Professor Cherif Matta

Mount Saint Vincent University, Halifax, NS, Canada

Visiting period: June 11-15, 2014

Seminar

The Evolution of Chemical Bonding over the Nuclear Transmutation Reaction Path

Abstract: Argon tetroxide (ArO₄) is the last member of the N = 50 e^– isoelectronic and isosteric series of ions: SiO₄^4–, PO₄^3–, SO₄^2–, and ClO₄–. While ArO₄ is kinetically stable it has a considerable positive enthalpy of formation (of ~298 kcal/mol) [R. Lindh et al., J. Phys. Chem. A 103, 8295 (1999)] which may explain why it has not been synthesized yet. A computational investigation of the changes in the chemical bonding of chlorate (ClO₄–) when the central chlorine atom undergoes a nuclear transmutation from ³⁸Cl to ³⁸Ar through b-decay, hence potentially leading to the formation of ArO₄, is reported. This work demonstrates how the of recoil energy imparted by ejected b-particles and antineutrinos to the daughter atom can cancel each other allowing a non-negligible yield of primary retention of the daughter atom in the bonding configuration of the parent compound. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a b-electron. Consideration of the recoil energy distribution of this nuclear reaction suggests a small, yet not insignificant, primary retention yield of this rare gas oxide. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311++G(3df,2pd)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM).

[1] M. Timm, C. F. Matta; 2014, submitted, in review.

Download presentation file here