Tags: Physical Seminar


Organic and Inorganic Compounds Synthesized by Laser Vaporization

Nanoparticles continue to be widely studied due to their many properties and applications.  Ultra-small inorganic clusters comprised of aluminum and phosphorus were produced using a laser desorption time-of-flight mass spectrometer (LD-TOF MS).  Samples were pressed pellets as opposed to the typical thin films.  Observed clusters had electron counts which correspond to the “closo,” “nido,” and “arachno” polyhedral structures…


Computational Investigation of the Sulfur Analog of the Criegee Intermediate

The ephemeral Criegee intermediate, first postulated over 70 years ago, has only recently been isolated in the gas phase. The sulfur analog of this canonical zwitterion, thioformaldehyde S-sulfide, has eluded similar analysis; however, argon matrix isolation has been achieved. In the present research, thioformaldehyde S-sulfide and its valence isomer dithiirane are examined with high-level electronic structure methods, including the minimum…


Creation of Formaldeyde and Acetaldehyde from n-butanol

Improvements in the production of biobutanol have sparked expanded interest in its viability as a commercially utilized fuel additive.  However, the carcinogens formaldehyde and acetaldehyde are undesirable byproducts of butanol combustion. Through the use of high-level quantum chemical methods, the mechanism by which these byproducts are created can be explored to a high degree of accuracy.  Insights gleaned from these specific…


Understanding Ring Opening Dynamics of 1,3-Cyclohexadiene: Advances with X-ray Free Electron Lasers

With the development of X-ray Free Electron Lasers (XFEL), new techniques for studying ultrafast chemical dynamics have been established. These experiments can provide dynamic and structural information with femtosecond temporal and angstrom spatial resolution. The electrocyclization of 1,3- cyclohexadiene is a model system for many photoinduced reactions such as production of vitamin D3 or photochromic optical switches. The previous studies of…


Coulomb Crystals: A Cool Way to Do Chemistry

Coulomb Crystals, formed from laser cooling of atomic ions, have become a selective way of measuring spectroscopic transitions, kinetics and dynamics of cold ion-molecule reactions. For accurate measurements, reactants and detection methods must be state-selective. This fairly new technique has the potential to provide insight into state-to-state ion-molecule reaction dynamics provided advances in product detection are made. A background of this…


Gas Phase Studies of Criegee Intermediates


Chirped Pulse Fourier Transform Microwave Spectroscopy

Since its invention in 2006, the broadband chirped pulse Fourier transform (CP-FTMW) spectrometer has transformed the field of microwave spectroscopy.  The technique enables the collection of a 10 GHz or greater bandwidth spectrum in a single shot of the spectrometer, which allows broadband, high resolution microwave spectra to be acquired several orders of magnitude faster than what was previously possible.  We will be looking at the…


Isolated Transition Metal Clusters and Complexes: Flying Surfaces

Clusters – in particular those of transition metals – may act like surfaces of limited size, this analogy being recognized long time ago [1]. By virtue of our tandem cryo ion trap instrument we study the adsorption kinetics of clusters under single collision conditions as well as the Infrared Multiple Photon Dissociation (IR-MPD) by application of optical parametric oscillator/amplifier (OPO/OPA) photon sources [2]. Also, one and two colour…


Atmospheric Chemistry Experiment (ACE): Monitoring Greenhouse Gases from Orbit

Climate change is often in the news. Traditionally greenhouse gases such as carbon dioxide and methane responsible for climate change are measured in situ. In this presentation, I will discuss how recent advances in remote sensing from satellites provide a global perspective on changes in atmospheric composition. This talk will focus particularly on the observations of the Atmospheric Chemistry Experiment (ACE) mission (http://www.ace.uwaterloo.…


Making Metal-Containing Materials with Laser Vaporization Flowtube Reactor

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