Ting Guo

We are building an interdisciplanary chemical research program that explores how to convert electromagnetic energies into chemical and mechanical energy forms using a network of nanomaterials. Analytic, physical, organic, biological, and inorganic chemistry, as well as materials chemistry are an integral part of this program.

NETWORKS OF NANOMATERIALS.
We synthesize many forms of nanomaterials such as nanoparticles, nanowires, nanobelts, nanoflowers, and nanotubes. They serve as individual building blocks for catalysts, radiation sensitizers, spectroscopy enhancers etc. They are also used to build networks of nanomaterials to function as lenses to focus radiation energy, as transducers to initiate chemical reactions, and as optical reporters.

DYNAMICS IN CONDENSED PHASE MATERIALS.
Ultrafast x-ray absorption spectroscopy is capable of measuring both the onset of electron transfer and the accompanying structural relaxation. Hence, by interrogating the oxidation-state and local atomic arrangement on an ultrafast timescale, we can elucidate both the dynamics of electron transfer and the mechanism of the accompanying structural relaxation in complexes, molecular wires, and other nanoscale structures. Electron transfer in metal complexes such as Ni porphyrins, ruthenium polypyridine complexes, Cs anions, and ZnPc (zinc phathalocynine), and those connected with DNA and peptide backbones, carbon nanotubes, and coated or composite metal clusters will be studied. In another front, cooperative, ultrafast electronic and structural dynamics in solid-state materials is being studied with both optical spectroscopic and ultrafast x-ray diffraction methods. Optical methods employing ultrafast laser pulses are used to initiate and investigate electronic phase transitions, and ultrafast x-ray diffraction methods are used to interrogate crystallographic phase transitions in crystalline metal oxides. The correlation between the two transitions and the driving force for them will be elucidated.

OPTICAL SPECTRO-MICROSCOPY.
The method is based on correlation coherent Raman spectro-microscopy (CCRS). It allows us to discern bonding changes in chemical and biological systems. An essential feature is the simultaneous acquisition of two or more coherently excited Raman modes that are affected by the changing bonding environments during those reactions or interactions. Research projects will center on identifying reaction pathways that are critical to understanding enzymatic reactions and interactions between drug and target molecules.