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Articles 1 - 9 of 9
Full-Text Articles in Chemistry
Theoretical Investigation Of The Co-C Bond Activation In Methylcobalamin And Adenosylcobalamin-Dependent Systems: Mechanistic Insights., Arghya Pratim Ghosh
Theoretical Investigation Of The Co-C Bond Activation In Methylcobalamin And Adenosylcobalamin-Dependent Systems: Mechanistic Insights., Arghya Pratim Ghosh
Electronic Theses and Dissertations
The vitamin B12 derivates, otherwise known as cobalamin (Cbl), are ubiquitous organometallic cofactors. The biologically active forms of Cbl, such as methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), act as cofactors in different physiological reactions for both prokaryotes and eukaryotes. A crucial aspect of the Cbl-mediated systems is the activation of the organometallic Co-C bond that plays a critical role in its catalytic activity. One of the most remarkable features of this Co-C bond is its unusual activation in AdoCbl-dependent enzymatic reactions, where a trillion-fold rate acceleration of the Co-C bond cleavage is observed inside the enzyme compared to the isolated …
Tracking The Amide I And Αcoo− Terminal Ν(C=O) Raman Bands In A Family Of L-Glutamic Acid-Containing Peptide Fragments: A Raman And Dft Study, Ashley E. Williams, Nathan I. Hammer, Ryan C. Fortenberry, Dana N. Reinemann
Tracking The Amide I And Αcoo− Terminal Ν(C=O) Raman Bands In A Family Of L-Glutamic Acid-Containing Peptide Fragments: A Raman And Dft Study, Ashley E. Williams, Nathan I. Hammer, Ryan C. Fortenberry, Dana N. Reinemann
Faculty and Student Publications
The E-hook of β-tubulin plays instrumental roles in cytoskeletal regulation and function. The last six C-terminal residues of the βII isotype, a peptide of amino acid sequence EGEDEA, extend from the microtubule surface and have eluded characterization with classic X-ray crystallographic techniques. The band position of the characteristic amide I vibration of small peptide fragments is heavily dependent on the length of the peptide chain, the extent of intramolecular hydrogen bonding, and the overall polarity of the fragment. The dependence of the E residue’s amide I ν(C=O) and the αCOO− terminal ν(C=O) bands on the neighboring side chain, the length …
Data For: Record Low Ionization Potentials Of Alkali Metal Complexes With Crown Ethers And Cryptands, Alexander I. Boldyrev, Nikolay Tkachenko
Data For: Record Low Ionization Potentials Of Alkali Metal Complexes With Crown Ethers And Cryptands, Alexander I. Boldyrev, Nikolay Tkachenko
Browse all Datasets
Electronic properties of series of alkali metals complexes with crown ethers and cryptands were studied via DFT hybrid functionals. For [M([2.2.2]crypt)] (M=Li, Na, K) extremely low (1.70–1.52 eV) adiabatic ionization potentials were found. Such low values of ionization energies are significantly lower than those of alkali metal atoms. Thus, the investigated complexes can be defined as superalkalis. As a result, our investigation opens up new directions in the designing of chemical species with record low ionization potentials and extends the explanation of the ability of the cryptates and alkali crown ether complexes to stabilize multiple charged Zintl ions.
