Organic fluorine compounds: a great opportunity for enhanced materials properties

Abstract

Interactions of "organic fluorine" have gained great interest not only in the context of crystal engineering, but also in the systematic design of functional materials. The first part of this tutorial review presents an overview on interactions known by organic fluorine. This involves π-π(F), C-F···H, F···F, C-F···π(F), C-F···π, C-F···M(+), C-F···C=O and anion-π(F) interactions, as well as other halogen bonds. The effect of the exchange of H vs. F is discussed by means of several examples and a short introduction to the young field of "fluorous" chemistry is given. The second part is dedicated to numerous applications of fluorine and fluorous interactions. It is shown how application of fluorination is used to enable a number of reactions, to improve materials properties and even open up new fields of research.

α‐Fluoro‐o‐cresols: The Key Role of Intramolecular Hydrogen Bonding in Conformational Preference and Hydrogen‐Bond Acidity

“…The effects of fluorination on molecular properties are well established, and their use in compound property optimisation in many fields like material 1, 2 and medicinal chemistry, [3][4][5][6] as well as crystal engineering 7,8 and agrochemistry 9,10 benefit from this strong influence. After the debate about the effective ability of fluorine to act as a hydrogen-bond (H-bond, HB) acceptor, [11][12][13][14][15] the occurrence of intermolecular OHF H-bonding is now clearly established through experimental and theoretical evidences.…”

Effect of Anion Size on Conductivity and Transference Number of Perfluoroether Electrolytes with Lithium Salts

“…It is known that fluorinated compounds are often only miscible in each other; this is often referred to as the fluorous effect. 12 While the fluorous effect is usually used to describe the mixing of neutral species, there is evidence of similar effects in mixtures of fluorinated ionic compounds and fluorinated polymers. 13 Our work is a departure from the traditional approach of exploiting interactions between the solvent and the cation.…”

Fluorine-induced J-aggregation enhances emissive properties of a new NLO push–pull chromophore

“…In this respect, uorination of A groups offers the possibility of modulating optical and electrical properties of push-pull organic chromophores, lowering their HOMO and LUMO energy levels and facilitating the charge transfer process, 3 thus enhancing the 2 nd order NLO response. 4 Fluorination also affects crystal packing of conjugated organic materials, 5 which is a key issue in determining their electronic and optical properties, 6 and therefore their potential use in electronic and optoelectronic devices. On the other hand, linear p-conjugated materials tend to strongly aggregate in the solid state and in concentrated solutions, yielding p-stacked structures, which oen suppress luminescence and NLO properties.…”