Research Projects

Oxygenated Volatile Organic Compounds (OVOCs) are used as solvents, fuel additives, and as cleaning disinfection products. These compounds can undergo many chemical transformations with various oxidants present in the atmosphere and can lead to more hazardous by-products upon release into the atmosphere [1,2]. The main route of oxidation of OVOCs in the troposphere is the OH-radicals initiated photo-oxidation reactions [3,4]. The main sink of these OVOCs are chemical transformation and wet deposition. Atmospheric VOCs have both natural and anthropogenic sources. They play a central role in the production of the tropospheric ozone (O3) and secondary organic aerosol (SOA), together with nitrogen oxides (NOx) and solar radiation, and can influence the atmospheric chemistry, air quality, and climate processes. For example, chloroacetoacetates, a class of OVOCs that are emitted from the paper industry are widely used as anti-slime agents (antimicrobial and pesticide agents) to kill slime-producing microorganisms such as algae, fungi, and slime molds on the pools [5]. Another example would be fluorinated diketones (FDKs), which are extensively used as chelating agents in the organic synthesis of drugs, special dyes and coatings and metallurgy [6]. Some of these applications implies metal-organic chemical vapor deposition techniques that is a potential source of airborne diketones. Due to their structure, possessing both C–F bonds and carbonyl moieties, they might bear a significant global warming potential. While a series of hydrofluoroolefins, -ethers, -alcohols and -ketones have been studied with respect to their atmospheric fate (kinetic and mechanistic information) and GWP values. However, for FDKs no data were yet reported. But prior to the use of OVOCs, it is very necessary to assess their atmospheric fate and environmental impact upon their release into the troposphere. It is therefore important to study the gas phase kinetics of these compounds with the primary atmospheric oxidants, i.e., hydroxyl radicals (OH), chlorine atoms (Cl), nitrate radicals (NO3) and ozone (O3) as well as to specify the final oxidation products under tropospheric conditions. The reaction between FDK and atmospheric oxidants are given below: CF3C(O)CH2C(O)CH3 + OH / Cl / NO3 → Products? + O3 → Products? Furthermore, the kinetics, thermo-chemical properties, and reaction mechanism for the reactions of FDKs with oxidants are of particular importance to the fundamental understanding of such molecular processes. Therefore, we will focus our study on the thermo-chemical properties, kinetics, and reaction mechanism for the gas phase reactions of FDKs with oxidants at temperature range (200 – 1000 K) using Ab-initio quantum methods and Density Functional Theory (DFT) method [7]. The theoretical quantum calculation provides detailed information on electronic structure and spectral characteristics of the reactants, and products.