PROOF OF CONCEPT FOR EFFICIENT APPLICATION OF QUANTUM-CHEMICAL TECHNIQUES TO MODEL ENVIRONMENTAL MERCURY DEPLETION REACTIONS THROUGH TRANSITION STATE THEORY
Abstract
The proof-of-concept project that focuses on development of efficient computational approaches to study atmospheric reactions of mercury is proposed. Modeling of atmospheric/environmental mercury depletion reactions are finding increasing importance as it is an effective tool to understand the origin of increased mercury level in the environment over the period of last two decades. Quantum-chemical methods could play an important role in such modeling. Earlier quantum chemical models were using collision theories to investigate the kinetics of basic mercury depletion reactions (involving diatomic molecules). The involvement of water particles were later found in such reactions in upper atmosphere in several investigations. Application of transition state theory is possible in such reactions if water molecule is considered as a third body. Our preliminary investigation at the density functional theory (DFT) level had shown that proper transition state could be located involving HgCl+ formation from Hg2+, Cl-, and H2O using continuum solvation model for the composite system. In the present project proposal, we have introduced the applications of various DFT techniques to investigate the kinetics of several such reactions. These approaches involve the calibration of various density functionals as well basis sets against higher level coupled cluster theories to identify effective functional to compute the kinetics of such reactions through transition state theory. The nature of transition states and the kinetics would decide whether the environmental mercury depletion reactions could alternatively be modeled through such simple transition state theory. The implementation of present idea would further enable us to investigate more complex mercury depletion reactions involving halogen radicals and multiple halogen depletion from more complex mercury halides at the DFT level of theories.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 19, 2019
- Source ID
- W911NF1610486
Entities
People
- Jerzy Leszczynski
Organizations
- Army Contracting Command
- Jackson State University
- United States Army