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Computational Chemistry Commons™

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2012

Articles 1 - 6 of 6

Full-Text Articles in Computational Chemistry

A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang Oct 2012

A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang

Journal of Electrochemistry

Research on diffusion behaviors is of significant value in that it is closely related to transport phenomena in micro-chemistry. However, the effects of variables on diffusion are still unclear. Here, we developed and programmed a simulation methodology along with data analysis, which was capable to simulate the diffusion of a particle within twodimensional heterogeneous space in large timescale; the effects of periodically arranged impenetrable barriers of specific shape and lateral drifting velocity on diffusion behavior were studied. As well as standard mean square displacement analysis, a new method, the appearance probability distribution method, was introduced, which revealed whether the particle …

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Identification Of Persistent Long Range Interactions In GA95 And GB95 Through Thermal Unfolding Simulations, Milen Redai Tesfamariam Jul 2012

Identification Of Persistent Long Range Interactions In GA95 And GB95 Through Thermal Unfolding Simulations, Milen Redai Tesfamariam

Chemistry & Biochemistry Theses & Dissertations

For over five decades, different experiments have been performed to research how proteins attain their native three dimensional structures. However, the folding problem continues to be a puzzle in modern science. The design of two proteins that have maximal sequence identity but different folds and functions is one method that is being used to study the relationship between protein structure and amino acid sequence. In particular, mutant proteins of Streptococcus protein G, GA and GB, have 95% sequence identity and a 3a helix fold and β4/a fold, respectively. Molecular dynamics simulations of GA95 …

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Application Of First Principles Calculations In Anode Materials For Lithium Ion Batteries, Tian-Ran Zhang, Dai-Xin Li, Si-Qi Yang, Zhan-Liang Tao, Jun Chen Jun 2012

Application Of First Principles Calculations In Anode Materials For Lithium Ion Batteries, Tian-Ran Zhang, Dai-Xin Li, Si-Qi Yang, Zhan-Liang Tao, Jun Chen

Journal of Electrochemistry

First principles calculations play an important role in the study and development of new materials for lithium batteries. In this paper, we review the application of first principles calculations in the design of anode materials, including the modeling of the interaction of lithium in the anode materials, capacity, voltage, electrochemical reaction process, diffusion, rate capability, the relationship between the structure and properties, and the experimental phenomena interpreting. Based on the discussions, we emphasize on the importance of first principles calculations and demonstrate their requirement for further development.

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Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown May 2012

Cloning And Characterization Of Sas0754, A Hypothetical Protein From Community Associated Staphylococcus Aureus, Unknown Unknown

Symposium 2012

Community associated Staphylococcus aureus (strain MSSA476) is a gram positive cocci capable of infecting many different parts of the body and known to cause serious infections that can be fatal, such as bacterial arthritis and acute endocarditis. To find effective ways of fighting against CA-MRSA strains we must learn more about their ability to infect. The focus of this study was cloning and characterization of a protein referred to as SAS0754. The size of SAS0754 is 340 amino acids and the gene sequence is 1023 nucleotides. The hypothetical function of this protein is that it is an extracellular matrix binding …

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A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch May 2012

A Convenient Synthesis Of 2,6-Dichlorohomonicotinic Acid, Chase Buchanan, Richard W. Fitch

Symposium 2012

In our synthetic efforts toward the alkaloid phantasmidine, we required a convenient source of the title compound. Herein, we describe a short synthesis of 2,6-dichlorohomonicotinic acid by direct allylation of 2,6-dichloropyridine with LDA/allyl chloride, followed by permanganate oxidation of the side chain [figure1]. Yields for the allylation are high, while permanganate oxidation required more adjustment. Successful conditions require the modest acidification of the mixture with acetic acid and cleanup by acid base workup. No chromatography is needed.

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Convenient Parallel Synthesis Of Alkyl- And Aryl-S-Tert-Butyl Thiothers, Rebecca Norcross, Jessica Stanfield, Richard W. Fitch May 2012

Convenient Parallel Synthesis Of Alkyl- And Aryl-S-Tert-Butyl Thiothers, Rebecca Norcross, Jessica Stanfield, Richard W. Fitch

Symposium 2012

While preparing novel cysteine derivatives as oxidation catalysts, we needed S-tert-butylcysteine. We also examined acid-promoted tert-butylation of thiols using tert-butanol as reagent and solvent. While cysteine and aminoethanethiol work well using tBuOH in 4M HCl, other thiols fail in the aqueous environment and aerobic conditions. We examined a variety of aliphatic and aromatic thiols in tBuOH with H2SO4 catalysis and found that argon sparging and the use of 1 eq of acid led to good yields in a parallel format.

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