Timothy M. Swager

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In a previous publication, we described the use of biradicals, in that case two TEMPO molecules tethered by an ethylene glycol chain of variable length, as polarizing agents for microwave driven dynamic nuclear polarization (DNP) experiments. The use of biradicals in place of monomeric paramagnetic centers such as TEMPO yields enhancements that are a factor(More)
Dynamic nuclear polarization (DNP) experiments in rotating solids have been performed for the first time using biradicals rather than monomeric paramagnetic centers as polarizing agents. Specifically, two TEMPO radicals were tethered with a poly(ethylene glycol) chain of variable length where the number of glycol units was 2, 3, or 4. NMR experiments show(More)
To date, the cross effect (CE) and thermal mixing (TM) mechanisms have consistently provided the largest enhancements in dynamic nuclear polarization (DNP) experiments performed at high magnetic fields. Both involve a three-spin electron-electron-nucleus process whose efficiency depends primarily on two electron-electron interactions--the interelectron(More)
During the three decades 1980-2010, magic angle spinning (MAS) NMR developed into the method of choice to examine many chemical, physical, and biological problems. In particular, a variety of dipolar recoupling methods to measure distances and torsion angles can now constrain molecular structures to high resolution. However, applications are often limited(More)
We report a chemiresistor that has been fabricated via simple spin-casting technique from stable CNT dispersion in hexafluoroisopropanol functionalized polythiophene. The sensor has shown high sensitivity and selectivity for a nerve reagent stimulant DMMP. A series of sensing studies, including field effect investigation, electrode passivation, and(More)
The utility of metal-organic frameworks (MOFs) as functional materials in electronic devices has been limited to date by a lack of MOFs that display high electrical conductivity. Here, we report the synthesis of a new electrically conductive 2D MOF, Cu3(HITP)2 (HITP=2,3,6,7,10,11-hexaiminotriphenylene), which displays a bulk conductivity of 0.2 S cm(-1)(More)
Near-infrared fluorescent probes for amyloid-beta (Aβ) are an exciting option for molecular imaging in Alzheimer’s disease research and may translate to clinical diagnostics. However, Aβ-targeted optical probes often suffer from poor specificity and slow clearance from the brain. We are designing smart optical probes that emit characteristic fluorescence(More)
Many pathogens that infect humans use cell surface carbohydrates as receptors to facilitate cell-cell adhesion. The hallmark of these interactions is their multivalency, or the simultaneous occurrence of multiple interactions. We have used a carbohydrate-functionalized fluorescent polymer, which displays many carbohydrate ligands on a single polymer chain,(More)