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Articles 1 - 10 of 10
Full-Text Articles in Computational Chemistry
First Principles Molecular Dynamics Simulations Of Infrared And Raman Vibrational Spectra Of H5o2 +, D5o2 +, Dh4o2 +, And D4ho2 + From 50 To 300 K, Oluwaseun Omodemi, Martina Kaledin
First Principles Molecular Dynamics Simulations Of Infrared And Raman Vibrational Spectra Of H5o2 +, D5o2 +, Dh4o2 +, And D4ho2 + From 50 To 300 K, Oluwaseun Omodemi, Martina Kaledin
Faculty Articles
We report molecular dynamics simulations of infrared (IR) and Raman spectra of H5O2+ and its deuterium-substituted analogs. We use the well-tested HBB potential and dipole surfaces along with a recently fitted polarizability surface of CCSD(T)/aug-cc-pVTZ quality. The focus of the present work is to provide new insights into the O···O stretch region, located in the [500–700] cm–1 spectral range, by means of analyzing the spectra over a broad range of temperatures: from 50 to 300 K. Also, rovibrational thermal averaging was performed to untangle the unusually complex spectra of partially deuterated isotopologues DH4O2+ and D4HO2+ with H and D minority …
Computational Study Of The Proton Transfer In The H7o3+ Cluster, Anna James, Martina Kaledin
Computational Study Of The Proton Transfer In The H7o3+ Cluster, Anna James, Martina Kaledin
Symposium of Student Scholars
Proton transfer (PT) from one molecule to another is among the most studied phenomena in chemistry. PT requires the bond cleavage and the formation of a new one, AH+ + B -> A+ BH+. In protonated water clusters, such a process consists of the interconversion of hydrogen bonds. Experimentally, such a process can be observed as a significant increase of a dipole moment. However, other vibrational transitions often occur with small changes in the dipole moment while large changes in polarizability. In this work, we study the PT process in a protonated water cluster, H7O …
Probing The Effect Of Nitrogen And Boron Doping On Structures, Properties, And Stability Of C20 Clusters, Ramsay Revennaugh, Martina Kaledin
Probing The Effect Of Nitrogen And Boron Doping On Structures, Properties, And Stability Of C20 Clusters, Ramsay Revennaugh, Martina Kaledin
Symposium of Student Scholars
Fullerenes are carbon molecules arranged in a closed hollow shell to form spherical-like structures. These clusters exist in various sizes, Cn, with the smallest being C20. C20, often when doped with other elements, has shown promise in creating new materials as a catalyst and as energy storage material. Here, we look at the existence of C20 doped with nitrogen or boron atoms using density functional theory (DFT). C20 is doped with one to three boron or nitrogen atoms, respectively, including the five different C18N2 / C18B2 …
Ab Initio Calculations Of Vibrational Spectra Of Model Peptides, Katheryn Foust, Martina Kaledin
Ab Initio Calculations Of Vibrational Spectra Of Model Peptides, Katheryn Foust, Martina Kaledin
Symposium of Student Scholars
The function of biological molecules is closely related to their spatial structure and conformational dynamics. Therefore, understanding the structure and functions of small peptides contributes to gaining insight into the behavior of more complex systems. The peptide bond (-CO-NH-) is among the very important binding patterns in biochemistry. It links amino acids together, specifies rigidity to the protein backbone, and includes the two essential docking sites for hydrogen-bond-mediated protein folding and protein aggregation, namely, the C=O acceptor and the N-H donor parts. Therefore, the C=O (amide-I) and N-H (amide-A) vibrations provide sensitive and widely used probes into the structure of …
Pyrrolopyrrole-Based Materials For High-Contrast Electrochromics, Allison Marie Hawks
Pyrrolopyrrole-Based Materials For High-Contrast Electrochromics, Allison Marie Hawks
Master of Science in Chemical Sciences Theses
Understanding structure-property relationships of underutilized p-conjugated chromophores is an important task for the continued discovery of materials that will find utility in organic electronic applications. Dihydropyrrolo[3,2-b]pyrroles (DHPPs) are synthetically simple and highly tailorable chromophores that can be decorated with diverse functionalities that readily manipulate optoelectronic properties useful for a variety of applications. However, a thorough understanding of how these functionalities influence properties of DHPPs that will be useful in applications such as electrochromism is unknown. Motivated to exploit the synthetic simplicity and tailorability of DHPPs, a family of DHPP chromophores was synthesized to probe how functionality and connectivity …
Hydrogen Bonding In Small Model Peptides; The Dft And Mp2 Study, Gracie Smith, Martina Kaledin
