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Full-Text Articles in Physical Sciences and Mathematics
Theoretical Studies Of The Reactions Xhn → Xhn-1- + H+ And Xhn-1- + Sih4 → [Sih4xhn-1]-, Mark S. Gordon, Larry P. Davis, Larry W. Burggraf, Robert Damrauer
Theoretical Studies Of The Reactions Xhn → Xhn-1- + H+ And Xhn-1- + Sih4 → [Sih4xhn-1]-, Mark S. Gordon, Larry P. Davis, Larry W. Burggraf, Robert Damrauer
Mark S. Gordon
Ab initio and MNDO calculations have been carried out to evaluate the gas-phase acidities of closed-shell XHn compounds (X= C, N, 0, F, Si, P, S, Cl) and the affinities of silane for the XHn_1- anions. Fourth-order perturbation theory with extended basis sets reproduces the experimental gas-phase acidities to within 2 kcaljmol. Stable pentacoordinated silicon anions are found for X = H, C, N, 0, and F. In contrast, only marginally stable charge-dipole complexes are found for X = Si, S, and Cl.
On The Glass Transition And Viscosity Of Phosphorus Pentoxide, C. A. Angell, Steve W. Martin
On The Glass Transition And Viscosity Of Phosphorus Pentoxide, C. A. Angell, Steve W. Martin
Steve W. Martin
The calorimetric glass transition temperature Tg for pure anhydrous P2Os melted in sealed Si02 ampules at 1000 “C has been obtained directly for the first time with differential scanning calorimetry, and the increase in heat capacity at Tg has been determined. Tg measured in this way is 57 K higher than the value quoted in the literature, which is probably based on an Arrhenius law extrapolation of viscosity data to 9 = lOI3 P. Combining the high-temperature viscosity data with the common observation that, for oxide glasses, 7 = 10l2 P at the DSC Tg, we find that the P,O, …
Iupac 7th International Symposium On Cationic Polymerization And Related Processes, Otto Vogl, Dietmar Lohmann
Iupac 7th International Symposium On Cationic Polymerization And Related Processes, Otto Vogl, Dietmar Lohmann
Otto Vogl
No abstract provided.
Centers Of Polymer Chemistry In Czechoslovakia 1: Institute Of Macromolecular Chemistry, Prague, Czechoslovakia, Otto Vogl, Vladimir Kubanek, Jan Sebenda
Centers Of Polymer Chemistry In Czechoslovakia 1: Institute Of Macromolecular Chemistry, Prague, Czechoslovakia, Otto Vogl, Vladimir Kubanek, Jan Sebenda
Otto Vogl
No abstract provided.
Polymer Science And Engineering In Universities Of The People's Republic Of China: South Of The Yangtze River - Part Ii, Otto Vogl, T. Y. Yu, S. L. Yang
Polymer Science And Engineering In Universities Of The People's Republic Of China: South Of The Yangtze River - Part Ii, Otto Vogl, T. Y. Yu, S. L. Yang
Otto Vogl
No abstract provided.
Second U.S.-Sweden Workshop On Photochemistry Of Polymers, Otto Vogl, Ann Christine Albertsson, Bengt Ranby
Second U.S.-Sweden Workshop On Photochemistry Of Polymers, Otto Vogl, Ann Christine Albertsson, Bengt Ranby
Otto Vogl
No abstract provided.
Polymer Science At Universities Of The German Democratic Republic, Otto Vogl, Margit T. Raetzsch, Werner Berger, Guenther Heublein, Joachim Ulbricht
Polymer Science At Universities Of The German Democratic Republic, Otto Vogl, Margit T. Raetzsch, Werner Berger, Guenther Heublein, Joachim Ulbricht
Otto Vogl
No abstract provided.
Vth International Congress Aplichem "85 International Chemistry Fair, Incheba, 1985, In Bratislava, Otto Vogl, Michal Ilavski, Eberhard Borsig
Vth International Congress Aplichem "85 International Chemistry Fair, Incheba, 1985, In Bratislava, Otto Vogl, Michal Ilavski, Eberhard Borsig
Otto Vogl
No abstract provided.
Scaling All Correlation Energy In Perturbation Theory Calculations Of Bond Energies And Barrier Heights, Mark S. Gordon, Donald G. Truhlar
Scaling All Correlation Energy In Perturbation Theory Calculations Of Bond Energies And Barrier Heights, Mark S. Gordon, Donald G. Truhlar
Mark S. Gordon
We present and test a new method for scaling all correlation energy as estimated by M0ller-Plesset many-body perturbation theory with popular basis sets. Scale factors that may be useful for future applications are estimated from known bond dissociation energies. We also use scale factors to estimate the barrier heights for two hydrogen-transfer reactions, CH3 + H2 = CH4 + H and OH + CH4 = H20 + CH3•
Makromolekulares Kolloquium Freiburg, Otto Vogl, Hans-Joachim Cantow
Makromolekulares Kolloquium Freiburg, Otto Vogl, Hans-Joachim Cantow
Otto Vogl
No abstract provided.
