When fluorine messes up: the impact of electron scavenger on properties of molecules

Abstract Fluorine and its impact on structure and selected properties of molecules (both organic and inorganic), with the key role of theoretical calculations for understanding of this impact, will be described in this personalized account. Key atomic and molecular properties, which render fluorine so different from other elements, will be briefly discussed. Theoretical chemistry methods have been widely applied to reproduce the geometric structure and calculate fundamental properties of fluorine-rich systems, and they are nowadays indispensable for understanding and deliberate tuning of desired properties; last but not the least calculations are used to predict novel systems with desirable characteristics, and to guide experimental research. The chapter brings bits and pieces from modern fluorine chemistry to illustrate some of its most spectacular—and often practical—aspects, augmented by the state-of-the-art theoretical modeling.