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Full-Text Articles in Chemistry
Determining Material Structures And Surface Chemistry By Genetic Algorithms And Quantum Chemical Simulations, Josiah Jesse Roberts
Determining Material Structures And Surface Chemistry By Genetic Algorithms And Quantum Chemical Simulations, Josiah Jesse Roberts
Theses and Dissertations--Chemistry
With the advent of modern computing, the use of simulation in chemistry has become just as important as experiment. Simulations were originally only applicable to small molecules, but modern techniques, such as density functional theory (DFT) allow extension to materials science. While there are many valuable techniques for synthesis and characterization in chemistry laboratories, there are far more materials possible than can be synthesized, each with an entire host of surfaces. This wealth of chemical space to explore begs the use of computational chemistry to mimic synthesis and experimental characterization. In this work, genetic algorithms (GA), for the former, and …
Multiscale Modeling Of Structure-Function Relationships Of Organic Semiconductors, Shi Li
Multiscale Modeling Of Structure-Function Relationships Of Organic Semiconductors, Shi Li
Theses and Dissertations--Chemistry
While optoelectronic devices built from organic semiconductors (OSC) continue to find their way into the commercial landscape, there remain numerous challenges to overcome to supplant traditional semiconductors in many technologies. Chief among these are low performance metrics relative to devices with conventional semiconductors and device stability. In order to overcome these challenges, a wide range of new OSC and processing technologies have been developed. However, there remains limited fundamental understanding of the relationship between molecular structure, packing in the solid state, and the resulting materials properties. Here, we make use of multiscale molecular models and utilize classical all-atom molecular dynamic …
Micro-Raman Imaging Of Isomeric Segregation In Small-Molecule Organic Semiconductors, Chiung-Wei Huang, Xiao You, Peter J. Diemer, Anthony Joseph Petty Ii, John E. Anthony, Oana D. Jurchescu, Joanna M. Atkin
Micro-Raman Imaging Of Isomeric Segregation In Small-Molecule Organic Semiconductors, Chiung-Wei Huang, Xiao You, Peter J. Diemer, Anthony Joseph Petty Ii, John E. Anthony, Oana D. Jurchescu, Joanna M. Atkin
Chemistry Faculty Publications
Charge transport in organic semiconductors is highly sensitive to film heterogeneity and intermolecular interactions, but probing these properties on the length scales of disorder is often difficult. Here we use micro-Raman spectroscopy to assign vibrational modes of isomerically pure syn and anti 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES ADT) by comparing to density functional theory calculations. With polarization-dependent measurements, we determine the orientation of crystallites in pure isomers. In mixed-isomer samples, we observe narrow linewidths and superposition spectra, indicating coexistence of isomerically pure sub-domains on length scales smaller than the probe area. Using the ring breathing modes close to 1300 cm−1 as indicators …
Mass-Analyzed Threshold Ionization Of Lanthanide Imide Lnnh (Ln = La And Ce) Radicals From N–H Bond Activation Of Ammonia, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang
Mass-Analyzed Threshold Ionization Of Lanthanide Imide Lnnh (Ln = La And Ce) Radicals From N–H Bond Activation Of Ammonia, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang
Chemistry Faculty Publications
Ln (Ln = La and Ce) atom reactions with ammonia are carried out in a pulsed laser vaporization supersonic molecular beam source. Lanthanide-containing species are observed with time-of-flight mass spectrometry, and LnNH molecules are characterized by mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and a scalar relativity correction, electron correlation, and spin-orbit coupling for the Ce species. The MATI spectrum of LaNH exhibits a single vibronic band system with a strong origin band and two weak vibronic progressions, whereas the spectrum of CeNH displays two band systems …