Iupac Polymer Chemistry Meeting, Leuven, Belgium, Otto Vogl, Marcel Van Beylen, Frans C. Deschryver
Iupac Polymer Chemistry Meeting, Leuven, Belgium, Otto Vogl, Marcel Van Beylen, Frans C. Deschryver
Otto Vogl
No abstract provided.
A Refined Model For The Space-Charge Layer In Composite Electrolyte Systems, Michael Setter
A Refined Model For The Space-Charge Layer In Composite Electrolyte Systems, Michael Setter
Michael P. Setter
No abstract provided.
Japan-U.S. Polymer Symposium, Kyoto, Japan 1985, Jane C. Vogl, T. Takahiko
Japan-U.S. Polymer Symposium, Kyoto, Japan 1985, Jane C. Vogl, T. Takahiko
Otto Vogl
No abstract provided.
Quantum Monte Carlo Study Of A Lattice Atom Model For Excitonic Fluids, Randall W. Hall, Peter G. Wolynes
Quantum Monte Carlo Study Of A Lattice Atom Model For Excitonic Fluids, Randall W. Hall, Peter G. Wolynes
Randall W. Hall
G. N. Lewis' Atom And Quantum Monte Carlo Studies Of Liquids, Randall W. Hall, Peter G. Wolynes
G. N. Lewis' Atom And Quantum Monte Carlo Studies Of Liquids, Randall W. Hall, Peter G. Wolynes
Randall W. Hall
Potential Primary Pyrolysis Processes For Disilane, Mark S. Gordon, Thanh N. Truong, Elizabeth K. Bonderson
Potential Primary Pyrolysis Processes For Disilane, Mark S. Gordon, Thanh N. Truong, Elizabeth K. Bonderson
Mark S. Gordon
Four competing unimolecular decomposition pathways for disilane are considered with use of MP4 energies obtained with an extended basis set and geometries obtained at the MP2/6-31G** computational level. The 1,1- and 1,2-eliminations of H2 and the elimination of silylene to form silane all have similar endothermicities, but the very high activation energy for the I ,2-elimination eliminates this process as a significant contributor at low energies. If disilene is formed in the thermal decomposition of disilane, the more likely source is its higher energy isomer silylsilylene via a relatively low energy I ,2-hydrogen shift.
Thermal Decomposition Of Silane, Mark S. Gordon, David R. Gano, J. Stephen Binkley, Michael J. Frisch
Thermal Decomposition Of Silane, Mark S. Gordon, David R. Gano, J. Stephen Binkley, Michael J. Frisch
Mark S. Gordon
The essential features of the potential energy surface for the thermal decomposition of silane have been calculated with extended basis sets, augmented by correlation corrections. It is predicted that the transition state for the molecular elimination lies 56.9 kcaljmol above silane. For the reverse reaction, the transition state is less than 2 kcal/mol above the separated fragments, silylene and molecular hydrogen, but 4.8 kcal/mol above a long-range potential well. In the latter, the silylene-H2 separation is 1.78 A, and the bond in H2 has stretched by more than 0.05 A. This indicates a significant electronic interaction between the fragments even …
Theoretical Studies Of Reactions Of Silanimine (H2sinh) And Its Isomer Aminosilylene (Hsinh2), Thanh N. Truong, Mark S. Gordon
Theoretical Studies Of Reactions Of Silanimine (H2sinh) And Its Isomer Aminosilylene (Hsinh2), Thanh N. Truong, Mark S. Gordon
Mark S. Gordon
The structure and reactivity of unsaturated singlet silicon-nitrogen compounds is theoretically investigated. Ab initio calculations demonstrate that the planar silylene HSiNH2 is the global minimum on the SiNH3 surface, with the planar doubly bound species H2SiNH 18 kcaljmol higher in energy. The internal rotational barriers are computed to be 26.9 kcaljmol for HSiNH2 and 37.9 kcaljmol for H2SiNH. However, the barrier for the inversion of H2SiNH is only 5.6 kcaljmol, so that inversion is favored over rotation for this species. The isomerization connecting H2SiNH to HSiNH2 has a barrier of 60 kcaljmol. The transition-state structures, as well as the exothermicities …
Improvement Of Trace Aluminum Determination By Electrothermal Atomic Absorption Spectrophotometry Using Phosphoric Acid, Chris Craney, Kurt Swartout, F. Smith, C. West
Improvement Of Trace Aluminum Determination By Electrothermal Atomic Absorption Spectrophotometry Using Phosphoric Acid, Chris Craney, Kurt Swartout, F. Smith, C. West
Chris L. Craney
No abstract provided.
