JHH couplings were carried out in 1,3-dithiane-l-oxide (2), cw-l,3-dithiane-l,3-dioxide (3), l,3-dithiane-l,l,3-trioxide (4), and 1,3-dithiane-1,1,3,3-tetraoxide (5) compounds. Hyperconjugative interactions were studied with the natural bond orbital, NBO, method. Hyperconjugative interactions involving the LP O, oxygen lone pair and σ*C2-S1 and σ*S1-C6 antibonding orbitals yield an increase of 4JHeq-Heq couplings. Long-range 4JHax-Hax couplings were also observed between hydrogen atoms in axial orientation, which are rationalized as originating in hyperconjugative interactions involving the bonding σC6-h axand antibonding σ*S=O orbitals. The symmetry for orbital interactions is possible only when the S=0 group is in the axial orientation. © 2009 American Chemical Society.1131126472651Soncini, A., Lazzeretti, P., (2003) J. Chem. Phys, 119, p. 1343Castillo, N., Matta, C.F., Boyd, R.J., (2005) J. Chem. Inf. Model, 45, p. 354Krivdin, L.B., Contreras, R.H., (2007) Annu. Rep. NMR Spectrosc, 61, p. 133Karplus, M., (1959) J. Chem. Phys, 30, p. 11Karplus, M., (1963) J. Am. Chem. Soc, 85, p. 2870Juaristi, E., Cuevas, G., (2007) Acc. Chem. Res, 40, p. 961Contreras, R.H., Esteban, A.L., Diez, E., Delia, E.W., Lochert, I.J., dos Santos, F.P., Tormena, C.F., (2006) J. Phys. Chem. A, 110, p. 4266Kleinpeter, E., Koch, A., Pihlaja, K., (2005) Tetrahedron, 61, p. 7349Perez, C., Suardíaz, R., Ortiz, P.J., Crespo-Otero, R., Bonetto, G.M., Gavín, J.A., García de la Vega, J.M., Contreras, R.H., (2008) Magn. Reson. Chem, 46, p. 846dos Santos, F.P., Tormena, C.F., Contreras, R.H., Rittner, R., Magalhães, A., (2008) Magn. Reson. Chem, 46, p. 107Aydin, R., Giinther, H., (1990) Magn. Reson. Chem, 28, p. 448Pedersoli, S., dos Santos, F.P., Rittner, R., Contreras, R.H., Tormena, C.F., (2008) Magn. Reson. Chem, 46, p. 202Tóth, G., Kovács, J., Lévai, A., Kleinpeter, E., Koch, A., (2001) Magn. Reson. Chem, 39, p. 251Kovács, J., Tóth, G., Simon, A., Lévai, A., Koch, A., Kleinpeter, E., (2003) Magn. Reson. Chem, 41, p. 193Heydenreich, M., Koch, A., Kovács, J., Tóth, G., Kleinpeter, E., (2004) Magn. Reson. Chem, 42, p. 667Anizelli, P.R., Vilcachagua, J.D., Cunha Neto, A., Tormena, C.F., (2008) J. Phys. Chem. A, 112, p. 8785Cedran, J.C., dos Santos, F.P., Basso, E.A., Tormena, C.F., (2007) J. Phys. Chem. A, 111, p. 11701Tormena, C.F., dos Santos, F.P., Cunha Neto, A., Rittner, R., Yoshinaga, F., Temístocles, J.C.T., (2007) J. Phys. Chem. A, 111, p. 295Sega, E.M., Tormena, C.F., Oliveira, P.R., Rittner, R., Tinoco, L.W., Figueroa-Villar, J.D., Hoer, N.F., (2006) J. Mol. Struct, 797, p. 44Bocca, C.C., Basso, E.A., Fiorin, B.C., Tormena, C.F., dos Santos, F.P., (2006) J. Phys. Chem. A, 110, p. 9438Sproviero, E.M., Ferrara, A., Contreras, R.H., Burton, G., (1996) J. Chem. Soc, Perkin Trans. 2, p. 933Garbisch, E.W., (1964) J. Am. Chem. Soc, 86, p. 5561Garbisch, E.W., Griffith, M.G., (1968) J. Am. Chem. Soc, 90, p. 3590Dias, L.C., Ferreira, M.A.B., Tormena, C.F., (2008) J. Phys. Chem. A, 112, p. 232Reed, A.L., Curtiss, L.A., Weinhold, F., (1988) Chem. Rev, 88, p. 899Juaristi, E., Notario, R., Roux, M.V., (2005) Chem. Soc. Rev, 34, p. 347Roux, M.V., Temprado, M., Jimenez, P., Davalos, J.Z., Notario, R., Guzman-Mejia, R., Juaristi, E., (2003) J. Org. Chem, 68, p. 1762Roux, M.V., Temprado, M., Jimenez, P., Notario, R., Guzman-Mejia, R., Juaristi, E., (2004) J. Org. Chem, 