Investigations Into Effects Of Modified Prolines On Cis-Trans Isomers And Polypeptide Secondary Structure & Prediction Of Spectroscopic Properties Of Phthalonitriles For Characterization, Jeffrey Raab
Seton Hall University Dissertations and Theses (ETDs)
Proline is a unique amino acid because it is the only amino acid whose side chain wraps around and bonds back to the peptide backbone. This ring shape helps proteins form conformations which would otherwise not be possible such as hairpin turns. The cis/trans isomerization of the peptide bond between the preceding amino acid (Xaa) and Proline is important in determining how the secondary structure folds. Thus, being able to control the cis/trans isomerization is important when a specific conformation is desired; Proline can be modified to get make the equilibrium shift whichever way is needed. The modifications …
Investigation Of The C—Cn Bond Activation Of Fluorinated Benzonitriles With [Ni(Dmpe)] And Dft Benchmarking Study With [Ni(Dippe)], Dominique C. Gallegos
Investigation Of The C—Cn Bond Activation Of Fluorinated Benzonitriles With [Ni(Dmpe)] And Dft Benchmarking Study With [Ni(Dippe)], Dominique C. Gallegos
Theses and Dissertations
Carbon-carbon bond activation has become a rapidly growing area of research due to its extensive range of applications. Despite the significant progress that has been made in this field, the cleavage of kinetically inert and thermodynamically stable C—C σ-bonds under mild homogeneous conditions remains a challenge. The activation is primarily limited to systems in which either relief of strain or aromatization serves as a driving force. A notable exception to this is the oxidative addition of unstrained C—CN bonds of nitriles. In this study, we are looking at the effect of fluoro substituents. We hypothesized …
A Dft Study Of The Adsorption Of Deep Eutectic Solvents Onto Graphene And Defective Graphene Nanoflakes, Mehdi Shakourian-Fard, S. Maryamdokht Taimoory, Hamid Reza Ghenaatian, Ganesh Kamath, John F. Trant
A Dft Study Of The Adsorption Of Deep Eutectic Solvents Onto Graphene And Defective Graphene Nanoflakes, Mehdi Shakourian-Fard, S. Maryamdokht Taimoory, Hamid Reza Ghenaatian, Ganesh Kamath, John F. Trant
Chemistry and Biochemistry Publications
The interaction of four deep choline chloride-derived eutectic solvents (DESs) with both graphene nanoflakes (GNF) and its defective double-vacancy and Stone–Wales forms (DV-GNF and SW-GNF), was evaluated using density functional theory (DFT). The presence of defects increases the adsorption energy of DESs, following the order DES∩DV-GNF > DES∩SW-GNF > DES∩GNF. Non-covalent interaction and energy decomposition analyses show that the interactions are noncovalent and dominated by dispersive forces. Furthermore, we find that the presence of aromatic moieties in the DESs increases the van der Waals interactions with the surfaces. These interactions decrease the HOMO-LUMO (Eg) energy gap of the surfaces and thus increase …
Theoretical Investigation Of The Interaction Between The Metal Phthalocyanine [Mpc] A(M = Sc, Ti, And V; A = ?1, 0, And +1) Complexes And Formaldehyde, Nasim Hassani
Turkish Journal of Chemistry
Formaldehyde (FA, CH2O) is one of the toxic volatile organic compounds that cause harmful effects on the human body. In this work, the interaction of FA gas with metal phthalocyanine (MPc) molecules was studied by employing density functional theory calculations. A variety of [MPc] a (M = Sc, Ti, and V; a = -1, 0, and +1) complexes were studied, and the electronic properties, interaction energies, and charge transfer properties of all of the studied molecules were systematically discussed. Among the studied complexes, the Sc and Ti phthalocyanines were more reactive toward the adsorption of FA gas. Moreover, it was …
Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word
Computational Study Of Radical Cation Rearrangements, Mi'kayla D. Word
Theses and Dissertations
A radical cation is a molecule that has one unpaired electron that holds a positive charge. The unpaired electron within a radical cation causes the molecule to be reactive. The high reactivity of these species allows for radical cations to be commonly studied experimentally using mass spectrometry and other multi-mass imaging techniques. However, these methods often cannot resolve the reaction mechanisms for these fast reactions. Specifically, radical cation rearrangement mechanisms are particularly unresolved within experiments. For this reason, radical cation rearrangements are computationally investigated to explain complex reaction pathways for processes to understand reactions leading to the initiation of detonation …
Extension Of Restricted Open-Shell Kohn-Sham Methodology To A Density-Functional Tight-Binding Framework, Reuben Szabo
Extension Of Restricted Open-Shell Kohn-Sham Methodology To A Density-Functional Tight-Binding Framework, Reuben Szabo
WWU Graduate School Collection
The restricted open-shell Kohn-Sham (ROKS) approach for singlet excited states provides some advantages over the ∆-self-consistent-field (∆SCF) method, requiring only a single SCF procedure and avoiding the problem of variational collapse. While ROKS is a powerful tool for DFT, its application to density functional tight-binding (DFTB) could offer significant improvements in time complexity when compared to DFT, enabling excited-state simulations of extended molecular systems on longer timescales than ROKS. In this work we discuss the implementation of an RO-DFTB approach in the DFTB+ package, as well as its suitability for the study of organic dyes and photoactive compounds. For benchmarking, …