Molecular structure studies
Electronic structure studies
We use a combination of experimental and computational methods to arrive at conclusions in our research.
employed either to explain experimental findings or to guide experiments. Depending on the state of the
particular project, students can often choose a more experimental or a more computational focus.
Most compounds of interest are not commercially available, and so have to be synthesized, isolated and
purified. Compounds may be sensitive to moisture or oxygen, and so inert gas techniques might be necessary.
Apart from using the full range of common spectroscopic and spectrometric techniques to characterize reaction
products, we use FTIR and NMR (1H, 13C, 17O) spectroscopies to detect weak
bonding interactions. FTIR and 300 and 500 MHz NMR spectrometers are readily available in the department.
The recent arrival of a single-crystal X-ray diffractometer in the department now allows us to obtain crystal
structures routinely, which will be of high value in hydrogen-bonding studies.
Flash pyrolysis is used for the thermolytic generation of reactive intermediates in the gas phase from suitable
Finally, electronic structures can be determined experimentally through ultraviolet photoelectron spectroscopy on
molecules in the gas phase. These studies are done in collaboration with Prof. Nick Werstiuk at
The department houses the Centre for Research in Molecular Modeling
(CERMM), which is where we perform most of our calculations. On occasion, we use supercomputers elsewhere
in Canada, but CERMM clusters are equipped with most of what we need. Most of our computational work revolves
around electronic structure calculations.
Studies start the usual way with geometry optimizations (minima, relaxed scans, transition states,
intrinsic reaction coordinates) and frequency calculations. We then calculate properties as needed (molecular
orbitals, spin densities, anharmonic frequencies, isotropic shieldings). Detailed analyses are carried out
using NBO or NRT (natural bond orbitals or resonance theory) approaches. For molecular structure studies, we
analyse the electron density within the framework of
QTAIM (the quantum theory of atoms in molecules).
H.M. Muchall HomePage |
Centre for Research in Molecular Modeling - CERMM
Last update: august10; hmm