Digital Commons Network^™

Constraints On Aerosol Nitrate Photolysis As A Potential Source Of Hono And Nox, Environmental Science And Technology, Paul S. Romer, Paul J. Woolridge, John D. Crounse, Michelle J. Kim, Paul O. Wennberg, Jack E. Dibb, Eric Scheuer, Donald R. Blake, Simone Meinardi, Alexandra L. Brosius, Alexander B. Thames, David O. Miller, William H. Brune, Samuel R. Hall, Thomas B. Ryerson, Ronald C. Cohen

Faculty Publications

The concentration of nitrogen oxides (NOx) plays a central role in controlling air quality. On a global scale, the primary sink of NOx is oxidation to form HNO3. Gas-phase HNO3 photolyses slowly with a lifetime in the troposphere of 10 days or more. However, several recent studies examining HONO chemistry have proposed that particle-phase HNO3 undergoes photolysis 10–300 times more rapidly than gas-phase HNO3. We present here constraints on the rate of particle-phase HNO3 photolysis based on observations of NOx and HNO3 collected over the Yellow Sea during the KORUS-AQ study in summer 2016. The fastest proposed photolysis rates are …

Ability Of Ir And Nmr Spectral Data To Distinguish Between A Tetrel Bond And A Hydrogen Bond, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The placement of a nucleophile X along the R-CH3 axis of a methyl group can be described as either a trifurcated H-bond or as a tetrel bond between C and X. Quantum calculation of the vibrational and NMR spectral features of a number of systems are used to provide a framework by which to distinguish between the presence of a tetrel or H-bond. Both cationic and neutral methyl-containing Lewis acids (SMe3+, NMe4+, SMe2) are paired with both neutral and anionic Lewis bases (NH3, OH2, OCHNH2, OCH3-, OH-, HCOO-). As the base is moved away from the R-CH3 axis of the …

Nanojars: Versatile Platform For Pyrazole Synthesis And Chemistry, And Selective Extraction Of Anions, Basil Mohammed Ahmed

Dissertations

This work is centered around nanojars, a family of nano-sized anion-incarcerating agents. It addresses various aspects of nanojar chemistry, such as synthesis strategies (including green methodologies) for pyrazole ligands needed for the preparation of nanojars, characterization and study of the mechanism of assembly of nanojars, and selective extraction of anions from water using nanojars.

Nanojars are neutral, supramolecular coordination complexes of the general formula [anion⊂ {Cu(μ-OH)(μ-pz)}_n], formed by the reaction of Cu²⁺, HO^‒ and pyrazolate ions (C₃H₂N₂‒, pz^‒) in the presence of oxoanions with large hydration energy …

Triple-Helicate Self-Assembly, Dynamics, And Anion Binding Of Halogen-Bonding M-Arylene-Ethynylene Oligomers, Casey John Massena

Graduate Student Theses, Dissertations, & Professional Papers

The form and function of biopolymers depend on the precise folding and organization of vast arrays of chemical groups. Hence, the simple yet elegant helix is one of the most pervasive structural elements in nature. Moreover, given the ubiquity and importance of anions, anion-interfacing helical structures hold promise as useful, stimuli-responsive supramolecules. Like metals, anions can powerfully coordinate organic ligands and promote helical self-assembly. However, anion coordination is far less understood than that of metals. Halide ions are an especially challenging target due to their small size, low charge, and variable coordination number/geometry. This work presents a new strategy that …

Stream Water And Soil Water Chemistry After The Table Mountain Wildfire, Washington, Usa, Vincent J. Roccanova

All Master's Theses

Analyses of major and trace elements, major ions, and nutrient concentrations were made to investigate how stream water and soil water chemistry changed over 16 months following the Table Mountain wildfire. Sites with different burn severity were also compared. The fire occurred in 2012 in Kittitas County, north of Ellensburg, Washington. Samples were collected at severely burned, moderately burned, and unburned field sites from within and adjacent to the wildfire perimeter. Total nitrogen concentrations increased in the second year after the fire in both the severely and moderately burned sites. In contrast, total phosphorus was variable at all three sites …