Hydrogen Bonding In Small Model Peptides; The Dft And Mp2 Study, Gracie Smith, Martina Kaledin
Symposium of Student Scholars
Formamide is a small model compound for the study of the peptide bond. The peptide bond links amino acids together, specifies rigidity to the protein backbone, and includes the essential docking sites for hydrogen-bond-mediated protein folding and protein aggregation, namely, the C=O acceptor and the N-H donor parts. Therefore, the infrared C=O (amide-I) and N-H (amide-A) vibrations provide sensitive and widely used probes into the structure of peptides. This computational chemistry work, we study hydrogen bonds in formamide dimer isomers. We evaluate the accuracy of the density functional theory (DFT) and many-body perturbation theory to the 2nd order (MP2) …
Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis
Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis
Symposium of Student Scholars
Azaborines are fascinating compounds because they possess valuable properties such as photochemical stability, have high molar absorption coefficient and high fluorescent quantum yields, as well as large Stokes shifts and tunable absorption/emission spectra. Here, we designed, synthesized, and will examine a novel reaction-based azaborine fluorescent probe capable of selectively detect carbon monoxide (CO) based on palladium-mediated carbonylation chemistry. This novel azaborine fluorescent probe will exhibit high selectivity for CO and display a robust turn-on fluorescent response in the presence of CO in aqueous buffer solution.
Ketal-Azaborine Versus Ketal-Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Heteroaromatic Polycyclic Chromophores, Albert Campbell, Janiyah Riley, Samuel Moore, Albert Campbell
Ketal-Azaborine Versus Ketal-Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Heteroaromatic Polycyclic Chromophores, Albert Campbell, Janiyah Riley, Samuel Moore, Albert Campbell
Symposium of Student Scholars
Flat-structured heteroaromatic polycyclic compounds with extended conjugated π-systems such as azaborines are in high demand in the material and imaging technology markets because of their unique features such as simultaneous tunability of fluorescence color and intensity. We have designed, synthesized, and investigated a series of novel conjugated thermally stable ketal-azaborine chromophores that contain a phenyl ring as a spacer between electronic moieties and the ketal-azaborine core as easily tunable high-luminescent organic materials. We investigated the impact of the phenyl spacer on the ketal-azaborine unit. We examined the structural effects on their photophysical properties by incorporating electron –donating and –withdrawing substituents …
Azaborine Versus Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Azaborine Chromophores, Kaia Ellis, Janiyah Riley, Lyric Gordon, Janiyah Riley
Azaborine Versus Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Azaborine Chromophores, Kaia Ellis, Janiyah Riley, Lyric Gordon, Janiyah Riley
Symposium of Student Scholars
Azaborines are fascinating compounds because of their valuable and interesting optical properties making them suitable to be utilized in many optoelectronic devices. We have designed, synthesized, and investigated a series of novel conjugated thermally stable azaborine chromophores by incorporating a phenyl ring as a spacer linking the chromophore to different electronic moieties as easily tunable high-luminescent organic materials. We investigated the effect of the phenyl spacer on the azaborine unit. The substituent effects of different electronic moieties were investigated by the insertion of electron –withdrawing and –donating moieties to the phenyl spacer. We examined the role of the electron –donating …
Computer Simulation Of Raman Spectra And Mode Assignment: Application To Methane, Oluwaseun Omodemi, Ciara Tyler, Martina Kaledin
Computer Simulation Of Raman Spectra And Mode Assignment: Application To Methane, Oluwaseun Omodemi, Ciara Tyler, Martina Kaledin
Symposium of Student Scholars
This work uses driven molecular dynamics (DMD) method, in conjunction with an analytic PES calculated using MP2/aug-cc-pVDZ energies to identify and assign Raman vibrational modes of methane. Recently, a new linearized approach was proposed for the Polarizability Tensor Surfaces (PTS) that yields a unique solution to the least-squares fitting problem and provides a competitive level of accuracy compared to the non-linear PTS model. We used the previously reported B3LYP/6-31+G(d) molecular geometries for CH4 and generated a new PTS at the MP2/aug-cc-pVDZ level of theory. The performance of the linearly parametrized functional form for the CH4 PTS is examined. …