Organic Fluorine Materials

Fluorocompounds are one of the important parts of our daily life, concerning alimentation, health care, or leisure time as well as the alternative energy sector, which is of an increasing significance in times of limited resources and climate change. Due to the strength of the C–F bond, fluorine-containing compounds exhibit high thermal and oxidative stability, low polarity, weak intermolecular interactions, and a small surface tension compared to hydrocarbons. These beneficial effects are utilized for the development of new compounds with unprecedented properties, e.g. liquid crystals, plastics, dyes, surfactants, membranes, conductive polymers, pharmaceuticals, and agrochemicals.

As fluorine is the most electronegative element of all elements, the atomic radius of fluorine is similar to that of hydrogen at the same time, so the size of the molecules is not affected much. Due to these properties, the number of compounds containing fluorine is increasing in pharmaceutical drugs, organic electronics materials, etc.

In nature fluorine occurs in the form of inorganic minerals like fluorite (CaF2)and cryolite (NaAlF6) and fluorinated organic compounds are extremely rare. C-F bonds have the strength and some unique properties, but mother nature doesn’t seem to have utilized them so much.

Fluorinated organic compounds have enhanced hydrophobicity and lipophobicity in perfluorinated substances. An inverted charge density distribution in fluorinated aromatic compounds, the ring is the center of positive charge, with respect to the corresponding hydrocarbons. This is a result of the balance between the negative inductive effect and the positive mesomeric effect of the halogen atom.

F…H–C interactions, similar to a hydrogen bond, but with much lower energy, are present in fluorinated organic compounds. Although there is not a precise understanding of these interactions, they may play an important role in the solid-state organization of fluorine compounds bearing both C–F and C–H bonds or between perfluorinated and hydrocarbon compounds.