Phillip Sheridan, PhD Associate Professor of Physical Chemistry
PhD, University of Arizona
Teaching areas include general and physical chemistry.
Understanding metal ligand bonding is important because metals play a central role in the function of many chemical systems. For example, metals occupy the active sites of many biologically important molecules and act as catalytic surfaces for hydrogenation and polymerization reactions. In many cases, the interaction of the metal with the surrounding atoms is not well understood. By studying small metal-containing molecules using spectroscopy, fundamental metal-ligand bonding and geometric information can be obtained and provide insight into larger molecular systems.
The research in Dr. Sheridan’s group focuses on determining the bonding and geometric properties of small metal-containing molecules using laser spectroscopy. The molecules of interest are usually chemically unstable and consist of a metal atom (for example Ca) bonded to a single ligand (CH3, CCH, NH2, etc.). The synthesis of these molecules in the gas phase requires extreme conditions (vacuum chamber, plasma, etc.). To this end, we have constructed a laser-ablation/molecular-jet laser spectrometer system . We have successfully synthesized and recorded low-resolution laser excitation spectra of CaCCH, CaNH2, CaOH, CaF and other calcium containing radicals in this spectrometer system. We are currently working to obtain high-resolution spectra of the deuterium substituted analogs of these species in order to investigate geometry changes on electronic excitation.
Dr. Sheridan's group also collaborates with the Ziurys group at the University of Arizona. We have traveled to Arizona to utilize the millimeter-wave and microwave spectrometers to study metal-containing molecules. Recently we have investigated alkali metal acetylides (MCCH) and hydrosulfides (MSH), including the first gas phase study of KSH. We have also synthesized IZnCH3 by the gas phase reaction of Zn metal with ICH3. Experimental evidence suggests that this molecule is formed by zinc insertion into the I-C bond.
"Fourier Transform Microwave Spectroscopy of LiCCH, NaCCH, and KCCH: Quadrupole Hyperfine Interactions in Alkali Monoacetylides”, P. M. Sheridan, M. K. L. Binns*, M. Sun, J. Min, M. P. Bucchino, D. T. Halfen and L. M. Ziurys, J. Mol. Spectrosc., 269, 231 (2011).