Highly Instrumented Low Temperature Reaction Chamber

ongoing

In this project, I will build, optimize, and apply a Highly Instrumented Low Temperature Reaction Chamber (HILTRAC) to study organosulfur chemical reactions. This chamber is the first of its kind to couple a uniform supersonic flow (USF) capable of achieving a wide range of cold temperatures (30 – 250 K) with the unique detection capabilities of an infrared direct frequency comb spectrometer (DFCS). The combination of DFCS with two additional detection methods (laser-induced fluorescence and time-of-flight mass spectrometry) will make HILTRAC a highly versatile instrument, with sufficient sensitivity and selectivity to measure very low concentrations of molecules in a gas phase chemical reaction. The spectrally broadband and high resolution frequency comb laser enables both reactants and products to be identified and monitored simultaneously as a function of reaction time. For the first time, a single instrument will have the ability to collect multiplexed information on temperature-dependent reaction kinetics, product identification, and product branching ratios. This will set a new benchmark for what should be considered a more complete understanding of the way a reaction progresses. As a first target for the newly commissioned HILTRAC, I will study three different organosulfur reactions relevant to chemical environments ranging from the interstellar medium to biological systems. There is very little information about organosulfur reactions in general and especially at low temperatures due to experimental challenges which the USF is able overcome. By using the combined power of the HILTRAC detection methods and the temperature controlled environment, with supporting quantum chemical calculations and reaction kinetics simulations, I will be able to draw conclusions about the reaction potential energy surfaces which govern the branching to reaction products. This in turn will allow predictive abilities beyond achievable experimental conditions.