Electrochemical Reduction Of Alkyl Halides At Vitreous Carbon Cathodes In Dimethylformamide, James Cleary, Mohammed Mubarak, Kenneth Viera, Mark Anderson, Dennis Peters
Electrochemical Reduction Of Alkyl Halides At Vitreous Carbon Cathodes In Dimethylformamide, James Cleary, Mohammed Mubarak, Kenneth Viera, Mark Anderson, Dennis Peters
Mark R. Anderson
At vitreous carbon electrodes in dimethylformamide which contains tetramethylammonium perchlorate, cyclic voltammograms for 1-iododecane, 1-bromodecane, and 2-bromooctane consist of one irreversible reduction wave signaling formation of the alkyl carbanion, whereas voltammograms for 2-iodooctane, t-butyl bromide, and t-butyl iodide reveal stepwise generation of the alkyl radical and carbanion. Large-scale electrolysis of 1-iododecane at reticulated vitreous carbon yields decane, eicosane, 1-decene, and 1-decanol; the first two compounds arise, respectively, from reaction of decyl carbanions with a proton donor and with unreduced alkyl iodide, whereas the last two species are produced via chemical attack of hydroxide ion on 1-iododecane. Reduction of 1-bromodecane results …
Electrochemistry Of 1,1,4,4-Tetraphenyl-1,3-Butadiene, 1,1,4,4-Tetraphenyl-1,2-Butadiene, And 1,1,4,4-Tetraphenyl-1-Butene In Dimethylformamide, Tsu-Yu Chen, Mark Anderson, Dennis Peters
Electrochemistry Of 1,1,4,4-Tetraphenyl-1,3-Butadiene, 1,1,4,4-Tetraphenyl-1,2-Butadiene, And 1,1,4,4-Tetraphenyl-1-Butene In Dimethylformamide, Tsu-Yu Chen, Mark Anderson, Dennis Peters
Mark R. Anderson
In dimethylformamide containing tetra-n-butylammonium perchlorate, 1,1,4,4-tetraphenyl-1-butene exhibits a single polarographic wave; preparative-scale reduction of the starting material produces 1,1,4,4-tetraphenylbutane.A polarogram for 1,1,4,4-tetraphenyl-1,3-butadiene consists of three waves. Large-scale electrolysis of 1,1,4,4-tetraphenyl-1,3-butadiene at potentials corresponding to either the first or second wave yields 1,1,4,4-tetraphenyl-1-butene in the absence of a proton donor and a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenyl-1-butene in the presence of excess glacial acetic acid. If 1,1,4,4-tetraphenyl-1,3-butadiene is electrolyzed at a potential on the third polarographic wave, one obtains 1,1,4,4-tetraphenylbutane in the absence of a proton donor but a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenylbutane in the presence of glacial acetic acid. …
Π-Bond Strengths In Hp=Ph, H2p=P, Hp=Nh, And Hn=Nh, Michael W. Schmidt, Mark S. Gordon
Π-Bond Strengths In Hp=Ph, H2p=P, Hp=Nh, And Hn=Nh, Michael W. Schmidt, Mark S. Gordon
Mark S. Gordon
The chemistry of the HP=PH 1r bond found in the recently isolated diphosphene compounds is considered in several ways. The P=P 1r-bond strength is found by computing the rotation barrier (36 kcalfmol) and is compared to that found for HN=NH (63.5 kcalfmol) and HP=NH (47 kcalfmol). The structure of the HPPH anion is presented. Various electronic states of the H2PP isomer are considered and compared to those of HPPH. Dipole moments and PP stretching frequencies are reported. The concerted hydrogenation of diphosphene is also examined.
A Highly Enantioselective Hydrolysis Of -3,5-Diacetoxycyclopent-1-Ene, Donald Deardorff, A. Matthews, D. Mcmeekin, Chris Craney
A Highly Enantioselective Hydrolysis Of -3,5-Diacetoxycyclopent-1-Ene, Donald Deardorff, A. Matthews, D. Mcmeekin, Chris Craney
Chris L. Craney
Exposure of -3,5-diacetoxycyclopent-1-ene () to the hydrolase enzyme acetylcholinesterase (from electric eel) affords In 94% yield 3()-acetoxy-5()-hydroxycyclopent-1-ene () with an e.e. of 96% (greater than 99% e.e. after one recrystallization).
Nuclease Activity Of 1,10-Phenanthroline-Copper Ion: Reaction With Cgcgaattcgcg And Its Complexes With Netropsin And Ecori, Thomas Goyne, Michio Kuwabara, Chun Yoon, Theodore Thederahn, David Sigman
Nuclease Activity Of 1,10-Phenanthroline-Copper Ion: Reaction With Cgcgaattcgcg And Its Complexes With Netropsin And Ecori, Thomas Goyne, Michio Kuwabara, Chun Yoon, Theodore Thederahn, David Sigman
Thomas Goyne
No abstract provided.