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Open Access. Powered by Scholars. Published by Universities.®

2003

Chemistry

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Selected Works

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Non-Steady-State Approach #11;To Steady-State Kinetics: #11;Case Study Of H2s Oxidation By Oxygen, Andrey N. Zagoruiko, Vladimir V. Mokrinskii Nov 2003

Non-Steady-State Approach #11;To Steady-State Kinetics: #11;Case Study Of H2s Oxidation By Oxygen, Andrey N. Zagoruiko, Vladimir V. Mokrinskii

Andrey N Zagoruiko

Non-steady-state kinetic models may be used for treatment of steady-state kinetic data in case when algebraic elaboration of steady-state kinetic equations is impossible or complicated. The proposed approach includes numerical integration of time-dependent differential equations until achievement of steady-state, resulting in possibility to numerically obtain the rate values for separate reaction stages for given composition of reaction mixture. The obtained non-steady-state model may be then applied in simulation of catalyst pellets and catalyst beds in research and engineering purposes. The case study demonstrates application of such approach for steady-state kinetic description of complicated reaction system of H2S oxidation by oxygen. …

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Three-Dimensional Quantitative Structure−Property Relationship (3d-Qspr) Models For Prediction Of Thermodynamic Properties Of Polychlorinated Biphenyls (Pcbs): Enthalpies Of Fusion And Their Application To Estimates Of Enthalpies Of Sublimation And Aqueous Solubilities, Swati Puri, James S. Chickos, William J. Welsh Apr 2003

Three-Dimensional Quantitative Structure−Property Relationship (3d-Qspr) Models For Prediction Of Thermodynamic Properties Of Polychlorinated Biphenyls (Pcbs): Enthalpies Of Fusion And Their Application To Estimates Of Enthalpies Of Sublimation And Aqueous Solubilities, Swati Puri, James S. Chickos, William J. Welsh

James Chickos

No abstract provided.

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Raman Spectroscopy Of Rhombohedral P4o10, Sean J. Gilliam, Scott Kirkby, Clifton N. Merrow, Daniel Zeroka, Ajit Banerjee, James O. Jensen Mar 2003

Raman Spectroscopy Of Rhombohedral P4o10, Sean J. Gilliam, Scott Kirkby, Clifton N. Merrow, Daniel Zeroka, Ajit Banerjee, James O. Jensen

Scott J. Kirkby

A complete Raman vibrational analysis has been performed on phase-pure rhombohedral phosphorus pentoxide (P4O10) at room temperature. The “molecular” Td symmetry is reduced to C3v symmetry when bound in the rhombohedral crystalline lattice. Therefore, the 15 fundamental modes of vibration irreducibly represented as Γvib = 3A1 + 3E + 3T1 + 6T2 reduce to 21 fundamental modes with a factor group analysis resulting in Γvib = 9A1 + 12E for the irreducible representation, all of which are Raman active. Complete vibrational assignments and relative intensities, including all T2 to E and A1 splittings, are reported. Five new E fundamentals (262, …

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Heat Capacities Of Thiane Sulfones And Thiane Sulfoxide: Refining Of Cp Group Values For Organosulfur Compounds And Their Oxides, Marı́A Victoria Roux, Manuel Temprado, Pilar Jiménez, Ramón Guzmán-Mejı́A, Eusebio Juaristi, James S. Chickos Jan 2003

Heat Capacities Of Thiane Sulfones And Thiane Sulfoxide: Refining Of Cp Group Values For Organosulfur Compounds And Their Oxides, Marı́A Victoria Roux, Manuel Temprado, Pilar Jiménez, Ramón Guzmán-Mejı́A, Eusebio Juaristi, James S. Chickos

James Chickos

No abstract provided.

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Enthalpies Of Vaporization Of Organic And Organometallic Compounds, 1880-2002, James S. Chickos, William E. Acree Jan 2003

Enthalpies Of Vaporization Of Organic And Organometallic Compounds, 1880-2002, James S. Chickos, William E. Acree

James Chickos

No abstract provided.

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Bismuth Compounds In Organic Synthesis. Synthesis Of Resorcinarenes Using Bismuth Triflate, Ram S. Mohan, Katherine E. Peterson, Russell C. Smith Dec 2002

Bismuth Compounds In Organic Synthesis. Synthesis Of Resorcinarenes Using Bismuth Triflate, Ram S. Mohan, Katherine E. Peterson, Russell C. Smith

Ram S. Mohan

Bismuth triflate (5 mol%) smoothly catalyzes the condensation of aromatic and aliphatic aldehydes with resorcinol to give tetrameric cyclic products, resorcinarenes. With benzaldehyde, the product is obtained as a mixture of two diastereomers and the ratio of the diastereomers depends on reaction time. On the other hand, a single diastereomer is obtained with aliphatic aldehydes. The low toxicity and ease of handling of bismuth compounds coupled with fast reaction times make this method an attractive alternative to the existing methods for resorcinarene formation

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Bismuth Compounds In Organic Synthesis. Deprotection Of Ketoximes Using Bismuth Bromide-Bismuth Triflate, Ram S. Mohan, Joshua N. Arnold, Patrick D. Hayes, Robert L. Kohaus Dec 2002

Bismuth Compounds In Organic Synthesis. Deprotection Of Ketoximes Using Bismuth Bromide-Bismuth Triflate, Ram S. Mohan, Joshua N. Arnold, Patrick D. Hayes, Robert L. Kohaus

Ram S. Mohan

Ketoximes undergo deprotection in CH3CN/acetone/H2O (3:6:1) in the presence of 20–40 mol% BiBr3/5 mol% Bi(OTf)3. Bismuth(III) salts are relatively non-toxic, insensitive to air and inexpensive. These features coupled with the use of a relatively non-toxic solvent system make this method an attractive alternative to existing routes for deprotection of ketoximes.

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Reactions Of Boranes And Metallaboranes With Phosphines, Lawrence Barton, Oleg Volkov, Mitsuhiro Hata, Paul Mcquade, Nigam P. Rath Dec 2002

Reactions Of Boranes And Metallaboranes With Phosphines, Lawrence Barton, Oleg Volkov, Mitsuhiro Hata, Paul Mcquade, Nigam P. Rath

Nigam Rath

This paper reports extensions of the well-established field of phosphine–borane chemistry. Linked clusters, for example, {[(PPh3)2(CO)OsB4H7-3-BH2-PPh2]2 [(Fe(C5H4)2]}, are formed in reactions of rigid backboned bidentate phosphines with {2,2,2-(PPh3)2(CO)-nido-2-OsB5H9]. Reaction of bidentate phosphines with the unsaturated clusters [8,8-PPh3)2-nido-8,7-RhSB9H10] and [9,9-(PPh3)2-nido-9,7,8-RhC2B8 H11] leads to the isolation of novel species such as {1-(PPh3)[1,3-(µ-dppm)]-closo -1,2-RhSB9H8},with a dppm molecule bridging adjacent metal and boron vertices in the cage, [1,1-(ç2-dppe)-3-(ç1-dppm)-closo-1,2-RhSB 9H8], a mixed ligand system, and {9,9-ç2-[(ç2-BH3)PPh2PCH2 PPh2]-nido- 9,7,8-RhC2B8H11} which contains a bidentate dppm BH3 moiety. The formation of bidentate phosphine-linked main group transition-metal moieties such as [BH3PPh2(CH)nPPh2IrCp*Cl2] is also described as is an example of …

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