69, p. 1670Roux, M.V., Temprado, M., Jimenez, P., Davalos, J.Z., Notario, R., Martin-Valcarcel, G., Garrido, L., Juaristi, E., (2004) J. Org. Chem, 69, p. 5454Roux, M.V., Temprado, M., Jimenez, P., Notario, R., Guzman-Mejia, R., Juaristi, E., (2006) J. Org. Chem, 71, p. 2581Roux, M.V., Temprado, M., Jimenez, P., Notario, R., Guzman-Mejia, R., Juaristi, E., (2007) J. Org. Chem, 72, p. 1143Gauze, G.F., Tormena, R., Basso, E.A., Tormena, C.F., (2006) Chem. Phys. Lett, 426, p. 176Wedel, T., Muller, M., Podlech, J., Goesmann, H., Feldmann, C., (2007) Chem.-Eur. J, 13, p. 4273Wedel, T., Gehring, T., Podlech, J., Kordel, E., Bihlmeier, A., Klopper, W., (2008) Chem.-Eur. J, 14, p. 4631Juaristi, E., Cuevas, J.G., Vela, A., (1994) J. Am. Chem. Soc, 116, p. 5796Cuevas, G., Juaristi, E., (2002) J. Am. Chem. Soc, 124, p. 13088Martinez-Mayorga, K., Juaristi, E., Cuevas, G., (2004) J. Org. Chem, 69, p. 7266Notario, R., Roux, M.V., Cuevas, G., Cardenas, J., Leyva, V., Juaristi, E., (2006) J. Phys. Chem. A, 110, p. 7703Abraham, R.J., Fisher, J., Loftus, P., (1988) Introduction to NMR spectroscopy, , John Wiley & Sons: ChichesterContreras, R.H., Peralta, J.E., (2000) Prog. NMR Spectrosc, 37, p. 321Wiberg, K.B., Conner, D.S., (1966) J. Am. Chem. Soc, 88, p. 4437Wiberg, K.B., Williams, V.Z., (1970) J. Org. Chem, 35, p. 369Lazzeretti, P., Malagoli, M., Zanasi, R., Delia, E.W., Lochert, I.J., Giribet, C.G., Ruiz de Azúa, M.C., Contreras, R.H., (1995) J. Chem. Soc, Faraday Trans, 91, p. 4031Perez, J.E., Ortiz, F.S., Contreras, R.H., Giribet, C.G., Ruiz de Azua, M.C., (1990) J. Mol. Struct. Theochem, 210, p. 193Parella, T., Sánchez-Ferrando, F., Virgili, A., (1994) Magn. Reson. Chem, 32, p. 657dos Santos, F.P., Tormena, C.F., Contreras, R.H., Rittner, R., Magalhães, A., (2008) Magn. Reson. Chem, 46, p. 107Barfield, M., Chakrabarti, B., (1969) Chem. Rev, 69, p. 757Thomas, W.A., (1997) Prog. NMR Spectrosc, 30, p. 183Becke, A.D., (1988) Phys. Rev. A, 38, p. 3098Becke, A.D., (1993) J. Chem. Phys, 98, p. 5648Lee, C.T., Yang, W.T., Parr, R.G., (1988) Phys. Rev. B, 37, p. 785Dunning, T.H., Peterson, K.A., Wonn, D.E., (1998) Encyclopedia of Computational Chemistry, 1, p. 88. , Wiley: New YorkFrisch, M. J, Trucks, G. W, Schlegel, H. B, Scuseria, G. E, Robb, M. A, Cheeseman, J. R, Montgomery, J. A, Jr, Vreven, T, Kudin, K. N, Burant, J. C, Millam, J. M, Iyengar, S. S, Tomasi, J, Barone, V, Mennucci, B, Cossi, M, Scalmani, G, Rega, N, Petersson, G. A, Nakatsuji, H, Hada, M, Ehara, M, Toyota, K, Fukuda, R, Hasegawa, J, Ishida, M, Nakajima, T, Honda, Y, Kitao, O, Nakai, H, Klene, M, Li, X, Knox, J. E, Hratchian, H. P, Cross, J. B, Bakken, V, Adamo, C, Jaramillo, J, Gomperts, R, Stratmann, R. E, Yazyev, O, Austin, A. J, Cammi, R, Pomelli, C, Ochterski, J. W, Ayala, P. Y, Morokuma, K, Voth, G. A, Salvador, P, Dannenberg, J. J, Zakrzewski, V. G, Dapprich, S, Daniels, A. D, Strain, M. C, Farkas, O, Malick, D. K, Rabuck, A. D, Raghavachari, K, Foresman, J. B, Ortiz, J. V, Cui, Q, Baboul, A. G, Clifford, S, Cioslowski, J, Stefanov, B. B, Liu, G, Liashenko, A, Piskorz, P, Komaromi, I, Martin, R. L, Fox, D. J, KeitReed, A.L., Curtiss, L.A., Weinhold, F., (1988) Chem. Rev, 88, p. 899Sychrovshý, V., Gräfenstein, J., Cremer, D., (2000) J. Chem. Phys, 113, p. 3530Barone, V., (1994) J. Chem. Phys, 101, p. 6834Peralta, J.E., Scuseria, G.E., Cheeseman, J.R., Frisch, M.J., (2003) Chem. Phys. Lett, 375, p. 452Carlson, R.M., Helquist, P.M., (1968) J. Org. Chem, 33, p. 2596Miranda, P., Zukerman-Schpector, J., Isolani, P.C., Vicentini, G., Zinner, L.B., (2001) J. Alloys. Compd, 323-324, p. 13Aggarwal, V.K., Davies, I.W., Franklin, R.J., Maddock, J., Mahon, M.F., Molloy, K.C., (1991) J. Chem. Soc, Perkin Trans 1, p. 662Bien, S., Celebi, S.K., Kapon, M., (1987) J. Chem. Soc, Perkin Trans. 