The goal of this project is to synthesize, characterize, and study the properties of new inorganic compounds that have novel photochemical, electronic, or biomimetic applications.
Tom Schmedake (CHEM), Daniel Rabinovich (CHEM) and Daniel Jones (CHEM)
The Rabinovich laboratory has been investigating the syntheses and molecular structures of novel N-heterocyclic thione (NHT) and selone (NHSe) ligands derived from caffeine. These are attractive ligands for various applications in coordination chemistry since they are air-stable, water-soluble, and display a high affinity for soft metal ions. For example, a systematic study of the coordination chemistry of these soft donor ligands towards mercury(II), copper(I) and gold(I) complexes have resulted in the isolation of several new complexes with interesting structures. NanoSURE participants will optimize the syntheses of some of these compounds and attempt to obtain single crystals amenable to study by X-ray crystallography. In addition, a combination of NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS) to evaluate the selenophilicity of copper (i.e., its preferential affinity for selenium over sulfur).
Undergraduate students in the Schmedake lab have synthesized a variety of hexacoordinate polypyridyl silicon-based complexes for potential electrochromic, catalytic, electronic, and photochemical applications. Silicon is the most abundant metal in the earth’s crust, and so we are looking for opportunities to replace exotic transition metals in coordination complexes with earth-abundant silicon in places where d-electrons are not needed. For example, we have found that hexacoordinate polypyridylsilicon(IV) complexes make excellent electrochromic materials, and the lack of d-electrons is beneficial since it allows for a colorless oxidized state. This summer REU students will synthesize new luminescent hexacoordinate silicon complexes for light emitting diode applications.
The technique of single-crystal X-ray crystallography is used by undergraduate students in the Jones lab to determine the detailed molecular structure of chemical compounds. Because this is a completely general method, it can be applied to almost any compound of chemical interest, and is thus an important tool in many different areas of research. The Department of Chemistry at UNC Charlotte acquired in July of 2011 a brand-new, state-of-the-art Gemini A Ultra diffractometer system with dual (Mo and Cu) Xray sources, which is now fully operational. Structure determinations of the compounds described above will be carried out by NanoSURE students, who will partake in every phase of the work, namely data acquisition, reduction and analysis, and manuscript preparation.
REU Students’ Role
Students will contribute to this project by choosing a synthetic based project (Rabinovich or Schmedake) or X-ray crystallography based project (Jones). Synthesis students will be trained in lab protocols and safety procedures by the Research mentors. Students joining the X-ray crystallography lab will be trained and certified to operate the X-ray diffractometer, following protocols established by the UNC Charlotte Safety Office in compliance with the North Carolina Regulations for Protection Against Radiation.