Spectroscopy and Chemistry of Radicals in High-temperature Reactions
The unusual nature of radicals makes them both elusive and of crucial chemical important at the same time. Their high reactivity requires advanced tools for their characterization, and is the same property that makes them important players in chemistry of extreme environments - plasma, pyrolysis, combustion and even in the interstellar medium.
Beyond their chemical importance, the open shell nature of radicals often causes their molecular physics to go beyond some of the most fundamental approximations, such as the Born-Oppenherimer approximation. Radicals are thus a rich testbed for pushing the limits of our understanding of quantum mechanics and molecular physics.
In our lab we employ various highly efficient and clean sources of radicals, and study their chemistry and spectroscopy, in a wide range of conditions, ranging from simple yet poorely understood pyrolysis reactions to rich bimolecular chemistry and combustion.
Our detection tools include laser induced fluoresence, time of flight mass spectromety, double resonance spectroscopy and novel spectroscopic schemes that we develop in our lab. We also collaborate with groups around the globe and take advantage of large-scale facilities, such as synchrotrons, to augment our capabilities.
Plasma Chemistry and Optical Diagnostics
Plasma, the fourth state of matter, is a collection of neutral and charged particles, which is electrically neutral on average and exhibits collective effects. Plasma provides an unprecedented opportunity for combustion and emission control owing to its unique capability to produce active species and enhance energy transport processes, especially in its non-equilibrium variants such as low-pressure or cold plasmas.
In our research group we are studying fundamental reactions mechanisms in our plasma chamber by controlling the plasma and gas flow conditions, and monitoring reactive species in situ using sophisticated plasma diagnostics tools. We have both a high resolution CCD camera detector and fast optical fiber spectrometer showing the in situ spectral behavior of the plasma species.
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We aim to understand how different molecules decompose under different sets of plasma conditions, towards producing desired species, or improving selectivity and efficiency of the plasma chemistry.
Additionally, we are developing new intracavity laser absorption techniques, to expand available capabilities for quantitative sensitive detection of reactive intermediates.
Ab-initio Calculations of Molecular Properties of Elusive Species
We use high accuracy ab initio quantum chemistry calculations, based on coupled-cluster techniques, to describe unusual properties of molecules, such as tunneling, large amplitude motions, resonances and vibronic interactions. Our goal is to calculate thermochemical, spectroscopic, and kinetic properties of molecules and radicals to obtain results that are both qualitatively and quantitatively directly comparable to experimental observables.
Our results are used in conjunction with experiments performed in house, or by collaborators around the world. These accurate calculations further deeper understanding of the chemical systems by driving future experimental design and assisting with analysis of experimental results.
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