The odd and contradictory relationship between chemists and theoretical chemistry

Abstract

Through a brief historical analysis we show how the chemistry language had evolved independently of other sciences until the end of the nineteenth century. At that time chemical models were entirely incompatible with those from physics. From the 1910 decade on, after the beginning of the physicists elucidation of some elements of atomic structure, chemists started using ideas from atomic physics in their models for the chemical bonding. But only with the advent of quantum mechanics in the decade of 1920 it became possible, in principle, to base an entire chemical model on the results of electronic structure theoretical considerations. However, the chemist problems were more complicated than what the physicists were able to deal with. For this reason, simplified models were formulated. The chemist choice of which model to use is only guided by availability, easiness to use and lack of need for extensive additional study. The consequence of such procedure is the proliferation of baseless concepts and ideas which eventually become present in many chemistry textbooks. A few examples are discussed where it is demonstrated that the utilization of wave functions that fully reflect the fact that the electrons are indistinguishable, can provide qualitatively correct and useful models. We conclude establishing the real purpose of theoretical chemistry and proposing ways to improve the chemistry teaching. Resumo