2, 1990Khan, A.S., Lambert, J.B., Hernandez, O., Carey, F.A., (1975) J. Am. Chem. Soc, 97, p. 1468Yavari, I., Haghdadi, M., Amiri, R., (2006) Phosphorus, Sulfur Silicon Relat. Elem, 181, p. 196
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Spectroscopic and theoretical studies of some N-methoxy-N-methyl-2-[(4 `-substituted) phenylthio]propanamides
No full textThe analysis of the IR carbonyl band of the N-methoxy-N-methyl-2-[(4`-substituted)phenylthio]propanamides Y-PhSCH(Me)C(O)N(OMe)Me (Y=OMe 1, Me 2, H 3, Cl 4, NO(2) 5), supported by B3LYP/cc-pVDZ calculations of 3, indicated the existence of two gauche conformers (g(1) and g(2)), the g(1) conformer being the more stable and the less polar one (in gas phase and in solution). Both conformers are present in solution of the polar solvents (CH(2)Cl(2) and CH(3)CN) for 1-5 and in solution of the less polar solvent (CHCl(3)) for 1-4, while only the g(1) conformer is present in solution of non polar solvents (n-C(6)H(14) and CCl(4)) and in solution of CHCl(3) for 5. NBO analysis shows that both the sigma(C-S) -> pi*(C=O) (hyperconjugative) and the pi(C=O) -> sigma*(C-S) orbital interactions contribute almost to the same extent for the stabilization of g(1) and g(2) conformers. The pi*(C=O) -> sigma*(C-S), n(S) -> pi*(C=O) and the n(S) -> pi*(C=O) orbital interactions stabilize more the g(1) conformer than the g(2) one. Moreover, the suitable geometry of the g(1) conformer leads to its stabilization through the LP(O2) -> sigma*(C8-H11) orbital interaction (hydrogen bond) along with the strong O([CO])(delta-) center dot center dot center dot H([O-Ph])(delta+) electrostatic interaction. On the other hand, the appropriate geometry of the g(2) conformer leads to its stabilization by the LP(O22) -> sigma*(C9-H13) orbital interaction (hydrogen bond) along with the weak O([OMe])(delta-) center dot center dot center dot H([o`-Ph])(delta+) electrostatic static interaction. As for the 4`-nitro derivative 5 the ortho-phenyl hydrogen atom becomes more acidic, leading to a stronger O([CO])(delta-) center dot center dot center dot H([o-Ph])(delta+) interaction and, thus, into a larger stabilization of the g(1) conformer in the whole series. This trend is responsible for the unique IR carbonyl band in CHCl(3) solution of 5. The larger occupancy of the pi*(C=O) orbital of the g(1) conformer relative to that of the g(2) conformer, along with the O([CO])(delta-) center dot center dot center dot H([o-Ph])(delta+) electrostatic interaction (hydrogen bond) justifies the lower carbonyl frequency of the g(1) conformer with respect to the g(2) one, in gas phase and in solution. (C) 2008 Elsevier B.V. All rights reserved.University of FerraraUniversity of Ferrar
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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