Mechanistic and computational studies of ferroin, simple organic acids, and bromine oxides : elucidating the complex electrochemical dance in an oscillating reaction

Abstract

Before the year 1950, many chemists in their 'right mind' held the archaic belief that all chemical reactions proceed strictly from reactants to products, though some could be coaxed into reverse. What we now know colloquially as a potential energy surface was only visualized in more than two dimensions by the greatest thinkers at the time. The Belousov-Zhabotinsky (BZ) reaction is perhaps the most well-known of the 'chemical oscillators' and a prime example of a phenomenon that simply cannot be demystified given a two-dimensional data set. Though simulations of the BZ reaction produce reasonable results, to this day, not one published model has been capable of completely describing the chemistry that occurs. Some sort of halidehalogen-oxide cycle drives almost, if not, all known inorganic chemical oscillators, including those that proceed naturally in Earth's atmosphere. Catalytic indicators like cerium and ferroin, when added to the reaction mixtures, provide intuitive views of the chemical environment that we cannot normally see while moderately altering the reaction dynamics. Researchers worldwide have invested countless man-hours into producing different sets of data, from which the ultimate goal of describing this type of oscillating chemical reaction in detail will eventually be realized. In this study, we examine both basic and obscure chemical processes that proceed in a BZ mixture with a focus on those prepared in a continuously stirred tank reactor (CSTR), ideally in order to pave a new path for researchers that choose to fixate on this phenomenon in the future and help complete the already daunting collections of reactions that have been devised to describe the peculiar chemistry that occurs. Most everyone that has studied the BZ reaction in the past knows that it is perhaps the single most influential process in the modern era of knowledge regarding non-linear chemical dynamics. Since we opt for an entire laboratory in silico, this study will primarily examine physical and electronic mechanisms at the single- 2 molecule scale.